176
|
Ignjatovic V, Ogru E, Heffernan M, Libinaki R, Lim Y, Ng F. Studies on the use of "slimax", a chinese herbal mixture, in the treatment of human obesity. PHARMACEUTICAL BIOLOGY 2000; 38:30-35. [PMID: 21214436 DOI: 10.1076/1388-0209(200001)3811-bft030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A phytochemical preparation known as "Slimax" was administered orally to human volunteers for a six week period, using a double-blind experimental method. This preparation is an aqueous extract of the Chinese medicinal plants Hordeum vulgare , Polygonatum multiflorum , Dimocarpus longan , Ligusticum sinense , Lilium brownii and Zingiber officinale . Treatment with Slimax resulted in a significant decrease in parameters such as body weight, waist and hip circumference, and Body Mass Index (BMI), in all subjects tested. The basis of action was shown to be through modification of lipid metabolism, with significant effects on both the accumulation and the release of lipid from adipose tissue. The experimental results indicate a great potential for the use of this herbal preparation in treatment of human obesity.
Collapse
|
177
|
Kim J, Lim Y, Noh I, Song E, Im M, Lee B, Hwang J, Park M, Yum M. Pregnancy induced hypertension (PIH) and altered fractal correlation behavior in fetal heart rate (FHR) variability. Int J Gynaecol Obstet 2000. [DOI: 10.1016/s0020-7292(00)86307-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
178
|
Kim JK, Lee WK, Lee EJ, Cho YJ, Lee KH, Kim HS, Chung Y, Kim KA, Lim Y. Mechanism of silica- and titanium dioxide-induced cytotoxicity in alveolar macrophages. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 1999; 58:437-450. [PMID: 10616192 DOI: 10.1080/009841099157160] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Particles can cause cytotoxicity in pulmonary alveolar macrophages (AM). Several mechanisms to explain this cytotoxicity have been suggested. However, the exact mechanism of particle-induced cytotoxicity in AM remains to be established. Silica and TiO2 produced a concentration-dependent cytotoxicity as evidenced by loss of cell viability and fall in ATP levels. While silica induced a greater cytotoxicity, TiO2 produced a higher reduction in ATP levels. Silica increased the release of LDH, but TiO2 did not affect enzymatic release. TiO2 suppressed succinate-triggered oxygen consumption, whereas silica did not markedly change the effect of succinate on oxygen consumption. Polyinosinic acid (PI), a ligand of the scavenger receptor, inhibited the TiO2-induced fall in ATP content, but could not prevent the effect of silica on cellular ATP content. Data suggest that silica and TiO2 can induce cytotoxicity in AM, probably through different mechanisms.
Collapse
|
179
|
Jin QH, Xin XL, Zhu FJ, Lim Y. Crystal structure of bromo-(1,10-phenathroline-N,N')(triphenylphosphine) silver(I) dihydrate, Ag(Phen)(PPh3)Br · 2H2O. Z KRIST-NEW CRYST ST 1999. [DOI: 10.1515/ncrs-1999-0452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
180
|
Seo MS, Kim JK, Lim Y, Kang SW, Cho YJ, Lee WK, Kim HJ, Cho KK, Lee KH, Rhee SG. Rapid degradation of PrxI and PrxII induced by silica in Rat2 cells. Biochem Biophys Res Commun 1999; 265:541-4. [PMID: 10558905 DOI: 10.1006/bbrc.1999.1709] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Peroxidases of the peroxiredoxin (Prx) family catalyze the reduction of H(2)O(2) and lipid peroxides. The effects of H(2)O(2), 12-O-tetradecanoylphorbol 13-acetate (TPA), and silica on the abundance of two cytosolic isoforms of Prx (PrxI and PrxII) were examined in Rat2 cells. TPA induces the production of reactive oxygen species (ROS) in various mammalian cell types, and silica induces the production of ROS in Rat2 cells. Whereas H(2)O(2) and TPA did not affect the concentration of PrxI or Prx II, silica triggered a rapid degradation of both Prx enzymes. Silica also induced degradation of the NF-kappaB inhibitor IkappaB-alpha. N-Acetylcysteine and diphenyleneiodonium, both of which inhibit the accumulation of intracellular ROS, each blocked silica-induced degradation of IkappaB-alpha but had no effect on that of the Prx enzymes, suggesting that ROS do not contribute to Prx proteolysis. The silica-induced degradation of Prx enzymes was also insensitive to the proteasome inhibitors MG132 and lactacystin, whereas IkappaB-alpha proteolysis was completely blocked by these inhibitors. Experiments with the Ca(2+) ionophore A23187 indicated that a Ca(2+)-dependent protease such as calpain might contribute substantially to silica-induced degradation of PrxII, but only moderately to that of PrxI. These results indicate that silica increases cellular oxidative stress not only by inducing ROS production, but also by triggering the degradation of Prx enzymes that are responsible for elimination of cellular ROS. Such aggravated oxidative stress might be important in the initial pathogenesis of silica-associated pulmonary diseases.
Collapse
|
181
|
Losonsky GA, Fantry GT, Reymann M, Lim Y. Validation of a gastrointestinal explant system for measurement of mucosal antibody production. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1999; 6:803-7. [PMID: 10548567 PMCID: PMC95779 DOI: 10.1128/cdli.6.6.803-807.1999] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A gastrointestinal explant culture system was developed and compared to the mononuclear cell extraction and enzyme-linked immunospot assay method for measurement of immunoglobulin A (IgA) and IgG antibody-secreting cells (ASCs) in gastric antral and duodenal biopsies of non-Helicobacter pylori-infected volunteers. IgA and IgG were detected in explant supernatants during 6 to 7 days of culture in all subjects. IgA containing secretory component was also detected throughout the culture period, although peak production occurred only in the first 3 days. During 7 days of culture, the cumulative geometric mean IgA levels produced were 2.2 and 8.02 microg/ml/10 mg of antral and duodenal biopsy tissues, respectively, while the cumulative geometric mean IgG levels were 1.54 and 2.92 microg/ml/10 mg of antral and duodenal biopsy tissues, respectively. Cycloheximide treatment resulted in a >90% reduction in both immunoglobulin classes after 6 days of treatment compared to levels in untreated controls. The detection of IgA and IgG ASCs extracted from biopsies on days 1 and 6 of culture confirmed that the antibody detected was derived from mucosal lamina propria. The IgA and IgG ASC responses were positively correlated with antibody concentrations detected in culture supernatants (r = 0.87 and 0.85, respectively). These results validate the potential usefulness of our gastrointestinal explant system for the evaluation of mucosal effector B-cell function.
Collapse
|
182
|
Baak YM, Ahn BY, Chang HS, Kim JH, Kim KA, Lim Y. Aplastic anemia in a petrochemical factory worker. ENVIRONMENTAL HEALTH PERSPECTIVES 1999; 107:851-3. [PMID: 10504154 PMCID: PMC1566621 DOI: 10.1289/ehp.99107851] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A petrochemical worker with aplastic anemia was referred to our hospital. He worked in a petroleum resin-producing factory and had been exposed to low-level benzene while packaging the powder resin and pouring lime into a deactivation tank. According to the yearly environmental survey of the working area, the airborne benzene level was approximately 0.28 ppm. Exposure to benzene, a common chemical used widely in industry, may progressively lead to pancytopenia, aplastic anemia, and leukemia. The hematotoxicity of benzene is related to the amount and duration of exposure. Most risk predictions for benzene exposures have been based on rubber workers who were exposed to high concentrations. In the petroleum industry, the concentration of benzene is relatively low, and there are disputes over the toxicity of low-level benzene because of a lack of evidence. In this paper we report the case of aplastic anemia induced by low-level benzene exposure.
Collapse
|
183
|
Cho YJ, Seo MS, Kim JK, Lim Y, Chae G, Ha KS, Lee KH. Silica-induced generation of reactive oxygen species in Rat2 fibroblast: role in activation of mitogen-activated protein kinase. Biochem Biophys Res Commun 1999; 262:708-12. [PMID: 10471390 DOI: 10.1006/bbrc.1999.1274] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Exposure to silica has been associated with progressive pulmonary inflammation and fibrosis. While the fibroblasts play an important role in the pathogenesis of silicosis, the direct interaction between silica and fibroblasts is poorly understood. We observed that silica particles stimulated intracellular ROS generation in Rat2 fibroblast, evidenced by DCFH oxidation. Silica-induced DCFH oxidation was inhibited by catalase and DPI, a flavoenzyme inhibitor. Additionally, the time course of elevation of the intracellular ROS was paralleled by the increases of MEK and ERK phosphorylation. Silica-induced ERK phosphorylation was also effectively attenuated by catalase and DPI. However, SOD enhanced the silica-induced ERK phosphorylation, indicating a role for H(2)O(2) in ERK activation. Furthermore, ERK and MEK phosphorylation are reproduced by H(2)O(2) treatment. Taken together, these results demonstrate that silica stimulates ROS production via flavoenzyme-dependent mechanism in Rat2 fibroblasts and the H(2)O(2), in turn, serves as a signal transduction element in activating MEK-ERK pathway.
Collapse
|
184
|
Lim Y, Kim JH, Kim KA, Chang HS, Park YM, Ahn BY, Phee YG. Silica-induced apoptosis in vitro and in vivo. Toxicol Lett 1999; 108:335-9. [PMID: 10511280 DOI: 10.1016/s0378-4274(99)00107-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Silica exposure results in an initially acute inflammatory response followed by chronic fibrotic change. The mechanism for the maintenance of silica-induced inflammation has not been understood yet. In silica-induced acute inflammation and chronic fibrosis, various mediators such as reactive oxygen species, cytokines and growth factors are released. And these substances are suggested to have the regulatory role for the inflammation and fibrosis by possessing the potential to influence apoptosis. To demonstrate the apoptosis as an underlying mechanism for the development of silicosis, in vitro and in vivo models were designed. In in vitro study, we evaluated that apoptotic cell fraction in silica (10, 50 microg/cm2)-treated A549 cells was significantly increased in comparison with control by FACS (fluorescein activated cell sorter). Also genomic DNA from silica (10, 50 microg/cm2)-treated A549 showed DNA ladder formation while control and 1 microg/cm2 groups didn't. In in vivo study, total cell numbers and apoptotic cell numbers of BAL (bronchoalveolar lavage) fluid from silica (10, 20, 40 mg/kg)-instilled rats were significantly higher than control group from 1 week. From these results, we concluded acute and chronic presence of apoptosis may contributes to silica-induced acute inflammation and chronic fibrosis.
Collapse
|
185
|
Kim KA, Lim Y, Kim JH, Kim EK, Chang HS, Park YM, Ahn BY. Potential biomarker of coal workers' pneumoconiosis. Toxicol Lett 1999; 108:297-302. [PMID: 10511274 DOI: 10.1016/s0378-4274(99)00101-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
It is well known that various cytokines and growth factors secreted from macrophages/monocytes play the key role in the pathogenesis of pneumoconiosis. These can act as biosensors for the prediction of pneumoconiosis. To evaluate which cytokines can be used as sensitive biomarkers in pneumoconiosis, we measured tumor necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8) and platelet-derived growth factor-AA (PDGF-AA) in supernatant of monocytes with or without coal dust (5 mg/ml) and serum in 42 coal miners with pneumoconiosis and ten healthy control. The coal-stimulated release of TNF-alpha and IL-8 from blood monocytes was significant increased in pneumoconiosis patients compared with controls. The level of TNF-alpha and IL-8 in blood serum was higher in subjects with pneumoconiosis than in controls.
Collapse
|
186
|
Chang SE, Lim Y, Lee H, Choi J, Sung K. Expression of p53, pRb, p16 and proliferating cell nuclear antigen in squamous cell carcinomas arising on a giant porokeratosis. Br J Dermatol 1999; 141:575-6. [PMID: 10583074 DOI: 10.1046/j.1365-2133.1999.03063.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
187
|
Kim JH, Chang HS, Kim KY, Park WM, Lee YJ, Choi HC, Kim KA, Lim Y. Environmental measurements of total dust and fiber concentration in manufacturer and user of man-made mineral fibers. INDUSTRIAL HEALTH 1999; 37:322-328. [PMID: 10441904 DOI: 10.2486/indhealth.37.322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Man-made mineral fibers (MMMF), most of which are referred to as man-made vitreous fibers (MMVF), are mostly amorphous silicates manufactured from glass, rock, or other minerals. Analysis for MMMF have been restricted largely to the measurement of total airborne mass concentrations, but more recently to the determination of airborne fiber levels by phase contrast optical microscopy. In Korea, many small factories are related with manufacturing and using MMMF without any special evaluation of environmental measurements. Though MMMF are known as the substitute of asbestos and their toxicity are regarded as very low, MMMF do not totally excluded from the respiratory and/or skin diseases now. Therefore, we evaluated the environments of many workplaces with total dust and fiber concentration. Most dust and fiber concentrations were below threshold limit value (TLV) at various industries and working processes. However, these data showed a slight relationship between total dust and fiber concentration.
Collapse
|
188
|
Lim Y, Shin SH, Jang IY, Rhee JH, Kim IS. A human transferrin-binding protein of Staphylococcus aureus is immunogenic in vivo and has an epitope in common with human transferrin receptor. FEMS Microbiol Lett 1998; 166:225-30. [PMID: 9770278 DOI: 10.1111/j.1574-6968.1998.tb13894.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
To understand human immune responses against the human transferrin-binding protein of Staphylococcus aureus (SA-tbp), we examined cell wall proteins from S. aureus ATCC 6538 using human convalescent sera, and a monoclonal antibody specific for human transferrin receptor (McAb-HTR). The SA-tbp, detected by immunoblot assay, was iron-repressible, reacted with the convalescent sera, and cross-reacted with McAb-HTR. Immunoelectron microscopy probed with McAb-HTR showed a reaction zone around the test strain from the deferrated BHI. After being preincubated with an S. aureus-bacteremic serum, the electroblot of the SA-tbp still reacted with McAb-HTR, but not with human transferrin-horseradish peroxidase conjugate. We conclude, there are at least two kinds of epitopes in the SA-tbp; one able to bind to human transferrin is immunogenic in humans, but the other sharing epitopes common with human transferrin receptor is not immunogenic in humans.
Collapse
|
189
|
Cha SH, Lee WK, Kim KA, Lim Y, Han JS, Lee KH. Effect of silica on phospholipase D activity in rat alveolar macrophages. INDUSTRIAL HEALTH 1998; 36:258-262. [PMID: 9701905 DOI: 10.2486/indhealth.36.258] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Silica may act as a stimulator of pulmonary inflammation and fibrosis. The effect of silica on phospholipase D (PLD) activity assayed as accumulation of [3H]phosphatidylethanol ([3H]PtdEt) was examined in [3H]palmitic acid-labeled primary cultures of rat alveolar macrophages. Silica induced a rapid accumulation of [3H]PtdEt in a time (0, 15, 30 and 45 min)- and concentration (0.5, 1.0, 2.5 and 5.0 mg/ml)-dependent manner indicating PLD activation. This silica-stimulated PLD activity was attenuated by the pretreatment with calcium chelator ethylene glycol-bis(beta-aminoethyl ether) N,N,N',N'-tetraacetic acid (EGTA) or/and 1,2-bis(2-aminophenoxy)ethane-N,N,N,N-tetraacetic acid acetoxymethyl ester (BAPTA/AM) (EGTA: 54.3 +/- 8.6%, BAPTA/AM: 67.5 +/- 7.8% and EGTA + BAPTA/AM: 35.8 +/- 2.9, respectively). Also, silica-induced PLD activation was partially inhibited by the pretreatment with nonspecific phospholipase C (PLC) and PLD inhibitor (neomycin; 66.4 +/- 4.8%) or specific PLC inhibitor (U73122; 70.8 +/- 4.6%). Sphingosine as a protein kinase C (PKC) inhibitor did not change silica-induced PLD activity indicating that PKC might not play a role in PLD activation by silica. Based on these results, we concluded that a silica-stimulated phospholipase D activity is present in the rat alveolar macrophages and is predominantly regulated by PLC-mediated intracellular calcium.
Collapse
|
190
|
Lim Y, Shin SH, Lee SI, Kim IS, Rhee JH. Iron repressibility of siderophore and transferrin-binding protein in Staphylococcus aureus. FEMS Microbiol Lett 1998; 163:19-24. [PMID: 9631540 DOI: 10.1111/j.1574-6968.1998.tb13020.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
In order to investigate whether the iron acquisition mechanisms of Staphylococcus aureus are induced by iron restriction in vitro, we examined S. aureus ATCC 6538 for production of siderophore and expression of transferrin-binding protein (SA-tbp) in normal or deferrated brain heart infusion broth (BHI). Siderophore production was earlier and greater in the deferrated BHI. The SA-tbp, detected by ligand blot assay, was expressed only in the deferrated BHI. When human transferrin was added to the deferrated BHI, siderophore production was later and lower than when transferrin was not present. In conclusion, both iron acquisition mechanisms of S. aureus were found to be iron-repressible and via both of them, human transferrin-bound iron was utilized for growth under iron-restricted condition.
Collapse
|
191
|
Lim Y. Iron repressibility of siderophore and transferrin-binding protein in Staphylococcus aureus. FEMS Microbiol Lett 1998. [DOI: 10.1016/s0378-1097(98)00143-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
|
192
|
Tacket CO, Taylor RK, Losonsky G, Lim Y, Nataro JP, Kaper JB, Levine MM. Investigation of the roles of toxin-coregulated pili and mannose-sensitive hemagglutinin pili in the pathogenesis of Vibrio cholerae O139 infection. Infect Immun 1998; 66:692-5. [PMID: 9453628 PMCID: PMC107958 DOI: 10.1128/iai.66.2.692-695.1998] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In this study, adult volunteers were fed tcpA and mshA deletion mutants of V. cholerae O139 strain CVD 112 to determine the role of toxin-coregulated pili (TCP) and mannose-sensitive hemagglutinin (MSHA) in intestinal colonization. Eight of 10 volunteers who received CVD 112 or CVD 112 delta mshA shed the vaccine strains in their stools; the geometric mean peak excretion for both groups was 1.4 x 10(5) CFU/g of stool. In contrast, only one of nine recipients of CVD 112 delta tcpA shed vibrios in his stool (P < 0.01); during the first 24 h after inoculation, 3 x 10(2) CFU/g was recovered from this volunteer. All recipients of CVD 112 and 8 (80%) of the recipients of CVD 112 delta mshA developed at least a fourfold rise in vibriocidal titer after immunization. In contrast, only one (11%) of the nine recipients of CVD 112 delta tcpA developed a fourfold rise in vibriocidal titer (P < 0.01). We conclude that TCP are an important colonization factor of V. cholerae O139 and probably of El Tor V. cholerae O1. In contrast, MSHA does not appear to promote intestinal colonization in humans.
Collapse
|
193
|
Lim Y, Kim SH, Kim KA, Oh MW, Lee KH. Involvement of protein kinase C, phospholipase C, and protein tyrosine kinase pathways in oxygen radical generation by asbestos-stimulated alveolar macrophage. ENVIRONMENTAL HEALTH PERSPECTIVES 1997; 105 Suppl 5:1325-1327. [PMID: 9400746 PMCID: PMC1470133 DOI: 10.1289/ehp.97105s51325] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Although asbestos stimulates oxygen radical generation in alveolar macrophages, the exact mechanism is still not clear. The purpose of this study was to compare the ability of three asbestos fibers (amosite, chrysotile, and crocidolite) to generate oxygen radicals in macrophages and examine the mechanism of this action. All asbestos fibers were able to induce chemiluminescence but chrysotile induced maximal chemiluminescence at higher concentrations than amosite and crocidolite. Protein kinase C (PKC) inhibitors (sphingosine and staurosporine) suppressed the ability of asbestos to induce oxygen radical generation. Phospholipase C (PLC) inhibitors (U73122 and neomycin) and protein tyrosine kinase (PTK) inhibitors (erbstatin and genistein) decreased oxygen radical generation of asbestos-stimulated alveolar macrophages. Oxygen radical generation was not suppressed by an adenylate cyclase activator (forskolin), a protein kinase A inhibitor (H-8), and a protein serine-threonine phosphatase inhibitor (okadaic acid). PLC and PTK inhibitors suppressed the increment of phosphoinositide turnover by amosite. These results suggest that asbestos fibers induce the generation of oxygen radicals through PTK, PLC, and PKC pathways in a dose-response pattern.
Collapse
|
194
|
Wine N, Lim Y, Fierer J. Pasteurella multocida epiglottitis. ARCHIVES OF OTOLARYNGOLOGY--HEAD & NECK SURGERY 1997; 123:759-61. [PMID: 9236599 DOI: 10.1001/archotol.1997.01900070103018] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Pasteurella multocida, a small gram-negative coccobacillus, colonizes the nasopharynx and gastrointestinal tract of many animals, including cats and dogs. Most human infections with P multocida are due to animal bites, but the respiratory tract is the second most common site of infection. We describe the third case report (to out knowledge) of acute P multocida epiglottitis. The mode of transmission in this case was inhalation of infectious nasopharyngeal secretions from cats. The patient responded well to treatment with penicillin, the drug of choice for P multocida infections. Therefore, infection with P multocida, though rare, should be considered in the differential diagnosis in any case involving acute epiglottitis and exposure to cats.
Collapse
|
195
|
Lim Y, Kim SH, Cho YJ, Kim KA, Oh MW, Lee KH. Silica-induced oxygen radical generation in alveolar macrophage. INDUSTRIAL HEALTH 1997; 35:380-387. [PMID: 9248222 DOI: 10.2486/indhealth.35.380] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Silica is a well-known occupational fibrogenic agent and its primary target cell is alveolar macrophage. Particle-stimulated macrophages are believed to release various mediator which can regulate the inflammation as well as pulmonary fibrosis. Even though oxygen radicals play the major role among these mediators, the mechanisms concerning the stimulation of alveolar macrophages are not clear yet. The present study was carried out to investigate the signal transduction pathway on oxygen radical generation in silica-stimulated alveolar macrophages. Silica induced oxygen radical generation in a dose-response pattern. Extracellular calcium depletion, calcium channel blockers, and calcium release blocker decreased the effect of silica on oxygen radical generation. Silica increased intracellular calcium through the influx of calcium through the calcium channel and the calcium release from the intracellular calcium store. To know the role of protein kinase C (PKC), phospholipase C (PLC), and protein tyrosine kinase (PTK) in silica-induced oxygen radical generation, we pretreated alveolar macrophages with inhibitors of these enzymes. Inhibitors of PKC (sphingosine and staurosporine), PLC (neomycin and U-73122), and PTK (genistein and erbstatin) suppressed the silica-induced oxygen radical generation. Silica increased the PLC activity at the concentration of 5 mg/ml. The inhibitors of PTK and PLC suppressed the action of silica on the PLC activity. From these results, we suggest that silica induces oxygen radical generation through PTK, PLC, and PKC in alveolar macrophages.
Collapse
|
196
|
Losonsky GA, Lim Y, Motamedi P, Comstock LE, Johnson JA, Morris JG, Tacket CO, Kaper JB, Levine MM. Vibriocidal antibody responses in North American volunteers exposed to wild-type or vaccine Vibrio cholerae O139: specificity and relevance to immunity. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1997; 4:264-9. [PMID: 9144361 PMCID: PMC170516 DOI: 10.1128/cdli.4.3.264-269.1997] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The emergence of a new agent of cholera, Vibrio cholerae O139, has prompted a reevaluation of the vibriocidal antibody assay. This assay, primarily directed to lipopolysaccharide, is an important correlate of O1 immunity. V. cholerae O139 strains are encapsulated, rendering them relatively resistant to killing by serum. Recent reports suggest that there is strain-to-strain variability in the sensitivity of the vibriocidal assay to fully encapsulated O139 strains. We have assessed a modified vibriocidal assay for fully encapsulated O139 strain AI-1837 and its unencapsulated mutant 2L in sera from 53 volunteers given wild-type AI-1837 or its attenuated derivative CVD 112 and from 48 controls challenged with V. cholerae O1 or strains of the family Enterobacteriaceae. Vibriocidal responses to the AI-1837 and 2L strains were seen in 67 and 89% of volunteers, respectively, following a single exposure to the wild-type strain. However, >50% of all controls had low-level vibriocidal responses to both strains. These nonspecific responses were transient and of the immunoglobulin G isotype. No binding activity against purified O139 lipopolysaccharide (LPS) by immunoblotting was seen in control sera. In contrast, vibriocidal assay and strain 2L LPS responses by immunoblotting were detectable in 91% of tested volunteers following a single exposure to O139. The presence of vibriocidal antibody to AI-1837 or 2L was not associated with protection in rechallenge studies with O139 strain AI-1837. The vibriocidal assay with unencapsulated strain 2L may be used to detect exposure to O139 strain AI-1837 in controlled research trials. However, its lack of specificity does not make it useful for determining exposure to V. cholerae O139 in the field.
Collapse
|
197
|
Farmer GM, Stankiewicz N, Michael B, Wojcik A, Lim Y, Ivkovic D, Rajakulendran J. Audit of waste collected over one week from ten dental practices. A pilot study. Aust Dent J 1997; 42:114-7. [PMID: 9153839 DOI: 10.1111/j.1834-7819.1997.tb00106.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
An audit of the waste practices of ten general dental surgeries identified problems that have occurred due to the lack of specific dental guidelines or codes of practice in this area. Occupational health and safety requirements for types and locations of sharps containers, and lack of consensus on what constitutes a sharp, were identified as areas needing attention. Cross-infection control items, such as gloves, masks, single-use cups, and protective coverings, were found to constitute up to 91 per cent of total waste. When infectious waste was reclassified by the audit team as 'that waste which was visibly blood stained,' a reduction in waste in this category was made, during the audit, at each practice. The practice of disposing of radiographic fixer and developer into the sewerage system occurred in three out of the ten practices, even though the Australian Dental Association Inc. has discouraged this practice.
Collapse
|
198
|
Lim Y, Lim K, Khan M. Effects of copper(II) mixed micelles on autooxidation of 3,5-di-tert-butylcatechol and hydrolysis of p-nitrophenyl diphenyl phosphate. Colloids Surf A Physicochem Eng Asp 1997. [DOI: 10.1016/s0927-7757(96)03981-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
199
|
Yi ES, Remick DG, Lim Y, Tang W, Nadzienko CE, Bedoya A, Yin S, Ulich TR. The intratracheal administration of endotoxin: X. Dexamethasone downregulates neutrophil emigration and cytokine expression in vivo. Inflammation 1996; 20:165-75. [PMID: 8728019 DOI: 10.1007/bf01487403] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Intratracheal instillation of endotoxin (LPS) causes acute pulmonary inflammation characterized by the accumulation of plasma proteins and leukocytes within the pulmonary airways. The synthetic glucocorticoid dexamethasone 1) inhibits the LPS-initiated vascular leak of plasma proteins into the airspace, 2) inhibits the LPS-initiated emigration of neutrophils and lymphocytes into the airspace in a dose-dependent fashion, and 3) inhibits LPS-initiated mRNA and/or bronchoalveolar lavage protein expression of cytokines (TNF, IL-1 and IL-6) and chemokines (MIP-1 alpha, MIP-2 and MCP-1). In conclusion, dexamethasone inhibits both the vascular and cellular aspects of acute inflammation by downregulation of a broad spectrum of inflammatory cytokines and chemokines.
Collapse
|
200
|
Yon C, Suh JW, Chang JH, Lim Y, Lee CH, Lee YS, Lee YW. AL072, a novel anti-Legionella antibiotic produced by Streptomyces sp. J Antibiot (Tokyo) 1995; 48:773-9. [PMID: 7592020 DOI: 10.7164/antibiotics.48.773] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
AL072 is a potent anti-Legionella antibiotic produced by Streptomyces strain AL91. The compound was isolated from the fermentation broth with 1 volume of isopropyl alcohol, followed by an ethyl acetate extraction and subsequent concentration under reduced pressure. Purification was performed on an octadecyl silica gel column followed by preparative HPLC. AL072 purified as mentioned above showed extremely specific activity only towards Legionella pneumophila. No antibacterial activity against any other bacteria tested was demonstrable. Its molecular weight was determined by FAB-MS (m/z 648) and the compound was identified as a novel 1,3-diacyl glycerol with the molecular formula C41H76O5. One of the two acyl groups is linoleyl and the other is 3,5-dimethyl octadecanoyl.
Collapse
|