Orientador: Marney Pascoli Cereda / Resumo: Durante o processamento de raízes de mandioca para a produção de farinha e fécula, são geradas grandes quantidades de resíduos, dentre os quais destacam-se a manipueira como água proveniente da prensa da massa de mandioca ralada para a produção de farinha ou água residual de fecularia, neste caso a manipueira diluída com água de extração. A linamarina é um b-glicosídeo de acetona cianidrina e etil-metil-cetona cianidrina, presente em todas as células da planta de mandioca. A clivagem deste glicosídeo, em decorrência da lise das paredes celulares da planta, dá início à cianogênese, ou seja, a produção de ácido cianídrico. A linamarina é solúvel em água, sendo carreada juntamente com os efluentes líquidos, gerando problemas tanto ambientais quanto econômicos, no que se refere à disposição final e aproveitamento dos mesmos como sub-produtos do processamento de mandioca. Na literatura há relatos sobre a habilidade de microrganismos a metabolizar a linamarina, como única fonte de carbono e energia. O presente estudo teve por objetivo o isolamento, seleção e identificação de microrganismos aeróbios, provenientes de amostras de manipueira e solo aos arredores de lagoas destinadas à decantação destes efluentes, avaliando-os quanto ao metabolismo de linamarina "in vitro", visando o emprego das linhagens selecionadas em estudos futuros de biorremediação dos resíduos. Das amostras foram isoladas 118 culturas, das quais 66 caracterizaram-se como morfotipos bacterianos e 52 como leveduras. Dentre estes microrganismos, 31 morfotipos, sendo 26 bactérias e 5 por leveduras, escolhidos aleatoriamente, foram avaliados em meio mínimo contendo linamarina como única fonte de carbono e energia...( Resumo completo, clicar acesso eletrônico abaixo). / Abstract: During the processing of cassava roots to produce flour and starch, residues are generated, where stand out the liquid effluents. The linamarin is a ß-glucoside of aceton cyanidrin and ethyl-methyl-ceton cyanidrin, it is present in all cassava plant. The cyanoglucoside broke begins the cyanogenese, thus producing cyanidric acid. The linamarin is soluble in water, and it is carried with the liquid effluents, and it generates ambiental and economics problems. The literature describe some microorganisms ability to metabolite linamarin. The present work aims the isolament, the selection and the identification of aerobies microorganisms from cassava liquid effluents and from adjacent soils samples of stabilization lagoons. Microbial cultures isolated have been available for linamarin "in vitro" metabolism. 118 strains are isolated, that 66 was characterized as bacteria and 52 as yeasts. 31 morfotypes were selected, choosed by chance, in minimum medium (MM), with linamarin as only carbon and energy source. Eight strains were selected ( seven bacterias and one yeast). The bacterias were identified by phylogenetic analyses, as three strains of Serratia marcescens, two strains of Bacillus, one strain of Acinetobacter johnnsonii, and one microbial culture of Proteobacteria group. The last one was not yet identified by literature. The yeast have been characterized by conventional taxonomy as Rhodotorulla glutinis...(Complete abstract, click electronic address below). / Mestre

Made available in DSpace on 2014-10-09T12:49:20Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:02:35Z (GMT). No. of bitstreams: 1 09998.pdf: 7978978 bytes, checksum: 0d05419d6a29044ea66445399e3ae075 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

No description available.

No description available.

Mycotoxins are toxic secondary metabolites produced by fungi that are a threat to the health of humans and domestic animals. The most important mycotoxin in the U.S. is deoxynivalenol (DON), which causes symptoms such as vomiting, feed refusal, and weight loss in farm animals. The fungus Fusarium graminearum produces DON in staple crops such as wheat, barley, and corn. It is estimated that the economic losses associated with DON contamination alone exceed $650 million per year in the U.S. New strategies are needed to mitigate DON and improve food safety in the U.S. The overall goal of my research is to discover and employ microorganisms and enzymes to detoxify DON. The specific objectives are to: (1) discover and characterize microorganisms that detoxify DON, (2) use a cell free protein synthesis (CFPS) system to study enzymes that modify DON, (3) engineer yeast to detoxify DON with a metabolic engineering strategy, and (4) deliver a high school unit to teach high school students about mycotoxins in food. In Objective 1, two mixed cultures were identified from environmental samples that converted DON into the less toxic 3-keto-deoxynivalenol (3-keto-DON). In Objective 2, a CFPS system was used to express three known acetyltransferase genes to convert DON to 3-acetyl-DON (3-A-DON). In Objective 3, we identified a potential DON transporter from a library of randomly amplified fragments from the genomes of mixed cultures of microbes isolated from the environment. In Objective 4, we developed and delivered a unique high school unit to educate high school students about potential mycotoxins in food and feed products. The work presented here represents new and improved methods for mitigating mycotoxin contamination in the United States. / Ph. D. / Some fungi produce dangerous toxins called mycotoxins that contaminate food and feed and cause adverse affects when consumed. The mycotoxin deoxynivalenol (DON) contaminates staple crops such as wheat, barley, and corn and when consumed by domesticated animals it can cause weight loss, feed refusal, vomiting, and even death. The goal of this research is to detoxify DON using miroorganisms such as bacteria or fungi as well as enzymes. The specific objectives are to: (1) discover and characterize microorganisms that detoxify DON, (2) utilize a cell free protein synthesis (CFPS) system to detoxify DON using known acetyltransferase genes, (3) engineer yeast to detoxify DON with a metabolic engineering strategy, and (4) deliver a high school unit to teach high school students about mycotoxins in food and strategies to mitigate them. For objective one, microorganisms were collected from plant and soil samples and incubated in solution containing 100 ppm DON. Two mixed cultures were discovered to convert DON to another metabolite, 3-keto-DON that is considered less toxic. In objective two, a cell free protein synthesis (CFPS) system was used to establish its functionality as a tool to screen for enzymes that will detoxify DON. Known acetyltransferase genes were expressed in the CFPS and DON was converted to the metabolite 3-acetyl-DON. The mixed cultures discovered in objective one were then utilized in objective three to determine what enzymes were responsible for the conversion of DON to 3-keto-DON. Objective four was established to shed light about the dangers of mycotoxins and how growers and scientists test for mycotoxins in food and feed.

Safeners protect crops by enhancing their ability to metabolize various compounds, including herbicides. They primarily work by increasing the crop's tolerance to herbicide damage, activating herbicide-metabolizing proteins, and aiding in their detoxification. This study aimed to investigate the chemical effects of safeners in tomato cultivation and focus on injury reduction and tissue protection. The experiment followed a randomized factorial design (5x4) with four replications repeated twice. We evaluated the effects of herbicides (dicamba, 2,4-D, metribuzin, and sulfentrazone at 1/100) and safeners (benoxacor, fenclorim, melatonin, 2,4,6-T, and an untreated control). Safeners were applied to the seeds before sowing, and herbicides were used as a foliar spray 25 days after sowing (DAS). Visual injury was evaluated 7, 14, and 21 days after application (DAA). Biomass measurements were taken 21 DAA. Results showed that preconditioning tomato seeds with 2,4,6-T, melatonin, and fenclorim 7 DAA significantly decreased injury by 25, 25, and 23%, respectively. Moreover, applying melatonin, benoxacor, and 2,4,6-T 21 DAA led to significantly greater dry biomass, which increased by 1.5, 1.42, and 1.44 times, respectively, compared to the control. This research provides valuable insights into the chemical effects of benoxacor, fenclorim, 2,4,6-T, and melatonin safeners in tomato cultivation. The findings demonstrate the potential for preconditional tomato plants with 2,4,6-T, melatonin, and fenclorim to reduce injury while applying melatonin, benoxacor, and 2,4,6-T can increase dry biomass. Understanding plant defense mechanisms and the protective effects of safeners against herbicide damage contributes to developing effective weed management strategies.

Thesis (M.S.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / Objectives: (1) To examine whether homelessness predicted earlier resumption of substance use after inpatient detoxification; and (2) to seek evidence concerning the impact of post-detoxification stabilization programs on homeless and housed persons in relation to recurrent substance use. Data Sources/Study Setting: Prospective six-month cohort of 470 addicted persons entering a publicly-funded urban detoxification program. Study Design: Survival analysis methods were used to determine the association between homelessness, stabilization program use, and time to recurrent substance use. Data Collection/Extraction Methods: The main analyses rely on baseline and six month interviews using standardized instruments. Additional analyses include interviews obtained after six months, and statewide administrative records of recurrent detoxification. Principal Findings: Among 254 persons available at six months, 76% reported recurrent substance use. Homeless persons not using stabilization programs experienced the greatest hazard of return to substance use after detoxification, Hazard Ratio (HR) 1.26, 95% CI (0.88,1.80). Homeless persons using these programs had the lowest rate of return to substance use: HR 0.61, 95% CI (0.40,0.94). A similar impact of stabilization programs was not seen among housed subjects. Analyses suggest that subjects available at six months were representative of the entire cohort. Conclusions: Post-detoxification stabilization programs were associated with improved outcomes for homeless addicted persons. / 2999-01-01

No description available.

Die vorliegende Arbeit beschäftigt sich mit zwei verschiedenen Therapieformen des Alkoholentzugs. Es geht um den Vergleich einer rein somatischen, sechs bis siebentätigen Kurzzeitentgiftung einerseits mit der ca. dreiwöchigen Qualifizierten Entgiftung andererseits. Im Verlauf der letzten Jahre belegten zahlreiche Untersuchungen die Überlegenheit der Qualifizierten Entgiftung (QE) gegenüber der Kurzzeitentgiftung (KE). Allerdings gab es bisher kaum Studien, die zeigen, welche Faktoren eine Teilnahme an der QE begünstigen. Ziel der vorliegenden Arbeit war es daher, patienten- und umweltbezogene Merkmale zu untersuchen, die mit der Qualifizierten Entgiftung assoziiert sind. Zu diesem Zweck erfolgte die retrospektive Auswertung der Krankenakten von 155 Patienten (KE: 99, QE: 56). Anhand eines selbsterstellten Auswertungsbogens wurden 55 Items erhoben. Davon gingen 47 in die Auswertung ein und wurden zunächst hinsichtlich ihres Einflusses auf die gewählte Therapieart untersucht. Anschließend wurden diese Items bezüglich geschlechts- und altersspezifischer Unterschiede beleuchtet. Nach Abschluss der univariaten Analyse erfolgte eine multivariate Analyse, um den unabhängigen Einfluss der Variablen zu prüfen. Da die Untersuchung als retrospektive Aktenauswertung erfolgte, sind die Ergebnisse vorsichtig zu interpretieren. Dennoch konnten zahlreiche Erkenntnisse gewonnen werden, die einen differenzierteren Umgang mit den Patienten ermöglichen und langfristig genutzt werden können, um mehr Patienten in die Qualifizierte Entgiftung zu integrieren. Angesichts der Tatsache, dass es bisher kaum Veröffentlichungen gibt, die zeigen, welche Faktoren eine Teilnahme an der QE begünstigen, liefert die vorliegende Arbeit wichtige neue Erkenntnisse, die gegebenenfalls in prospektiven Studien näher untersucht werden sollten. Unsere Daten zeigen deutlich, dass die Teilnehmer der QE häufiger männlich waren, meist geplant zur Aufnahme kamen, besser sozial integriert und häufig fremdmotiviert waren sowie eine größerer Eigenmotivation aufwiesen. Außerdem zeigten sie weniger Alkoholfolgesyndrome und befanden sich zum Zeitpunkt der Aufnahme in einem besseren Gesundheitszustand. Desweiteren fiel auf, dass Frauen nur sehr selten geplant an einer Qualifizierten Entgiftung teilnahmen, sondern meist nur eine Kurzzeitentgiftung im Rahmen akuter alkoholbedingter Komplikationen oder psychiatrischer Begleiterkrankungen absolvierten. Zusammenfassend lässt sich sagen, dass es nur selten gelang, notfallmäßig aufgenommene Patienten, v.a. Frauen, zur QE zu motivieren. Dies könnte u.a. daran liegen, dass eine sechs- bis siebentägige Entgiftung nicht genügt, um eine ausreichende Rückbildung kognitiver Defizite zu erreichen und eine Motivation zur QE herbeizuführen. Außerdem ist es speziell für Frauen schwierig, sich aufgrund ihres Rollenverständnisses und ihrer Biografie in gemischtgeschlechtlichen Gruppen mit der Alkoholabhängigkeit auseinanderzusetzen. Für die Zukunft wäre es daher wünschenswert, den zeitlichen Rahmen für die Entgiftung zu erweitern und mehr Therapien anzubieten, die speziell auf die Bedürfnisse alkoholabhängiger Frauen ausgerichtet sind. In unserer Klinik waren die Ergebnisse der vorliegenden Studie Anlass, den Anteil der weiblichen Therapeuten in der Qualifizierten Entgiftung zu erhöhen. Wir hoffen, dadurch mehr Frauen für die Teilnahme an der QE zu motivieren und traumatische Biografien in einem geschützten Rahmen aufzuarbeiten. Inwieweit dies langfristig zu einer verstärkten Teilnahme weiblicher Alkoholabhängiger an der QE führt, sollte in weiterführenden Studien geprüft werden. Außerdem sollte versucht werden, das soziale Netz der Patienten und insbesondere die niedergelassenen Haus- und Fachärzte noch stärker in das Suchthilfesystem einzubinden, um eine Qualifizierte Entgiftung langfristig und effektiv vorbereiten zu können. Insgesamt bleibt festzuhalten, dass eine Qualifizierte Entgiftung möglichst frühzeitig erfolgen sollte. Sind bereits Alkoholfolgeschäden, kognitive Defizite und soziale Isolation eingetreten, fällt es zunehmend schwerer Patienten in eine QE zu integrieren. / This study deals with two different forms of alcohol detoxification therapy. A “simple” somatic detoxification program (KE), lasting six to seven days, was compared with a qualified detoxification program (QE) having a duration of approximately 3 weeks. In recent years research has shown that qualified detoxification programs are more effective than simple somatic detoxification. However, so far there have been few publications showing which factors cause patients to take part in QE. Consequently, the aim of our study was to examine patient-related and environmental factors that are associated with the assignment to qualified detoxification. We completed a retrospective analysis of 155 patients´ charts (KE: 99, QE: 56). With the help of a self-made questionnaire, 55 items were evaluated, of which 47 were included into statistical analysis. First, their influence on the type of chosen therapy was examined. Then the same items were tested on gender-specific and age-related differences. After finishing the univariate analysis a multivariate analysis was completed to investigate the independent influence of the variables. This study was designed as a retrospective data analysis, and the results should be interpreted critically. Nevertheless useful information could be gained, that allows dealing with the patients in a more differentiated way. This knowledge can be used to increase the number of patients taking part in qualified detoxification. Considering the fact that so far there have been very few publications, examining which factors support assignment to QE, our study provides important new data which should be further examined in prospective studies. Our data clearly shows that participants of qualified detoxification were mostly male and that their admission to hospital was planned in advance. Moreover, they had a good social network, better motivation for therapy, and were motivated more often to take part in therapy by their social network. They showed less negative consequences as a result of drinking and were in a better state of health at the time of admission. Another remarkable aspect was that women hardly ever took part in a planned QE. Mostly they only did a KE during treatment for acute alcohol-related complications or psychiatric comorbidities. Patients who had been admitted to the hospital as an emergency, especially women, rarely could be motivated to take part in QE. One reason might be that the time frame of 6 to 7 days for somatic detoxification might not be long enough to allow patients to recover from cognitive deficits and to motivate them to take part in QE. Another issue is that, due to their social role and personal history, dealing with their addiction is difficult for women, especially in mixed-gender groups. For the future it would be desirable to extend the time frame for somatic detoxification and to offer more programs that specifically deal with problems of female alcoholics. In our clinic, the results of this study caused us to increase the number of female therapists in our qualified detoxification program. This way we hope to motivate more women to take part in QE and to be able to deal with their personal problems in a protected atmosphere. Whether this will increase participation of female alcoholics in QE should be further examined by future studies. The social network of the patient, general practitioners, and outpatient specialists should be better integrated into treatment programs to successfully prepare patients for participation in QE programs. We believe that patients should take part in qualified detoxification programs early in the course of their disease. Once adverse effects of alcohol abuse, cognitive deficits, and social isolation have occurred, it becomes increasingly difficult to integrate patients into QE.

Master of Science / Department of Entomology / Kun Yan Zhu / Cytochrome P450 monooxygenases (P450s) are important enzymes involved in the metabolism of a variety of xenobiotics, including insecticides and plant allelochemicals, and endogenous compounds, including juvenile hormones, ecdysteroids and fatty acids, in insects. Despite rapid advances in revealing various P450 genes in insects, our knowledge on the role of these genes in detoxification of insecticides is very limited. This research was to perform a genome-wide analysis of P450 genes and evaluate the role of selected P450 genes in detoxification of three commonly used pyrethroid insecticides in the yellow fever mosquito (Aedes aegypti). Our genome-wide analysis of revealed 159 P450 genes that can be classified into 18 families and 63 subfamilies. These genes are distributed in four clans, including 11 genes in the CYP2 clan, 80 in the CYP3 clan, 58 in the CYP4 clan and 10 in the mitochondrial CYP clan. The largest families are CYP6, CYP9, CYP4 and CYP325. The intron-exon organization of the genes is very diverse among the gene families, and the highest conservation of gene structures was observed in the CYP6 and CYP9 families predominantly containing single-intron genes. The phylogenetic analysis suggested that the CYP6 and CYP9 families might be derived from a common ancestor. The expression patterns of five transcripts including three individual genes (CYP6AA5, CYP6AL1 and CYP9J32) and two alternative splicing variants (CYP4J16A and CYP4J16B) of CYP4J16 were investigated in various tissues and at different developmental stages of the mosquito. Our results indicated differential expressions of these transcripts in different tissues and at different developmental stages examined. Furthermore, the exposure of the mosquitoes (larvae and adults) to each of three pyrethroid insecticides (permethrin, cypermethrin and deltamethrin) resulted in either down or up-regulation of these transcripts. Functional analyses of the selected P450 transcripts were conducted by using RNA interference (RNAi) followed by insecticide bioassay. RNAi was achieved by feeding mosquito larvae with chitosan/double stranded RNA (dsRNA) nanoparticles or injecting dsRNA to the adults. For the larvae, we obtained relatively low repressions of the P450 transcripts but the repressions were sufficient for carrying out our functional studies. Our study showed increased mortalities by 41.2% to cypermethrin when CYP6AA5 was silenced and 46.0% to permethrin when CYP9J32 was silenced. Similarly, the injection of dsRNAs in adults resulted in significant repressions of the P450 transcripts, and subsequent insecticide exposures led to a 29.3% increase in the adult mortality to cypermethrin when CYP6AA5 was silenced. Our further analysis of the nuclear receptor HR96 in the up-regulation of the P450 genes showed that when HR96 was silenced by RNAi, the up-regulation of CYP4J16B by cypermethrin was reduced by 10.1-fold but silencing HR96 did not affect the up-regulation of other P450 genes examined. These results suggest that HR96 is likely involved in regulating the expression of CYP4J16B in Ae. aegypti. However, different regulatory mechanism (s) may be involved in the up-regulation of other P450 genes examined. Model structure of CYP6AA5 was created by homology modeling and insecticides substrates were docked into the active site of this protein. Our results indicate that all three insecticides can fit into the catalytic pocket. The interaction distances between the heme iron and the putative aromatic hydroxylation site were 9.2, 9.4 and 7.2 Å for permethrin, cypermethrin and deltamethrin, respectively, whereas for aliphatic hydroxylation site these distances were 5.3, 2.8 and 2.9 Å. These results showed that CYP6AA5 may be able to metabolize cypermethrin and deltamethrin preferentially by aliphatic hydroxylation as indicated by the close interaction with the heme iron.