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BACKGROUND: No standard treatment guidelines have been established for postpartum hemorrhage (PPH). We aimed to assess the differences in outcomes and prognoses between patients with PPH who underwent surgical and non-surgical treatment. METHODS: This retrospective study included 230 patients diagnosed with PPH at two referral hospitals between August 2013 and October 2023. The patients were divided into non-surgical (group 1, n = 159) and surgical intervention groups (group 2, n = 71). A subgroup analysis was performed by dividing the surgical intervention group into immediate (n = 45) and delayed surgical intervention groups (n = 26). RESULTS: Initial lactic acid levels and shock index were significantly higher in group 2 (2.85 ± 1.37 vs. 4.54 ± 3.63 mmol/L, p = 0.001, and 0.83 ± 0.26 vs. 1.10 ± 0.51, p < 0.001, respectively). Conversely, initial heart rate and body temperature were significantly lower in group 2 (92.5 ± 21.0 vs. 109.0 ± 28.1 beat/min, p < 0.001, and 37.3 ± 0.8 °C vs. 37.0 ± 0.9 °C, p = 0.011, respectively). Logistic regression analysis identified low initial body temperature, high lactic acid level, and shock index as independent predictors of surgical intervention (p = 0.029, p = 0.027, and p = 0.049, respectively). Regarding the causes of PPH, tone was significantly more prevalent in group 1 (57.2% vs. 35.2%, p = 0.002), whereas trauma was significantly more prevalent in group 2 (24.5% vs. 39.4%, p = 0.030). Group 2 had worse overall outcomes and prognoses than group 1. The subgroup analysis showed significantly higher rates of uterine atony combined with other causes, hysterectomy, and disseminated intravascular coagulopathy in the delayed surgical intervention group than the immediate surgical intervention group (42.2% vs. 69.2%, p = 0.027; 51.1% vs. 73.1%, p = 0.049; and 17.8% vs. 46.2%, p = 0.018, respectively). CONCLUSIONS: Patients with PPH presenting with increased lactic acid levels and shock index and decreased body temperature may be surgical candidates. Additionally, immediate surgical intervention in patients with uterine atony combined with other causes of PPH could improve prognosis and reduce postoperative complications.
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Hemorragia Pós-Parto , Humanos , Feminino , Estudos Retrospectivos , Adulto , Prognóstico , Gravidez , Ácido Láctico/sangueRESUMO
BACKGROUND: The navigable percutaneous disc decompression (PDD) device L'DISQ is an effective and safe option for the treatment of lumbar discogenic pain. However, few studies have evaluated the prognostic factors of successful PDD using this device. OBJECTIVE: This study aimed to evaluate the prognostic factors associated with the successful outcome of PDD using the L'DISQ for treating lumbar discogenic pain by following up patients before and one, 2, 3, and 6 months after the procedure. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary university hospital. METHODS: A successful outcome was defined as a >= 50% reduction in the numeric rating scale scores for pain and a >= 40% reduction in the Oswestry Disability Index scores at 6 months after the procedure. Clinical parameters and patient demographics, including pain duration, history of surgery, number of treatment levels, and the radiographic findings of lumbar magnetic resonance imaging (MRI), were also examined. RESULTS: Of the 106 patients included, 80 (75.5%) had successful outcomes at 6 months. Multivariable logistic regression analysis revealed that the presence of high-intensity zones (HIZs) (P = 0.016) was an independent positive predictor of successful PDD outcomes; conversely, migration of the herniated disc (P = 0.017) and bilaterally herniated discs (P = 0.001) were negative predictors. LIMITATIONS: The limitations of this study were its retrospective design, absence of a control group, and difficulty in predicting the effect when multiple levels were involved because of the use of MRI characteristics of the disc as a predictor. CONCLUSIONS: The presence of HIZs, the absence of migration of herniated discs, and the presence of unilaterally herniated discs are positive predictors of successful outcomes of PDD using the L'DISQ.
Assuntos
Vértebras Lombares , Dor , Descompressão Cirúrgica/efeitos adversos , Humanos , Vértebras Lombares/patologia , Vértebras Lombares/cirurgia , Dor/etiologia , Prognóstico , Estudos RetrospectivosRESUMO
Incidences of brain death due to nicotine overdose by e-cigarettes have been increasing. In such cases, liver donation has been not reported because of the secondary damage to the liver due to metabolism of large amounts of nicotine. However, kidneys have been considered acceptable for transplant. Here, we present a successful case of liver transplant from a brain-dead donor due to intentional nicotine ingestion who did not have extensive steatosis. To the best of our knowledge, this is the first report of such a case.
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Sistemas Eletrônicos de Liberação de Nicotina , Cirrose Hepática/cirurgia , Transplante de Fígado , Nicotina/intoxicação , Agonistas Nicotínicos/intoxicação , Suicídio , Doadores de Tecidos , Adulto , Morte Encefálica , Seleção do Doador , Evolução Fatal , Humanos , Cirrose Hepática/diagnóstico , Masculino , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
2'-Fucosyllactose (2-FL), one of the most abundant oligosaccharides in human milk, has been spotlighted for its neutraceutical and pharmaceutical potentials. Microbial production of 2-FL is promising since it is efficient as compared to other production methods. In 2-FL microbial production via the salvage pathway for biosynthesis of guanosine 5'-diphosphate (GDP)-l-fucose from fucose, the conversion yield from fucose is important because of the high price of fucose. In this study, deletion of the genes (araA and rhaA) coding for arabinose isomerase (AraA) and rhamnose isomerase (RhaA) was attempted in engineered Escherichia coli for improving 2-FL production by using fucose, lactose, and glycerol. The engineered E. coli constructed previously is able to express fucokinase/GDP-l-fucose pyrophosphorylase (Fkp) from Bacteroides fragilis and the α-1,2-fucosyltransferase (FucT2) from Helicobacter pylori and deficient in ß-galactosidase (LacZ), fucose isomerase (FucI), and fuculose kinase (FucK). The additional double-deletion of the araA and rhaA genes in the engineered E. coli enhanced the product yield of 2-FL to 0.52 mole 2-FL/mole fucose, and hence the concentration of 2-FL reached to 47.0 g/L, which are 44% and two-fold higher than those (23.1 g/L and 0.36 mole 2-FL/mole fucose) of the control strain in fed-batch fermentation. Elimination of sugar isomerases exhibiting promiscuous activities with fucose might be critical in the microbial production of 2-FL through the salvage pathway of GDP-l-fucose.
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Proteínas de Escherichia coli , Escherichia coli , Fucose/metabolismo , Deleção de Genes , Engenharia Metabólica , Trissacarídeos/biossíntese , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Fucose/genética , Trissacarídeos/genéticaRESUMO
3-Fucosyllactose (3-FL), one of the major oligosaccharides in human breast milk, is produced in engineered Escherichia coli. In order to search for a good α-1,3-fucosyltransferase, three bacterial α-1,3-fucosyltransferases are expressed in engineered E. coli deficient in ß-galactosidase activity and expressing the essential enzymes for the production of guanosine 5'-diphosphate-l-fucose, the donor of fucose for 3-FL biosynthesis. Among the three enzymes tested, the fucT gene from Helicobacter pylori National Collection of Type Cultures 11637 gives the best 3-FL production in a simple batch fermentation process using glycerol as a carbon source and lactose as an acceptor. In order to use glucose as a carbon source, the chromosomal ptsG gene, considered the main regulator of the glucose repression mechanism, is disrupted. The resulting E. coli strain of ∆LP-YA+FT shows a much lower performance of 3-FL production (4.50 g L-1 ) than the ∆L-YA+FT strain grown in a glycerol medium (10.7 g L-1 ), suggesting that glycerol is a better carbon source than glucose. Finally, the engineered E. coli ∆LW-YA+FT expressing the essential genes for 3-FL production and blocking the colanic acid biosynthetic pathway (∆wcaJ) exhibits the highest concentration (11.5 g L-1 ), yield (0.39 mol mol-1 ), and productivity (0.22 g L-1 h) of 3-FL in glycerol-limited fed-batch fermentation.
Assuntos
Escherichia coli/metabolismo , Fucosiltransferases/metabolismo , Helicobacter pylori/enzimologia , Oligossacarídeos/metabolismo , Escherichia coli/genética , Fucose/metabolismo , Fucosiltransferases/genética , Lactose/metabolismoRESUMO
Emissivity-tunable metamaterials of layered refractory metal and dielectric have great potentials as a simple thermophotovoltaic (TPV) selective emitter due to its near-omnidirectional, polarization-independent, and broadband selective emissivity. However, it is known that the stability of the layered structure is limited by the oxidation of metals. While there still exists ambiguity concerning the main source of oxygen between adjacent oxide layers and external residual oxygen, most reports focus on the adjacent layers. In this report, thermal stability of a tungsten-based layered metamaterial is investigated under a high-vacuum environment with great care to reduce residual oxygen. The results show unprecedented thermal stability up to 1200 °C for 3 h without any measurable oxidation of metal. This implies that the interlayer diffusion of oxygen from adjacent oxide layers is not exclusively responsible for the oxidation of metal. At such a high temperature, the layered metamaterial theoretically yields a high convertible radiative power density of 3.04 W/cm2 with comparable spectral efficiency of 40.2%. Finally, after performing series of thermal tests under higher thermal loads, we propose a novel high-temperature degradation model for layered metamaterials, the stability of which is ultimately limited by the agglomeration of thin metal layers.
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L-Fucose (6-deoxy-L-galactose) is a major constituent of glycans and glycolipids in mammals. Fucosylation of glycans can confer unique functional properties and may be an economical way to manufacture L-fucose. Research can extract L-fucose directly from brown algae, or by enzymatic hydrolysis of L-fucose-rich microbial exopolysaccharides. However, these L-fucose production methods are not economical or scalable for various applications. We engineered an Escherichia coli strain to produce L-fucose. Specifically, we modified the strain genome to eliminate endogenous L-fucose and lactose metabolism, produce 2'-fucosyllactose (2'-FL), and to liberate L-fucose from 2'-FL. This E. coli strain produced 16.7 g/L of L-fucose with productivity of 0.1 g·L-1 ·h-1 in a fed-batch fermentation. This study presents an efficient one-pot biosynthesis strategy to produce a monomeric form of L-fucose by microbial fermentation, making large-scale industrial production of L-fucose feasible.
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Técnicas de Cultura Celular por Lotes/métodos , Escherichia coli/metabolismo , Fucose/metabolismo , Reatores Biológicos , Vias Biossintéticas , Escherichia coli/genética , Fermentação , Fucose/genética , Microbiologia Industrial/métodos , Engenharia Metabólica/métodosRESUMO
Fucosyllactoses (FLs), present in human breast milk, have been reported to benefit human health immensely. Especially, 3-fucosyllactose (3-FL) has numerous benefits associated with a healthy gut ecosystem. Metabolic engineering of microorganisms is thought to be currently the only option to provide an economically feasible route for large-scale production of 3-FL. However, engineering principles for α-1,3-fucosyltransferases (1,3-FTs) are not well-known, resulting in the lower productivity of 3-FL than that of 2'-fucosyllactose (2'-FL), although both 2'-FL and 3-FL follow a common pathway to produce GDP-L-fucose. The C-terminus of 1,3-FTs is composed of heptad repeats, responsible for dimerization of the enzymes, and a peripheral membrane anchoring region. It has long been thought that truncation of most heptad repeats, retaining just 1 or 2, helps the soluble expression of 1,3-FTs. However, whether the introduction of truncated version of 1,3-FTs enhances the production of 3-FL in a metabolically engineered strain, is yet to be tested. In this study, the effect of these structural components on the production of 3-FL in Escherichia coli was evaluated through systematic truncation and elongation of the C-terminal regions of three 1,3-FTs from Helicobacter pylori. Although these three 1,3-FTs contained heptad repeats and membrane-anchoring regions of varying lengths, they commonly exhibited an optimal performance when the number of heptad repeats was increased, and membrane-binding region was removed. The production of 3-FL could be increased 10-20-fold through this simple strategy.
Assuntos
Proteínas de Bactérias , Escherichia coli , Fucosiltransferases , Helicobacter pylori/genética , Lactose , Engenharia Metabólica , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Escherichia coli/enzimologia , Escherichia coli/genética , Fucosiltransferases/biossíntese , Fucosiltransferases/genética , Helicobacter pylori/enzimologia , Humanos , Lactose/análogos & derivados , Lactose/biossíntese , Lactose/genética , Engenharia de ProteínasRESUMO
An optical signal suppression technique based on a cascaded SOA and RSOA is proposed for the reflective passive optical networks (PONs) with wavelength division multiplexing (WDM). By suppressing the downstream signal of the optical carrier, the proposed reflective PON effectively reuses the downstream optical carrier for upstream signal transmission. As an experimental demonstration, we show that the proposed optical signal suppression technique is effective in terms of the signal bandwidth and bit-error-rate (BER) performance of the remodulated upstream transmission.
RESUMO
2'-Fucosyllactose (2-FL) is one of most abundant oligosaccharides in human milk, which is involved in many biological functions for infant health. Since 2-FL has a great potential in application to functional food materials and pharmaceuticals, several microbial systems for mass production of 2-FL have been developed in recent years. Microbial production of 2-FL was suggested to be influenced by a number of factors including fucosylation activity of α-1,2-fucosyltransferase. In the present study, the wcfB gene coding for α-1,2-fucosyltransferase from Bacteroides fragilis was screened from eleven candidates of putative α-1,2-fucosyltransferase. Introduction of the wcfB gene allows the lacZ-deleted strain of E. coli expressing the genes for guanosine 5'-diphosphate (GDP)-l-fucose biosynthetic enzymes to produce 2-FL. As a result of fed-batch fermentation, 15.4g/L extracellular concentration of 2-FL with 2-FL yield of 0.858g/g lactose and productivity of 0.530g/L/h were obtained. In addition, the feasibility of industrial production of 2-FL using this microbial system was demonstrated by performing fed-batch fermentation in a 75L bioreactor.
Assuntos
Bacteroides fragilis/enzimologia , Bacteroides fragilis/genética , Escherichia coli/genética , Fucosiltransferases/genética , Fucosiltransferases/metabolismo , Trissacarídeos/biossíntese , Proteínas de Bactérias/genética , Técnicas de Cultura Celular por Lotes , Reatores Biológicos , Fermentação , Fucose , Regulação Bacteriana da Expressão Gênica , Engenharia Genética , Vetores Genéticos , Óperon Lac , Leite Humano/química , Recombinação Genética , Deleção de SequênciaRESUMO
Orthogonal frequency division multiple access-based passive optical network (OFDMA-PON) is considered as a strong candidate for next-generation optical access network. In intensity modulation/direct detection system, OFDMA-PON downlink transmission is relatively stable, but critical issues exist in uplink multiple access. Because of different optical paths, optical beat interference (OBI) and timing offset effect are generated, which seriously disturb signal detection. We propose optical pulse division multiplexing-based OBI reduction. By considering both the spectrum broadening effect and the time domain near orthogonality, OBI could be reduced. We demonstrate that the spectral efficiency can be improved from 0.37 to 3.8 bit/s/Hz in 1-GHz signal bandwidth.
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Whole-cell biotransformation of fatty acids can be influenced by the activities of catalytic enzymes and by the efficiency of substrate transport into host cells. Here, we improved fatty acid hydration activity of the recombinant Escherichia coli expressing an oleate hydratase of Stenotrophomonas maltophilia by targeting the catalytic enzyme into the periplasm instead of the cytoplasm. Recombinant E. coli producing OhyA in the periplasm under guidance of the PelB signal sequence (E. coli OhyA_PP) exhibited significantly greater hydration activity with oleic acid and linoleic acid compared to a recombinant E. coli producing OhyA in the cytoplasm (E. coli OhyA_CS). For example, the oleate double bond hydration rate of E. coli OhyA_PP was >400 µmol/g dry cells/min (400 U/g dry cells), which is >10-fold higher than that of E. coli OhyA_CS. As the specific activities of the enzymes targeted into the cytoplasm and periplasm were comparable, we assumed that targeting OhyA into the periplasm could accelerate fatty acid transport to the catalytic enzymes by skipping the major mass transport barrier of the cytoplasmic membrane. Our results will contribute to the development of whole-cell biocatalysts for fatty acid biotransformation.
Assuntos
Enzimas/metabolismo , Escherichia coli/genética , Ácidos Graxos/metabolismo , Periplasma/enzimologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bioengenharia , Citoplasma/metabolismo , Enzimas/genética , Escherichia coli/enzimologia , Ácido Oleico/metabolismo , Polissacarídeo-Liases/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
INTRODUCTION: A high-flow nasal cannula (HFNC) has been used to treat patients with dyspnea. We identified changes in arterial blood gas (ABG) of patients visiting the emergency department (ED) with hypercapnic and nonhypercapnic respiratory failure after use of an HFNC. METHODS: This study was a retrospective chart review of patients with respiratory failure who visited the hospital and used an HFNC in the ED. The study period was July 1, 2011, to December 31, 2013. Patients with Paco2 greater than 45 mm Hg before the HFNC ABG analyses were included in the hypercapnia group; others comprised the nonhypercapnia group. Primary outcomes were the changes in ABG before and after use of an HFNC in the hypercapnia and nonhypercapnia groups. Progression to noninvasive or invasive ventilation and mortality rates were also assessed. RESULTS: A total of 173 patients were included after exclusion of 92 according to exclusion criteria. Eighty-one patients (hypercapnia group, 46, and nonhypercapnia group, 35) were included. Paco2 significantly decreased among all patients after use of HFNC (from 54.7±26.4 mm Hg to 51.3±25.8 mm Hg; P=.02), but the reduction was significant only in the hypercapnia group (from 73.2±20.0 to 67.2±23.4; P=.02). Progression to noninvasive or invasive ventilation and mortality rates were similar between the groups. CONCLUSIONS: Use of an HFNC in patients with hypercapnia could show a significant trend of decrease in Paco2. Progression to noninvasive or invasive ventilation and mortality rates were similar in patients with and without hypercapnia.
Assuntos
Mortalidade Hospitalar , Hipercapnia/terapia , Pneumopatias/complicações , Oxigenoterapia/métodos , Insuficiência Respiratória/terapia , Idoso , Gasometria/instrumentação , Gasometria/métodos , Catéteres/efeitos adversos , Catéteres/estatística & dados numéricos , Comorbidade , Progressão da Doença , Registros Eletrônicos de Saúde , Serviço Hospitalar de Emergência/estatística & dados numéricos , Humanos , Hipercapnia/diagnóstico , Hipercapnia/etiologia , Masculino , Oximetria , Oxigenoterapia/instrumentação , Respiração Artificial/métodos , Respiração Artificial/mortalidade , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/mortalidade , Estudos RetrospectivosRESUMO
In orthogonal frequency division multiple access based passive optical network (OFDMA-PON) uplink, synchronization between optical network units (ONUs) is very important to maintain orthogonality. The synchronization among uplink signals is considered as one of the main challenges in OFDMA-PON due to optical path difference. In this paper, the performance degradation according to timing offset between ONUs is experimentally analyzed. And we propose and demonstrate timing offset effect reduction in asynchronous multiple access by using CP extension and filter bank based multicarrier (FBMC) system in intensity modulation/direct detection (IM/DD) based OFDMA-PON uplink transmission.
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A novel technique for mitigating the optical beat interference (OBI) noise in an optical orthogonal frequency division multiple access passive optical network (OFDMA-PON) uplink transmission is presented. By using an out of signal band RF clipping tone to the optical seed carrier, the OBI noise has been reduced and the resulting throughput and spectral efficiency has been improved. As an experimental verification, we demonstrate that the spectral efficiency of 23 km and 50 km have been doubled in the OFDMA-PON uplink transmission.
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OBJECTIVE: Suicide by organophosphate insecticide (OPI) poisoning is a major clinical concern (predominantly in developing countries), and 200000 deaths occur annually worldwide. Red cell distribution width (RDW) has been used to predict outcome in several clinical conditions. Here, we aimed to investigate the relationship between the RDW and 30-day mortality during OPI poisoning. METHODS: This retrospective analysis was performed between January 2008 and July 2013 in patients admitted to the emergency department after OPI poisoning. A Kaplan-Meier 30-day survival curve was analyzed in patients stratified according to the optimal cut-off point of RDW defined using a receiver operating characteristic (ROC) curve. Multivariate Cox proportional hazards analyses were conducted to determine the independent prognostic factors for 30-day mortality. RESULTS: Among 102 patients, 21 died, yielding a mortality of 20.6%. Elevated RDW was significantly associated with early mortality in patients with OPI poisoning. Levels of RDW that exceeded 13.5% (hazard ratio, 2.64; 95% confidence interval [CI], 1.05-6.60) were associated with increased mortality in the multivariate analysis. The area under the ROC curve of RDW was 0.675 (95% CI, 0.522-0.829). CONCLUSIONS: This study showed that RDW is an independent predictor of 30-day mortality in patients with OPI poisoning.
Assuntos
Índices de Eritrócitos , Inseticidas/intoxicação , Intoxicação por Organofosfatos/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Intoxicação por Organofosfatos/mortalidade , Prognóstico , Modelos de Riscos Proporcionais , Curva ROC , Estudos RetrospectivosRESUMO
The laccase gene of Polyporus brumalis was genetically transformed to overexpress its laccase. The transformants exhibited increased laccase activity and effective decolorization of the dye Remazol Brilliant Blue R than the wild type. When the transformants were pretreated with wood chips from a red pine (softwood) and a tulip tree (hardwood) for 15 and 45 days, they showed higher lignin-degradation activity as well as higher wood-chip weight loss than the wild type. When the wood chips treated with the transformant were enzymatically saccharified, the highest sugar yields were found to be 32.5 % for the red pine wood and 29.5 % for the tulip tree wood, on the basis of the dried wood weights, which were 1.6-folds higher than those for the wild type. These results suggested that overexpression of the laccase gene from P. brumalis significantly contributed to the pretreatment of lignocellulose for increasing sugar yields.
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Proteínas Fúngicas/metabolismo , Lacase/metabolismo , Lignina/metabolismo , Polyporus/enzimologia , Madeira/metabolismo , Biodegradação Ambiental , Proteínas Fúngicas/genética , Lacase/genética , Polyporus/genética , Polyporus/metabolismo , Madeira/microbiologiaRESUMO
Resveratrol, a polyphenol compound found in grape skins, has been proposed to account for the beneficial effects of red wine against heart disease. To produce resveratrol in Saccharomyces cerevisiae, four heterologous genes were introduced: the phenylalanine ammonia lyase gene from Rhodosporidium toruloides, the cinnamic acid 4-hydroxylase and 4-coumarate:coenzyme A ligase genes both from Arabidopsis thaliana, and the stilbene synthase gene from Arachis hypogaea. When this recombinant yeast was cultivated by batch fermentation in YP medium containing 2% galactose, it produced 2.6 mg/L p-coumaric acid and 3.3 mg/L resveratrol. In order to increase the pool of malonyl-CoA, a key precursor in resveratrol biosynthesis, the acetyl-CoA carboxylase (ACC1) gene was additionally overexpressed in the yeast by replacing the native promoter of the ACC1 gene with the stronger GAL1 promoter and this resulted in enhanced production of resveratrol (4.3 mg/L). Furthermore, when tyrosine was supplemented in the medium, the concentration of resveratrol increased up to 5.8 mg/L. This result illustrates a possible strategy for developing metabolically engineered yeast strain for the economical production of resveratrol from cheap amino acids.
Assuntos
Engenharia Genética/métodos , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Estilbenos/metabolismo , Tirosina/metabolismo , Aciltransferases/genética , Aciltransferases/metabolismo , Arabidopsis/enzimologia , Arabidopsis/genética , Arachis/enzimologia , Arachis/genética , Biotecnologia/métodos , Coenzima A Ligases/genética , Coenzima A Ligases/metabolismo , Ácidos Cumáricos/metabolismo , Fenilalanina Amônia-Liase/genética , Fenilalanina Amônia-Liase/metabolismo , Propionatos , Proteínas Recombinantes/genética , Resveratrol , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/metabolismoRESUMO
The S domain of hepatitis B virus surface antigen (sHBsAg) is the primary component for vaccine development against virus infection. For stable expression of sHBsAg in recombinant Saccharomyces cerevisiae, new accessory genes necessary for foreign protein expression were screened by DNA microarray. Among 600 genes of interest, genes coding for an activating protein of ATPase in Hsp90 (Aha1p), S. cerevisiae DnaJ (Scj1p), thioredoxin 2 (Trx2p) and a GTPase-activator specific for Sar1 (Sec23p) as well as Pdi1p were selected in transcriptome analysis, which are known to facilitate disulfide bond formation or induce protein transport in the secretion pathway. Individual and combinatorial expression of SEC23, TRX2 and PDI1 increased total sHBsAg concentration by 1.9-6.5-fold, relative to the control strain expressing sHBsAg only. Additionally, moderate expression of Kex2p protease able to cut off the signal peptide enhanced the portion of the authentic sHBsAg to total sHBsAg. Fed-batch fermentation of the S. cerevisiae 2805 strain coexpressing the sHBsAg, SEC23, PDI1 and KEX2 genes resulted in 70.6mg/L final sHBsAg concentration which was 5.6 times higher than that of the control. Transmission electron microscopic analysis of the yeast cells elucidated the effects of the accessory gene coexpression on the intracellular localization of sHBsAg. Like PDI1, coexpression of both SEC23 and/or TRX2 newly isolated in this study is expected to improve the target protein expression in S. cerevisiae.
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Vesículas Revestidas pelo Complexo de Proteína do Envoltório/metabolismo , Proteínas Ativadoras de GTPase/metabolismo , Antígenos de Superfície da Hepatite B/biossíntese , Engenharia de Proteínas/métodos , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiologia , Tiorredoxinas/metabolismo , Vesículas Revestidas pelo Complexo de Proteína do Envoltório/genética , Proteínas Ativadoras de GTPase/genética , Antígenos de Superfície da Hepatite B/genética , Proteínas Recombinantes/metabolismo , Recombinação Genética/genética , Proteínas de Saccharomyces cerevisiae/genética , Tiorredoxinas/genéticaRESUMO
BACKGROUND: Oncoprotein HCCR-1 functions as a negative regulator of the p53 and contributes breast tumorigenesis. The serum HCCR-1 assay is useful in diagnosing breast cancer and mice transgenic for HCCR developed breast cancers. But it is unknown how HCCR-1 contributes to human breast tumorigenesis. METHODS: Oncogene HCCR-1 expression levels were determined in normal breast tissues, breast cancer tissues and cancer cell lines. We examined whether HCCR-1 protein expression in breast cancer is related to different biological characteristics, including ER, PR, p53 genotype, and HER2 status in 104 primary breast cancer tissues using immunohistochemical analyses. RESULTS: HCCR-1 was upregulated in breast cancer cells and tissues compared with normal breast tissues. In this study, overexpression of HCCR-1 was well correlated with known breast cancer prognostic markers including the presence of steroid receptors (ER and PR), p53 mutation and high HER2 overexpression. HCCR-1 was not detected in the ER-negative, PR-negative, p53 negative and low HER2 breast cancer tissues. These data indicate that the level of HCCR-1 in breast cancer tissues is relatively well correlated with known breast cancer factors, including the HER2 overexpression, p53 mutation, and ER/PR status. CONCLUSION: Determination of HCCR-1 levels as options for HER2 testing is promising although it needs further evaluation.