• Tuberculosis and Respiratory Diseases
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• v.46 no.3
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• pp.338-349
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• 1999

Polymorphonuclear leukocytes(PMN) are the predominant inflammatory cells recruited in acute lung injury such as adult respiratory distress syndrome, pneumonia and also chronic lung disease such as idiopathic pulmonary fibrosis and pulmonary emphysema. Interleukin-8(IL-8) is an 8,000 D protein produced by many cells and has potent neutrophil chemoattractant and activating properties. The GRO, also called melanoma growth-stimulatory activity(MGSA), referring to a peptide of 73 amino acids, was reported to be mitogenic for cultured human melanoma cells. Mature GRO/MGSA has marked sequence similarity to IL-8. In view of the structural similarities to IL-8, it was of particular interest to test GRO for neutrophil activating and chemotactic properties. We found a significant release of IL-8 and GRO/MGSA from the cultured human umbilical vein endothelial cell(HUVEC) which was stimulated either with TNF$\alpha$ or IL-1$\beta$ and also found the expression of IL-8 and GRO/MGSA mRNA. Neutrophil chemotactic activity was enhanced in accordance with the increased IL-8 and GRO/MGSA. Our study also suggest that the IL-8 is more important in the increased neutrophil chemotactic activity than GRO/MGSA when endothelial cell is stimulated with TNF$\alpha$ or IL-1$\beta$ in vitro.

• Tuberculosis and Respiratory Diseases
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• v.58 no.4
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• pp.375-384
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• 2005

Background and Aims : Pre-induction of heat shock protein 70 (HSP70) is known to effectively attenuate the lipopolysaccharide (LPS)-induced inflammatory response in lung tissue. However, it is unclear if HSP70 induction after LPS exposure attenuates the subsequent LPS-induced inflammatory response in alveolar epithelial cells. This study examined the effects of HSP70 induction after LPS exposure on the IL-6 production and the cell viability after a subsequent LPS challenge in murine alveolar epithelial cells, and investigated whether or not HSP70 itself may be involved in those effects. Methods : Murine alveolar epithelial cells were cultured and divided into two groups; the Non-Pre-LPS group without a LPS pre-treatment and the Pre-LPS group with a LPS pre-treatment. Each group was subdivided into the following four subgroups: subgroup C (control), subgroup Q (quercetin), subgroup HSP70 (HSP70 induction), and subgroup HSP70-Inh (HSP70 inhibition). HSP70 expression, which was induced by sodium arsenite and inhibited by quercetin, was analyzed by western blot analysis. The IL-6 levels in the culture supernatant were measured by ELISA, and the cell viability was measured using a simplified MTT assay. Results : The IL-6 levels were lower in subgroup HSP70 than in subgroup C (P<0.01), and were higher in subgroup HSP70-Inh than in subgroup HSP70 in both the Non-Pre-LPS and Pre-LPS groups (P<0.05, P<0.01). The cell viability tended to decrease in the Pre-LPS group compared with the Non-Pre-LPS group. While the cell viability was higher in subgroups Q, HSP70, and HSP70-Inh than in subgroup C in the Non-Pre-LPS group (P<0.05, P<0.05, P<0.01), there was no difference in cell viability among the subgroups in the Pre-LPS group. Conclusion : HSP70 induction after a LPS pre-treatment in murine alveolar epithelial cells inhibits the subsequent LPS-induced IL-6 production without affecting the cell viability, and HSP70 by itself may play an important role in this proccess.

• Journal of Yeungnam Medical Science
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• v.15 no.1
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• pp.55-66
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• 1998

Pathophysiological mechanism of hemorrhagic fever with renal syndrome (HFRS) is not fully understood. Major clinical findings of HFRS patients are widespread hemorrhage, acute renal failure and shock. Basic lesion is vascular injury with microvascular hemorrhage and relatively little inflammation. According to autopsy findings, renal medulla shows focal hemorrhage, tubular necrosis and interstitial mononuclear infiltrates. The predominant cell type in the renal and pulmonary interstitium is a fibroblast and it participates in the healing process at the injury site by secreting a large amount of extracellular matrix proteins. Cultured human lung fibroblasts and Mongolian gerbil fibroblasts were known to be good host cells for the hantaan virus. It is possible that not only the endothelial cell but also the fibroblast is a target of Hantaan virus and the fibroblast might be involved in the pathogenesis and the healing process in HFRS. Integrins are adhesion molecules, and act as receptors for many extracellular matrix proteins. Recently, there are many reports that cell surface integrins influence on some viral infections or reversely viruses influence on the expression of integrins. The ${\alpha}_5{\beta}_1$ integrin is a major receptor for the fibronectin which is an important extracellular matrix protein secreted by fibroblasts. In this study, the role of ${\alpha}_5{\beta}_1$ integrin in the infection of Hantaan virus was examined by using anti-${\alpha}_5{\beta}_1$, integrin, anti-${\alpha}_5$ integrin and anti-${\beta}_1$, integrin antibodies in chicken embryo fibroblasts (CEF) and Mongolian gerbil fibroblasts(MGF). The treatment of anti-${\alpha}_5{\beta}_1$, integrin antibody in CEF reduced the virion titers 26.8% and the amount of nucleocapsid N protein 32.6% when compared with control CEF. When MGF were treated with anti-${\alpha}_5$, anti-${\beta}_1$ and anti-${\alpha}_5{\beta}_1$ integrin antibodies, virion titers were reduced by 26.5%, 29.4% and 28.7% and the amount of nucleocapsid N protein were reduced by 65.2%, 59.7% and 72.6%. These results suggested that ${\alpha}_5{\beta}_1$ integrin might act as a receptor for the Hantaan virus or blocking of ${\alpha}_5{\beta}_1$ integrin influences on the viral replication in CEF and MGF. It is also possible that the blocking of only one subunit of integrin represents similar results in that of whole molecule.

• Tuberculosis and Respiratory Diseases
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• v.44 no.6
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• pp.1318-1325
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• 1997

Background : Since the late 1960s, mechanical ventilation has been accomplished primarily using volume controlled ventilation(VCV). While VCV allows a set tidal volume to be guaranteed, VCV could bring about excessive airway pressures that may be lead to barotrauma in the patients with acute lung injury. With the increment of knowledge related to ventilator-induced lung injury, pressure controlled ventilation(PCV) has been frequently applied to these patients. But, PCV has a disadvantage of variable tidal volume delivery as pulmonary impedance changes. Since the concept of combining the positive attributes of VCV and PCV(dual control ventilation, DCV) was described firstly in 1992, a few DCV modes were introduced. Pressure-regulated volume control(PRVC) mode, a kind of DCV, is pressure-limited, time-cycled ventilation that uses tidal volume as a feedback control for continuously adjusting the pressure limit However, no clinical studies were published on the efficacy of PRVC until now. 'This investigation studied the efficacy of PRVC in the patients with unstable respiratory mechanics. Methods : The subjects were 8 mechanically ventilated patients(M : F=6 : 2, $56{\pm}26$ years) who showed unstable respiratory mechanics, which was defined by the coefficients of variation of peak inspiratory pressure for 15 minutes greater than 10% under VCV, or the coefficients of variation of tidal volume greater than 10% under PCV. The study was consisited of 3 modes application with VCV, PCV and PRVC for 15 minutes by random order. To obtain same tidal volume, inspiratory pressure setting was adjusted in PCV. Respiratory parameters were measured by pulmonary monitor(CP-100 pulmonary monitor, Bicore, Irvine, CA, USA). Results : 1) Mean tidal volumes($V_T$) in each mode were not different(VCV, $431{\pm}102ml$ ; PCV, $417{\pm}99ml$ ; PRVC, $414{\pm}97ml$) 2) The coefficient of variation(CV) of $V_T$ were $5.2{\pm}3.9%$ in VCV, $15.2{\pm}7.5%$ in PCV and $19.3{\pm}10.0%$ in PRVC. The CV of $V_T$ in PCV and PRVC were significantly greater than that in VCV(p<0.01). 3) Mean peak inspiratory pressure(PIP) in VCV($31.0{\pm}6.9cm$ $H_2O$) was higher than PIP in PCV($26.0{\pm}6.5cm$ $H_2O$) or PRVC($27.0{\pm}6.4cm$ $H_2O$)(p<0.05). 4) The CV of PIP were $13.9{\pm}3.7%$ in VCV, $4.9{\pm}2.6%$ in PVC and $12.2{\pm}7.0%$ in PRVC. The CV of PIP in VCV and PRVC were greater than that in PCV(p<0.01). Conclusions : Because of wide fluctuations of VT and PIP, PRVC mode did not seem to have advantages compared to VCV or PCV in the patients with unstable respiratory mechanics.

• Tuberculosis and Respiratory Diseases
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• v.45 no.6
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• pp.1252-1264
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• 1998

Background : Patients with established ARDS have a mortality rate that exceeds 50 percent despite of intensive care including artificial ventilation modality, Mortality has been associated with sepsis and organ failure preceding or following ARDS ; APACHE II score ; old age and predisposing factors. Revised ventilator strategy over last 10 years especially at ARDS appeared to improve the mortality of it. We retrospectively investigated 40 ARDS patients of respiratory-care unit to examine how these factors influence outcome. Methods : A retrospective investigation of 40 ARDS patients in respiratory-care unit with ventilator management over 46 months was performed. We investigated the clinical characteristics such as a risk factor, cause of death and mortality, and also parameters such as APACHE II score, number of organ dysfunction, and hypoxia score (HS, $PaO_2/FIO_2$) at day 1, 3, 7 of severe acute lung injury, and simultaneously the PEEP level and tidal volume. Results : Clinical conditions associated with ARDS were sepsis 50%, pneumonia 30%, aspiration pneumonia 20%, and mortality rate based on the etiology of ARDS was sepsis 50%, pneumonia 67%(p<0.01 vs sepsis), aspiration pneumonia 38%. Overall mortality rate was 60%. In 28 day-nonsurvivors, leading cause of death was severe sepsis(42.9%) followed by MOF(28.6%), respiratory failure(19.1 %), and others(9.5%). There were no differences in variables of age, sex, APACHE II score, HS, and numbers of organ dysfunction at day 1 of ARDS between 28-days survivor and nonsurvivors. In view of categorized variables of age(>70), APACHE II score(>26), HS(<150) at day 1 of ARDS, there were significant differences between 28-days survivor and nonsurvivors(p<0.05). After day 1 of ARDS, the survivors have improved their APACHE II score, HS, numbers of organ dysfunction over the first 3d to 7d, but nonsurvivors did not improve over a seven-day course. There were significant differences in APACHE II score and numbers of organ dysfunction of day 3, 7 of ARDS, and HS of day 7 of ARDS between survivors and nonsurvivors(p<0.05). Fatality rate of ARDS has been declined from 68% to less than 40% between 1995 and 1998. There were no differences in APACHE II score, HS, numbers of organ dysfunction, old age at presentation of ARDS. In last years, mean PEEP level was significantly higher and mean tidal volume was significantly lower than previous years during seven days of ARDS(p<0.01). Conclusions : Improvement of HS, APACHE II score, organ dysfunction over the first 3d to 7d is associated with increased survival Decline in ARDS fatality rates between 1995 and 1998 seems that this trend must be attributed to improved supportive therapy including at least high PEEP instead of conventional-least PEEP approach in ventilator management of acute respiratory distress syndrome.

• Journal of Chest Surgery
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• v.37 no.3
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• pp.201-209
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• 2004

Extracorporeal life support (ECLS) system is a device for respiratory and/or heart failure treatment, and there have been many trials for development and clinical application in the world. Currently, a non-pulsatile blood pump is a standard for ECLS system. Although a pulsatile blood pump is advantageous in physiologic aspects, high pressure generated in the circuits and resultant blood cell trauma remain major concerns which make one reluctant to use a pulsatile blood pump in artificial lung circuits containing a membrane oxygenator. The study was designed to evaluate the hypothesis that placement of a pressure-relieving compliance chamber between a pulsatile pump and a membrane oxygenator might reduce the above mentioned side effects while providing physiologic pulsatile blood flow. The study was performed in a canine model of oleic acid induced acute lung injury (N=16). The animals were divided into three groups according to the type of pump used and the presence of the compliance chamber, In group 1, a non-pulsatile centrifugal pump was used as a control (n=6). In group 2 (n=4), a single-pulsatile pump was used. In group 3 (n=6), a single-pulsatile pump equipped with a compliance chamber was used. The experimental model was a partial bypass between the right atrium and the aorta at a pump flow of 1.8∼2 L/min for 2 hours. The observed parameters were focused on hemodynamic changes, intra-circuit pressure, laboratory studies for blood profile, and the effect on blood cell trauma. In hemodynamics, the pulsatile group II & III generated higher arterial pulse pressure (47$\pm$ 10 and 41 $\pm$ 9 mmHg) than the nonpulsatile group 1 (17 $\pm$ 7 mmHg, p<0.001). The intra-circuit pressure at membrane oxygenator were 222 $\pm$ 8 mmHg in group 1, 739 $\pm$ 35 mmHg in group 2, and 470 $\pm$ 17 mmHg in group 3 (p<0.001). At 2 hour bypass, arterial oxygen partial pressures were significantly higher in the pulsatile group 2 & 3 than in the non-pulsatile group 1 (77 $\pm$ 41 mmHg in group 1, 96 $\pm$ 48 mmHg in group 2, and 97 $\pm$ 25 mmHg in group 3: p<0.05). The levels of plasma free hemoglobin which was an indicator of blood cell trauma were lowest in group 1, highest in group 2, and significantly decreased in group 3 (55.7 $\pm$ 43.3, 162.8 $\pm$ 113.6, 82.5 $\pm$ 25.1 mg%, respectively; p<0.05). Other laboratory findings for blood profile were not different. The above results imply that the pulsatile blood pump is beneficial in oxygenation while deleterious in the aspects to high pressure generation in the circuits and blood cell trauma. However, when a pressure-relieving compliance chamber is applied between the pulsatile pump and a membrane oxygenator, it can significantly reduce the high circuit pressure and result in low blood cell trauma.

• Tuberculosis and Respiratory Diseases
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• v.52 no.4
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• pp.376-384
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• 2002

Background : The mortality from acute respiratory distress syndrome(ARDS) in the late stage, which is characterized by progressive pulmonary fibroproliferation, is ${\geq}80%$. Although previous prospective trials failed to show a survival benefit of steroid therapy in early ARDS, recently, a few of reports have described the survival benefit of the long-term use of steroid in patients with late ARDS. In this study, we analyzed the effect of steroid therapy on patients with late ARDS retrospectively in a single. Medral intensive care unit (MICU). Methods : Over a 3-year period, the medical records of 48 ARDS patients who had been on mechanical ventilation more than 8 days were reviewed. 14 patients were treated by the long-term use of methylprednisolone and another 34 patients served as a control. Both groups were comparable regarding clinical and physiologic data lung injury score(LIS), multiple organ failure score, APACHE III and SAPS II score. Because steroid was instituted after 8 days of advanced mechanical ventilatory support in average, we arbitrarily defined the $8^{th}$ day of ARDS as first day of the study. Results : Initially, the groups had similar PF($PaO_2/FiO_2$) ratio, LIS, APACHE III and SAPS II score. By 7th day after the start of steroid therapy, there were significant improvements in PF ratio, LIS, APACHE III and SAPS II score. The mortality in the steroid treated group was significantly lower(42.9% vs 73.5%, p<0.05). Conclusion : Although the data of this study was retrospective and was not randomized, in order to improve the patient's outcomes, steroid therapy should be considered in late ARDS patients. However, prospective trials are needed to define the indication and the effect of steroid therapy in late ARDS.

• Tuberculosis and Respiratory Diseases
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• v.42 no.4
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• pp.522-534
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• 1995

Background: In the pathogenesis of acute lung injury induced by lipopolysaccharide(LPS), oxygen radiclls are known to be involved in one part. Superoxide dismutase(SOD) protects oxygen radical-induced tissue damage by dismutating superoxide to hydrogen peroxide. In eukaryotic cells, two forms of SOD exist intracellularly as a cytosolic, dimeric copper/zinc-containing SOD(CuZnSOD) and a mitochondrial, tetrameric manganese-containing SOD(MnSOD). But there has been little information about SOD gene expression and its regulation in pulmonary alveolar macrophages(PAMs). The objective of this study is to evaluate the SOD gene expression induced by LPS and its regulation in PAMs of rat. Method: In Sprague-Dawley rats, PAMs obtained by broncholaveolar lavage were purified by adherence to plastic plate. To study the effect of LPS on the SOD gene expression of PAMs, they were stimulated with different doses of LPS($0.01{\mu}g/ml{\sim}10{\mu}g/ml$) and for different intervals(0, 2, 4, 8, 24hrs). Also for evaluating the level of SOD gene regulation actinomycin D(AD) or cycloheximide(CHX) were added respectively. To assess whether LPS altered SOD mRNA stability, the rate of mRNA decay was determined in control group and LPS-treated group. Total cellular RNA extraction by guanidinium thiocyanate/phenolfchlorofonn method and Northern blot analysis by using a $^{32}P$-labelled rat MnSOD and CuZnSOD cDNAs were performed. Results: The expression of mRNA in MnSOD increased dose-dependently, but not in CuZnSOD. MnSOD mRNA expression peaked at 8 hours after LPS treatment. Upregulation of MnSOD mRNA expression induced by LPS was suppressed by adding AD or CHX respectively. MnSOD mRNA stability was not altered by LPS. Conclusion: These findings show that PAMs of rat could be an important source of SOD in response to LPS, and suggest that their MnSOD mRNA expression may be regulated transcriptionally and require de novo protein synthesis without affecting mRNA stability.

• Tuberculosis and Respiratory Diseases
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• v.41 no.5
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• pp.452-461
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• 1994

Background: Tumor necrosis factor(TNF)-$\alpha$ and Interleukin(lL)-$1{\beta}$ are thought to play a major role in the pathogenesis of the septic syndrome, which is frequently associated with adult respiratory distress syndrome(ARDS). In spite of many reports for the role of TNF-$\alpha$ in the pathogenesis of ARDS, including human studies, it has been reported that TNF-$\alpha$ is not sensitive and specific marker for impending ARDS. But there is a possibility that the results were affected by the diversity of pathogenetic mechanisms leading to the ARDS because of various underlying disorders of the study group in the previous reports. The purpose of the present study was to evaluate the roles of TNF-$\alpha$ and IL-$1{\beta}$ as a predictable marker for development of ARDS in the patients with septic syndrome, in which the pathogenesis is believed to be mainly cytokine-mediated. Methods: Thirty-six patients of the septic syndrome hospitalized in the intensive care units of the Asan Medical Center were studied. Sixteens suffered from ARDS, whereas the remaining 20 were at the risk of developing ARDS(acute hypoxemic respiratory failure, AHRF). In all patients venous blood samples were collected in heparin-coated tubes at the time of enrollment, at 24 and 72 h thereafter. TNF-$\alpha$ and IL-$1{\beta}$ was measured by an enzyme-linked immunosorbent assay (ELISA). All data are expressed as median with interquartile range. Results: 1) Plama TNF-$\alpha$ levels: Plasma TNF-$\beta$ levels were less than 10pg/mL, which is lowest detection value of the kit used in this study within the range of the $mean{\pm}2SD$, in all of the normal controls, 8 of 16 subjects of ARDS and in 8 in 20 subjects of AHRF. Plasma TNF-$\alpha$ levels from patients with ARDS were 10.26pg/mL(median; <10-16.99pg/mL, interquartile range) and not different from those of patients at AHRF(10.82, <10-20.38pg/mL). There was also no significant difference between pre-ARDS(<10, <10-15.32pg/mL) and ARDS(<10, <10-10.22pg/mL). TNF-$\alpha$ levels were significantly greater in the patients with shock than the patients without shock(12.53pg/mL vs. <10pg/mL) (p<0.01). There was no statistical significance between survivors(<10, <10-12.92pg/mL) and nonsurvivors(11.80, <10-20.8pg/mL) (P=0.28) in the plasma TNF-$\alpha$ levels. 2) Plasma IL-$1{\beta}$ levels: Plasma IL-$1{\beta}$ levels were less than 0.3ng/mL, which is the lowest detection value of the kit used in this study, in one of each patients group. There was no significant difference in IL-$1{\beta}$ levels of the ARDS(2.22, 1.37-8.01ng/mL) and of the AHRF(2.13, 0.83-5.29ng/mL). There was also no significant difference between pre-ARDS(2.53, <0.3-8.34ngfmL) and ARDS(5.35, 0.66-11.51ng/mL), and between patients with septic shock and patients without shock (2.51, 1.28-8.34 vs 1.46, 0.15-2.13ng/mL). Plasma IL-$1{\beta}$ levels were significantly different between survivors(1.37, 0.4-2.36ng/mL) and nonsurvivors(2.84, 1.46-8.34ng/mL). Conclusion: Plasma TNF-$\alpha$ and IL-$1{\beta}$ level are not a predictable marker for development of ARDS. But TNF-$\alpha$ is a marker for shock in septic syndrome. These result could not exclude a possibility of pathophysiologic roles of TNF-$\alpha$ and IL-$1{\beta}$ in acute lung injury because these cytokine could be locally produced and exert its effects within the lungs.