• 제목/요약/키워드: Pasteur

검색결과 120건 처리시간 0.03초

Identification of a Novel Cassette Array in Integron-bearing Helicobacter Pylori Strains Isolated from Iranian Patients

  • Goudarzi, Mehdi;Seyedjavadi, Sima Sadat;Fazeli, Maryam;Roshani, Maryam;Azad, Mehdi;Heidary, Mohsen;Navidinia, Masoumeh;Goudarzi, Hossein
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권7호
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    • pp.3309-3315
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    • 2016
  • Helicobacter pylori as the second most common cause of gastric cancer in the world infects approximately half of the developed countries population and 80% of the population living in developing countries. Integrons as genetic reservoirs play major roles in dissemination of antimicrobial resistance genes. To the best of our knowledge, this is the first study to report carriage of class 1 and 2 integrons and associated gene cassettes in H. pylori isolates from Iran. This cross-sectional study was conducted in Tehran among 110 patients with H. pylori infection. Antimicrobial susceptibility testing (AST) for H. pylori strains were assessed by the micro broth dilution method. Class 1 and 2 integrons were detected using PCR. In order to determine gene cassettes, amplified fragments were subjected to DNA sequencing of both amplicon strands. The prevalence of resistance to clarithromycin, metronidazole, clarithromycin, tetracycline, amoxicillin, rifampin, and levofloxacin were 68.2% (n=75), 25.5% (n=28), 24.5% (n=27), 19.1% (n=21), 18.2% (n=20) and 16.4% (n=18), respectively. Frequency of multidrug resistance among H. pylori isolates was 12.7%. Class 2 integron was detected in 50 (45.5%) and class 1 integron in 10 (9.1%) H. pylori isolates. The most predominant gene cassette arrays in class 2 integron-bearing H. pylori were included sat-era-aadA1, dfrA1-sat2-aadA1, blaoxa2 and, aadB whereas common gene cassette arrays in class 1 integron were aadB-aadA1-cmlA6, aacA4, blaoxa2, and catB3. The high frequency of class 2 integron and multidrug resistance in the present study should be considered as a warning for clinicians that continuous surveillance is necessary to prevent the further spread of resistant isolates.

Alcohol Fermentation을 위한 배지로서의 Cheese Whey의 이용 (Utilization of Cheese Whey for Alcohol Fermentation Medium)

  • 김상필;박희경;김도환;허태련
    • 한국식품과학회지
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    • 제27권6호
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    • pp.878-884
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    • 1995
  • 본 연구는 유청을 에탄올 발효에 이용하기 위하여 유청에 함유된 유당을 ${\beta}-D-galactosidase$로 가수분해한 후 Saccharomyces cerevisiae와 Kluyveromyces fragilis의 발효 조건을 비교하였으며, 효모의 특성인 pasteur effect를 이용하여 용존 산소의 조절에 의한 유청에서의 K. fragilis와 S. cerevisiae의 에탄올 발효 조건을 실험하였다. 또한 탁주의 제조에 에탄올 발효된 유청을 용수에 혼합, 응용하기 위한 최적 조건을 조사하였다. pH6.5로 조절된 유청에 0.7%(v/v)의 ${\beta}-D-galactosidase$를 첨가하여 30분만에 93%의 유당이 가수분해 되었다. 이를 배지로 이용하여 에탄올 발효한 결과 S. cerevisiae는 galactose를 이용하지 못하므로 에탄올 생산력이 K. fragilis에 비하여 낮았으나 glucose를 첨가한 배지에서는 S. cerevisiae의 에탄올 생산량이 K. fragilis 보다 증가하였다. 용존 산소를 조절하고 glucose를 첨가하여준 실험에서는 K. fragilis와 S. cerevisiae의 에탄올 생산량이 각각 18.9 g/l와 34.5 g/l로 에탄올 생산량이 11.8% 22.1% 증가하였다. 즉 용존산소를 조절한 조건에서는 S. cerevisiae의 에탄올 생산력이 더 우수하였다. 미분을 첨가한 에탄올 발효에서는 Aspergilus oryzae가 발효 60시간만에 80% 이상의 당화력을 보였으며, 이때 생산되는 에탄올의 양은 80.2 g/l였다.

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Identification of a Glucokinase that Generates a Major Glucose Phosphorylation Activity in the Cyanobacterium Synechocystis sp. PCC 6803

  • Lee, Jung-Mi;Ryu, Jee-Youn;Kim, Hyong-Ha;Choi, Sang-Bong;de Marsac, Nicole Tandeau;Park, Youn-Il
    • Molecules and Cells
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    • 제19권2호
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    • pp.256-261
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    • 2005
  • In silico analysis of genome of the cyanobacterium Synechocystis sp. PCC 6803 identified two genes, slr0329 and sll0593, that might participate in glucose (Glc) phosphorylation (www.kazusa.or.jp/cyano). In order to determine the functions of these two genes, we generated deletion mutants, and analyzed their phenotypes and enzymatic activities. In the presence of 10 mM Glc, wild-type (WT) and slr0329 defective strain (M1) grew fast with increased respiratory activity and NADPH production, whereas the sll0593 deletion mutant (M2) failed to show any of the Glc responses. WT and M1 were not significantly different in their glucokinase activity, but M2 had 90% less activity. Therefore, we propose that Sll0593 plays a major role in the phosphorylation of glucose in Synechocystis cells.

전기자극 하에서 알콜 산화효소의 안정화연구; 당, 히드로젤, 계면활성제 효과 (Stabilization of Alcohol Oxidase under Electrostimulation; Sugars, Hydrogels and Surfactants Effect)

  • 김범수;이강민;;김경숙
    • KSBB Journal
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    • 제21권6호
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    • pp.456-460
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    • 2006
  • 효소는 환경과 조건에 따라 상이한 활성도를 나타내며, 전기 자극에 의하여 비활성화된 알콜 산화효소는 당, 계면활성제, 히드로젤 들에 의하여 안정화되었다. 이들 효소는 trehalose, TritonX-100, Brij에서 보다 안정하였으며, 이들 효소의 안정도는 Hansenula sp., P. pastoris, C. boidinii에서 분리된 효소가 순서적으로 보다 안정하였다. 전기자극하에서 효소의 안정화에 대한 이 연구는 생물공학, 단백질공학, 의료공학 분야에 널리 이용될 수 있으리라 사료된다.

Human Papillomavirus Burden in Different Cancers in Iran: a Systematic Assessment

  • Jalilvand, Somayeh;Shoja, Zabihollah;Hamkar, Rasool
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권17호
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    • pp.7029-7035
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    • 2014
  • Certain types of human papillomaviruses (HPVs) are undoubtedly involved in genesis of human malignancies. HPV plays an etiological role in cervical cancer, but also in many vaginal, vulvar, anal and penile cancers, as well as head and neck cancers. In addition, a number of non-malignant diseases such as genital warts and recurrent respiratory papillomatosis are attributable to HPV. Moreover, HPV forms have detected in several other cancers including esophageal squamous cell carcinoma, lung, prostate, ovarian, breast, skin, colorectal and urinary tract cancers, but associations with etiology in these cases is controversial. The aim of this systematic assessment was to estimate the prevalence of HPV infection and HPV types in HPV-associated cancers, HPV-related non-malignant diseases and in cancers that may be associated with HPV in Iran. The present investiagtion covered 61 studies on a variety of cancers in Iranian populations. HPV prevalence was 77.5 % and 32.4% in cervical cancer and head and neck cancers, respectively. HPV was detected in 23.1%, 22.2%, 10.4%, 30.9%, 14% and 25.2% of esophageal squamous cell, lung, prostate, urinary tract cancers, breast and skin cancers, respectively. HPV16 and 18 were the most frequent HPV types in all cancers. The findings of present study imply that current HPV vaccines for cervical cancer may decrease the burden of other cancers if they are really related to HPV.

Convergence of Cancer Metabolism and Immunity: an Overview

  • Van Dang, Chi;Kim, Jung-whan
    • Biomolecules & Therapeutics
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    • 제26권1호
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    • pp.4-9
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    • 2018
  • Cancer metabolism as a field of research was founded almost 100 years ago by Otto Warburg, who described the propensity for cancers to convert glucose to lactate despite the presence of oxygen, which in yeast diminishes glycolytic metabolism known as the Pasteur effect. In the past 20 years, the resurgence of interest in cancer metabolism provided significant insights into processes involved in maintenance metabolism of non-proliferating cells and proliferative metabolism, which is regulated by proto-oncogenes and tumor suppressors in normal proliferating cells. In cancer cells, depending on the driving oncogenic event, metabolism is re-wired for nutrient import, redox homeostasis, protein quality control, and biosynthesis to support cell growth and division. In general, resting cells rely on oxidative metabolism, while proliferating cells rewire metabolism toward glycolysis, which favors many biosynthetic pathways for proliferation. Oncogenes such as MYC, BRAF, KRAS, and PI3K have been documented to rewire metabolism in favor of proliferation. These cell intrinsic mechanisms, however, are insufficient to drive tumorigenesis because immune surveillance continuously seeks to destroy neo-antigenic tumor cells. In this regard, evasion of cancer cells from immunity involves checkpoints that blunt cytotoxic T cells, which are also attenuated by the metabolic tumor microenvironment, which is rich in immuno-modulating metabolites such as lactate, 2-hydroxyglutarate, kynurenine, and the proton (low pH). As such, a full understanding of tumor metabolism requires an appreciation of the convergence of cancer cell intrinsic metabolism and that of the tumor microenvironment including stromal and immune cells.

Investigation on the Surface Hydrophobicity and Aggregation Kinetics of Human Calprotectin in the Presence of Calcium

  • Yousefi, Reza;Ardestani, Susan K.;Saboury, Ali Akbar;Kariminia, Amina;Zeinali, Madjid;Amani, Mojtaba
    • BMB Reports
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    • 제38권4호
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    • pp.407-413
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    • 2005
  • Calcium and zinc binding protein, calprotectin is a multifunctional protein with broad spectrum antimicrobial and antitumoural activity. It was purified from human neutrophil, using a two-step ion exchange chromatography. Since surface hydrophobicity of calprotectin may be important in membrane anchoring, membrane penetration, subunits oligomerization and some biological roles of protein, in this study attempted to explore the effect of calcium in physiological range on the calprotectin lipophilicity. Incubation of human calprotectin ($50\;{\mu}g/ml$) with different calcium concentrations showed that 1-anilino-8-naphthalene sulfonic acid (ANS) fluorescence intensity of the protein significantly elevates with calcium in a dose dependent manner, suggesting an increase in calprotectin surface hydrophobicity upon calcium binding. Our study also indicates that calcium at higher concentrations (6, 8 and 10 mM) induces aggregation of human calprotectin. Our finding demonstrates that the starting time and the rate constant of calprotectin aggregation depend on the calcium concentration.

Effect of IGF-I Rich Fraction from Bovine Colostral Whey on Murine Immunity

  • Hwang, Kyung-A;Ha, Woel-Kyu;Yang, Hee-Jin;Lee, Soo-Won
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권2호
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    • pp.297-304
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    • 2006
  • Insulin-like growth factor-I (IGF-I) rich fraction, collected components between 1 kDa and 30 kDa, was fractionated from bovine colostral whey using an ultrafiltration membrane. IGF-I was confirmed in the collected IGF-I rich fraction by both SDS-PAGE and Western blotting. The concentration of IGF-I in the IGF-I rich fraction was 10 ng/mg protein. One hundred microliters of the reconstituted IGF-I rich fraction was intraperitoneally injected into ICR male mice for 2 weeks at 24 h intervals. The functions of peritoneal macrophages, including phagocytosis, interleukin (IL)-6 and tumor necrosis factor (TNF)-${\alpha}$ production, and nitric oxide and hydrogen peroxide production, were enhanced significantly by the administration of the IGF-I rich fraction in a dose-dependent manner (p<0.01). The proliferation of Concanavalin (Con) A-stimulated and Lipopolysaccharide (LPS)-stimulated splenocytes was also determined to have been enhanced significantly by the administration of the IGF-I rich fraction in a dose-dependent manner (p<0.01). Our results indicate that the administration of IGF-I rich fraction obtained from bovine colostral whey enhances both innate and acquired immunity for ICR male mice.

Characterization of Lactic Bacterial Strains Isolated from Raw Milk

  • Kim, Hyun-jue;Shin, Han-seung;Ha, Woel-kyu;Yang, Hee-jin;Lee, Soo-won
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권1호
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    • pp.131-136
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    • 2006
  • During lactic acid bacteria (LAB) transit through the gastrointestinal tract, ingested microorganisms were exposed to successive stress factors, including low pH in the human stomach and in bile acid. These stress factors can be used as criteria for the selection of a viable probiotic strain. Four such strains (Lactobacillus helveticus SGU 0011, Lactobacillus pentosus SGU 0010, Streptococcus thermophilus SGU 0021 and Lactobacillus casei SGU 0020) were isolated from raw milk. When the identified LAB were exposed to synthetic gastric juice, whereas L. casei SGU 0020 and S. thermophilus SGU 0021 exhibited a 0% survival rate, L. helveticus SGU 0011 and L. pentosus SGU 0010 exhibited 60% and 95% survival rates. L. casei SGU 0020 and S. thermophilus SGU 0021 could not be examined with regard to their tolerances to artificial bile juice, as they uniformly died upon exposure. However, L. helveticus SGU 0011 and L. pentosus SGU 0010 individually survived at rates of 39% and 93%. Also, all four of these strains were confirmed to be tolerant of ten different antibiotics.

초유 유청분획의 EL-4 세포 증식 효과 (Effect of Colostral Whey Fraction on the Proliferation of EL-4 Cell)

  • 하월규;원도희;양희진;황경아;이수원
    • 한국축산식품학회지
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    • 제25권2호
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    • pp.244-249
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    • 2005
  • To investigate the effect of Holstein colostrum peptide fraction on proliferation of immune cell, polypeptide fractions were separated from acid whey into 3 fractions depending on molecular weight by ultrafiltration: Fraction I, which contains the polypeptide larger than 10,000 Da, Fraction n, which contains the polypeptide ranging from 1,000 Da to 10,000 Da and Fraction III, which contains the polypeptide smaller than 1,000 Da. EL-4 cell (murine T lymphoma cell) was used to evaluate immune enhancing effect of each fraction from Holstein colostrum. Fraction n showed the highest proliferative effect of the colostrum whey fractions on EL-4 cell at 1mg/mL compared with whole whey and other fractions and this proliferative activity was shown in dose dependent manner. Fraction n showed the highest proliferative effect on PMA (Phorbol 12-myristate 13-acetate) stimulated EL-4 cell. Heated Fraction n showed similar effect to native one on proliferation of both EL-4 cell and PMA stimulated EL-4 cell.