Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 51
Filtrar
1.
Microb Cell Fact ; 23(1): 85, 2024 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-38493086

RESUMO

BACKGROUND: The abundance of glucuronoxylan (GX) in agricultural and forestry residual side streams positions it as a promising feedstock for microbial conversion into valuable compounds. By engineering strains of the widely employed cell factory Saccharomyces cerevisiae with the ability to directly hydrolyze and ferment GX polymers, we can avoid the need for harsh chemical pretreatments and costly enzymatic hydrolysis steps prior to fermentation. However, for an economically viable bioproduction process, the engineered strains must efficiently express and secrete enzymes that act in synergy to hydrolyze the targeted polymers. RESULTS: The aim of this study was to equip the xylose-fermenting S. cerevisiae strain CEN.PK XXX with xylanolytic enzymes targeting beechwood GX. Using a targeted enzyme approach, we matched hydrolytic enzyme activities to the chemical features of the GX substrate and determined that besides endo-1,4-ß-xylanase and ß-xylosidase activities, α-methyl-glucuronidase activity was of great importance for GX hydrolysis and yeast growth. We also created a library of strains expressing different combinations of enzymes, and screened for yeast strains that could express and secrete the enzymes and metabolize the GX hydrolysis products efficiently. While strains engineered with BmXyn11A xylanase and XylA ß-xylosidase could grow relatively well in beechwood GX, strains further engineered with Agu115 α-methyl-glucuronidase did not display an additional growth benefit, likely due to inefficient expression and secretion of this enzyme. Co-cultures of strains expressing complementary enzymes as well as external enzyme supplementation boosted yeast growth and ethanol fermentation of GX, and ethanol titers reached a maximum of 1.33 g L- 1 after 48 h under oxygen limited condition in bioreactor fermentations. CONCLUSION: This work underscored the importance of identifying an optimal enzyme combination for successful engineering of S. cerevisiae strains that can hydrolyze and assimilate GX. The enzymes must exhibit high and balanced activities, be compatible with the yeast's expression and secretion system, and the nature of the hydrolysis products must be such that they can be taken up and metabolized by the yeast. The engineered strains, particularly when co-cultivated, display robust growth and fermentation of GX, and represent a significant step forward towards a sustainable and cost-effective bioprocessing of GX-rich biomass. They also provide valuable insights for future strain and process development targets.


Assuntos
Edição de Genes , Saccharomyces cerevisiae , Xilanos , Saccharomyces cerevisiae/metabolismo , Fermentação , Hidrólise , Sistemas CRISPR-Cas , Etanol/metabolismo , Polímeros/metabolismo , Glucuronidase , Xilose/metabolismo
2.
J. coloproctol. (Rio J., Impr.) ; 43(2): 75-81, Apr.-June 2023. graf, ilus
Artigo em Inglês | LILACS | ID: biblio-1514427

RESUMO

Introduction: Anal examination and videoanoscopy (VA) are rarely performed during colonoscopies. In recent years, there has been a considerable increase in lesions of sexually transmitted anal and rectal infections, but these conditions are not noticed or reported during routine colonoscopy. Objective: To raise awareness regarding the fortuitous findings of lesions and sexually transmitted infections (STIs) in colonoscopy exams and to demonstrate that anal examination and VA provide important information and should be routinely performed. Methods: We conducted a descriptive retrospective study in 16,132 patients screened by colonoscopy and VA between 2006 and 2018. Among numerous other findings, the presence of anal condylomata and sexually transmitted retitis or perianal dermatitis was observed. The rates of each finding were calculated, and the patients were subdivided by sex and into age groups by blocks of ten years. Results: Among the 16,132 colonoscopies performed, 26 cases of condyloma (0.16%) and 50 cases of proctitis or perianal dermatitis suspicious for STI (0.33%) were found. Conclusion: Performing anal examination and VA systematically in all routine colonoscopies enabled the identification of numerous anal conditions, including several fortuitous cases of STIs. The study proposes that anal examination and VA should be performed in all routine colonoscopies and, in suspected cases, complementary tests for STIs. (AU)


Assuntos
Canal Anal/lesões , Neoplasias do Ânus/diagnóstico , Colonoscopia , Infecções por Papillomavirus/diagnóstico , Carcinoma in Situ/diagnóstico , Infecções por Papillomavirus/terapia , Dermatite de Contato/diagnóstico
3.
Neurooncol Adv ; 4(1): vdac104, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35892048

RESUMO

Background: Intra-arterial administration of chemotherapy with or without osmotic blood-brain barrier disruption enhances delivery of therapeutic agents to brain tumors. The aim of this study is to evaluate the safety of these procedures. Methods: Retrospectively collected data from a prospective database of consecutive patients with primary and metastatic brain tumors who received intra-arterial chemotherapy without osmotic blood-brain barrier disruption (IA) or intra-arterial chemotherapy with osmotic blood-brain barrier disruption (IA/OBBBD) at Oregon Health and Science University (OHSU) between December 1997 and November 2018 is reported. Chemotherapy-related complications are detailed per Common Terminology Criteria for Adverse Events (CTCAE) guidelines. Procedure-related complications are grouped as major and minor. Results: 4939 procedures (1102 IA; 3837 IA/OBBBD) were performed on 436 patients with various pathologies (primary central nervous system lymphoma [26.4%], glioblastoma [18.1%], and oligodendroglioma [14.7%]). Major procedure-related complications (IA: 12, 1%; IA/OBBBD: 27, 0.7%; P = .292) occurred in 39 procedures including 3 arterial dissections requiring intervention, 21 symptomatic strokes, 3 myocardial infarctions, 6 cervical cord injuries, and 6 deaths within 3 days. Minor procedure-related complications occurred in 330 procedures (IA: 41, 3.7%; IA/OBBBD: 289, 7.5%; P = .001). Chemotherapy-related complications with a CTCAE attribution and grade higher than 3 was seen in 359 (82.3%) patients. Conclusions: We provide safety and tolerability data from the largest cohort of consecutive patients who received IA or IA/OBBBD. Our data demonstrate that IA or IA/OBBBD safely enhance drug delivery to brain tumors and brain around the tumor.

4.
Carbohydr Polym ; 294: 119737, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-35868741

RESUMO

Enzymatic degradation of plant polysaccharide networks is a complex process that involves disrupting an intimate assembly of cellulose and hemicelluloses in fibrous matrices. To mimic this assembly and to elucidate the efficiency of enzymatic degradation in a rapid way, models with physicochemical equivalence to natural systems are needed. Here, we employ xylan-coated cellulose thin films to monitor the hydrolyzing activity of an endo-1,4-ß-xylanase. In situ surface plasmon resonance spectroscopy (SPRS) revealed a decrease in xylan areal mass ranging from 0.01 ± 0.02 to 0.52 ± 0.04 mg·m-2. The extent of digestion correlates to increasing xylanase concentration. In addition, ex situ determination of released monosaccharides revealed that incubation time was also a significant factor in degradation (P > 0.01). For both experiments, atomic force microscopy confirmed the removal of xylans from the cellulose thin films. We provide a new model platform that offers nanoscale sensitivity for investigating biopolymer interactions and their susceptibility to enzymatic hydrolysis.


Assuntos
Celulose , Xilanos , Biopolímeros , Celulose/química , Endo-1,4-beta-Xilanases/metabolismo , Hidrólise , Xilanos/química
5.
IEEE Robot Autom Lett ; 7(2): 4789-4796, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35582267

RESUMO

The COVID-19 pandemic has become a worldwide concern and has motivated the entire scientific community to join efforts to fight it. Studies have shown that SARS-CoV-2 remains viable onsurfaces for days, increasing the chances of human infection. Environmental disinfection is thus an important action to prevent the transmission of the virus. Despite the valuable contribution of the research community to the field of UV-C disinfection by robots, there still lacks a disinfection system that is fully autonomous and computes its trajectory in real-time and in unknown environments. To meet this need, we propose an autonomous UV-C disinfection strategy for indoor environments based on a dynamic Irradiation Map that indicates the amount of energy applied in each region. Our method was tested in different scenarios and compared with other disinfection strategies. Experiments show that our approach delivers better results, especially when targeting high ideal UV-C doses.

6.
J Appl Microbiol ; 132(2): 822-840, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34327773

RESUMO

Hyaluronic acid (HA) is a biopolymer of repeating units of glucuronic acid and N-acetylglucosamine. Its market was valued at USD 8.9 billion in 2019. Traditionally, HA has been obtained from rooster comb-like animal tissues and fermentative cultures of attenuated pathogenic streptococci. Various attempts have been made to engineer a safe micro-organism for HA synthesis; however, the HA titres obtained from these attempts are in general still lower than those achieved by natural, pathogenic producers. In this scenario, ways to increase HA molecule length and titres in already constructed strains are gaining attention in the last years, but no recent publication has reviewed the main genetic strategies applied to improve HA production on heterologous hosts. In light of that, we hereby compile the advances made in the engineering of micro-organisms to improve HA synthesis.


Assuntos
Galinhas , Ácido Hialurônico , Animais , Fermentação , Masculino , Streptococcus
7.
Coluna/Columna ; 20(3): 207-211, July-Sept. 2021. tab
Artigo em Inglês | LILACS | ID: biblio-1339751

RESUMO

ABSTRACT Objective To determine the prevalence of low back pain and to establish a correlation with risk factors for the development of low back pain in a teaching hospital in the East Zone of São Paulo. Method This is a cross-sectional, observational, analytical study, in which 90 patients from the teaching hospital wards were evaluated. Internationally validated instruments were used to assess clinical, epidemiological and behavioral aspects. Results The prevalence rate obtained was 57.73%, which is considered high compared to the rates in studies conducted outside of the hospital environment. There was predominance in the female sex, at 30.13% (SSD 5.32%). Sleep disturbances, measured indirectly through hours of sleep and the average pain score (p = 0.007), seem to act as a risk factor. The instruments for checking pain seem to be more effective when used together, with an association being observed between the Oswestry questionnaire (ODI) and the visual analog scale (VAS) for pain (p = 0.000). Conclusions There is a prevalence of low back pain among institutionalized individuals, especially those who are hospitalized, compared to rates observed outside the hospital environment. Level of evidence IV; Cross-sectional observational.


RESUMO Objetivo Determinar a prevalência de lombalgia e estabelecer correlação com fatores de risco para o desenvolvimento de dor lombar em um Hospital Escola da Zona Leste de São Paulo. Métodos Trata-se de um estudo analítico observacional transversal, no qual foram avaliados 90 pacientes provenientes das enfermarias do Hospital Escola. Foram empregados instrumentos internacionalmente validados para avaliar aspectos clínicos, epidemiológicos e comportamentais. Resultados A taxa de prevalência obtida foi de 57,73%, considerada alta em comparação com as taxas das pesquisadas realizadas fora do ambiente hospitalar. Houve predomínio do sexo feminino, com 30,13% (DPa 5,32%). Os distúrbios do sono, medidos indiretamente por meio de horas de sono e a média da graduação de dor (p = 0,007), parecem agir como fator de risco. Os instrumentos para verificação da dor parecem ter maior eficácia quando usados em conjunto, sendo observada uma associação entre o questionário de Oswestry (ODI) e a escala visual analógica (EVA) de dor (p = 0,000). Conclusões Constatou-se maior taxa da prevalência de lombalgia entre os indivíduos institucionalizados, principalmente, os hospitalizados, comparada a taxas observadas fora do contexto hospitalar. Nível de evidência IV; Estudo Observacional Transversal.


RESUMEN Objetivo Determinar la prevalencia de lumbalgia y establecer una correlación con los factores de riesgo para el desarrollo del dolor lumbar en un hospital universitario en la Zona Este de São Paulo. Métodos Este es un estudio analítico observacional de corte transversal, en el que se evaluaron 90 pacientes de las enfermerías del hospital universitario. Se utilizaron instrumentos validados internacionalmente para evaluar aspectos clínicos, epidemiológicos y de comportamiento. Resultados La tasa de prevalencia obtenida fue de 57,73%, considerada alta en comparación con las tasas de los encuestados fuera del ámbito hospitalario. Predominó el sexo femenino, con un 30,13%(SSD 5,32%). Los trastornos del sueño, medidos indirectamente a través de horas de sueño y la puntuación promedio de dolor (p = 0,007), parecen actuar como un factor de riesgo. Los instrumentos para controlar el dolor parecen ser más efectivos cuando se usan juntos, con una asociación entre el cuestionario de Oswestry (ODI) y la escala visual analógica (EVA) del dolor (p = 0,000). Conclusiones Se encontró una mayor tasa de prevalencia de dolor lumbar entre los individuos institucionalizados, especialmente los hospitalizados, en comparación con las tasas observadas fuera del contexto hospitalario. Nivel de Evidencia IV; Estudio Observacional Transversal.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Dor Lombar/epidemiologia , Hospitalização , Prevalência , Estudos Transversais , Fatores de Risco
8.
Microb Biotechnol ; 14(6): 2448-2462, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33533574

RESUMO

Whole-cell bioconversion of technical lignins using Pseudomonas putida strains overexpressing amine transaminases (ATAs) has the potential to become an eco-efficient route to produce phenolic amines. Here, a novel cell growth-based screening method to evaluate the in vivo activity of recombinant ATAs towards vanillylamine in P. putida KT2440 was developed. It allowed the identification of the native enzyme Pp-SpuC-II and ATA from Chromobacterium violaceum (Cv-ATA) as highly active towards vanillylamine in vivo. Overexpression of Pp-SpuC-II and Cv-ATA in the strain GN442ΔPP_2426, previously engineered for reduced vanillin assimilation, resulted in 94- and 92-fold increased specific transaminase activity, respectively. Whole-cell bioconversion of vanillin yielded 0.70 ± 0.20 mM and 0.92 ± 0.30 mM vanillylamine, for Pp-SpuC-II and Cv-ATA, respectively. Still, amine production was limited by a substantial re-assimilation of the product and formation of the by-products vanillic acid and vanillyl alcohol. Concomitant overexpression of Cv-ATA and alanine dehydrogenase from Bacillus subtilis increased the production of vanillylamine with ammonium as the only nitrogen source and a reduction in the amount of amine product re-assimilation. Identification and deletion of additional native genes encoding oxidoreductases acting on vanillin are crucial engineering targets for further improvement.


Assuntos
Pseudomonas putida , Benzilaminas , Lignina , Engenharia Metabólica , Pseudomonas putida/genética
9.
Microorganisms ; 9(2)2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33546444

RESUMO

Hyaluronic acid (HA) is a biopolymer formed by UDP-glucuronic acid and UDP-N-acetyl-glucosamine disaccharide units linked by ß-1,4 and ß-1,3 glycosidic bonds. It is widely employed in medical and cosmetic procedures. HA is synthesized by hyaluronan synthase (HAS), which catalyzes the precursors' ligation in the cytosol, elongates the polymer chain, and exports it to the extracellular space. Here, we engineer Ogataea (Hansenula) polymorpha for HA production by inserting the genes encoding UDP-glucose 6-dehydrogenase, for UDP-glucuronic acid production, and HAS. Two microbial HAS, from Streptococcus zooepidemicus (hasAs) and Pasteurella multocida (hasAp), were evaluated separately. Additionally, we assessed a genetic switch using integrases in O. polymorpha to uncouple HA production from growth. Four strains were constructed containing both has genes under the control of different promoters. In the strain containing the genetic switch, HA production was verified by a capsule-like layer around the cells by scanning electron microscopy in the first 24 h of cultivation. For the other strains, the HA was quantified only after 48 h and in an optimized medium, indicating that HA production in O. polymorpha is limited by cultivation conditions. Nevertheless, these results provide a proof-of-principle that O. polymorpha is a suitable host for HA production.

10.
Neurosurgery ; 88(4): E336-E342, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33548921

RESUMO

BACKGROUND: Progressive and/or unresectable pilocytic astrocytomas (PAs) carry a poor prognosis compared to typical PA. Early radiotherapy (RT) may have severe long-term neurocognitive side effects in this patient population. Intra-arterial (IA) chemotherapy is a viable alternative or addition to intravenous (IV) chemotherapy, which may be beneficial in avoidance of early RT. OBJECTIVE: To evaluate the safety and efficacy of IA chemotherapy in this subset of patients. METHODS: This is a retrospective review of medical records of PA patients who are treated with IA chemotherapy at Oregon Health & Science University from 1997 until 2019. Response to treatment was categorized as complete response (CR), partial response (PR), stable disease (SD), or progressive disease (PD). Progression free survival (PFS) and overall survival (OS) are also reported. RESULTS: Twelve patients were identified. All patients experienced progression prior to initiation of IA chemotherapy. The most common grade 3 or 4 toxicities related to chemotherapy were thrombocytopenia (66%), neutropenia (66%), leukopenia (50%), anemia (33%), and lymphopenia (16%). Responses achieved were CR in 1, PR in 3, SD in 7, and PD in 1. Median PFS and median OS were 16.5 and 83.5 mo, respectively. A total of 112 procedures (IA injections) were performed and 250 arteries were catheterized. There were 3 minor and no major complications attributable to procedures. CONCLUSION: This study demonstrates that IA chemotherapy can be safely used in patients with unresectable or progressive PA.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Astrocitoma/tratamento farmacológico , Neoplasias Encefálicas/tratamento farmacológico , Progressão da Doença , Infusões Intra-Arteriais/métodos , Neoplasias da Coluna Vertebral/tratamento farmacológico , Adolescente , Adulto , Astrocitoma/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico por imagem , Criança , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Resultado do Tratamento , Adulto Jovem
11.
Pituitary ; 23(6): 672-680, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32870441

RESUMO

PURPOSE: To investigate demographic, imaging and laboratory characteristics, and treatment outcomes of acromegaly patients who have bihormonal (BA) growth hormone (GH) and prolactin (PRL) immunoreactive adenomas compared to patients who have densely granulated GH adenomas (DGA) and sparsely granulated GH adenomas (SGA). METHODS: Retrospective review of single-center surgically treated acromegaly patients; pathology was analyzed by a single neuropathologist using 2017 WHO criteria. Preoperative magnetic resonance imaging was assessed to evaluate tumor size, cystic component, invasion and T2 signal intensity. RESULTS: Seventy-seven patients; 19 BA (9 mammosomatotroph and 10 mixed GH and PRL adenomas) were compared with 30 DGA, and 28 SGA. Patients with BA were older than SGA (49.6 vs 38.5 years, p = 0.035), had a higher IGF-1 index (3.3 vs 2.3, p = 0.040) and tumors were less frequently invasive (15.8% vs 57.1%, p = 0.005). BA more frequently had a cystic component on MRI than both SGA and DGA (52.6% vs 14.3%, and 22%, p = 0.005 and 0.033, respectively). When all histological types were combined, biochemical remission postoperatively was more common in non-cystic than cystic tumors (50% vs 22.5%, p = 0.042). Somatostatin receptor ligand response rate was 66.7%, 90.9% and 37.5% in BA, DGA and SGA patients, respectively (p = 0.053). CONCLUSION: Imaging characteristics are an increasingly important adenoma behavior determinant. An adenoma cystic component may suggest that a GH adenoma is a BA. Cystic tumors exhibited lower rates of surgical remission in this series; therefore, optimized individual patient treatment is needed, as patients could be candidates for primary medical treatment.


Assuntos
Acromegalia/diagnóstico por imagem , Acromegalia/metabolismo , Hormônio do Crescimento Humano/metabolismo , Imageamento por Ressonância Magnética/métodos , Prolactina/metabolismo , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Hipófise , Neoplasias Hipofisárias
12.
Sci Total Environ ; 746: 141305, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32771762

RESUMO

In this review, we present the state of art regarding rhizosphere effects on eucalypt plantations. It provides a greater understanding of carbon (C) and nitrogen (N) turnover in forest soils. P organic hydrolysis, soil mineral solubilization, indoleacetic acid, gibberellin, resistance factors, and production of siderophores by rhizosphere microbial populations help to explain the tolerance of Eucalyptus plants to biotic and abiotic stresses and the apparent steady-state condition of C and N soil stocks in many planted forests. This work aims to present the main findings on Eucalyptus rhizosphere processes and highlights their importance for trees nutrition, especially for N mineralization triggered by microbial activation or microbial community structure changes regarding the so-called rhizosphere priming effect and N fixation. Furthermore, we present an explanatory conceptual model of the steady-state condition for soil organic matter (SOM) stocks and its relation with fertilization based on a nutrient balance model. This review also considers the main experimental and modeling studies that demonstrate the quantitative importance of rhizosphere processes to Eucalyptus genus and their shortcomings. This provides a framework for process modeling under scenarios of global climate change. A better understanding of rhizosphere microbiological processes may allow improvements in Eucalyptus nutrition and production, as well as in accurate long-term estimates of SOM stocks and C-CO2 exchanges between forest soils and the atmosphere.


Assuntos
Florestas , Rizosfera , Carbono , Nitrogênio , Solo , Microbiologia do Solo , Árvores
13.
Biotechnol Lett ; 42(6): 885-904, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32246346

RESUMO

The study of the epigenetic regulation of gene function has reached pivotal importance in life sciences in the last decades. The mechanisms and effects of processes such as DNA methylation, histone posttranslational modifications and non-coding RNAs, as well as their impact on chromatin structure and dynamics, are clearly involved in physiology homeostasis in plants, animals and microorganisms. In the fungal kingdom, studies on the model yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe contributed enormously to the elucidation of the eukaryote epigenetic landscape. Epigenetic regulation plays a central role in the expression of virulence attributes of human pathogens such as Candida albicans. In this article, we review the most recent studies on the effects of drugs capable of altering epigenetic states and on the impact of chromatin structure-related genes deletion in filamentous fungi. Emphasis is given on plant and insect pathogens, endophytes, secondary metabolites and cellulases/xylanases producing species.


Assuntos
Epigênese Genética , Fungos , Regulação Fúngica da Expressão Gênica , Biotecnologia , Candida albicans , Deleção de Genes , Inibidores de Histona Desacetilases
14.
Microorganisms ; 7(9)2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31466214

RESUMO

Hyaluronic Acid (HA) is a biopolymer composed by the monomers Glucuronic Acid (GlcUA) and N-Acetyl Glucosamine (GlcNAc). It has a broad range of applications in the field of medicine, being marketed between USD 1000-5000/kg. Its primary sources include extraction of animal tissue and fermentation using pathogenic bacteria. However, in both cases, extensive purification protocols are required to prevent toxin contamination. In this study, aiming at creating a safe HA producing microorganism, the generally regarded as safe (GRAS) yeast Kluyveroymyces lactis is utilized. Initially, the hasB (UDP-Glucose dehydrogenase) gene from Xenopus laevis (xlhasB) is inserted. After that, four strains are constructed harboring different hasA (HA Synthase) genes, three of humans (hshasA1, hshasA2, and hshasA3) and one with the bacteria Pasteurella multocida (pmhasA). Transcript values analysis confirms the presence of hasA genes only in three strains. HA production is verified by scanning electron microscopy in the strain containing the pmHAS isoform. The pmHAS strain is grown in a 1.3 l bioreactor operating in a batch mode, the maximum HA levels are 1.89 g/L with a molecular weight of 2.097 MDa. This is the first study that reports HA production in K. lactis and it has the highest HA titers reported among yeast.

15.
Artigo em Inglês | MEDLINE | ID: mdl-31119131

RESUMO

The methylotrophic yeast Hansenula polymorpha, known as a non-conventional yeast, is used for the last 30 years for the production of recombinant proteins, including enzymes, vaccines, and biopharmaceuticals. Although a large number of reviews have been published elucidating the applications of this yeast as a cell factory, the latest was released about 10 years ago. Therefore, this review aimed at summarizing available information on the use of H. polymorpha as a host for recombinant protein production in the last decade. Examples of chemicals and virus-like particles produced using this yeast also are discussed. Firstly, the aspects that feature this yeast as a host for recombinant protein production are highlighted including the techniques available for its genetic manipulation as well as strategies for cultivation in bioreactors. Special attention is given to the novel genomic editing tools, mainly CRISPR/Cas9 that was recently established in this yeast. Finally, recent examples of using H. polymorpha as an expression platform are presented and discussed. The production of human Parathyroid Hormone (PTH) and Staphylokinase (SAK) in H. polymorpha are described as case studies for process establishment in this yeast. Altogether, this review is a guideline for this yeast utilization as an expression platform bringing a thorough analysis of the genetic aspects and fermentation protocols used up to date, thus encouraging the production of novel biomolecules in H. polymorpha.

16.
J. bras. nefrol ; 40(3): 266-272, July-Sept. 2018. tab
Artigo em Inglês | LILACS | ID: biblio-975906

RESUMO

ABSTRACT Introduction: The incidence of gastrointestinal disorders among patients with chronic kidney disease (CKD) is high, despite the lack of a good correlation between endoscopic findings and symptoms. Many services thus perform upper gastrointestinal (UGI) endoscopy on kidney transplant candidates. Objectives: This study aims to describe the alterations seen on the upper endoscopies of 96 kidney-transplant candidates seen from 2014 to 2015. Methods: Ninety-six CKD patients underwent upper endoscopic examination as part of the preparation to receive kidney grafts. The data collected from the patients' medical records were charted on Microsoft Office Excel 2016 and presented descriptively. Mean values, medians, interquartile ranges and 95% confidence intervals of the clinic and epidemiological variables were calculated. Possible associations between endoscopic findings and infection by H. pylori were studied. Results: Males accounted for 54.17% of the 96 patients included in the study. Median age and time on dialysis were 50 years and 50 months, respectively. The most frequent upper endoscopy finding was enanthematous pangastritis (57.30%), followed by erosive esophagitis (30.20%). Gastric intestinal metaplasia and peptic ulcer were found in 8.33% and 7.30% of the patients, respectively. H. pylori tests were positive in 49 patients, and H. pylori infection was correlated only with non-erosive esophagitis (P = 0.046). Conclusion: Abnormal upper endoscopy findings were detected in all studied patients. This study suggested that upper endoscopy is a valid procedure for kidney transplant candidates. However, prospective studies are needed to shed more light on this matter.


RESUMO Introdução: A incidência de doenças gastrointestinais altas em pacientes com doença renal crônica é elevada, porém não há boa correlação entre achados endoscópicos e sintomas. Assim, muitos serviços preconizam a realização de Endoscopia Digestiva Alta (EDA) nos candidatos a transplante renal. Objetivos: Descrever alterações endoscópicas presentes em 96 candidatos a transplante renal no período de 2014 a 2015. Métodos: Noventa e seis pacientes renais crônicos submetidos à EDA como preparo para transplante renal. Prontuários médicos dos pacientes foram revisados, os dados tabulados no programa Microsoft Office Excel 2016 e apresentados de maneira descritiva. Calculou-se média, mediana, intervalo interquartílico e intervalo de confiança de 95% das variáveis utilizadas. Alterações endoscópicas foram apresentadas quanto ao número, intervalo de confiança e valor de P, e correlacionadas com a presença ou ausência de infecção por Helicobacter pylori. Resultados: Dos 96 pacientes, 54,17% eram homens e 45,83% mulheres. As medianas de idade e tempo em diálise foram 50 anos e 50 meses, respectivamente. O achado mais comum na EDA foi pangastrite enantematosa (57,30%), seguida de esofagite erosiva (30,20%). Metaplasia intestinal gástrica e úlcera péptica foram encontradas em 8,33% e 7,30% dos pacientes, respectivamente. Pesquisa para H. pylori foi positiva em 49 pacientes, e somente houve correlação entre infecção por H. pylori e esofagite não erosiva (P = 0,046). Conclusão: Afecções gastrointestinais foram detectadas em todos os pacientes estudados. Os achados deste estudo sugerem que a realização de EDA em candidatos a receber transplante renal é desejável. Entretanto, estudos prospectivos são necessários para responder a esta questão.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Gastropatias/etiologia , Duodenopatias/etiologia , Doenças do Esôfago/etiologia , Insuficiência Renal Crônica/complicações , Gastropatias/diagnóstico , Estudos Transversais , Endoscopia Gastrointestinal , Transplante de Rim , Duodenopatias/diagnóstico , Doenças do Esôfago/diagnóstico , Insuficiência Renal Crônica/cirurgia
17.
J Bras Nefrol ; 40(3): 266-272, 2018.
Artigo em Inglês, Português | MEDLINE | ID: mdl-29771269

RESUMO

INTRODUCTION: The incidence of gastrointestinal disorders among patients with chronic kidney disease (CKD) is high, despite the lack of a good correlation between endoscopic findings and symptoms. Many services thus perform upper gastrointestinal (UGI) endoscopy on kidney transplant candidates. OBJECTIVES: This study aims to describe the alterations seen on the upper endoscopies of 96 kidney-transplant candidates seen from 2014 to 2015. METHODS: Ninety-six CKD patients underwent upper endoscopic examination as part of the preparation to receive kidney grafts. The data collected from the patients' medical records were charted on Microsoft Office Excel 2016 and presented descriptively. Mean values, medians, interquartile ranges and 95% confidence intervals of the clinic and epidemiological variables were calculated. Possible associations between endoscopic findings and infection by H. pylori were studied. RESULTS: Males accounted for 54.17% of the 96 patients included in the study. Median age and time on dialysis were 50 years and 50 months, respectively. The most frequent upper endoscopy finding was enanthematous pangastritis (57.30%), followed by erosive esophagitis (30.20%). Gastric intestinal metaplasia and peptic ulcer were found in 8.33% and 7.30% of the patients, respectively. H. pylori tests were positive in 49 patients, and H. pylori infection was correlated only with non-erosive esophagitis (P = 0.046). CONCLUSION: Abnormal upper endoscopy findings were detected in all studied patients. This study suggested that upper endoscopy is a valid procedure for kidney transplant candidates. However, prospective studies are needed to shed more light on this matter.


Assuntos
Duodenopatias/etiologia , Doenças do Esôfago/etiologia , Insuficiência Renal Crônica/complicações , Gastropatias/etiologia , Adulto , Estudos Transversais , Duodenopatias/diagnóstico , Endoscopia Gastrointestinal , Doenças do Esôfago/diagnóstico , Feminino , Humanos , Transplante de Rim , Masculino , Pessoa de Meia-Idade , Insuficiência Renal Crônica/cirurgia , Gastropatias/diagnóstico
18.
Radiology ; 286(1): 122-128, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28873045

RESUMO

Purpose To determine whether gadolinium remains in juvenile nonhuman primate tissue after maternal exposure to intravenous gadoteridol during pregnancy. Materials and Methods Gravid rhesus macaques and their offspring (n = 10) were maintained, as approved by the institutional animal care and utilization committee. They were prospectively studied as part of a pre-existing ongoing research protocol to evaluate the effects of maternal malnutrition on placental and fetal development. On gestational days 85 and 135, they underwent placental magnetic resonance imaging after intravenous gadoteridol administration. Amniocentesis was performed on day 135 prior to administration of the second dose of gadoteridol. After delivery, the offspring were followed for 7 months. Tissue samples from eight different organs and from blood were harvested from each juvenile macaque. Gadolinium levels were measured by using inductively coupled plasma mass spectrometry. Results Gadolinium concentration in the amniotic fluid was 0.028 × 10-5 %ID/g (percentage injected dose per gram of tissue) 50 days after administration of one gadoteridol dose. Gadolinium was most consistently detected in the femur (mean, 2.5 × 10-5 %ID/g; range, [0.81-4.1] × 10-5 %ID/g) and liver (mean, 0.15 × 10-5 %ID/g; range, [0-0.26] × 10-5 %ID/g). Levels were undetectable in the remaining sampled tissues, with the exception of one juvenile skin sample (0.07 × 10-5 %ID/g), one juvenile spleen sample (0.039 × 10-5 %ID/g), and one juvenile brain (0.095 × 10-5 %ID/g) and kidney (0.13 × 10-5 %ID/g) sample. Conclusion The presence of gadoteridol in the amniotic fluid after maternal injection enables confirmation that it crosses the placenta. Extremely low levels of gadolinium are found in juvenile macaque tissues after in utero exposure to two doses of gadoteridol, indicating that a very small amount of gadolinium persists after delivery. © RSNA, 2017.


Assuntos
Meios de Contraste/farmacocinética , Compostos Heterocíclicos/farmacocinética , Exposição Materna , Compostos Organometálicos/farmacocinética , Líquido Amniótico/química , Animais , Meios de Contraste/efeitos adversos , Feminino , Gadolínio/efeitos adversos , Gadolínio/farmacocinética , Compostos Heterocíclicos/efeitos adversos , Macaca mulatta , Imageamento por Ressonância Magnética/métodos , Compostos Organometálicos/efeitos adversos , Gravidez , Distribuição Tecidual
19.
J Basic Microbiol ; 58(2): 144-153, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29193198

RESUMO

Humicola grisea var. thermoidea (Hgvt) is a thermophilic ascomycete that produces lignocellulolytic enzymes and it is proposed for the conversion of agricultural residues into useful byproducts. Drugs that inhibit the DNA methyltransferases (DNMTs) activity are employed in epigenetic studies but nothing is known about a possible effect on the production of fungal enzymes. We evaluated the effect of 5-aza-2'-deoxycytidine (5-Aza; a chemical inhibitor of DNMTs activity) on the secreted enzyme activity and on the transcription of cellulase and xylanase genes from Hgvt grown in agricultural residues and in glucose. Upon cultivation on wheat bran (WB), the drug provoked an increase in the xylanase activity at 96 h. When Hgvt was grown in glucose (GLU), a repressor of Hgvt glycosyl hydrolase genes, 5-Aza led to increased transcript accumulation for the cellobiohydrolases and for the xyn2 xylanase genes. In WB, 5-Aza enhanced the expression of the transcription factor CreA gene. Growth on WB or GLU, in presence of 5-Aza, led to a significant increase in transcripts of the pH-response regulator PacC gene. To our knowledge, this is the first report on the effect of a DNMT inhibitor in the production of fungal plant cell wall degradation enzymes.


Assuntos
Azacitidina/análogos & derivados , Repressão Catabólica/efeitos dos fármacos , Celulase/biossíntese , Inibidores Enzimáticos/metabolismo , Enzimas/metabolismo , Sordariales/efeitos dos fármacos , Xilosidases/biossíntese , Azacitidina/metabolismo , Decitabina , Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Sordariales/crescimento & desenvolvimento , Triticum/metabolismo , Triticum/microbiologia
20.
Magn Reson Med ; 80(1): 224-230, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29205477

RESUMO

PURPOSE: Delayed ferumoxytol enhancement on T1 -weighted images appears visually similar to gadoteridol enhancement. The purpose of this study was to quantitatively compare ferumoxytol T1 enhancement to gadoteridol enhancement with an objective, semi-automated method. METHODS: 206 sets of post-gadoteridol and 24 h post-ferumoxytol T1 -weighted scans from 58 high grade glioma patients were analyzed (9 pre-chemoradiation, 111 < 90 days post-chemoradiation, 21 > 90 days post-chemoradiation, 65 post-bevacizumab scans). Enhancement volumes and signal intensities normalized to normal appearing tissue proximal to enhancement were calculated with a semi-automated method. Enhancement cube root volumes (D) and signal intensities (SI) were compared between the 2 contrast agents, and relative difference of D and SI were compared in different treatment groups with multivariate analysis. Within patient differences in D and SI before and after treatment with bevacizumab or steroid were assessed in 26 patients in each treatment group. RESULTS: When compared to gadoteridol, ferumoxytol D was 13.83% smaller and SI was 7.24% lower (P < 0.0001). The relative differences in D and SI between the 2 contrast agents were not significantly different between treatment groups (P > 0.05). Relative difference in D and SI did not change significantly in response to bevacizumab (P = 0.5234 and P = 0.2442, respectively) or to steroid (P = 0.3774, P = 0.0741) in the within patient comparison. CONCLUSION: The correlation between the 2 contrast agents' enhancement size and signal intensity and their similar behavior in response to therapy suggest that ferumoxytol can be used for revealing enhancement in high grade glioma patients. Magn Reson Med 80:224-230, 2018. © 2017 International Society for Magnetic Resonance in Medicine.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Meios de Contraste/química , Óxido Ferroso-Férrico/química , Glioma/diagnóstico por imagem , Compostos Heterocíclicos/química , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética , Compostos Organometálicos/química , Adulto , Bevacizumab , Quimiorradioterapia , Feminino , Gadolínio/química , Humanos , Aumento da Imagem/métodos , Masculino , Pessoa de Meia-Idade , Reconhecimento Automatizado de Padrão
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...