• Tuberculosis and Respiratory Diseases
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• v.38 no.3
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• pp.228-235
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• 1991

Pulmonary surfactant is a lipoprotein complex composed primarily of phospholipid and lungspecific apoproteins that reduces surface tension in the alveolus and maintains alveolar stability at low lung volume. Three families of lung-specific apoproteins have been described: SP-A, a glycoprotein with a reduced molecular weight of 28~36 KDa. SP-B a hydrophobic protein with a nonreduced molecular weight of 18 KDa, and SP-C a hydrophobic protein with a non-reduced molecular weight of 5~8 KDa. Surfactant proteins have important roles in regulating surfactant metabolism as well as in determining its physical properties. The synthesis of the active surfactant peptides appears to be modulated by system with considerable complexity, including numerous levels of regulation such as cell-specific, hormonal and developmental controls. Endotoxin appears to alter surfactant protein mRNAs differentially. It is hoped that the elucidation of the factors controlling the synthesis and metabolism of the surfactant proteins will aid in understanding the pathogenesis of hyaline membrane disease and offer new avenues for the therapy and diagnosis of ther pulmonary disorders as well.

• Tuberculosis and Respiratory Diseases
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• v.48 no.4
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• pp.513-521
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• 2000

Background : TNF may play an important role(central mediator) in the development of an acute respiratory distress syndrome. Since TNF induced lung injury in the acute respiratory distress syndrome and abnormalities in surfactant function have been described in acute respiratory distress syndrome, the authors investigated the effects of TNF on the regulation of surfactant protein A, B and C mRNA accumulation. Methods : The effects of TNF on gene expression of surfactant protein A, B, and C were analyzed using filter hybridization, 12 and 24 hours after intravenous injection of TNF in rats. Results : 1. The accumulation of SP-A mRNA in the TNF treated group (12 and 24 hours after TNF injection) was significantly decreased by 22.9% and 27.4%, respectively, compared to the control group (P<.025, P<.025). 2. The accumulation of SP-B mRNA in 24 hours after TNF treated group was significantly decreased by 20.5% compared to that of the control group(P<.01). 3. The accumulation of SP-C mRNA in 12 hours after TNF treated group was significantly decreased by 31% the compared to that of the control group(P<.01). Conclusions : These findings indicate the marked inhibitory effects of tumor necrosis factor on surfactant proteins expression in vivo. This finding. in turn, supports the idea of inhibitory effects of tumor necrosis factor on surfactant proteins expression as it relates to pathogenesis of acute respiratory distress syndrome.

• The Korean Journal of Physiology
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• v.28 no.1
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• pp.71-77
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• 1994

In the animal model of acute respiratory distress syndrome (ARDS) induced by N-nitroso-N-methylurethane (NNNMU) the secretory activity of alveolar type H cells during acute alveolar injury was investigated by determining phospholipid and pulmonary surfactant associated proteins in crude surfactant. The mechanism of the secretory change was studied by determination of DNA and RNA levels in the lung tissue. After induction of acute alveolar injury with NNNMU, pulmonary hemorrhage, atelectasis and gross hypertrophy were observed. Seven days after NNNMU treatment the level of total DNA in lung homogenate was increased markedly indicating that a hypertrophy was induced by cellular proliferation. Although the total DNA level increased, the RNA/DNA ratio was gradually decreased after NNNMU treatment. Seven days after NNNMU treatment the RNA/DNA ratio returned to the normal control level. During the acute alveolar injury, phospholipid and surfactant associated proteins were reduced significantly as compared with the control, implying that the secretory activity of alveolar type II cells was altered during acute alveolar injury induced by NNNMU. The protein content in crude surfactant during peak injury(7 days after NNNMU) was decreased significantly but phospholipid/protein ratios were identical in both control and NNNMU treatment groups. SDS-PAGE of proteins in crude pulmonary surfactant showed a decrease in major surfactant associated protein(M.W. 38,000) during acute alveolar injury. The present study may suggest that while alveolar type H cells proliferate markedly, transcription of alveolar type ll cell gene was inhibited by an unknown mechanism such as DNA methylation induced by NNNMU. Such an inhibition of transcriptional activity is thought to be associated with the decreased secretory activity of alveolar type ll cells, which may lead to pulmonary atelectasis and edema during the acute alveolar injury.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.131-136
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• 2005

The selective extraction behavior of lactoferrin (Lf) from whey protein mixture was examined using reverse micelles formed by the cationic surfactant, cetyldimethylammonium bromide (CDAB). The major whey proteins, including ${\beta}$-lactoglobulin, ${\alpha}$-lactalbumin and bovine serum albumin, were solubilized from aqueous phase to organic phase while Lf was recovered in the aqueous phase. The solubilization behaviors of the proteins were manipulated by the process parameters such as the pH and salt concentration of the aqueous phase and the surfactant concentration in the organic phase. Efficient forward extraction was achieved with sodium borate buffer (50 mM, pH 9) containing 50 mM KCl and organic phase containing 100 mM CDAB. Based on SDS-PAGE and densitometry, about 96% of the initial Lf remained in the aqueous phase after forward extraction. The dialyzed Lf fully maintained its bacteriostatic activity against E. coli O157:H7.

• Clinical and Experimental Pediatrics
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• v.57 no.4
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• pp.157-163
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• 2014

Respiratory distress syndrome (RDS) among preterm infants is typically due to a quantitative deficiency of pulmonary surfactant. Aside from the degree of prematurity, diverse environmental and genetic factors can affect the development of RDS. The variance of the risk of RDS in various races/ethnicities or monozygotic/dizygotic twins has suggested genetic influences on this disorder. So far, several specific mutations in genes encoding surfactant-associated molecules have confirmed this. Specific genetic variants contributing to the regulation of pulmonary development, its structure and function, or the inflammatory response could be candidate risk factors for the development of RDS. This review summarizes the background that suggests the genetic predisposition of RDS, the identified mutations, and candidate genetic polymorphisms of pulmonary surfactant proteins associated with RDS.

• Journal of the Korean Applied Science and Technology
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• v.19 no.2
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• pp.79-85
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• 2002

The cutaneous tolerability of detergent formulations can be improved by means of suitable additives. They complex the surfactant molecules lowering the concentration of their free monomeric species. Proteins derivatives used as additives for detergency are usually prepared by partial hydrolysis of plant reserve proteins. The main purpose of the hydrolytic cleavage is to make them water soluble and suitable for liquid products. Water solubility and stability are obtained by means of complexation with surfactants which also increase their actual hydrophobicity, an important parameter affecting cosmetic properties of proteins. Transepidermal water loss (TEWL) and electric capacitance (EC) have been adopted as investigation technigues to evaluate the skin integrity/damage in vitro tests, The performance of native wheat protein / surfactant complexes has been compared with traditional protein hydrolysates as detergent additives. The results show a noticeable reduction of skin irritation in surfactant formulations with addition of native wheat protein.

• Clinical and Experimental Pediatrics
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• v.62 no.5
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• pp.155-161
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• 2019

Following the first successful trial of surfactant replacement therapy for preterm infants with respiratory distress syndrome (RDS) by Fujiwara in 1980, several animal-derived natural surfactants and synthetic surfactants have been developed. Synthetic surfactants were designed to overcome limitations of natural surfactants such as cost, immune reactions, and infections elicited by animal proteins contained in natural surfactants. However, first-generation synthetic surfactants that are protein-free have failed to prove their superiority over natural surfactants because they lack surfactant protein (SP). Lucinactant, a second-generation synthetic surfactant containing the SP-B analog, was better or at least as effective as the natural surfactant, suggesting that lucinactant could act an alternative to natural surfactants. Lucinactant was approved by the U. S. Food and Drug Administration in March 2012 as the fifth surfactant to treat neonatal RDS. CHF5633, a second-generation synthetic surfactant containing SP-B and SP-C analogs, was effective and safe in a human multicenter cohort study for preterm infants. Many comparative studies of natural surfactants used worldwide have reported different efficacies for different preparations. However, these differences are believed to due to site variations, not actual differences. The more important thing than the composition of the surfactant in improving outcome is the timing and mode of administration of the surfactant. Novel synthetic surfactants containing synthetic phospholipid incorporated with SP-B and SP-C analogs will potentially represent alternatives to natural surfactants in the future, while improvement of treatment modalities with less-invasive or noninvasive methods of surfactant administration will be the most important task to be resolved.

• Journal of Plant Biotechnology
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• v.48 no.3
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• pp.165-172
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• 2021

The solubilization of isolated proteins into the adequate buffer containing of surfactants is primary step for proteomic analysis. Particularly, sodium dodecyl sulfate (SDS) is the most widely used surfactant, however, it is not compatible with mass spectrometry (MS). Therefore, it must be removed prior to MS analysis through rigorous washing, which eventually results in inevitable protein loss. Recently, photocleavable surfactant, 4-hexylphenylazosulfonate (Azo), was reported which can be easily degraded by UV irradiation and is compatible with MS during proteomic approach using animal tissues. In this study, we employed comparative label-free proteomic analysis for evaluating the solubilization efficacies of the Azo and SDS surfactants using rice leave proteins. This approach led to identification of 3,365 proteins of which 682 proteins were determined as significantly modulated. Further, according to the subcellular localization prediction in SDS and Azo, proteins localized in the chloroplast were the major organelle accounting for 64% of the total organelle in the SDS sample, while only 37.5% of organelle proteins solubilized in the Azo were predicted to be localized in chloroplast. Taken together, this study validates the efficient solubilization of total protein isolated from plant material for bottom-up proteomics. Azo surfactant is suitable as substitute of SDS and promising for bottom-up proteomics as it facilitates robust protein extraction, rapid washing step during enzymatic digestion, and MS analysis.

• Tuberculosis and Respiratory Diseases
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• v.39 no.3
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• pp.242-247
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• 1992

Background: The ability to precisely measure specific mRNA levels by hybridization to complementary DNA probes is an important tool for analyzing the regulation of gene expression. Surfactant proteins have important roles in regulating surfactant metabolism as well as in determing its physical properties. Method: The complete coding regions for rat surfactant protein complementary DNA of surfactant protein B were subcloned into pGem 3Z or 4Z such that either antisense or sense transcripts were obtained by using SP 6 RNA polymerase. Surfactant protein B mRNA was measured by filter hybridization. Results: Equation of standard curve between counts per minute (Y) and surfactant protein B mRNA transcript input (X) was Y=2034.9 X+159.1. Correlation coefficient was 1.0. Couclusions: Filter hybridization assay is suited to situation when rapid, accurate quantitation of multiple samples is required.

• Tuberculosis and Respiratory Diseases
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• v.54 no.5
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• pp.510-521
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• 2003

Background : The surfactant specific proteins, SP-B and SP-C are believed to be important regulators of the surfactant function and homeostasis. Since acute respiratory distress syndrome(ARDS) is usually viewed as the functional and morphological expression of a similar underlying lung injury caused by a variety of insults, and since abnormalities in the surfactant function have been described in ARDS, the authors investigated the different effects of endotoxin and thiourea on the accumulation of mRNA encoding SP-B and SP-C. Methods : Sprague-Dawley rats were given 5 mg/kg of an intraperitoneal endotoxin from Salmonella enteritidis and 3.5 mg/kg intraperitoneal thiourea and were sacrificed at different time periods. Results : 1. The SP-B mRNA levels 6 and 24 hours after the 5 mg/kg endotoxin treatment was significantly reduced by 26.1% and 50%, respectively(P<0.01, P<0.001). 2. The SP-B mRNA levels 24 hours after the 3.5 mg/kg thiourea treatment was reduced by 9.8% and 12.5%, respectively. 3. The SP-C mRNA levels 6 and 24 hours after the 5 mg/kg endotoxin treatment was significantly reduced by 38.7% and 53.6%, respectively(P<0.01, P<0.001). 4. The SP-C mRNA level 6 hours after the 3.5 mg/kg thiourea treatment was reduced by 22.8%(P<0.05). Conclusion : These results indicate that the differential regulation of the hydrophobic surfactant proteins in vivo is evident, and suggest that the hydrophobic surfactant proteins might be differentially regulated during lung injury at different time periods without altering the lung wet to dry ratios. The mechanism of these alternations at the different time periods and the different kinds of etiology remain to be determined.