• Title/Summary/Keyword: size exclusion

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Expression and Purification of Transmembrane Protein MerE from Mercury-Resistant Bacillus cereus

  • Amin, Aatif;Sarwar, Arslan;Saleem, Mushtaq A.;Latif, Zakia;Opella, Stanley J.
    • Journal of Microbiology and Biotechnology
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    • v.29 no.2
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    • pp.274-282
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    • 2019
  • Mercury-resistant ($Hg^R$) bacteria were isolated from heavy metal polluted wastewater and soil collected near to tanneries of district Kasur, Pakistan. Bacterial isolates AZ-1, AZ-2 and AZ-3 showed resistance up to $40{\mu}g/ml$ against mercuric chloride ($HgCl_2$). 16S rDNA ribotyping and phylogenetic analysis were performed for the characterization of selected isolates as Bacillus sp. AZ-1 (KT270477), Bacillus cereus AZ-2 (KT270478) and Bacillus cereus AZ-3 (KT270479). Phylogenetic relationship on the basis of merA nucleotide sequence confirmed 51-100% homology with the corresponding region of the merA gene of already reported mercury-resistant Gram-positive bacteria. The merE gene involved in the transportation of elemental mercury ($Hg^0$) via cell membrane was cloned for the first time into pHLV vector and transformed in overexpressed C43(DE3) E. coli cells. The recombinant plasmid (pHLMerE) was expressed and the native MerE protein was obtained after thrombin cleavage by size exclusion chromatography (SEC). The purification of fusion/recombinant and native protein MerE by Ni-NTA column, dialysis and fast protein liquid chromatography (FPLC/SEC) involved unfolding/refolding techniques. A small-scale reservoir of wastewater containing $30{\mu}g/ml$ of $HgCl_2$ was designed to check the detoxification ability of selected strains. It resulted in 83% detoxification of mercury by B. cereus AZ-2 and B. cereus AZ-3, and 76% detoxification by Bacillus sp. AZ-1 respectively (p < 0.05).

Effect of Cardiopulmonary Physiotherapy on Patients With Percutaneous Coronary Intervention - Systematic Review and Meta-Analysis (경피적 관상동맥 중재술을 받은 환자를 대상으로 심장호흡물리치료에 대한 효과 - 체계적 고찰과 메타분석)

  • Kang, Na-yoon;Park, Beom-seok;Kim, Min-hee
    • Journal of the Korean Society of Physical Medicine
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    • v.14 no.1
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    • pp.63-73
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    • 2019
  • PURPOSE: This study examined the effects of cardiopulmonary physiotherapy on the cardiopulmonary function, metabolism, inflammatory markers, and quality of life in patients with coronary artery disease who underwent percutaneous coronary intervention (PCI). METHODS: Electronic bibliographic databases of a regional information sharing system (RISS) and PubMed were searched to identify studies with randomized and non-randomized controlled trials. As the final outcome, 320 publications were identified and 18 studies met the inclusion and exclusion criteria. All studies were assessed for the quality of study using Cochrane's risk of bias. RESULTS: Sixteen studies met the inclusion criteria, in which meta-analysis had been conducted to examine the effectiveness of cardiopulmonary physiotherapy on the cardiopulmonary function, metabolism, inflammatory markers, and quality of life in patients undergoing PCI. Meta-analysis based on a random effect model showed that the cardiopulmonary physiotherapy was beneficial in improving the cardiopulmonary function, metabolism, inflammatory markers, and quality of life. In particular, there was a significant effect on the peak oxygen uptake (effect size 5.30%; 95% confidence interval 3.62~6.97). Cardiopulmonary physiotherapy for a during period of 6 weeks or more was effective in significantly improving the cardiopulmonary function and metabolism function in a subgroup analysis, but cardiopulmonary physiotherapy for less than 6 weeks was not effective. CONCLUSION: Cardiopulmonary physiotherapy has positive effects on the cardiopulmonary function, metabolism, inflammatory markers, and quality of life in patients undergoing PCI.

Systematic Review of Acupuncture Treatment for Mild Cognitive Impairment

  • Kim, Min Wook;Yoo, Jae Hee;Go, Hong Je;Kim, Seon Woo;Jang, Seung Won;Jeong, Hyun Jin;Kim, Jae Hong
    • Journal of Acupuncture Research
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    • v.36 no.2
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    • pp.72-79
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    • 2019
  • Background: The aim of this study was to review clinical efficacy of acupuncture treatment of mild cognitive impairment. Methods: Randomized controlled trials that performed acupuncture treatment for mild cognitive impairment were retrieved from 6 online databases (PubMed, Cochrane Library, EMBASE, CNKI, NDSL, OASIS) on September $30^{th}$, 2018. Studies were selected according to inclusion and exclusion criteria, and were reviewed by Risk of Bias assessment. Results: In total, 21 studies were included in this review. All studies were Chinese (19 studies published in Chinese and 2 in English). The sample size, 50 to 100, and the number of treatment times, 20 to 30, were the largest range in all studies. The most treatments performed was 30. The longest treatment period was 56 days, which accounted for 33% of the studies. The most frequently used evaluation index was the Mini Mental State Examination followed by the Montreal Cognitive Assessment, each used 17 times and 15 times, respectively. The most frequently used acupoints were GV20, EX-HN1, GB20, and GV24, which accounted for 47% of total number of acupoints used. In 48% of the studies, needle retention time was 30 minutes. Western medicine treatment was the most common control group. Most studies reported that the intervention group was statistically significantly different to the control group. Conclusion: These results suggest that acupuncture for mild cognitive impairment was effective. However, it is difficult to confirm this conclusion because the quality of most of these studies were of low quality.

Molecular and Enzymatic Features of Homoserine Dehydrogenase from Bacillus subtilis

  • Kim, Do Hyeon;Nguyen, Quyet Thang;Ko, Gyeong Soo;Yang, Jin Kuk
    • Journal of Microbiology and Biotechnology
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    • v.30 no.12
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    • pp.1905-1911
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    • 2020
  • Homoserine dehydrogenase (HSD) catalyzes the reversible conversion of ʟ-aspartate-4-semialdehyde to ʟ-homoserine in the aspartate pathway for the biosynthesis of lysine, methionine, threonine, and isoleucine. HSD has attracted great attention for medical and industrial purposes due to its recognized application in the development of pesticides and is being utilized in the large scale production of ʟ-lysine. In this study, HSD from Bacillus subtilis (BsHSD) was overexpressed in Escherichia coli and purified to homogeneity for biochemical characterization. We examined the enzymatic activity of BsHSD for ʟ-homoserine oxidation and found that BsHSD exclusively prefers NADP+ to NAD+ and that its activity was maximal at pH 9.0 and in the presence of 0.4 M NaCl. By kinetic analysis, Km values for ʟ-homoserine and NADP+ were found to be 35.08 ± 2.91 mM and 0.39 ± 0.05 mM, respectively, and the Vmax values were 2.72 ± 0.06 μmol/min-1 mg-1 and 2.79 ± 0.11 μmol/min-1 mg-1, respectively. The apparent molecular mass determined with size-exclusion chromatography indicated that BsHSD forms a tetramer, in contrast to the previously reported dimeric HSDs from other organisms. This novel oligomeric assembly can be attributed to the additional C-terminal ACT domain of BsHSD. Thermal denaturation monitoring by circular dichroism spectroscopy was used to determine its melting temperature, which was 54.8℃. The molecular and biochemical features of BsHSD revealed in this study may lay the foundation for future studies on amino acid metabolism and its application for industrial and medical purposes.

Headache related to mask use of healthcare workers in COVID-19 pandemic

  • Toksoy, Cansu Koseoglu;Demirbas, Hayri;Bozkurt, Erhan;Acar, Hakan;Boru, Ulku Turk
    • The Korean Journal of Pain
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    • v.34 no.2
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    • pp.241-245
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    • 2021
  • Background: It has been reported that a new type of headache may develop as a result of face mask use during the COVID-19 pandemic. The aim of this study is to investigate the clinical features of face mask-related headache during the COVID-19 pandemic. Methods: This is a cross-sectional study carried out on healthcare workers at the Afyonkarahisar Health Sciences University. The number of workers at our university was established. Sample size was calculated using the G*Power program. A questionnaire consisting of questions relating to pre-existing headache, an aggravation in headache, and de-novo headache was filled out by 3 neurologists with all participants. Results: Data was collected from a total of 375 participants, after the exclusion of 5 individuals who refused to participate. Out of all participants, 26 (6.9%) used a filtering mask, 274 (73.1%) used a surgical mask, 75 (20.0%) participants used a combination of both masks. The number of participants with preexisting headache was 114 (30.4%) had pre-existing headache. Of those with pre-existing headache, 77 (67.5%) healthcare workers had reported an aggravation in their headache after mask use. De-novo headache was observed in 116 (30.9%) of participants. De-novo headache characteristics included throbbing in 17 (14.7%) participants and pressing in 99 (85.3%) participants. In addition, symptoms such as tachypnea, sleep disturbance, and fatigue were found to be significantly higher. Conclusions: This study indicates that healthcare workers develop headaches due to use of masks during the COVID-19 outbreak.

Environmental Factors Influencing the Prevalence of Falls in South Korea

  • Kim, Beomryong;Do, Kwangsun;Yim, Jongeun
    • Physical Therapy Rehabilitation Science
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    • v.11 no.1
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    • pp.66-77
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    • 2022
  • Objective: This study is a systematic review conducted to analyze the environmental factors that cause falls in the older adult. Design: Systematic review Methods: The study was conducted by searching the Research Information Sharing Service (RISS), Korean studies Information Service System (KISS), and Data Base Periodical Information Academic (DBpia) databases for literature published in South Korea up to July 2020. A total of 12 studies were selected for analysis based on the inclusion and exclusion criteria. Results: The results of the analysis revealed that all the selected literature were surveys and the study subjects were 65 years of age and above. The sample size ranged from a minimum of 95 subjects to a maximum of 3,278. A total of eight tools were used to measure the environmental factors associated with falls. The prevalence and recurrence of falls increase with age and deterioration of health. Older adult individuals who experience falls encounter difficulties in recovering from impaired physical function and disability; moreover, in severe cases, falls may lead to death. Falls are largely associated with a combination of intrinsic and extrinsic (i.e., environmental) factors. The purpose of this study was to assess potential extrinsic risk factors for falls. Falls occur in indoor environments, such as washrooms, bathrooms and living rooms, and outdoor environments, including roads and stairways, depending on the season, time of day, and use of ambulatory aids. In such environments, falls are mainly caused by slipping and stuttering. Conclusions: Therefore, as the rate of fall is influenced by several factors, extrinsic factors should be improved by developing comprehensive accident prevention programs that address the improvement of environmental risk factors around places of residence to reduce risk factors among the older adult, who, especially, are at a high risk for falls.

Clinical Research Trends of Gut Microbiome for Respiratory Diseases (호흡기질환에 대한 장내 미생물의 임상 연구 동향)

  • Lee, Su Won;Choi, Jin Kwan;Yang, Won Kyung;Kim, Seung Hyung;Lyu, Yee Ran;Park, Yang Chun
    • The Journal of Korean Medicine
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    • v.42 no.3
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    • pp.119-138
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    • 2021
  • Objectives: This study aimed to review the clinical research of the gut microbiome for respiratory diseases to assist the design of trials for respiratory diseases by regulating the gut microbiome with herbal medicine later. Methods: We searched three international databases (PubMed, CENTRAL and EMBASE) to investigate randomized controlled trials (RCTs) of the gut microbiome for respiratory diseases. The selected trials were analyzed by study design, subject diseases, inclusion/exclusion criteria, sample size, study period, intervention group, control group, outcome measures, and study results. Results: A total of 25 studies were included and published from 1994 to 2021 mostly in Europe and Asia. Subject diseases were many in the order of respiratory tract infection, cystic fibrosis, allergy, and so on. As outcome measures, the gut microbiome in a fecal sample was analyzed by 16S rRNA sequencing analysis method, and symptom assessment tools related each disease were used. Major intervention drugs were probiotics and the results were mostly improved in the composition and diversity of the gut microbiome. Conclusion: Clinical studies of the gut microbiome for respiratory diseases have confirmed various effects and this review provides basic data for a well-designed clinical study for respiratory diseases by regulating the gut microbiome with herbal medicine.

The Retrospective Study of Advanced Cancer Patients Receiving Integrative Cancer Treatments in single Comprehensive and Integrative Medicine Hospital

  • Jeonghyun Joo;Songha Chon;Kicheul Sohn;Sanghun Lee
    • The Journal of Korean Medicine
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    • v.43 no.3
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    • pp.16-26
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    • 2022
  • Objectives: Traditional Korean medicine (TKM) has been supplied as part of a national health care system in South Korea under a dual medical system, however it has been difficult to mix western medicine and TKM medical practices in existing hospitals. For the objective of innovative integration between them, Comprehensive and Integrative Medicine Hospital were founded in Daegu, South Korea. Here, we discussed the clinical outcomes of cancer patients who received integrative cancer treatment (ICT). Methods: A total of 678 patients previously diagnosed with cancer were retrospectively checked in our institution for 2 years. After applying inclusion/exclusion criteria, 573 patients were eligible for the final analysis. The overall survival (OS) of these patients in the aftercare period were determined. We looked at how clinical factors and treatments including chemotherapy, complementary and alternative medicine (CAM), and TKM affected the OS. Results: At the first visit, 212 subjects had no evidence of disease after tumor resection and 355 ones with advanced cancer, who receiving ICT including chemotherapy, CAM, and TKM showed better OS compared to the CAM including TKM or the best supportive care (median OS = 216, 78, and 46 days, respectively). The median OS was not reached in TKM only, even though the sample size was small (N=12). Even after adjusting for clinical factors associated to liver, renal, and hematologic manifestation, ICT still remained significant. Conclusions: We demonstrated that ICT might be beneficial for advanced cancer regardless of the performance status, liver and renal function, since it positively affected the OS.

Column cleaning, regeneration and storage of silica-based columns (실리카 기반 컬럼의 세척, 재생 및 보관 가이드)

  • Matt James;Mark Fever
    • FOCUS: LIFE SCIENCE
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    • no.1
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    • pp.1.1-1.4
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    • 2024
  • This article provides comprehensive guidance on the maintenance, cleaning, regeneration, and storage of silica-based HPLC (High-Performance Liquid Chromatography) columns. The general considerations emphasize the importance of using in-line filters and guard cartridges to protect columns from blockage and irreversible sample adsorption. While these measures help, contamination by strongly adsorbed sample components can still occur over time, leading to an increase in back pressure, loss of efficiency, and other issues. To maximize column lifetime, especially with UHPLC (Ultra-High Performance Liquid Chromatography) columns, it is advisable to use ultra-pure solvents, freshly prepared aqueous mobile phases, and to filter all samples, standards, and mobile phases. Additionally, an in-line filter system and sample clean-up on dirty samples are recommended. However, in cases of irreversible compound adsorption or column voiding, regeneration may not be possible. The document also provides specific recommendations for column cleaning procedures, including the flushing procedures for various types of columns such as reversed phase, unbonded silica, bonded normal phase, anion exchange, cation exchange, and size exclusion columns for proteins. The flushing procedures involve using specific solvents in a series to clean and regenerate the columns. It is emphasized that the flow rate during flushing should not exceed the specified limit for the particular column, and the last solvent used should be compatible with the mobile phase. Furthermore, the article outlines the storage conditions for silica based HPLC columns, highlighting the impact of storage conditions on the column's lifetime. It is recommended to flush all buffers, salts, and ion-pairing reagents from the column before storage. The storage solvent should ideally match the one used in the initial column test chromatogram provided by the manufacturer, and column end plugs should be fitted to prevent solvent evaporation and drying out of the packing bed.

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Reduction of the Antigenicity of Whey Protein by Enzymatic Hydrolysis (효소가수분해에 의한 유청단백질의 항원성 저하)

  • Ha, Woel-Kyu;Juhn, Suk-Lak;Kim, Jung-Wan;Lee, Soo-Won;Lee, Jae-Young;Shon, Dong-Hwa
    • Korean Journal of Food Science and Technology
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    • v.26 no.1
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    • pp.74-80
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    • 1994
  • As a preliminary study about the reduction of the antigenicity of whey protein isolate(WPI) by treatment of chymotrypsin, trypsin, pancreatin, and protease from Aspergillus oryzae, the properties and antigenicities of whey protein hydrolysates(WPH) were investigated. When degrees of hydrolysis (DH) were measured by use of trinitrobenzensulfonic acid(TNBS), the DH of the WPH treated by pancreatin or protease from Aspergillus oryzae$(5.05{\sim}11.47)$ were much higher than those of the tryptic or chymotryptic WPH$(15.67{\sim}20.20)$. And the pretreatments of heat$(75^{\circ}C)$, 20 min and/or pepsin resulted in higher DH of WPH, generally. When the molecular distributions of the WPH were determined by high performance size exclusion chromatography(HPSEC), the ratios of polypeptides with molecular weight more than 10kDa ranged from 12% to 36%, and the average molecular weights and the average peptide lengths of the WPH were $4,252{\sim}9,132$ dalton and $38{\sim}83$ amino acids, respectively. And there was no bitter taste in all of the WPH. Results of SDS-PAGE showed that most of intact native proteins were eliminated by the enzymatic hydrolysis but there were a few bands of peptides larger than 14.2 kDa in some WPH. When antigenicity was assayed by competitive inhibition enzyme-linked immunosorbent assay(cELISA), monovalent antigenicity of WPH to rabbit anti-WPI antiserum were lowered to $10^{-1.7}-10^{-4.9}$ times and less by the enzymatic hydrolysis. And the pretreatments of heat and pepsin resulted in the lowest antigenicicy within a group of enzymatic hydrolysis, especially in case of the pancreatic hydrolysate(PDP) whose antigenicity was found almost to be removed.

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