Design of a polyepitope construct for the induction of HLA-A0201-restricted HIV 1-specific CTL responses using HLA-A*0201 transgenic, H-2 class IKO mice

HLA-A*0201 transgenic, H-2D(b)/mouse beta2-microglobulin double-knockout mice were used to compare and optimize the immunogenic potential of 17HIV 1-derived, HLA-A0201-restricted epitopic peptides. A tyrosine substitution in position 1 of the epitopic peptides, which increases both their affinity for and their HLA-A0201 molecule stabilizing capacity, was introduced in a significant proportion, having verified that such modifications enhance their immunogenicity in respect of their natural antigenicity. Based on these results, a 13-polyepitope construct was inserted in the pre-S2 segment of the hepatitis B middle glycoprotein and used for DNA immunization. Long-lasting CTL responses against most of the inserted epitopes could be elicited simultaneously in a single animal with cross-recognition in several cases of their most common natural variants.

Ginseng administration protects skeletal muscle from oxidative stress induced by acute exercise in rats

Enzymatic activity was analyzed in the soleus, gastrocnemius (red and white) and plantaris muscles of acutely exercised rats after long-term administration of Panax ginseng extract in order to evaluate the protective role of ginseng against skeletal muscle oxidation. Ginseng extract (3, 10, 100, or 500 mg/kg) was administered orally for three months to male Wistar rats weighing 200 ± 50 g before exercise and to non-exercised rats (N = 8/group). The results showed a membrane stabilizing capacity of the extract since mitochondrial function measured on the basis of citrate synthase and 3-hydroxyacyl-CoA dehydrogenase activities was reduced, on average, by 20% (P < 0.05) after exercise but the activities remained unchanged in animals treated with a ginseng dose of 100 mg/kg. Glutathione status did not show significant changes after exercise or treatment. Lipid peroxidation, measured on the basis of malondialdehyde levels, was significantly higher in all muscles after exercise, and again was reduced by about 74% (P < 0.05) by the use of ginseng extract. The administration of ginseng extract was able to protect muscle from exercise-induced oxidative stress irrespective of fiber type.

Influence Of Additives On The Drain Down Characteristics Of Stone Matrix Asphalt Mixtures

In Kerala highways, where traditional dense graded mixtures are used for the surface courses, major distress is due to moisture induced damages. Development of stabilized Stone Matrix Asphalt (SMA) mixtures for improved pavement performance has been the focus of research all over the world for the past few decades. Many successful attempts are made to stabilize SMA mixtures with synthetic fibres and polymers. India, being an agricultural economy produces fairly huge quantity of natural fibres such as coconut, sisal, banana, sugar cane, jute etc.. Now- a -days the disposal of waste plastics is a major concern for an eco- friendly sustainable environment. This paper focuses on the influence of additives like coir, sisal, banana fibres (natural fibres), waste plastics (waste material) and polypropylene (polymer) on the drain down characteristics of SMA mixtures. A preliminary investigation is conducted to characterize the materials used in this study. Drain down sensitivity tests are conducted to study the bleeding phenomena and drain down of SMA mixtures. Based on the drain down characteristics of the various stabilized mixtures it is inferred that the optimum fibre content is 0.3% by weight of mixture for all fibre mixtures irrespective of the type of fibre. For waste plastics and polypropylene stabilized SMA mixtures, the optimum additive contents are respectively 7% and 5% by weight of mixture. Due to the absorptive nature of fibres, fibre stabilizers are found to be more effective in reducing the drain down of the SMA mixture. The drain values for the waste plastics mix is within the required specification range. The coir fibre additive is the best among the fibres investigated. Sisal and banana fibre mixtures showed almost the same characteristics on stabilization.

Les sHsps en surera: Estudis de funcionalitat

Aquesta tesi es centra en la caracterització funcional d'una proteïna de xoc de calor de baix pes molecular (Small Heat Shock Protein - sHSP) de classe I de surera pel que fa a la seva capacitat per protegir les cèl·lules de l'estrès i per estabilitzar les membranes. Les sHsps són proteïnes que s'expressen en condicions d'estrès cel·lular. Encara que certs aspectes funcionals de les sHsps són ben coneguts, el nostre treball aporta informacions noves sobre el paper de les diferents regions de la proteïna, especialment de la regió N-terminal. L'objectiu concret d'aquest treball és determinar la funció termoprotectora de QsHsp17.4-CI, una sHsp de classe I oobtinguda a partir de les cèl·lules de fel·lema d'alzina surera, en un model bacterià i analitzar la importància de les diferents regions de la proteïna en aquesta funció. Amb aquesta finalitat s'han dissenyat dues proteïnes parcials derivades de QsHsp17.4-CI: una a la que li falta la regió N-terminal (C105) i una altra amb pràcticament tot el domini -cristal·lí deleccionat (N61), i una tercera, derivada de QsHs10-CI, a la que li falta la meitat del domini -cristal·lí (Hsp10). També s'estudia la possible capacitat estabilitzadora de membranes i la capacitat de modificar l'expressió d'altres Hsps quan s'expressa de forma heteròloga. Els nostres resultats demostren que l'expressió de QsHsp17.4-CI protegeix a les cèl·lules d'E.coli de l'estrès tèrmic alhora que la regió N-terminal i la regió consens II del domini -cristal·lí són imprescindibles per aquesta funció de protecció. En relació a un possible paper en les membranes, els estudis de localització subcel·lular mostren que QsHsp17.4-CI colocalitza amb la fracció membranes i que la regió N-terminal de la proteïna és responsable d'aquesta colocalització. No s'ha pogut demostrar, però, que la localització amb la membrana estigui associada a un efecte protector d'aquesta: en cap cas la sobrexpressió de les proteïnes modifica la composició d'àcids grassos i només N61, que no té acció termoprotectora, altera l'estat fisico-químic de la membrana. En estudis d'expressió de novo en E.coli s'ha observat que, a diferència de les altres proteïnes heteròlogues, N61 activa l'expressió de la majoria de Hsps d'E.coli fent pensar en una possible relació entre l'estat físic de la membrana i l'activació de la resposta a l'estrès. En resum, en aquest treball hem provat la capacitat protectora de QsHsp17.4 i aportem noves dades sobre la importància de la regió N-terminal i la regió consens II del domini -cristal·lí en aquesta funció. Per altra banda, es suggereix que QsHsp17.4 podria interaccionar amb la membrana d'E.coli i que la regió N-terminal seria imprescindible per aquesta interacció. Finalment hem determinat que les proteïnes que provoquen variacions en l'estat de fluïdesa de la membrana poden activar la resposta al xoc de calor per part de la cèl·lula bacteriana.

Noves aproximacions a la síntesi i caracterització de poliglicols al·lílics, polihidrosiloxans i surfactants copolimèrics. Avaluació d'aquests surfactants en formulacions de poliuretà

Els polímers són una sèrie de compostos que troben un ampli ventall d'aplicacions en la indústria actual. Un exemple són les espumes de poliuretà, estructures de tipus cel·lular obtingudes mitjançant la reacció química entre compostos de tipus isocianat i compostos de tipus poliol (polièters amb diferent nombre de grups hidroxil). És imprescindible l'ús d'additius d'estructura tensioactiva (surfactants de silicona) per estabilitzar el procés d'espumació i per proporcionar una estructura cel·lular ordenada i homogènia en mida i distribució. La síntesis i caracterització de les molècules precursores (polihidrosiloxans i polièters al·lílics), l'estudi de la reacció d'hidrosililació com a via d'obtenció dels diferents surfactants per reacció d'addició entre els polihidrosiloxans i els polièters al·lílics i la caracterització i avaluació en formulacions comercials de poliuretà dels surfactants sintetitzats han constituït els objectius del present treball. MEMÒRIA La Tesi Doctoral ha estat presentada seguint el següent esquema: CAPÍTOL I. INTRODUCCIÓ A LA QUÍMICA DEL POLIURETÀ. Es presenten els principis de la química del poliuretà, fent esment dels recents avenços en la síntesis i caracterització d'aquests compostos polimèrics, així com un apartat concret centrat en els surfactants de silicona. Es presenten les estructures habituals d'aquests compostos comercials i es detallen les reaccions de síntesi i les característiques físiques que aquests compostos proporcionen a les espumes de poliuretà. CAPÍTOL II. OBJECTIUS. 1.- Síntesis y caracterització d'una àmplia gamma de poliglicols al·lílics i de polihidrosiloxans amb grups hidrur reactius, ambdós precursors d'estructures polimèriques de tipus surfactant. 2.- Estudi de la reacció d'hidrosililació com a via de formació d'enllaços Si-C no hidrolitzables, mitjançant la reacció d'addició entre els substrats al·lílics insaturats i els polisiloxans amb grups hidrur reactius. 3.- Caracterització de les estructures polimèriques de tipus surfactant sintetitzades i avaluació d'aquestes en formulacions de poliuretà, a fi de relacionar l'estructura química d'aquests oligómers amb els efectes físics que originen en l'espuma de poliuretà. CAPÍTOL III. SÍNTESI I CARACTERITZACIÓ DE SUBSTRATS AL·LÍLICS INSATURATS DE TIPUS POLIGLICOL. S'han caracteritzat per HPLC-UV una sèrie de polietilenglicols comercials. S'ha estudiat la reacció de derivatització al·lílica sobre els grups hidroxil dels polièters comercials (PEG, PPG i copolímers PEG-PPG) i s'han caracteritzat exhaustivament els productes sintetitzats (1H,13C-RMN, GC, GC-MS, FTIR, ESI-MS, HPLC-UV). S'ha iniciat un estudi de polimerització aniònica sobre nous epòxids amb un punt de diversitat molecular, sintetitzant-se i caracteritzant-se els corresponents nous polièters obtinguts. CAPÍTOL IV. SÍNTESI I CARACTERITZACIÓ DE POLIHIDROSILOXANS REACTIUS. S'estudia la síntesis de polihidrosiloxans amb grups hidrur reactius, mitjançant la reacció de polimerització aniònica d'obertura d'anell ("AROP, anionic ring opening polimerization") i mitjançant la reacció de polimerització per equilibració catiònica. Es presenta una caracterització exhaustiva dels productes sintetitzats i es descriu la naturalesa de la microestructura polimèrica a partir de la distribució bivariant dels copolímers PDMS-co-PHMS (poli(dimetilsiloxà)-co-poli(hidrometilsiloxà)). CAPÍTOL V. ESTUDI SISTEMÀTIC DE LA REACCIÓ D'HIDROSILILACIÓ. S'ha estudiat la reacció d'hidrosililació amb la finalitat de sintetitzar estructures copolimèriques poliglicol-polisiloxà a partir de la reacció de polisiloxans hidrur reactius i polièters al·lílics. S'han provat diferents catalitzadors (Pt/C 5%, cat. de Speier i cat. de Karstedt), s'han sintetitzat diferents estructures tensoactives (lineals i ramificades) i s'ha modelitzat les diferents reaccions secundàries observades, per presentar un estudi mecanístic de la reacció d'hidrosililació aplicada a la síntesis de molècules d'elevat PM a partir de la reacció entre substrats al·lílics insaturats i polihidrosiloxans. CAPÍTOL VI. AVALUACIÓ DELS SURFACTANTS EN FORMULACIONS DE POLIURETÀ. S'ha estudiat la idoneïtat dels surfactants de silicona sintetitzats en diferents formulacions de poliuretà comercials. S'ha relacionat el comportament físic d'aquests surfactants en les espumes de poliuretà amb la seva estructura química a partir de l'anàlisi per microscòpia electrònica de rastreig. CAPÍTOL VII. CONCLUSIONS. S'han esposat les conclusions extretes de cada capítol.

Production of exopolysaccharide from rhizobia with potential biotechnological and bioremediation applications

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The stabilizing effects of the acquired immunity on the schistosomiasis transmission modeling - the sensitivity Analysis

A mathematical model is proposed to analyze the effects of acquired immunity on the transmission of schistosomiasis in the human host. From this model the prevalence curve dependent on four parameters can be obtained. These parameters were estimated fitting the data by the maximum likelihood method. The model showed a good retrieving capacity of real data from two endemic areas of schistosomiasis: Touros, Brazil (Schistosoma mansoni) and Misungwi, Tanzania (S. haematobium). Also, the average worm burden per person and the dispersion of parasite per person in the community can be obtained from the model. In this paper, the stabilizing effects of the acquired immunity assumption in the model are assessed in terms of the epidemiological variables as follows. Regarded to the prevalence curve, we calculate the confidence interval, and related to the average worm burden and the worm dispersion in the community, the sensitivity analysis (the range of the variation) of both variables with respect to their parameters is performed.

The Influence Of The Buffering Capacity On The Production Of Organic Acids And Alcohols From Wastewater In Anaerobic Reactor.

Some bacteria common in anaerobic digestion process can ferment a broad variety of organic compounds to organic acids, alcohols, and hydrogen, which can be used as biofuels. Researches are necessary to control the microbial interactions in favor of the alcohol production, as intermediary products of the anaerobic digestion of organic compounds. This paper reports on the effect of buffering capacity on the production of organic acids and alcohols from wastewater by a natural mixed bacterial culture. The hypothesis tested was that the increase of the buffering capacity by supplementation of sodium bicarbonate in the influent results in benefits for alcohol production by anaerobic fermentation of wastewater. When the influent was not supplemented with sodium bicarbonate, the chemical oxygen demand (COD)-ethanol and COD-methanol detected in the effluent corresponded to 22.5 and 12.7 % of the COD-sucrose consumed. Otherwise, when the reactor was fed with influent containing 0.5 g/L of sodium bicarbonate, the COD-ethanol and COD-methanol were effluents that corresponded to 39.2 and 29.6 % of the COD-sucrose consumed. Therefore, the alcohol production by supplementation of the influent with sodium bicarbonate was 33.6 % higher than the fermentation of the influent without sodium bicarbonate.

Metodologia para analise cinematica de volumes respiratorios parciais de nadadores

Universidade Estadual de Campinas . Faculdade de Educação Física

Evaluation of the diffusion capacity of calcium hydroxide pastes through the dentinal tubules

This study aimed to evaluate the diffusion capacity of calcium hydroxide pastes with different vehicles through dentinal tubules. The study was conducted on 60 extracted single-rooted human teeth whose crowns had been removed. The root canals were instrumented and divided into 4 groups according to the vehicle of the calcium hydroxide paste: Group I - distilled water; Group II - propylene glycol; Group III - 0.2% chlorhexidine; Group IV - 2% chlorhexidine. After placement of the root canal dressings, the teeth were sealed and placed in flasks containing deionized water. After 1, 2, 7, 15, 30, 45 and 60 days, the pH of the water was measured to determine the diffusion of calcium hydroxide through the dentinal tubules. The data were recorded and statistically compared by the Tukey test. The results showed that all pastes presented a similar diffusion capacity through dentin. Group IV did not present difference compared to group I. Group II presented difference compared to the other groups, as did Group III. In conclusion, groups I and IV presented a better diffusion capacity through dentin than groups II and III; 2% chlorhexidine can be used as a vehicle in calcium hydroxide pastes.

Hydrodynamics and suspended sediment transport in the Camboriú estuary - Brazil: pre jetty conditions

Estuarine hydrodynamics is a key factor in the definition of the filtering capacity of an estuary and results from the interaction of the processes that control the inlet morphodynamics and those that are acting in the mixing of the water in the estuary. The hydrodynamics and suspended sediment transport in the Camboriú estuary were assessed by two field campaigns conducted in 1998 that covered both neap and spring tide conditions. The period measured represents the estuarine hydrodynamics and sediment transport prior to the construction of the jetty in 2003 and provides important background information for the Camboriú estuary. Each field campaign covered two complete tidal cycles with hourly measurements of currents, salinity, suspended sediment concentration and water level. Results show that the Camboriú estuary is partially mixed with the vertical structure varying as a function of the tidal range and tidal phase. The dynamic estuarine structure can be balanced between the stabilizing effects generated by the vertical density gradient, which produces buoyancy and stratification flows, and the turbulent effects generated by the vertical velocity gradient that generates vertical mixing. The main sediment source for the water column are the bottom sediments, periodically resuspended by the tidal currents. The advective salt and suspended sediment transport was different between neap and spring tides, being more complex at spring tide. The river discharge term was important under both tidal conditions. The tidal correlation term was also important, being dominant in the suspended sediment transport during the spring tide. The gravitational circulation and Stokes drift played a secondary role in the estuarine transport processes.

Aerobic capacity and skeletal muscle function in children with asthma

Background Peripheral muscle strength and endurance are decreased in patients with chronic pulmonary diseases and seem to contribute to patients' exercise intolerance. However, the authors are not aware of any studies evaluating peripheral muscle function in children with asthma. It seems to be implied that children with asthma have lower aerobic fitness, but there are limited studies comparing the aerobic capacity of children with and without asthma. The present study aimed to evaluate muscle strength and endurance in children with persistent asthma and their association with aerobic capacity and inhaled corticosteroid consumption. Methods Forty children with mild persistent asthma (MPA) or severe persistent asthma (SPA) (N=20 each) and 20 children without asthma (control group) were evaluated. Upper (pectoralis and latissimus dorsi) and lower (quadriceps) muscle strength and endurance were assessed, and cardiopulmonary exercise testing was performed. Inhaled corticosteroid consumption during the last 6 and 24 months was also quantified. Results Children with SPA presented a reduction in peak oxygen consumption (VO(2)) (28.2 +/- 8.1 vs 34.7 +/- 6.9 ml/kg/min; p<0.01) and quadriceps endurance (43.1 +/- 6.7 vs 80.9 +/- 11.9 repetitions; p<0.05) compared with the control group, but not the MPA group (31.5 +/- 6.1 ml/kg/min and 56.7 +/- 47.7 repetitions respectively; p>0.05). Maximal upper and lower muscle strength was preserved in children with both mild and severe asthma (p>0.05). Finally, the authors observed that lower muscle endurance weakness was not associated with reductions in either peak VO(2) (r=0.22, p>0.05) or corticosteroid consumption (r=-0.31, p>0.05) in children with asthma. Conclusion The findings suggest that cardiopulmonary exercise and lower limb muscle endurance should be a priority during physical training programs for children with severe asthma.

Adipose Tissue-Derived Stem Cells from Humans and Mice Differ in Proliferative Capacity and Genome Stability in Long-Term Cultures

Adipose tissue-derived stem cells (ASCs) are among the more attractive adult stem cell options for potential therapeutic applications. Here, we studied and compared the basic biological characteristics of ASCs isolated from humans (hASCs) and mice (mASCs) and maintained in identical culture conditions, which must be examined prior to considering further potential clinical applications. hASCs and mASCs were compared for immunophenotype, differentiation potential, cell growth characteristics, senescence, nuclear morphology, and DNA content. Although both strains of ASCs displayed a similar immunophenotype, the percentage of CD73(+) cells was markedly lower and CD31(+) was higher in mASC than in hASC cultures. The mean population doubling time was 98.08 +/- 6.15 h for hASCs and 52.58 +/- 3.74 h for mASCs. The frequency of nuclear aberrations was noticeably lower in hASCs than in mASCs regardless of the passage number. Moreover, as the cells went through several in vitro passages, mASCs showed changes in DNA content and cell cycle kinetics (frequency of hypodiploid, G0/G1, G2/M, and hyperdiploid cells), whereas all of these parameters remained constant in hASCs. Collectively, these results suggest that mASCs display higher proliferative capacity and are more unstable than hASCs in long-term cultures. These results underscore the need to consider specificities among model systems that may influence outcomes when designing potential human applications.

Effect of Er:YAG Laser Parameters on Ablation Capacity and Morphology of Primary Enamel

Objective: The purpose of this study was to evaluate the ablation capacity of different energies and pulse repetition rates of Er:YAG laser energy on primary molar enamel, by assessing mass loss and by analyzing the surface morphology with scanning electron microscopy. Background Data: Previous studies have demonstrated the capacity of the Er:YAG laser to ablate enamel substrate. Methods: Forty-two sound primary molars were bisected in a mesiodistal direction. The enamel surfaces were flattened and their initial mass (in milligrams) was obtained. An area of 4 mm(2) was delimited. The specimens were randomly assigned to 12 groups according to the combination of energy (160, 200, 250, and 300 mJ) and pulse repetition rate (2, 3, and 4 Hz). Er: YAG laser irradiation was performed on each specimen for 20 sec. After irradiation, the final mass was obtained and specimens were prepared for examination with scanning electron microscopy. The data obtained by subtracting the final mass from the initial mass were statistically analyzed using ANOVA and the Tukey test (p < 0.05). Results: The pulse repetition rate of 4 Hz provided greater mass loss, different from that seen with 2 Hz, and similar to that seen with 3 Hz. The energy level of 300 mJ resulted in greater mass loss, similar to that seen with 200 and 250 mJ. Scanning electron photomicrographs showed that there was non-selective enamel removal, with fused and cracked areas in all specimens. Conclusion: The parameters of 200 mJ and 2 Hz produced a good ablation rate with fewer surface alterations in primary molar enamel.

Nickel sorption capacity of ground xylem of Quercus ilex trees and effects of selected ligands present in the xylem sap

In this work the influence of four different ligands present in the xylem sap of Quercus ilex (histidine, citric, oxalic and aspartic acids) on Ni(II) adsorption by xylem was investigated. Grinded xylem was trapped in acrylic columns and solutions of Ni(II), in the absence and presence of the four ligands prepared in KNO(3) 0-1 mol L(-1) at pH 5.5, were percolated through the column. Aliquots of solutions were recovered in the column end for Ni determination by graphite furnace atomic absorption spectrometry (GFAAS). The experimental. data to describe Ni sorption by xylem in both the presence and absence of ligands was better explained by the Freundlich isotherm model. The decreasing affinity order of ligands for Ni was: oxalic acid > citric acid > histidine > aspartic acid. On the other hand, the Ni(II) adsorption by xylem increased following the inverse sequence of ligands. Potentiometric titrations of acidic groups were carried out to elucidate the sorption site groups available in Q. ilex xylem. The potentiometric titration has shown three sorption sites: pK(a) 2.6 (57.7% of the sorption sites), related to monobasic aliphatic carboxylic acids or nitrogen aromatic bases, pK(a) 8.1 (9.6%) and pK(a) 9.9 (32.7%), related to phenolic groups. (C) 2008 Elsevier GmbH. All rights reserved.