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1.
Front Oncol ; 12: 949910, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36046038

RESUMO

Mucormycosis caused by Lichtheimia ramosa is an emerging and uncommon opportunistic infection in patients with hematological malignancies, with high mortality rates. Herein, we first report a case of pulmonary mucormycosis with Lichtheimia ramosa in a 3-year-old girl recently diagnosed with B-cell acute lymphoblastic leukemia. The diagnosis was made using computerized tomography of the lung, metagenomic next-generation sequencing (mNGS) of blood and sputum specimens, and microscopic examination to detect the development of Lichtheimia ramosa on the surgical specimen. She was effectively treated after receiving prompt treatment with amphotericin B and posaconazole, followed by aggressive surgical debridement. In our case, the fungal isolates were identified as Lichtheimia ramosa using mNGS, which assisted clinicians in quickly and accurately diagnosing and initiating early intensive treatment. This case also indicated the importance of strong clinical suspicion, as well as aggressive antifungal therapy combined with surgical debridement of affected tissues.

2.
World J Gastroenterol ; 27(31): 5232-5246, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34497447

RESUMO

BACKGROUND: Artificial intelligence in colonoscopy is an emerging field, and its application may help colonoscopists improve inspection quality and reduce the rate of missed polyps and adenomas. Several deep learning-based computer-assisted detection (CADe) techniques were established from small single-center datasets, and unrepresentative learning materials might confine their application and generalization in wide practice. Although CADes have been reported to identify polyps in colonoscopic images and videos in real time, their diagnostic performance deserves to be further validated in clinical practice. AIM: To train and test a CADe based on multicenter high-quality images of polyps and preliminarily validate it in clinical colonoscopies. METHODS: With high-quality screening and labeling from 55 qualified colonoscopists, a dataset consisting of over 71000 images from 20 centers was used to train and test a deep learning-based CADe. In addition, the real-time diagnostic performance of CADe was tested frame by frame in 47 unaltered full-ranged videos that contained 86 histologically confirmed polyps. Finally, we conducted a self-controlled observational study to validate the diagnostic performance of CADe in real-world colonoscopy with the main outcome measure of polyps per colonoscopy in Changhai Hospital. RESULTS: The CADe was able to identify polyps in the test dataset with 95.0% sensitivity and 99.1% specificity. For colonoscopy videos, all 86 polyps were detected with 92.2% sensitivity and 93.6% specificity in frame-by-frame analysis. In the prospective validation, the sensitivity of CAD in identifying polyps was 98.4% (185/188). Folds, reflections of light and fecal fluid were the main causes of false positives in both the test dataset and clinical colonoscopies. Colonoscopists can detect more polyps (0.90 vs 0.82, P < 0.001) and adenomas (0.32 vs 0.30, P = 0.045) with the aid of CADe, particularly polyps < 5 mm and flat polyps (0.65 vs 0.57, P < 0.001; 0.74 vs 0.67, P = 0.001, respectively). However, high efficacy is not realized in colonoscopies with inadequate bowel preparation and withdrawal time (P = 0.32; P = 0.16, respectively). CONCLUSION: CADe is feasible in the clinical setting and might help endoscopists detect more polyps and adenomas, and further confirmation is warranted.


Assuntos
Pólipos do Colo , Aprendizado Profundo , Inteligência Artificial , Pólipos do Colo/diagnóstico por imagem , Colonoscopia , Computadores , Humanos
3.
PLoS One ; 16(1): e0244520, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33439872

RESUMO

Two new wood-inhabiting fungal species, Steccherinum tenuissimum and S. xanthum spp. nov. are described based on a combination of morphological features and molecular evidence. Steccherinum tenuissimum is characterized by an annual growth habit, resupinate basidiomata with an odontioid hymenial surface, a dimitic hyphal system with clamped generative hyphae, strongly encrusted cystidia and basidiospores measuring 3-5 × 2-3.5 µm. Steccherinum xanthum is characterized by odontioid basidiomata and a monomitic hyphal system with generative hyphae bearing clamp connections and covering by crystals, colourless, thin-walled, smooth, IKI-, CB-and has basidiospores measuring 2.7-5.5 × 1.8-4.0 µm. Sequences of the ITS and nLSU nrRNA gene regions of the studied samples were generated, and phylogenetic analyses were performed with maximum likelihood, maximum parsimony and Bayesian inference methods. The phylogenetic analyses based on molecular data of ITS + nLSU sequences showed that two new Steccherinum species felled into the residual polyporoid clade. Further investigation was obtained for more representative taxa in Steccherinum based on ITS + nLSU sequences, which demonstrated that S. tenuissimum and S. xanthum were sister to S. robustius with high support (100% BP, 100% BS and 1.00 BPP).


Assuntos
Filogenia , Polyporales/genética , China , DNA Fúngico/genética , Hifas/classificação , Hifas/genética , Hifas/crescimento & desenvolvimento , Polyporales/classificação , Polyporales/crescimento & desenvolvimento , Análise de Sequência de DNA , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/crescimento & desenvolvimento
4.
Folia Histochem Cytobiol ; 58(4): 264-271, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33118610

RESUMO

INTRODUCTION: Osteoarthritis (OA) is a severe joint degeneration disease in elderly people described by the advanced degradation of articular cartilage, which ultimately leads to chronic pain. Trans-cinnamaldehyde (TCA) exerted its anti-inflammatory function in numerous disease syndromes; however, its role in the pathogenesis of OA remains unknown. The current research aimed to explore the potential protective impact of TCA in the progression of osteoarthritis in vitro. MATERIAL AND METHODS: Human knee articular chondrocytes were treated with 10 ng/ml IL-1b alone for 24 h or in a combination in a pretreatment with TCA at different concentrations (2, 5, 10 µg/mL, 24 h). The viability and cell apoptosis were determined by CCK-8 assay and flow cytometry methods. The protein levels of IL-8, PGE2, and TNF-a and the levels of phosphorylated AKT and PI3K were evaluated using ELISA assay. Moreover, RT-qPCR was used to measure the relative mRNA expression of MMP-13, iNOS, COX-2, and ADAMTS-5 in IL-1b-induced chondrocytes. RESULTS: Our results revealed that the treatment with TCA had no effect on chondrocytes' proliferation and apoptosis. Moreover, the protein levels of IL-8, TNF-a, and PGE2 were considerably reduced in IL-1b-induced chondrocytes treated with different concentrations of TCA. Furthermore, the mRNA expression of MMP-13, iNOS, COX-2, and ADAMTS-5 and the phosphorylation of AKT and PI3K were markedly reduced in IL-1b-induced chondrocytes with the increase in the concentration of TCA. CONCLUSIONS: Trans-cinnamaldehyde inhibited the inflammation induced by IL-1b in chondrocytes through the PI3K/AKT pathway, which suggests that TCA might serve as a potential therapeutic agent for osteoarthritis treatment.


Assuntos
Acroleína/análogos & derivados , Inflamação/prevenção & controle , Osteoartrite/prevenção & controle , Substâncias Protetoras/farmacologia , Transdução de Sinais/efeitos dos fármacos , Acroleína/farmacologia , Acroleína/toxicidade , Células Cultivadas , Condrócitos/efeitos dos fármacos , Dinoprostona/metabolismo , Humanos , Inflamação/induzido quimicamente , Inflamação/metabolismo , Interleucina-1beta , Interleucina-8/metabolismo , Osteoartrite/induzido quimicamente , Osteoartrite/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Substâncias Protetoras/toxicidade , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
5.
J Ind Microbiol Biotechnol ; 46(2): 125-132, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30623269

RESUMO

Typical N-acetyl-D-neuraminic acid (Neu5Ac) production uses N-acetyl-D-glucosamine (GlcNAc) and excess pyruvate as substrates in the enzymatic or whole-cell biocatalysis process. In a previous study, a Neu5Ac-producing biocatalytic process via engineered Escherichia coli SA-05/pDTrc-AB/pCDF-pck-ppsA was constructed without exogenous pyruvate. In this study, glycerol was found to be a good energy source compared with glucose for the catalytic system with resting cells, and Neu5Ac production increased to 13.97 ± 0.27 g L-1. In addition, a two-stage pH shift strategy was carried out, and the Neu5Ac yield was improved to 14.61 ± 0.31 g L-1. The GlcNAc concentration for Neu5Ac production was optimized. Finally, an integrated strategy was developed for Neu5Ac production, and the Neu5Ac yield reached as high as 18.17 ± 0.27 g L-1. These results provide a new biocatalysis technology for Neu5Ac production without exogenous pyruvate.


Assuntos
Escherichia coli/genética , Microrganismos Geneticamente Modificados/genética , Ácido N-Acetilneuramínico/biossíntese , Acetilglucosamina/metabolismo , Técnicas de Cultura Celular por Lotes , Biocatálise , Escherichia coli/metabolismo , Glicerol/metabolismo , Concentração de Íons de Hidrogênio , Engenharia Metabólica , Ácido Pirúvico/metabolismo
6.
Zhongguo Dang Dai Er Ke Za Zhi ; 20(4): 290-294, 2018 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-29658453

RESUMO

OBJECTIVE: To investigate the clinical significance of BRAF-V600E mutation in children with Langerhans cell histiocytosis (LCH). METHODS: Real-time fluorescence quantitative PCR was used to detect BRAF-V600E mutation in paraffin-embedded tissue samples from 26 children with LCH. A retrospective analysis was performed for the association of BRAF-V600E mutation with clinical features and prognosis of children with LCH. RESULTS: Of the 26 children, 25 received standard chemotherapy, with a 2-year overall survival (OS) rate of 100% and a 2-year event-free survival (EFS) rate of 88%. Of the 26 pathological samples, 18 (70%) came from bone tissue, and the positive rate of BRAF-V600E mutation reached 50% (13/26). The positive rate of BRAF-V600E gene mutation was not associated with age, sex, affected organ, clinical classification, early treatment response, recurrence, and 2-year OS and EFS rates of the children with LCH (P>0.05), but it was associated with clinical grouping of LCH (P<0.05). CONCLUSIONS: Children with LCH tend to have a high OS rate and a high incidence rate of BRAF-V600E mutation. BRAF-V600E mutation is associated with clinical grouping of LCH.


Assuntos
Histiocitose de Células de Langerhans/genética , Mutação , Proteínas Proto-Oncogênicas B-raf/genética , Adolescente , Criança , Pré-Escolar , Feminino , Histiocitose de Células de Langerhans/classificação , Histiocitose de Células de Langerhans/mortalidade , Humanos , Lactente , Masculino , Estudos Retrospectivos
7.
Mater Sci Eng C Mater Biol Appl ; 79: 516-524, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28629048

RESUMO

A high-strength regenerated bacterial cellulose (RBC)/bacterial cellulose (BC) microfilament of potential use as a biomaterial was successfully prepared via a wet spinning process. The BC not only consists of a 3-D network composed of nanofibers with a diameter of several hundred nanometers but also has a secondary structure consisting of highly oriented nanofibrils with a diameter ranging from a few nanometers to tens of nanometers which explains the reason for the high mechanical strength of BC. Furthermore, a strategy of partially dissolving BC was used and this greatly enhanced the mechanical performance of spun filament and a method called post-treatment was utilized to remove residual solvents from the RBC/BC filaments. A comparison of structure, properties, as well as cytocompatibility between BC nanofibers and RBC/BC microfilaments was achieved using morphology, mechanical properties, X-ray Diffraction (XRD) and an enzymatic hydrolysis assay. The RBC/BC microfilament has a uniform groove structure with a diameter of 50-60µm and XRD indicated that the crystal form was transformed from cellulose Iα to cellulose IIII and the degree of crystallinity of RBC/BC (33.22%) was much lower than the original BC (60.29%). The enzymatic hydrolysis assay proved that the RBC/BC material was more easily degraded than BC. ICP detection indicated that the residual amount of lithium was 0.07mg/g (w/w) and GC-MS analysis showed the residual amount of DMAc to be 8.51µg/g (w/w) demonstrating that the post-treatment process is necessary and effective for removal of residual materials from the RBC/BC microfilaments. Also, a cell viability assay demonstrated that after post-treatment the RBC/BC filaments had good cytocompatibility.


Assuntos
Celulose/química , Citoesqueleto de Actina , Materiais Biocompatíveis , Nanofibras , Difração de Raios X
8.
Zhongguo Dang Dai Er Ke Za Zhi ; 16(9): 939-43, 2014 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-25229964

RESUMO

OBJECTIVE: To study the roles of type II 11ß-hydroxysteroid dehydrogenase (11ß-HSD2) and it's signaling factors in the lung tissue in pathogenesis of persistent pulmonary hypertension (PPH) in neonatal rats. METHODS: Six Sprague-Dawley rats on the 19th day of pregnancy were randomly divided into PPH and control groups (n=3 each). The PPH group was intraperitoneally injected with indomethacin (0.5 mg/kg) twice daily and exposed in 12% oxygen for three days, in order to prepare a fetal rat model of PPH. The control group was intraperitoneally injected with an equal volume of normal saline and exposed to air. Neonatal rats were born by caesarean section from both groups on the 22nd day of pregnancy. In each group, 15 neonatal rats were randomly selected and sacrificed. 11ß-HSD2 expression in the lung tissue of neonatal rats were observed by Confocal laser technology, and serum cortisol levels and prostacyclin, renin, angiotensin and aldosterone in the lung tissue of both groups were measured using ELISA. RESULTS: 11ß-HSD2 protein was widely expressed in the lung tissue of the control and PPH groups. The levels of 11ß-HSD2 and prostacyclin in the lung tissue were lower in the PPH group than in the control group, while serum cortisol levels and renin, angiotensin and aldosterone in the lung tissue were higher in the PPH group than in the control group (P<0.05). CONCLUSIONS: 11ß-HSD2 and it's signaling factors play roles in pathogenesis of PPH in neonatal rats.


Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 2/fisiologia , Hipertensão Pulmonar/etiologia , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/análise , Animais , Animais Recém-Nascidos , Feminino , Hipertensão Pulmonar/enzimologia , Masculino , Ratos , Ratos Sprague-Dawley , Transdução de Sinais
9.
Bioresour Technol ; 151: 120-7, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24215768

RESUMO

The effect of osmotic pressure on erythritol and mannitol production by an osmophilic yeast strain of Yarrowia lipolytica CICC 1675 using glycerol as the sole carbon source was investigated. Appropriately high osmotic pressure was found to enhance erythritol production and inhibit mannitol formation. A novel two-stage osmotic pressure control fed-batch strategy based on the kinetic analysis was developed for higher erythritol yield and productivity. During the first 96 h, the osmotic pressure was maintained at 4.25 osmol/kg by feeding glycerol to reduce the inhibition of cell growth. After 132 h, the osmotic pressure was controlled at 4.94 osmol/kg to maintain a high dp(ery)/dt. Maximum erythritol yield of 194.3g/L was obtained with 0.95 g/L/h productivity, which were 25.7% and 2.2%, respectively, improvement over the best results in one-stage fed-batch fermentation. This is the first report that a novel osmotic pressure control fed-batch strategy significantly enhanced erythritol production.


Assuntos
Técnicas de Cultura Celular por Lotes/métodos , Eritritol/biossíntese , Fermentação , Glicerol/metabolismo , Pressão Osmótica , Yarrowia/metabolismo , Biomassa , Fermentação/efeitos dos fármacos , Manitol/metabolismo , Pressão Osmótica/efeitos dos fármacos , Polímeros/metabolismo , Cloreto de Sódio/farmacologia , Fatores de Tempo , Yarrowia/efeitos dos fármacos
10.
Appl Biochem Biotechnol ; 171(5): 1262-75, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23609905

RESUMO

Effective expression of porcine interferon-α (pIFN-α) with recombinant Pichia pastoris was conducted in a bench-scale fermentor using an in situ methanol electrode-based feeding process with the control level of methanol concentration linearly increased to 10 g l⁻¹ for the first 20 h and maintained at 10 g l⁻¹ for the rest of expression phase. With this two-stage control process, the highest pIFN-α concentration reached a level of 1.81 g l⁻¹, which was 1.5-fold of that in the previous constant 10 g l⁻¹ induction experiments. There is an improvement of the pIFN-α productivity from more distribution of carbon flux to protein expression. The pIFN-α expression stability could be further enhanced by a simple on-line fault diagnosis method for methanol overfeeding based on oxygen uptake rate changing patterns. By implementing corrective action of feeding glycerol after fault detection, the production yield increased to twice the amount it would have been without the diagnosis.


Assuntos
Técnicas de Cultura Celular por Lotes/métodos , Interferon-alfa/biossíntese , Metanol/metabolismo , Oxigênio/metabolismo , Pichia/metabolismo , Animais , Técnicas de Cultura Celular por Lotes/instrumentação , Reatores Biológicos/microbiologia , Meios de Cultura/análise , Meios de Cultura/metabolismo , Fermentação , Interferon-alfa/genética , Metanol/análise , Oxigênio/análise , Pichia/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Suínos
11.
Tumour Biol ; 34(2): 1245-53, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23355336

RESUMO

Lymph node metastasis is a major prognostic factor in resected non-small cell lung cancer (NSCLC). However, 30-40 % rate of recurrence after performing complete resection in node-negative patients suggests that their nodal staging is suboptimal. We aimed to evaluate the molecular diagnosis and prognostic significance of lymph node micrometastasis in patients with node-negative NSCLC. Primary tumor samples from 62 patients with resected stage I-IIB NSCLC were screened for fragile histidine triad (FHIT) and CDKN2A mRNA deletion using reverse transcriptase polymerase chain reaction (RT-PCR). The molecular alternations were found in tumors of 49 patients. A total of 269 lymph nodes from these 49 NSCLC patients with FHIT or/and CDKN2A deletion tumors were examined. Fifteen positive-control nodes and ten negative-control nodes were also analyzed for FHIT and CDKN2A mRNA deletion. Thirty-nine (22 %) and 22 (18 %) lymph nodes from the 49 patients with FHIT and CDKN2A mRNA deletion in primary tumor had FHIT and CDKN2A mRNA deletion, respectively. The types of FHIT and CDKN2A mRNA deletion in lymph nodes were identical with those in their primary tumors. By combination of two markers, 16 patients (32.7 %) were found to have nodal micrometastasis. Survival analysis showed that patients with nodal micrometastasis had reduced disease-free survival (P = 0.001) and overall survival (P = 0.002) rates. Multivariate analysis demonstrated that nodal micrometastasis was an independent predictor for worse prognosis. Thus, the detection of lymph node micrometastasis by FHIT and CDKN2A mRNA deletion RT-PCR will be helpful to predict the recurrence and prognosis of patients with completely resected stage I-IIB NSCLC.


Assuntos
Adenocarcinoma/patologia , Carcinoma Adenoescamoso/secundário , Carcinoma de Células Grandes/secundário , Carcinoma Pulmonar de Células não Pequenas/secundário , Carcinoma de Células Escamosas/secundário , Neoplasias Pulmonares/patologia , Linfonodos/patologia , Hidrolases Anidrido Ácido/genética , Adenocarcinoma/genética , Adenocarcinoma/mortalidade , Adulto , Idoso , Carcinoma Adenoescamoso/genética , Carcinoma Adenoescamoso/mortalidade , Carcinoma de Células Grandes/genética , Carcinoma de Células Grandes/mortalidade , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/mortalidade , Inibidor p16 de Quinase Dependente de Ciclina/genética , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/mortalidade , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Micrometástase de Neoplasia , Proteínas de Neoplasias/genética , Estadiamento de Neoplasias , Prognóstico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taxa de Sobrevida
12.
Pediatr Blood Cancer ; 60(6): 940-5, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23335088

RESUMO

BACKGROUND: Growth differentiation factor 15 (GDF15), a divergent TGFß superfamily, has recently been implicated in the modulation of iron homeostasis, acting as an upstream negative regulator of hepcidin, the key iron regulatory hormone produced primarily by hepatocytes. However, little is known about possible roles that GDF15 might play in the regulation of iron homeostasis and development of hyperferritinemia in children with hemophagocytic lymphohistiocytosis (HLH). PROCEDURES: We compared serum GDF15 level and mRNA expressions of GDF15 and key molecules of iron metabolism, and made correlations between their expressions in children with HLH and control children. RESULTS: Serum GDF15 level was remarkably higher in HLH group than that in controls, with median serum concentration of 1,700 and 260 pg/ml, respectively (P < 0.001). In addition, GDF15 mRNA was significantly upregulated but independent of hypoxia-inducible factor-mediated oxygen signaling pathway. More importantly, GDF15 induction was positively correlated to upregulation of ferroportin, the only cellular iron exporter, and to upregulation of ferritin heavy chain. CONCLUSIONS: Our study suggests that GDF15 induction helps suppress further activation of macrophages in stressful physiologic states as HLH, and is intimately implicated in the development of hyperferritinemia by modulating the hepcidin-ferroportin axis, resulting in enhanced ferroportin-mediated iron efflux.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , Fator 15 de Diferenciação de Crescimento/metabolismo , Ferro/metabolismo , Linfo-Histiocitose Hemofagocítica/metabolismo , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Regulação para Cima
13.
Appl Microbiol Biotechnol ; 97(6): 2405-12, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23090056

RESUMO

To determine the factors influencing the resulting molecular weight of polysialic acid (PSA), batch fermentations by using Escherichia coli were conducted. It was found that temperature and pH were significant factors affecting the PSA production and its resulting molecular weight. When pH was set at 6.4, temperature of 37 °C was suitable for cell growth and PSA production while 33 °C facilitated production of higher molecular weight of PSA. pH 6.4 was favorable for PSA production while pH 7.4 was good for higher molecular weight of PSA at 37 °C. Intramolecular self-cleavage of PSA might lead to relatively low molecular weight under mild acidic condition. Our data suggest that the PSA molecular weight is significantly affected by the pH condition rather than the temperature. It is concluded that the resulting PSA molecular weight not only depends on fermentation conditions but also relates to cell growth rate and PSA production rate. Higher PSA molecular weight was made when its production rate was faster than degradation rate. A novel two-stage pH control fermentation process for production of high molecular weight PSA was developed. At the first stage, pH was set at 6.4 to encourage cell growth and PSA production, whereas pH was set at 7.4 at the second stage to promote the formation of higher molecular weight PSA. PSA yield up to 5.65 g/L and its resulting molecular weight of 260 kDa was attained, the highest level ever reported.


Assuntos
Biotecnologia/métodos , Meios de Cultura/química , Escherichia coli/metabolismo , Ácidos Siálicos/química , Ácidos Siálicos/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/efeitos da radiação , Fermentação , Concentração de Íons de Hidrogênio , Peso Molecular , Temperatura
14.
Bioprocess Biosyst Eng ; 35(7): 1125-36, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22349926

RESUMO

The production of porcine interferon-α (pIFN-α) by Pichia pastoris was largely enhanced when adopting sorbitol/methanol co-feeding induction strategy at 30 °C in a 10-L fermentor. Analysis of energy regeneration pattern and carbon metabolism revealed that major energy metabolism energizing pIFN-α synthesis shifted from formaldehyde dissimilatory energy metabolism pathway to TCA cycle under the methanol/sorbitol co-feeding induction strategy. The sorbitol/methanol co-feeding induction strategy weakened formaldehyde dissimilatory pathway and repressed the accumulation of toxic metabolite-formaldehyde, reduced theoretical oxygen consumption rate and oxygen supply requirement, and increased energy/methanol utilization efficiency so that more methanol could be effectively used for pIFN-α synthesis. As a result, pIFN-α antiviral activity reached a highest level of 1.8 × 10(7) IU/mL which was about 10- to 200-folds of those obtained under pure methanol induction at 20 and 30 °C, respectively.


Assuntos
Metabolismo Energético , Interferon-alfa/biossíntese , Metanol/metabolismo , Pichia/metabolismo , Sorbitol/metabolismo , Animais , Bovinos , Ciclo do Ácido Cítrico , Suínos
15.
Appl Microbiol Biotechnol ; 93(1): 367-79, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21739265

RESUMO

A significant problem in scale-down cultures, rarely studied for metabolic characterization and curdlan-producing Agrobacterium sp. ATCC 31749, is the presence of dissolved oxygen (DO) gradients combined with pH control. Constant DO, between 5% and 75%, was maintained during batch fermentations by manipulating the agitation with PID system. Fermentation, metabolic and kinetic characterization studies were conducted in a scale-down system. The curdlan yield, intracellular nucleotide levels and glucose conversion efficiency into curdlan were significantly affected by DO concentrations. The optimum DO concentrations for curdlan production were 45-60%. The average curdlan yield, curdlan productivity and glucose conversion efficiency into curdlan were enhanced by 80%, 66% and 32%, respectively, compared to that at 15% DO. No apparent difference in the gel strength of the resulting curdlan was detected. The comparison of curdlan biosynthesis and cellular nucleotide levels showed that curdlan production had positive relationship with intracellular levels of UTP, ADP, AMP, NAD(+), NADH and UDP-glucose. The curdlan productivity under 45% DO and 60% DO was different during 20-50 h. However, after 60 h curdlan productivity of both conditions was similar. On that basis, a simple and reproducible two-stage DO control process for curdlan production was developed. Curdlan production yield reached 42.8 g/l, an increase of 30% compared to that of the single agitation speed control process.


Assuntos
Agrobacterium/metabolismo , Fermentação , Oxigênio/metabolismo , beta-Glucanas/metabolismo , Agrobacterium/crescimento & desenvolvimento , Meios de Cultura/química , Glucose/metabolismo , Concentração de Íons de Hidrogênio , Nucleotídeos/metabolismo , Fatores de Tempo
16.
Appl Microbiol Biotechnol ; 93(4): 1437-45, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21983708

RESUMO

Effective expression of porcine interferon-α (pIFN-α) with recombinant Pichia pastoris was conducted in a bench-scale fermentor. The influence of the glycerol feeding strategy on the specific growth rate and protein production was investigated. The traditional DO-stat feeding strategy led to very low cell growth rate resulting in low dry cell weight (DCW) of about 90 g/L during the subsequent induction phase. The previously reported Artificial Neural Network Pattern Recognition (ANNPR) model-based glycerol feeding strategy improved the cell density to 120 g DCW/L, while the specific growth rate decreased from 0.15 to 0.18 to 0.03-0.08 h(-1) during the last 10 h of the glycerol feeding stage leading to a variation of the porcine interferon-α production, as the glycerol feeding scheme had a significant effect on the induction phase. This problem was resolved by an improved ANNPR model-based feeding strategy to maintain the specific growth rate above 0.11 h(-1). With this feeding strategy, the pIFN-α concentration reached a level of 1.43 g/L, more than 1.5-fold higher than that obtained with the previously adopted feeding strategy. Our results showed that increasing the specific growth rate favored the target protein production and the glycerol feeding methods directly influenced the induction stage. Consequently, higher cell density and specific growth rate as well as effective porcine interferon-α production have been achieved by our novel glycerol feeding strategy.


Assuntos
Glicerol/metabolismo , Interferon-alfa/metabolismo , Pichia/crescimento & desenvolvimento , Pichia/metabolismo , Animais , Biotecnologia/métodos , Meios de Cultura/química , Fermentação , Interferon-alfa/genética , Redes Neurais de Computação , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Suínos
17.
Curr Microbiol ; 63(1): 60-7, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21533781

RESUMO

The regulatory function of global regulator NtrC on curdlan biosynthesis and nitrogen consumption under nitrogen-limited condition in Agrobacterium sp. ATCC 31749 was investigated. The ntrC mutant of Agrobacterium sp. was constructed by homologous recombination. The ability to utilize NH4Cl and KNO3 was impaired in the mutant. Other nitrogenous compounds, such as glutamic acid and glutamine, were utilized normally. Curdlan production capability was impaired severely in the mutant. Curdlan production was 5-fold lower than the wild type strain in batch fermentation with NH4Cl as the sole nitrogen source. However, up to 6.5 g l(-1) of a newly found alkali-insoluble biopolymer was produced by the ntrC mutant when glutamic acid was used as nitrogen source. The new biopolymer had glycosidic bond and hydroxyl group but no ß-configuration absorption peak on IR spectrum was found as different from curdlan. In addition, the mutant exhibited a rapid morphological change from the dot to rod form. These results deduced that the global regulator NtrC was involved in curdlan and other biopolymer biosynthesis in Agrobacterium sp. ATCC 31749 in response to nitrogen-limited condition.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Mutação , Compostos de Nitrogênio/metabolismo , Rhizobium/metabolismo , beta-Glucanas/metabolismo , Nitrogênio/metabolismo , Rhizobium/genética
18.
Appl Microbiol Biotechnol ; 91(1): 163-75, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21472535

RESUMO

Expression at the mRNA level of ten selected genes in Agrobacterium sp. ATCC 31749 under various dissolved oxygen (DO) levels during curdlan fermentation related to electron transfer chain (ETC), tricarboxylic acid (TCA) cycle, peptidoglycan/lipopolysaccharide biosynthesis, and uridine diphosphate (UDP)-glucose biosynthesis were determined by qRT-PCR. Experiments were performed at DO levels of 30%, 50%, and 75%, as well as under low-oxygen conditions. The effect of high cell density on transcriptional response of the above genes under low oxygen was also studied. Besides cytochrome d (cyd A), the transcription levels of all the other genes were increased at higher DO and reached maximum at 50% DO. Under 75% DO, the transcriptional levels of all the genes were repressed. In addition, transcription levels of icd, sdh, cyo A, and fix N genes did not exhibit significant fluctuation with high cell density culture under low oxygen. These results suggested a mechanism for DO regulation of curdlan synthesis through regulation of transcriptional levels of ETCs, TCA, and UDP-glucose synthesis genes during curdlan fermentation. To our knowledge, this is the first report that DO concentration apparently regulates curdlan biosynthesis in Agrobacterium sp. ATCC 31749 providing essential lead for the optimization of the fermentation at the industrial scale.


Assuntos
Oxigênio/metabolismo , Rhizobium/genética , Rhizobium/metabolismo , Transcrição Gênica , beta-Glucanas/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Dados de Sequência Molecular
19.
Biotechnol Lett ; 32(12): 1939-45, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20820880

RESUMO

The optimal process for the polysialylation reaction was as follows: polysialicacid (PSA) was activated by periodate oxidation, then coupled to CuZn superoxide dismutase (SOD) with a PSA:SOD molar ratio of 40:1 for 24 h. The resulting polysialylated protein contained 3.9 ± 0.3 mol PSA per mol SOD. SDS-PAGE and atomic force microscopy revealed that the molecular weight of polysialylated SOD was about 90-100 kDa. The average size was 10-15 nm, about four-fold of the native enzyme. Compared to the native enzyme, the activity and stability of the polysialylated SOD, as well as resistance to heat, acid, alkali and proteases present in human digestive system such as pepsin and trypsin, were improved significantly as therapeutic agent.


Assuntos
Ácidos Siálicos/metabolismo , Superóxido Dismutase/química , Superóxido Dismutase/metabolismo , Ácidos/química , Álcalis/química , Eletroforese em Gel de Poliacrilamida , Estabilidade Enzimática , Temperatura Alta , Microscopia de Força Atômica , Peso Molecular , Peptídeo Hidrolases/metabolismo , Ácido Periódico/metabolismo , Superóxido Dismutase/ultraestrutura , Fatores de Tempo
20.
Asia Pac J Clin Oncol ; 6(1): 57-65, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20398039

RESUMO

AIM: To evaluate the efficacy of current chemoradiotherapy on improvement of survival in patients with superior sulcus non-small cell lung cancer (NSCLC). METHODS: We retrospectively reviewed the data of 39 patients with superior sulcus NSCLC treated with induction therapy followed surgery. The patients were divided into two groups according to the induction approach: the induction radiotherapy (RT) group (1993-1999), and the induction chemoradiotherapy (CT/RT) group (since 1999). RESULTS: The rate of complete resection was 65 percent in the RT group (n = 17) compared with 91 percent in the CT/RT group (n = 22, P = 0.024). Complete pathological responses from induction therapy were 12 percent in the RT group and 45 percent in the CT/RT group (P = 0.032). Overall survival (OS) was significantly longer in patients who received CT/RT than that in those who received RT, with 2- and 5-year survival rates of 77.3 percent and 36.4 percent versus 41.2 percent and 11.8 percent, respectively (P = 0.007). CT/RT also associated with a markedly longer tumor-free survival (TFS), with a median TFS of 40 and 17 months, respectively (P = 0.007). Patients achieved complete resection or complete pathological response had a significantly better survival than those with incomplete resection or pathological partial responses and no change (P < 0.0005 and P = 0.001, respectively). CONCLUSION: Our results indicate that CT/RT followed by surgery can significantly improve OS and TFS, and may be considered as an optimal option in treatment of patients with superior sulcus NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/terapia , Neoplasias Pulmonares/terapia , Síndrome de Pancoast/terapia , Adulto , Idoso , Terapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
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