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1.
Transplant Direct ; 9(12): e1555, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37954681

RESUMEN

Background: Although hypothermic oxygenated perfusion (HOPE) improves posttransplant outcomes, setting up machine perfusion programs may be subjected to specific obstacles under different conditions. This study aims to describe the establishment of HOPE in a real-life setting in Brazil. Methods: Extended criteria donors in donation after brain death organs preserved by HOPE were accepted for higher-risk candidates needing expedited transplantation, perceived as those who would benefit most from the technique because of its limited availability. Extended criteria donors was defined by the Eurotransplant criteria. High-risk transplant candidates were characterized by suboptimal surgical conditions related to the recipient or the procedure. Results: Six HOPE-preserved grafts were transplanted from February 2022 to August 2022. The mean donor risk index was 1.7 (SD 0.5). One organ was severely steatotic, and 3 had an anticipated cold ischemia time above 12 h. Recipients' mean model for end-stage liver disease was 28.67 (SD 6.79), with 1 case of retransplant, 1 of refractory ascites, and 1 of acute-on-chronic liver failure. The mean cold ischemia time was 5 h 42 min (SD 82 min), HOPE 6 h 3 min (SD 150 min), and total preservation time 11 h 46 min (SD 184 min). No case had early allograft dysfunction. The mean length of hospital stay was 10 d with 100% graft and patient survival and no ischemic cholangiopathies at a median follow-up of 15 mo (min 12, max 18). Costs and country-specific legal regulations for device utilization were the major hurdles to implementing the program. Conclusion: We presented a pathway to introduce and rationalize the use of HOPE in a scenario of challenging donor-recipient matching with good results. These findings may aid in implementing machine perfusion programs, especially in settings with limited resources or complex transplant logistics.

2.
Pathogens ; 12(7)2023 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-37513765

RESUMEN

Pseudomonas aeruginosa, an opportunistic pathogen causing infections in immunocompromised patients, usually shows pronounced antimicrobial resistance. In recent years, the frequency of carbapenemases in P. aeruginosa has decreased, which allows use of new beta-lactams/combinations in antimicrobial therapy. Therefore, the in vitro evaluation of these drugs in contemporary isolates is warranted. We evaluated the antimicrobial susceptibility and genomic aspects of 119 clinical P. aeruginosa isolates from 24 different hospitals in Brazil in 2021-2022. Identification was performed via MALDI-TOF-MS, and antimicrobial susceptibility was identified through broth microdilution, gradient tests, or disk diffusion. Whole-genome sequencing was carried out using NextSeq equipment. The most active drug was cefiderocol (100%), followed by ceftazidime-avibactam (94.1%), ceftolozane-tazobactam (92.4%), and imipenem-relebactam (81.5%). Imipenem susceptibility was detected in 59 isolates (49.6%), and the most active aminoglycoside was tobramycin, to which 99 (83.2%) isolates were susceptible. Seventy-one different sequence types (STs) were detected, including twelve new STs described herein. The acquired resistance genes blaCTX-M-2 and blaKPC-2 were identified in ten (8.4%) and two (1.7%) isolates, respectively. Several virulence genes (exoSTUY, toxA, aprA, lasA/B, plcH) were also identified. We found that new antimicrobials are effective against the diverse P. aeruginosa population that has been circulating in Brazilian hospitals in recent years.

3.
Artif Organs ; 47(8): 1413-1415, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37357827

RESUMEN

This case report describes the longest reported HOPE treatment ever for an extended criteria donor organ in donation after brain death performed to enable the transplantation of a surgically complex retransplant case. Although further evidence is required, HOPE may facilitate liver retransplantation, expanding the donor organ pool and reducing time constraints on the operation.


Asunto(s)
Trasplante de Hígado , Reoperación , Preservación de Órganos , Hígado , Perfusión , Supervivencia de Injerto
4.
Curr Microbiol ; 79(9): 250, 2022 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-35834136

RESUMEN

Emergence of resistance to classical antimicrobial agents is a public health issue, especially in countries with high antimicrobial consumption rates. Carbapenems have been employed as first-choice option for empirical treatment complicated infections. However, in the last decades, frequency of carbapenemase-producing Gram-negative bacteria has rising, demanding the use of alternative antimicrobial agents. By sequencing the entire genomes with short and long reads technologies, we report the isolation and genomic characterization of a carbapenem-resistant Pseudomonas clinical isolate. The identification based on average nucleotide identity indicates a putative new species into the Pseudomonas putida Group, which carries both the blaBKC-1 and blaVIM-2 carbapenemase genes. The blaBKC-1 was found to be on a transferable IncQ plasmid backbone, whereas blaVIM-2 was found in a new integron, In2126 (intl1∆-blaVIM-2-aacA7-blaVIM-2∆-aacA27-3'CS), described in this study. Our findings indicate that co-occurrence of classes A and B carbapenemase enzymes underscores the evolving emergence of more complex antimicrobial resistance in opportunistic pathogens.


Asunto(s)
Pseudomonas putida , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Proteínas Bacterianas/genética , Brasil , Carbapenémicos/farmacología , Pruebas de Sensibilidad Microbiana , Pseudomonas , Pseudomonas putida/genética , beta-Lactamasas/genética
5.
Transplant Proc ; 54(5): 1329-1332, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35690491

RESUMEN

BACKGROUND: The number of elderly patients who have end-stage liver disease and require liver transplantation has dramatically increased. On the other hand, liver grafts from elderly donors have been offered more frequently for transplantation. The present study aims to analyze the results of liver transplants performed with donors and recipients aged ≥70 years. METHODS: We performed a single-center retrospective study of deceased donors liver transplants that involved recipients aged ≥7070 years or recipients who received grafts from donors aged ≥70 years from 2011 to 2021. A literature review on the results of liver transplantation in elderly recipients was also performed. RESULTS: Thirty septuagenarian recipients were included; their overall 1- and 5-years survival was 80% and 76.6%, respectively. The prevalence of recipients aged ≥70 years in our department was 2.65%. Twenty recipients received grafts form septuagenarian donors; their overall 1- and 5-years survival was 75%. The prevalence of donors aged ≥70 years in our department was 1%. In the literature review, 17 articles were analyzed. The 5-years survival of recipients aged ≥70 years ranged from 47.1% to 78.5%. CONCLUSIONS: Septuagenarian recipients and patients who received grafts from elderly brain-dead donors present adequate overall survival after liver transplantation. Optimized donor-recipient matching is paramount for achieving good outcomes. The combination of high-risk donors with septuagenarian recipients should be avoided as well as using grafts of elderly donors that present others risk factors. Thus, the age of the donor or recipient alone cannot be considered an absolute contraindication for liver transplantation.


Asunto(s)
Trasplante de Hígado , Anciano , Brasil , Supervivencia de Injerto , Humanos , Trasplante de Hígado/métodos , Donadores Vivos , Estudios Retrospectivos , Donantes de Tejidos , Resultado del Tratamiento
6.
Transplant Proc ; 54(5): 1345-1348, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35599202

RESUMEN

INTRODUCTION: Donor hepatic artery thrombosis (dHAT) identified during liver procurement and backtable is a rare and little-reported event that can make liver transplants unfeasible. METHODS: This is a retrospective study of dHAT identified during liver grafts procurements or backtable procedures. All grafts were recovered from brain-dead donors. The demographic characteristics of the donors and the incidence of dHAT were analyzed. The data were also compared to a cohort of donors without dHAT. RESULTS: There was a total of 486 donors during the study period. The incidence of dHAT was 1.85% (n = 9). The diagnosis of dHAT was made during procurement in 5 cases (55.5%) and during the backtable in 4 (44.4%). Most donors were female (n = 5), with an average BMI of 28.14 ± 6.9 kg/m2, hypertensive (n = 5), and with stroke as cause of brain death (n = 8). The most prevalent site of dHAT was a left hepatic artery originating from the left gastric artery (n = 4). Of the 9 cases reported, 2 livers were used for transplantation, and 7 were discarded. Comparing those cases to a cohort of 260 donors without dHAT, we found a higher incidence of anatomic variations in the hepatic artery (P = .01) and of stroke as cause of brain death (P = .05). CONCLUSION: The occurrence of dHAT before liver procurement is a rare event, however it may become a treacherous pitfall if the diagnosis is late. Grafts with anatomic variations recovered from women with brain death due to stroke and with past history of hypertension seem to be at a higher risk of presenting dHAT.


Asunto(s)
Hepatopatías , Trasplante de Hígado , Accidente Cerebrovascular , Trombosis , Obtención de Tejidos y Órganos , Muerte Encefálica , Femenino , Arteria Hepática , Humanos , Incidencia , Hígado/irrigación sanguínea , Trasplante de Hígado/efectos adversos , Trasplante de Hígado/métodos , Masculino , Estudios Retrospectivos , Trombosis/epidemiología , Trombosis/etiología , Donantes de Tejidos
7.
Transplant Proc ; 52(5): 1399-1401, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32276834

RESUMEN

INTRODUCTION: Uterine transplantation (UTx) is a surgical therapeutic modality designed for the treatment of patients with exclusive uterine factor infertility. Experimental models are paramount to study this transplant modality, and as the ewes' uteri are very similar to that of humans, they are frequently used with this purpose. The aim of this study is to describe a novel technical variation for UTx in sheep. METHODS: This study was conducted at Laboratory of Medical Investigation 37 of the University of São Paulo School of Medicine in São Paulo, Brazil, and was approved by the Ethics Committee of Animal Use of the university. We used 3 adult female sheep that weighed approximately 45 kg and were not pregnant. We performed the technique of uterine autotransplantation with a novel technical variation that we called sequential vascularization: first, we performed the right uterine artery and vein anastomoses, after which the uterine graft was vascularized, and then the contralateral vascular anastomoses were performed. CONCLUSION: We described 3 successful uterine autotransplants in sheep models with sequential vascularization. This variation technique will probably allow warm ischemia time in UTx to significantly decrease.


Asunto(s)
Útero/trasplante , Anastomosis Quirúrgica/métodos , Animales , Brasil , Femenino , Humanos , Infertilidad Femenina/cirugía , Ovinos , Trasplante Autólogo , Arteria Uterina/cirugía
8.
Transplant Proc ; 52(5): 1329-1331, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32276836

RESUMEN

INTRODUCTION: Size mismatch between donor and recipients may negatively influence postoperative results of liver transplantation (LT). In deceased donor LT for adults, large grafts are occasionally rejected due to the fear of primary nonfunction. The aim of this study is to assess the feasibility of using large liver grafts in adults undergoing deceased donor LT. METHODS: We performed a retrospective study including adult patients who underwent deceased donor LT at our center between January 2006 and September 2019. Recipients with donors aged less than 18 years and those receiving split-liver grafts were excluded. Graft weight of 1800 grams was the cutoff used to divide patients in 2 groups: group 1 (graft weighing < 1800 g) and group 2 (grafts weighing ≥ 1800 g). RESULTS: A total of 806 patients were included in the study. group 1 and 2 included 722 and 84 recipients, respectively. A larger proportion of male recipients was obseved in group 2: 64.8% vs 76.2% (P = .0037). Mean graft weight in group 1 and 2 was, respectively, 1348 ± 231.81 g and 1986.57 ± 165.51 g (P < .001), which resulted in significantly higher graft weight/recipient weight ratio and graft weight/standard liver volume ratio in group 2. In group 2, there were 9 (10.71%) patients with portal vein thrombosis as well as 24 patients (28.5%) with bulky ascites and 44 grafts (52.3%) with steatosis. Primary closure of the abdominal wall was not possible in 5 patients (5.9%) from this group. Primary nonfunction was diagnosed in 14 cases (16.6%), with liver retransplantation being performed in 6 of them. Male to female sex combination occurred in 19% of LT in group 2. CONCLUSION: The use of large grafts is feasible; however, proper matching between donor and recipient is paramount, especially taking into consideration graft steatosis, portal vein thrombosis and the presence of bulky ascites.


Asunto(s)
Trasplante de Hígado/métodos , Trasplantes/anatomía & histología , Adulto , Estudios de Factibilidad , Femenino , Supervivencia de Injerto , Humanos , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Estudios Retrospectivos , Donantes de Tejidos
9.
Prosthes. Esthet. Sci ; 7(26): 72-78, 20180100.
Artículo en Portugués | LILACS, BBO - Odontología | ID: biblio-885184

RESUMEN

Atualmente, com o domínio tecnológico das técnicas reabilitadoras, a prevenção ao máximo das estruturas dentárias e um adequado diagnóstico são de extrema importância para as tomadas de decisões. As reabilitações protéticas são uma excelente alternativa para os tratamentos de reposição e estética do sorriso. O desenvolvimento de um plano de tratamento apropriado e uma excelência na estética farão com que o paciente adquira trabalhos cerâmicos altamente precisos e estéticos. Assim, estes tratamentos reabilitadores associados ao condicionamento das estruturas envolvidas e as excelentes propriedades química e física dos compostos fazem com que os resultados sejam fantásticos. O presente trabalho tem como objetivo realizar um estudo com base na literatura sobre os sistemas cerâmicos e suas propriedades, confrontando-as e discutindo qual tratamento atende melhor as necessidades estéticas do paciente. Podemos concluir que o cirurgião-dentista juntamente com paciente irão estabelecer a melhor opção de tratamento reabilitador estético, sabendo que existem atualmente no mercado materiais odontológicos e tratamentos minimamente invasivos que viabilizam um tratamento altamente estético, funcional e biológico.


Currently, with the technological know-how of rehabilitation techniques, the prevention of dental structures and an adequate diagnosis are extremely important for decision making. Prosthetic rehabilitations are an excellent treatment alternative for repositioning and smile aesthetic. A correct treatment plan development and smile aesthetic excellence will enable the patient to obtain accurate and precise ceramic work. Thus, these rehabilitative treatments associated to the conditioning of the structures involved and the excellent chemical and physical properties of the compounds will bring fantastic results. The aim of this study is to conduct a study based on the literature about ceramic systems and their properties, comparing them and discussing which treatment best meets the patient aesthetic need. We can conclude that the dental surgeon, together with the patient, will establish the best aesthetic rehabilitative treatment option, knowing that there are currently in the market dental materials and minimally invasive treatments which enable a highly aesthetic, functional and biological treatment.


Asunto(s)
Humanos , Cerámica , Materiales Dentales , Porcelana Dental , Estética Dental , Rehabilitación Bucal/métodos
10.
Movimento (Porto Alegre) ; 21(3): 831-845, 2015. tab, graf
Artículo en Portugués | LILACS | ID: biblio-834953

RESUMEN

O objetivo do trabalho é analisar tendências da pesquisa em Educação Física Escolar no Brasil. Desenvolveu-se revisão sistemática em periódicos nacionais, de 2006 a 2012. A produção dessa área representa apenas 16,20% do total de artigos publicados. Entre os delineamentos, pesquisas bibliográficas e de campo se destacaram. Os estudos de enfoque diagnóstico se sobressaíram. Observa-se ainda uma tendência de crescimento em estudos de intervenção pedagógica, tal como no cenário internacional. Considerando a relevância social da Educação Física Escolar, faz-se necessário fomentar políticas de pesquisa e pós-graduação que atendam às especificidades da área.


This study aims at assessing research trends on school physical education in Brazil. A systematic review was conducted in national journals published from 2006 to 2012. Production in the field represents only 16.20% of the total of articles published, and bibliographic and field research stood out. Diagnostic studies were prominent. There is also an increasing trend in pedagogical intervention studies, as well as in the international scenario. Considering the social relevance of school Physical Education, it is necessary to foster research and graduate policies that meet the specifics of that field.


El objetivo de este trabajo es analizar tendencias en la investigación en Educación Física escolar en Brasil. Fue realizada una revisión sistemática en publicaciones científicas nacionales entre 2006 y 2012. La producción en el área representa sólo un 16,20% del total de artículos publicados. Destacaron las investigaciones bibliográficas y de campo. Los estudios con enfoque diagnóstico también tuvieron destaque. Además, se observa una tendencia de crecimiento en estudios de intervención pedagógica, tal como ocurre en el escenario internacional. Considerando la importancia social de la Educación Física escolar, se hace necesario fomentar políticas de investigación y posgrado centradas en las especificidades del área.


Asunto(s)
Humanos , Brasil , Conocimiento , Educación y Entrenamiento Físico
12.
Biotechnol Biofuels ; 7(1): 10, 2014 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-24438499

RESUMEN

BACKGROUND: The search for promising and renewable sources of carbohydrates for the production of biofuels and other biorenewables has been stimulated by an increase in global energy demand in the face of growing concern over greenhouse gas emissions and fuel security. In particular, interest has focused on non-food lignocellulosic biomass as a potential source of abundant and sustainable feedstock for biorefineries. Here we investigate the potential of three Brazilian grasses (Panicum maximum, Pennisetum purpureum and Brachiaria brizantha), as well as bark residues from the harvesting of two commercial Eucalyptus clones (E. grandis and E. grandis x urophylla) for biofuel production, and compare these to sugarcane bagasse. The effects of hot water, acid, alkaline and sulfite pretreatments (at increasing temperatures) on the chemical composition, morphology and saccharification yields of these different biomass types were evaluated. RESULTS: The average yield (per hectare), availability and general composition of all five biomasses were compared. Compositional analyses indicate a high level of hemicellulose and lignin removal in all grass varieties (including sugarcane bagasse) after acid and alkaline pretreatment with increasing temperatures, whilst the biomasses pretreated with hot water or sulfite showed little variation from the control. For all biomasses, higher cellulose enrichment resulted from treatment with sodium hydroxide at 130°C. At 180°C, a decrease in cellulose content was observed, which is associated with high amorphous cellulose removal and 5-hydroxymethyl-furaldehyde production. Morphological analysis showed the effects of different pretreatments on the biomass surface, revealing a high production of microfibrillated cellulose on grass surfaces, after treatment with 1% sodium hydroxide at 130°C for 30 minutes. This may explain the higher hydrolysis yields resulting from these pretreatments, since these cellulosic nanoparticles can be easily accessed and cleaved by cellulases. CONCLUSION: Our results show the potential of three Brazilian grasses with high productivity yields as valuable sources of carbohydrates for ethanol production and other biomaterials. Sodium hydroxide at 130°C was found to be the most effective pretreatment for enhanced saccharification yields. It was also efficient in the production of microfibrillated cellulose on grass surfaces, thereby revealing their potential as a source of natural fillers used for bionanocomposites production.

14.
Biotechnol Biofuels ; 6(1): 75, 2013 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-23657132

RESUMEN

BACKGROUND: In recent years, the growing demand for biofuels has encouraged the search for different sources of underutilized lignocellulosic feedstocks that are available in sufficient abundance to be used for sustainable biofuel production. Much attention has been focused on biomass from grass. However, large amounts of timber residues such as eucalyptus bark are available and represent a potential source for conversion to bioethanol. In the present paper, we investigate the effects of a delignification process with increasing sodium hydroxide concentrations, preceded or not by diluted acid, on the bark of two eucalyptus clones: Eucalyptus grandis (EG) and the hybrid, E. grandis x urophylla (HGU). The enzymatic digestibility and total cellulose conversion were measured, along with the effect on the composition of the solid and the liquor fractions. Barks were also assessed using Fourier-transform infrared spectroscopy (FTIR), solid-state nuclear magnetic resonance (NMR), X-Ray diffraction, and scanning electron microscopy (SEM). RESULTS: Compositional analysis revealed an increase in the cellulose content, reaching around 81% and 76% of glucose for HGU and EG, respectively, using a two-step treatment with HCl 1%, followed by 4% NaOH. Lignin removal was 84% (HGU) and 79% (EG), while the hemicellulose removal was 95% and 97% for HGU and EG, respectively. However, when we applied a one-step treatment, with 4% NaOH, higher hydrolysis efficiencies were found after 48 h for both clones, reaching almost 100% for HGU and 80% for EG, in spite of the lower lignin and hemicellulose removal. Total cellulose conversion increased from 5% and 7% to around 65% for HGU and 59% for EG. NMR and FTIR provided important insight into the lignin and hemicellulose removal and SEM studies shed light on the cell-wall unstructuring after pretreatment and lignin migration and precipitation on the fibers surface, which explain the different hydrolysis rates found for the clones. CONCLUSION: Our results show that the single step alkaline pretreatment improves the enzymatic digestibility of Eucalyptus bark. Furthermore, the chemical and physical methods combined in this study provide a better comprehension of the pretreatment effects on cell-wall and the factors that influence enzymatic digestibility of this forest residue.

15.
R. Inst. Adolfo Lutz ; 71(2): 237-243, abr.-jun. 2012. tab
Artículo en Inglés | VETINDEX | ID: vti-8371

RESUMEN

Prevalence and antimicrobial susceptibility of Enterococcus spp. were evaluated in 360 frozen unse asoned chicken carcasses samples collected from September 2004 to June 2006 from the retail stores in São Paulo State, Brazil. Enterococcus spp. was isolated from all analyzed samples, and 1,332 strains were identified from them. Among the ten identified species, the predominance of E. faecalis, E. gallinarum, E.casseliflavus and E. faecium was occurred. All of the Enterococci strains showed some degree of resistanceto the nine antimicrobials utilized in the study. The percentages of antimicrobial resistance were: 89.2% for tetracycline, 91.4% for quinupristin-dalfopristin, 83.5% for erythromycin, 65% for ciprofloxacin, 55.4% for chloramphenicol, 6.5% for linezolid, 2.3% for vancomycin, 2.3% for teicoplanin and 0.2% for ampicillin. The occurrence of the high level resistance to amyno glicosides (HLR-A) was detected in 57.4% of the isolates. E. faecalis and E. faecium species, which are considered as important agents in nosocomial infections, showed resistance to eight and seven antibiotics, respectively. (AU)


Asunto(s)
Enterococcus/aislamiento & purificación , Pollos , Antiinfecciosos
16.
Rev. Inst. Adolfo Lutz ; 71(2): 237-243, abr.-jun. 2012. tab
Artículo en Inglés | LILACS, Sec. Est. Saúde SP, SESSP-CTDPROD, Sec. Est. Saúde SP, SESSP-ACVSES, SESSP-IALPROD, Sec. Est. Saúde SP, SESSP-IALACERVO | ID: lil-688222

RESUMEN

Prevalence and antimicrobial susceptibility of Enterococcus spp. were evaluated in 360 frozen unse asoned chicken carcasses samples collected from September 2004 to June 2006 from the retail stores in São Paulo State, Brazil. Enterococcus spp. was isolated from all analyzed samples, and 1,332 strains were identified from them. Among the ten identified species, the predominance of E. faecalis, E. gallinarum, E.casseliflavus and E. faecium was occurred. All of the Enterococci strains showed some degree of resistanceto the nine antimicrobials utilized in the study. The percentages of antimicrobial resistance were: 89.2% for tetracycline, 91.4% for quinupristin-dalfopristin, 83.5% for erythromycin, 65% for ciprofloxacin, 55.4% for chloramphenicol, 6.5% for linezolid, 2.3% for vancomycin, 2.3% for teicoplanin and 0.2% for ampicillin. The occurrence of the high level resistance to amyno glicosides (HLR-A) was detected in 57.4% of the isolates. E. faecalis and E. faecium species, which are considered as important agents in nosocomial infections, showed resistance to eight and seven antibiotics, respectively.


Asunto(s)
Antiinfecciosos , Enterococcus/aislamiento & purificación , Pollos
17.
Biotechnol Biofuels ; 4(1): 54, 2011 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-22122978

RESUMEN

BACKGROUND: In recent years, biorefining of lignocellulosic biomass to produce multi-products such as ethanol and other biomaterials has become a dynamic research area. Pretreatment technologies that fractionate sugarcane bagasse are essential for the successful use of this feedstock in ethanol production. In this paper, we investigate modifications in the morphology and chemical composition of sugarcane bagasse submitted to a two-step treatment, using diluted acid followed by a delignification process with increasing sodium hydroxide concentrations. Detailed chemical and morphological characterization of the samples after each pretreatment condition, studied by high performance liquid chromatography, solid-state nuclear magnetic resonance, diffuse reflectance Fourier transformed infrared spectroscopy and scanning electron microscopy, is reported, together with sample crystallinity and enzymatic digestibility. RESULTS: Chemical composition analysis performed on samples obtained after different pretreatment conditions showed that up to 96% and 85% of hemicellulose and lignin fractions, respectively, were removed by this two-step method when sodium hydroxide concentrations of 1% (m/v) or higher were used. The efficient lignin removal resulted in an enhanced hydrolysis yield reaching values around 100%. Considering the cellulose loss due to the pretreatment (maximum of 30%, depending on the process), the total cellulose conversion increases significantly from 22.0% (value for the untreated bagasse) to 72.4%. The delignification process, with consequent increase in the cellulose to lignin ratio, is also clearly observed by nuclear magnetic resonance and diffuse reflectance Fourier transformed infrared spectroscopy experiments. We also demonstrated that the morphological changes contributing to this remarkable improvement occur as a consequence of lignin removal from the sample. Bagasse unstructuring is favored by the loss of cohesion between neighboring cell walls, as well as by changes in the inner cell wall structure, such as damaging, hole formation and loss of mechanical resistance, facilitating liquid and enzyme access to crystalline cellulose. CONCLUSIONS: The results presented herewith show the efficiency of the proposed method for improving the enzymatic digestibility of sugarcane bagasse and provide understanding of the pretreatment action mechanism. Combining the different techniques applied in this work warranted thorough information about the undergoing morphological and chemical changes and was an efficient approach to understand the morphological effects resulting from sample delignification and its influence on the enhanced hydrolysis results.

18.
Braz. arch. biol. technol ; Braz. arch. biol. technol;54(4): 709-716, July-Aug. 2011. graf, tab
Artículo en Inglés | LILACS | ID: lil-595623

RESUMEN

A study from cows with mastitis was performed and Staphylococcus aureus was the predominant pathogen in 46.4 percent among 153 studied strains from 276 milk samples of infected cows. Antibiotic resistance of 71 S. aureus isolates was determined in order to search resistant strains to antibiotics of clinical interest, as well as to determine their degree of multi-resistance. It was found that 60 percent of the S. aureus strains presented resistance to β-lactams, but none to oxacillin, teicoplamin or vancomycin. On the other hand, with the aim of reducing the use of current antibiotics and their associated resistance, a new formulation was introduced. The antimicrobial compounds (P22-P32), demonstrated to be effective in 55 percent of the 76 mastitis cases studied. The use of P22-P32 reduced the number of somatic cell to less than 300,000 SCC/mL-1 in 75.2 percent of milk samples analyzed, normalizing the milk quality, fat and lactose levels and increasing the volume of production in 10.1 percent.

19.
Am J Infect Control ; 38(5): 406-9, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20006408

RESUMEN

To describe the effect of active surveillance to control vancomycin-resistant enterococci (VRE) after an outbreak, 549 surveillance rectal cultures were performed in 308 patients (35% positive). An educational intervention to prevent transmission was implemented. Infection and colonization by VR- Enterococcus faecalis decreased, but Enterococcus faecium persisted despite control measures. Infections by VR-E faecalis fell to zero in 2008. We observed difficulties in controlling colonization with measures directed mainly by surveillance cultures and differences between responses of E faecium and E faecalis.


Asunto(s)
Brotes de Enfermedades/prevención & control , Enterococcus faecalis/efectos de los fármacos , Enterococcus faecium/efectos de los fármacos , Infecciones por Bacterias Grampositivas/prevención & control , Control de Infecciones/métodos , Resistencia a la Vancomicina , Antibacterianos/farmacología , Desinfección , Enterococcus faecalis/aislamiento & purificación , Enterococcus faecium/aislamiento & purificación , Monitoreo del Ambiente , Monitoreo Epidemiológico , Heces/microbiología , Infecciones por Bacterias Grampositivas/epidemiología , Infecciones por Bacterias Grampositivas/transmisión , Desinfección de las Manos , Hospitales Públicos , Humanos , Pruebas de Sensibilidad Microbiana , Aislamiento de Pacientes , Vigilancia de la Población , Prevención Terciaria , Vancomicina/farmacología
20.
Braz. j. pharm. sci ; 45(4): 677-685, Oct.-Dec. 2009. tab, ilus
Artículo en Inglés | LILACS | ID: lil-543663

RESUMEN

A total of 22 endophytic fungi isolated from coffee (Coffea arabica L.) were cultivated in vitro and their crude extracts tested. The screening was carried out using the agar diffusion method against Staphylococcus aureus, Escherichia coli and Candida albicans. The most effective isolate was Alternaria alternata, and subsequently, its extract was assayed. The total phenolic content was 3.44 μg GAE/mg of the crude extract. For the antibacterial and antifungal activity assays, minimum inhibitory concentrations (MIC) and minimum bactericidal and fungicidal concentrations (MBC and MFC) were determined. The ranges of MIC values were 50-100 μg/mL for S. aureus and 400-800 μg/mL for E. coli. The extract did not show activity in the tested concentrations for C. albicans. The fungal crude extract was assayed for antioxidant activities. Its ability to scavenge DPPH radicals and antioxidant activity by β-carotene/linoleic acid system oxidation was not significant. In addition, antitumor activity was studied using the MTT assay. At a dilution of 400 μg/mL, the extract displayed a cytotoxic activity of approximately 50 percent towards HeLa cells in vitro. The results indicate that endophytic fungi could be a promising source of bioactive compounds and warrant further study.


Total de 22 fungos endofíticos isolados de café (Coffea arabica L.) foi cultivado in vitro e seus extratos testados. A triagem foi conduzida pelo método de difusão em agar contra bactérias Gram-positiva, Gram-negativa e uma levedura. O isolado mais efetivo foi Alternaria alternata e, subsequentemente, seu extrato foi analisado. O conteúdo de fenólicos totais do extrato bruto foi de 3,44 μg EAG/mg de extrato. Para os testes de atividade antimicrobiana, a concentração inibitória mínima (CIM) e concentração bactericida e fungicida mínima (CBM e CFM) contra Staphylococcus aureus, Escherichia coli e Candida albicans foram determinadas. Resultados da CIM variaram entre 50-100 μg/mL para S. aureus e 400-800 μg/mL para E. coli. O extrato bruto não apresentou atividade nas concentrações testadas para C. albicans. Foram analisadas as atividades antioxidantes do extrato bruto. Sua habilidade para seqüestrar radicais DPPH e a atividade antioxidante pela oxidação do sistema β-caroteno/ácido linoléico não foram significativas. Além disso, a atividade antitumoral foi estudada pelo teste do MTT. À diluição de 400 μg/mL, o extrato apresentou atividade de aproximadamente 50 por cento sobre as células HeLa in vitro. Os resultados indicam que fungos endófitos poderiam ser uma fonte promissora de compostos bioativos necessitando de estudos futuros.


Asunto(s)
Alternaria/crecimiento & desarrollo , Alternaria/química , Coffea Cruda/análisis , Fermentación , Antioxidantes/metabolismo , Compuestos Químicos/análisis , Sinergismo Farmacológico
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