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Y Lee

Publications and source records attributed to Y Lee.

At least 253 records · Page 14Linked to original sources
PubMed1999

Human anti-Pseudomonas aeruginosa outer membrane proteins IgG cross-protective against infection with heterologous immunotype strains of P. aeruginosa.

In order to develop an effective means to treat and prevent Pseudomonas aeruginosa infections, we have purified P. aeruginosa outer membrane protein (Oprs)-specific human IgG antibody using a large-scale affinity column. In this study, we investigated the cross-protective activity of the purified anti-Oprs IgG against various immunotype strains of P. aeruginosa. The anti-Oprs IgG reacted with Oprs isolated from seven Fisher-Devlin immunotype strains of P. aeruginosa and was able to promote opsonophagocytic killing of all seven immunotype strains by human phagocytic cells. Administration of 500 microg anti-Oprs IgG to mice raised the LD50 of the P. aeruginosa strains by 8-250-fold, indicating the protective capacity against heterologous P. aeruginosa strains as well as homologous strains. In contrast, despite high titers against P. (aeruginosa Oprs, total serum IgG isolated from burn patient sera was no better than normal serum IgG in protecting mice from infection with P. aeruginosa. These data demonstrate that the affinity-purified human anti-Oprs IgG could afford protection against heterologous immunotype P. aeruginosa strains and provide a rationale to use anti-Oprs IgG as an adjunct for treatment of P. aeruginosa infections in humans.

Animals↗
PubMed1999

Efficient processing of the immunodominant, HLA-A*0201-restricted human immunodeficiency virus type 1 cytotoxic T-lymphocyte epitope despite multiple variations in the epitope flanking sequences.

Immune escape from cytotoxic T-lymphocyte (CTL) responses has been shown to occur not only by changes within the targeted epitope but also by changes in the flanking sequences which interfere with the processing of the immunogenic peptide. However, the frequency of such an escape mechanism has not been determined. To investigate whether naturally occurring variations in the flanking sequences of an immunodominant human immunodeficiency virus type 1 (HIV-1) Gag CTL epitope prevent antigen processing, cells infected with HIV-1 or vaccinia virus constructs encoding different patient-derived Gag sequences were tested for recognition by HLA-A*0201-restricted, p17-specific CTL. We found that the immunodominant p17 epitope (SL9) and its variants were efficiently processed from minigene expressing vectors and from six HIV-1 Gag variants expressed by recombinant vaccinia virus constructs. Furthermore, SL9-specific CTL clones derived from multiple donors efficiently inhibited virus replication when added to HLA-A*0201-bearing cells infected with primary or laboratory-adapted strains of virus, despite the variability in the SL9 flanking sequences. These data suggest that escape from this immunodominant CTL response is not frequently accomplished by changes in the epitope flanking sequences.

Adolescent↗
PubMed1999

CD40L activation in circulating platelets in patients with acute coronary syndrome.

The CD40-CD40L interaction, which was initially shown to have important roles in the T cell-mediated activation of B cells during humoral immune responses, is now known to have roles in activation of endothelial cells, smooth muscle cells, and macrophages within atherosclerotic plaques. Recently, CD40L expression was found in activated platelets in the thrombus in vivo and CD40L was reported to be responsible for the platelet-mediated activation of endothelial cells in vitro. To investigate the activation status of platelets in coronary artery disease patients, we tested expression levels of CD40L, and platelet-endothelial cell adhesion molecule-1 (PECAM-1/CD31) in platelets isolated from peripheral blood, using flow cytometric analysis. Twenty-nine patients with acute coronary syndrome (10 acute myocardial infarction and 19 unstable angina patients) were compared with 14 normal subjects or 14 stable angina patients. In platelets isolated from normal subjects, the expression of CD40L was not detected in all subjects. In the patients with acute coronary syndrome, the average level of CD40L showed a significant increase (p = 0.0028), while stable angina patients did not have any increase when compared to normal subjects. Patients with more complex lesions or vessel occlusion tended to have a high platelet CD40L level compared to patients who do not. The expression levels of CD31 were increased in a small portion of the ACS patients. These data indicate that the rupture of plaque and subsequent formation of thrombus may lead to the activation of CD40L expression in circulating platelets of ACS patients.

Acute Disease↗
PubMed1999

Fos expression in the female rat brain during the proestrous prolactin surge and following mating.

A prolactin (PRL) surge occurs in the female rat during proestrus in response to elevated estradiol levels. The elevated release of ovarian steroids on the day of proestrus is also associated with sexual receptivity. Mating triggers twice-daily PRL surges that supplant the proestrous PRL surge and are responsible for maintaining luteal function during the first half of pregnancy. In order to understand the neuronal mechanisms controlling the proestrous- and mating-induced PRL surges, we examined patterns of Fos expression by immunocytochemistry in specific brain regions as a measure of neuronal activity. Intact female rats were sacrificed at 09.00, 15.00, and 18.00 h on the day of proestrus and the day of diestrus. Brain tissues were also collected at 21.00 h on the day of proestrus from rats receiving intromissions or mounts from males or taken directly from their homecage. On the day of proestrus, the number of neurons expressing Fos in the medial preoptic area (mPOA), medial amygdaloid nucleus (mAMYG), and ventromedial nucleus of the hypothalamus (VMH) was few and was associated with low plasma PRL levels at 09.00 h; however, the number of Fos-positive cells in these brain regions significantly increased at 15.00 and 18.00 h when the proestrous PRL surge occurred. Mating during the evening of proestrus resulted in a dramatic increase in the number of Fos-positive cells in the mPOA, mAMYG, and VMH as well as in the arcuate nucleus (ARC). Nonmated animals in diestrus showed low and unchanged PRL levels and Fos expression in all the brain areas throughout the day. These results suggest that the mPOA, mAMYG, VMH and ARC may be important brain sites for the integration of stimuli associated with proestrous- and mating-induced PRL surges.

Amygdala↗
PubMed1999

Linear demasking techniques are unreliable for estimating the circadian phase of ambulatory temperature data.

Clinical investigators often use ambulatory temperature monitoring to assess the endogenous phase and amplitude of an individual's circadian pacemaker for diagnostic and research purposes. However, an individual's daily schedule includes changes in levels of activity, in posture, and in sleep-wake state, all of which are known to have masking or evoked effects on core body temperature (CBT) data. To compensate for or to correct these masking effects, many investigators have developed "demasking" techniques to extract the underlying circadian phase and amplitude data. However, the validity of these methods is uncertain. Therefore, the authors tested a variety of analytic methods on two different ambulatory data sets from two different studies in which the endogenous circadian pacemaker was not synchronized to the sleep-wake schedule. In both studies, circadian phase estimates calculated from CBT collected when each subject was ambulatory (i.e., free to perform usual daily activities) were compared to those calculated during the same study when the same subject's activities were controlled. In the first study, 24 sighted young and older subjects living on a 28-h scheduled "day" protocol were studied for approximately 21 to 25 cycles of 28-h each. In the second study, a blind man whose endogenous circadian rhythms were not synchronized to the 24-h day despite his maintenance of a regular 24-h sleep-wake schedule was studied for more than 80 consecutive 24-h days. During both studies, the relative phase of the endogenous (circadian) and evoked (scheduled activity-rest) components of the ambulatory temperature data changed progressively and relatively slowly, enabling analysis of the CBT rhythm at nearly all phase relationships between the two components. The analyses of the ambulatory temperature data demonstrate that the masking of the CBT rhythm evoked by changes in activity levels, posture, or sleep-wake state associated with the evoked schedule of activity and rest can significantly obscure the endogenous circadian component of the signal, the object of study. In addition, the masking effect of these evoked responses on temperature depends on the circadian phase at which they occur. These nonlinear interactions between circadian phase and sleep-wake schedule render ambulatory temperature data unreliable for the assessment of endogenous circadian phase. Even when proposed algebraic demasking techniques are used in an attempt to reveal the endogenous temperature rhythm, the phase estimates remain severely compromised.

Adolescent↗
PubMed1999

Feedback effects of placental lactogens on prolactin levels and Fos-related antigen immunoreactivity of tuberoinfundibular dopaminergic neurons in the arcuate nucleus during pregnancy in the rat.

PRL in the rat exerts its luteotropic action during the first half of pregnancy. After midpregnancy, placental lactogens (PLs) take the place of PRL to stimulate progesterone secretion from the corpus luteum. Simultaneously, PLs trigger a negative feedback on PRL secretion. However, the brain mechanisms for the negative feedback induced by PLs are not fully understood. Here, we report changes in plasma PRL levels, tuberoinfundibular dopaminergic (TIDA) neuronal activity as measured by Fos-related antigen (FRA)/tyrosine hydroxylase (TH) immunoreactivity, and TH catalytic activity as measured by dihydroxyphenylalanine (DOPA) accumulation in the stalk-median eminence (SME) after experimental manipulation of PL levels. On day 4 of pregnancy, animals received Rcho-1 cells intracerebroventricularly (i.c.v.) to increase the level of PLs in the brain or HRP-1 cells as controls. On day 12 of pregnancy, hysterectomy alone or i.c.v. HRP-1 injection plus hysterectomy were performed to remove the source of PLs. Rcho-1 i.c.v. injection plus hysterectomy were performed to examine the effect of replacement of the PL source. Sham-hysterectomized animals were used as a control group. Animals were killed 2 days after each treatment at 0200 and 1800 h, which represent the peak times of PRL surges, and at 1400 h, which represents the intersurge time, by either transcardial perfusion for FRA/TH immunocytochemistry or decapitation 30 min after NSD 1015 injection to assess DOPA accumulation with HPLC-electrochemical detection. Rcho-1 cells completely abolished PRL surges on day 6 of pregnancy and increased the percentage of FRA/TH immunoreactivity in the dorsomedial, ventrolateral, and caudal subdivisions of the arcuate nucleus. This change in neuronal activity reflected the amount of DOPA accumulation in the SME, which was high at all time points. On day 14 of pregnancy, removal of the PL source by hysterectomy resulted in increased PRL levels and decreased neuronal activity of TIDA neurons at all three time points. Similar profiles were observed in animals that received i.c.v. HRP-1 injection plus hysterectomy. Replacement of the source of PL with Rcho-1 cells in hysterectomized rats resulted in low PRL secretion, high neuronal activity of TIDA neurons, and high TH catalytic activity. These patterns were the same as those in sham-operated animals. Our results demonstrate that PLs induce an increase in the neuronal activity of dopaminergic neurons, as measured by FRA/TH immunoreactivity and TH catalytic activity in the SME. Removal of the PL source elevates plasma PRL levels at all times during the second half of pregnancy and does not restore PRL surges.

Animals↗
PubMed1999

Production and characterization of an antibody specific for a novel protein serine/threonine kinase, MPK38, highly expressed in hematopoietic cells.

We report an antibody that selectively recognizes MPK38, a new protein serine/threonine kinase closely related to the SNF1 serine/threonine kinase family. This antibody recognized a region of the N-terminal kinase catalytic domain and part of the remaining C-terminal portion and was sensitive enough to detect a 72-kDa recombinant MPK38 in insect cells by Western blotting. Immunoblot analysis showed that the recombinant MPK38 was expressed in a time-dependent manner and reached a maximum after 48 h postinfection. In addition, the immune complex kinase assay revealed that the recombinant and endogenous MPK38 protein autophosphorylated in vitro. Phosphoamino acid analysis of autophosphorylated MPK38 protein showed that the phosphorylation was exclusively on serine and threonine residues, suggesting that MPK38 is a protein serine/threonine kinase. Thus, this antibody could be helpful for elucidating the biological functions of MPK38 in the MPK38-expressing cells.

Animals↗
PubMed1999

Adenovirus-mediated overexpression of uncoupling protein-2 in pancreatic islets of Zucker diabetic rats increases oxidative activity and improves beta-cell function.

The discovery of uncoupling protein (UCP)-2, a ubiquitously expressed protein homologous to UCP-1, has raised the possibility that energy balance of cells might be regulated in tissues other than brown adipocytes. In normal pancreatic islets, UCP-2 is upregulated by leptin and is low in leptin-resistant islets of ZDF rats. To determine whether UCP-2 does, in fact, have uncoupling activity and, if so, whether such activity would favorably influence the abnormalities in leptin-unresponsive UCP-2-underexpressing islets of diabetic ZDF rats, we transferred the UCP-2 gene to the islets of diabetic ZDF rats and lean (+/+) ZDF control rats. Although ATP was reduced by 23% in both groups of islets, the ATP:ADP ratio increased by 42 and 141%, respectively. [3H]palmitate oxidation was increased by 50%, and [3H]glucose oxidation was 42-63% higher. Preproinsulin mRNA was 2.9-fold above control levels, and glucose-stimulated insulin secretion, which was negligible in control ZDF rat islets, was improved in UCP-2-overexpressing islets. The high fat content of the islets was not reduced, however. We conclude that UCP-2 has uncoupling function when overexpressed in leptin-insensitive islets and that its overexpression corrects the underexpression of the insulin gene and ameliorates glucose-stimulated insulin secretion, possibly by increasing the ATP:ADP ratio.

Adenosine Diphosphate↗
PubMed1999

Age differences in ratings of medical care among older adults living in the community.

Patients ratings of care serve as an indicator of quality of care, as well as a predictor of patient behavior. In spite of the heterogeneity of the older population and their disproportionate consumption of health care resources, relatively little attention has been paid to assessing the elderly's satisfaction with medical care. Using data from the 1991 Medicare Current Beneficiary Survey, we compare ratings of medical care and quality of physician care between the young-old (65-79 years) and old-old (80+ years) living in the community. Multivariate logistic regression analyses are performed to assess the independent effect of age on patients' ratings of care. Results show a significant negative association between age and highly positive ratings of care in the elderly; the old-old are less likely than the young-old to give very favorable opinions (e.g., very satisfied vs other) of the care they received. The relationship remains even after controlling for measures of health status and experience and use of health care. However, variations were observed when more negative ratings (e.g., satisfied/very satisfied vs dissatisfied/very dissatisfied) were considered. Although elderly people as a group usually are found to rate their care more positively than younger adults, this study indicates there is heterogeneity in the older population regarding views of medical care.

Aged↗
PubMed1999

Dual-plane lipoplasty for the superficial and deep layers.

Two embryologically and histologically distinct layers of the subcutaneous adipose tissue were treated individually by different modalities. The authors performed ultrasound-assisted lipoplasty at the superficial layer and traditional suction-assisted lipectomy in the deep subcutaneous tissue. The ultrasound procedure allowed tissue-specific destruction of the superficial layer supported by dense fibrous networks without disrupting them. Skin retractions caused by this procedure could diminish the necessity of surgical dermolipectomy such as an abdominoplasty in moderately deformed cases. On the other hand, the traditional liposuction was performed to remove the excessive deep fat contained in the loose fibrous network in a limited area. Although the advancement of ultrasound devices and regimens has now reduced their operating times significantly, the ultrasonic lipoplasty was slower than traditional liposuction at the beginning of our procedure. In the abdominal wall, the procedure was performed only in a confined area, because the skin retractions made over the locally managed areas created a circumferential tightness around the trunk, using the nontreated area as a bridge. Confinement on the managed area prevented unnecessary blood loss and tissue destruction. It was less a matter of fat volume to remove in the superficial layer; rather, a precise application to the exact target area was required to get a more natural result. Dual-plane lipoplasty was performed for 2 years in 35 patients, mostly for the abdomen. No serious complication such as seromas or skin loss was observed in our series of patients.

Abdominal Muscles↗
PubMed1999

Multiplane face lift with the subperiosteal dissection for orientals.

A subperiosteal face lift rejuvenates the midface and periorbital region by restoring facial muscle tone. Since 1993, the authors have performed this procedure on Oriental patients who have their own distinct facial contours: the brachycephalic cranium and a prominent zygoma and mandibular angle. Although it was thought that these protuberances might disturb the subperiosteal procedure, especially in the anterior midface, the procedure could be performed easily by adopting the ancillary upper buccovestibular and subciliary incisions; the authors found that the protuberances actually act as fulcrums to keep up the lifting vectors reliably. For older patients, the procedure was combined with a deep subcutaneous dissection. A simple lift of the periosteum would not improve a severe nasolabial fold deformity and prominent wrinkles adequately because of "lag-lifting" of the superficial layer. It was concluded that the multiplane face lift, consisting of the subperiosteal and the deep subcutaneous approaches, achieves a natural-appearing rejuvenation of the Oriental aging face.

Aged↗
PubMed1999

Mandibular contouring: a surgical technique for the asymmetrical lower face.

Correcting facial asymmetry is a difficult problem for plastic surgeons. From 1991 to 1996, the authors treated 53 cases of mandibular angle resection, 13 of which were of patients with an asymmetrical lower face. On the basis of these experiences, the authors highlight two important points in dealing with the asymmetrical lower face. The first is accurate resection of each side of the face. A cloth pattern was used to improve the accuracy of the procedure and to make the final result match the preoperative design regarding amount and shape. The second concerns soft-tissue change after the operation. Satisfactory results are obtained by the accurate resection of the bone coupled with the correct management of the surrounding soft tissue. The amount of bone to be resected was determined not simply by cephalometry, but by both cephalometry and external appearance. Postoperative cephalometry is not always symmetrical, and it is important that the final external appearance be harmonious and symmetrical. Using the above method, results have been satisfactory to both the surgeons and the patients, with the exception of three patients who had residual asymmetry. No permanent sensory loss or motor nerve palsy was observed, and no infections occurred.

Adult↗
PubMed1998

Bacterial expression of tenecin 3, an insect antifungal protein isolated from Tenebrio molitor, and its efficient purification.

Tenecin 3, an antifungal protein isolated from the insect Tenebrio molitor larvae, inhibits growth of the fungus Candida albicans. However, the antifungal mechanism and functions of tenecin 3 have not yet been studied due to its very low availability from the natural source. Here we report an expression system of the recombinant tenecin 3 in E. coli, whose amino acid composition is the same with that of the natural tenecin 3. We also devised a simple and easy procedure to isolate the recombinant protein from the bacterial cell extracts. The recombinant tenecin 3 showed an antifungal activity against C. albicans as the natural tenecin 3 did. Therefore large quantities of tenecin 3 can be easily obtained by the expression and purification system of tenecin 3 described in this report.

Amino Acid Sequence↗
PubMed1998

A novel mutant loxP containing part of long terminal repeat of HIV-1 in spacer region: presentation of possible target site for antiviral strategy using site-specific recombinase.

A site-specific recombinase Cre is responsible for the recombination at a 34 bp loxP site. This system has been investigated for the antiviral strategy to excise proviral DNA from retrovirus-infected cells. It was reported that loxP sites could be inserted into long terminal repeat (LTR) of retrovirus to delete proviral DNA. To apply this system to human immunodeficiency virus type 1 (HIV-1) without inserting any DNA, one 34 bp sequence was selected from LTR of recombinant HIV-1 clone, loxLTR-1, based on sequence similarity between LTR and loxP, and sequence arrangement of 8 bp middle part in 34 bp LTR segment. When the 8 bp spacer region of loxP was changed into the corresponding middle part of loxLTR-1, this variant loxP would allow Cre to specifically recombine between themselves but not with wild-type loxP in vitro. This study suggests that site-specific excision of proviral DNA of HIV-1 could be catalyzed by the least modified Cre recognizing the loxLTR-1 sites.

HIV Infections↗
PubMed1998

Preparation of slightly hydrophobic heparin derivatives which can be used for solvent casting in polymeric formulation.

Heparin is clinically administered mainly by intravenous injection because of its highly hydrophilic property. A slightly hydrophobic heparin derivative which can be dissolved in organic solvent can be widely used in polymeric devices for clinical applications. In this study, hydrophobic heparin derivatives were prepared by coupling heparin with deoxycholic acid, cholesterol, lauric acid, and palmitic acid, respectively. The hydrophobicity of these heparin derivatives depended on the feed mole ratio of heparin to hydrophobic agents, and they showed good solubility in the co-solvent of acetone and water, as well as in water alone. Also, these heparin derivatives showed high anticoagulant activity. This approach for preparing hydrophobic heparin is expected to advance the drug delivery system by further extending the applications of heparin to medical devices such as cardiopulmonary bypass circuits, heart lung oxygenators, and kidney dialyzers.

Cholesterol↗
PubMed1998

An infectious viral disease of penaeid shrimp newly found in Korea.

Since 1993, massive mortalities have occurred among the penaeid shrimp Penaeus orientalis cultured in Korea. The major gross findings of the naturally occurring cases were 2 to 6 mm sized white spots on the inside of the carapace and reddish discolorization. Amphophilic to basophilic intranuclear inclusion bodies were readily observed in the epithelia of epidermis, foregut, gills, and lymphoid organs. Electron microscopy revealed enveloped and non-occluded ellipsoid to rod-shaped virus particles within the nucleus of lymphoid organ cells and the interstitial cells of the hepatopancreas of both naturally and experimentally infected shrimp. The size of the virions was 375 x 167 nm and the nucleocapsid was 290 x 75 nm. The agent which caused ectodermal and mesodermal necrosis in penaeid shrimp in Korea resembled white spot syndrome virus (WSSV) found in Taiwan with respect to gross signs, histological changes and viral morphology. Its viral morphology differed from that of the rod-shaped nuclear virus of Penaeus japonicus (RV-PJ) found in Japan. However, a 643 bp PCR product with an identical sequence to that from RV-PJ was detected. The results suggested that the Korean agent combined characters described for WSSV and RV-PJ.

Animals↗
PubMed1998

Propranolol attenuates haloperidol-induced Fos expression in discrete regions of rat brain: possible brain regions responsible for akathisia.

Neuroleptics induce several extra-pyramidal side effects, such as akathisia, acute dystonia and parkinsonism. Although recently developed atypical neuroleptics ameliorate some of these side effects, akathisia remains a common and severely distressing adverse reaction. Several drugs are reported to be of clinical use for the pharmacological treatment of akathisia. In particular, the beta-adrenoceptor blocker, propranolol, has been widely used for the treatment of akathisia, but it does not ameliorate other extra-pyramidal side effects. To identify the neural substrates of akathisia, we investigated the effects of propranolol on haloperidol-induced Fos expression in rat brain. Haloperidol (1 mg/kg) induced Fos-positive nuclei in several regions of the brain, including the cingulate cortex area 3, piriform cortex nucleus accumbens, caudate-putamen, ventral lateral septum and parietal cortex. Pretreatment with propranolol (5 mg/kg) reduced the number of Fos-positive nuclei in the cingulate cortex area 3, the piriform cortex and area 1 of the parietal cortex. Injection of vehicle by itself tended to increase Fos expression in the cingulate cortex area 3 and the piriform cortex. Considering the functions of these brain regions, we speculate that the most plausible neural framework for haloperidol-induced akathisia involves area I of the parietal cortex, but possible roles for the cingulate cortex area 3 and the piriform cortex cannot be ruled out.

Adrenergic beta-Antagonists↗