972 resultados para Brezhnev, L. I.
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Paginated 1-24.
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The class II major histocompatibility complex molecule I-A(g7) is strongly linked to the development of spontaneous insulin-dependent diabetes mellitus (IDDM) in non obese diabetic mice and to the induction of experimental allergic encephalomyelitis in Biozzi AB/H mice. Structurally, it resembles the HLA-DQ molecules associated with human IDDM, in having a non-Asp residue at position 57 in its beta chain. To identify the requirements for peptide binding to I-A(g7) and thereby potentially pathogenic T cell epitopes, we analyzed a known I-A(g7)-restricted T cell epitope, hen egg white lysozyme (HEL) amino acids 9-27. NH2- and COOH-terminal truncations demonstrated that the minimal epitope for activation of the T cell hybridoma 2D12.1 was M12-R21 and the minimum sequence for direct binding to purified I-A(g7) M12-Y20/K13-R21. Alanine (A) scanning revealed two primary anchors for binding at relative positions (p) 6 (L) and 9 (Y) in the HEL epitope. The critical role of both anchors was demonstrated by incorporating L and Y in poly(A) backbones at the same relative positions as in the HEL epitope. Well-tolerated, weakly tolerated, and nontolerated residues were identified by analyzing the binding of peptides containing multiple substitutions at individual positions. Optimally, p6 was a large, hydrophobic residue (L, I, V, M), whereas p9 was aromatic and hydrophobic (Y or F) or positively charged (K, R). Specific residues were not tolerated at these and some other positions. A motif for binding to I-A(g7) deduced from analysis of the model HEL epitope was present in 27/30 (90%) of peptides reported to be I-A(g7)-restricted T cell epitopes or eluted from I-A(g7). Scanning a set of overlapping peptides encompassing human proinsulin revealed the motif in 6/6 good binders (sensitivity = 100%) and 4/13 weak or non-binders (specificity = 70%). This motif should facilitate identification of autoantigenic epitopes relevant to the pathogenesis and immunotherapy of IDDM.
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This volume includes numerous introductory chapters on the basic concepts and practice of prokaryotic taxonomy in addition to detailed descriptions of the Archaea, phototrophic bacteria and some very deep bacterial phyla. Introductory chapters include the topics of classification of prokaryotes, the concept of bacterial speciation, numerical and polyphasic taxonomy, bacterial nomenclature and the etymology of prokaryotic names, nucleic acid probes and their application in environmental microbiology, culture collections, and the intellectual property of prokaryotes. The first Road Map to the prokaryotes is included as well as an overview of the phylogenetic backbone and taxonomic framework for prokaryotic systematics.
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This was a prospective study carried out during a period over 2 years (May/2006-September/2008) with a cohort of 1,099 individuals of both genders, aged 1 year old and older, from an endemic area of American visceral leishmaniasis (AVL) in Para state, Brazil. The object was to analyze the prevalence and incidence of human Leishmania (L.) infantum chagasi infection as well as the dynamics evolution of its clinical-immunological profiles prior identified: (1) asymptomatic infection (AI); (2) symptomatic infection (SI = AVL); (3) sub-clinical oligosymptomatic infection (SOI); (4) sub-clinical resistant infection (SRI) and; (5) indeterminate initial infection (III). The infection diagnosis was performed by using both the indirect fluorescent antibody test and leishmanin skin test with amastigotes and promastigotes antigens of L. (L.) i. chagasi, respectively. A total of 187 cases of infection were recorded in the prevalence (17%), 117 in the final incidence (6.9%), and 304 in the accumulated prevalence (26.7%), which provided the following distribution into the clinical-immunological profiles: AI, 51.6%; III, 22.4%; SRI, 20.1%; SOI, 4.3%; and SI (=AVL), 1.6%. The major finding regarding the dynamics evolution of infection was concerned to III profile, from which the cases of infection evolved to either the resistant profiles, SRI (21 cases, 30.8%) and AI (30 cases, 44.1%), or the susceptible SI (=AVL; 1 case, 1.5%); the latter 16 cases remained as III till the end of the study. These results provided the conclusion that this diagnostic approach may be useful for monitoring human L. (L.) i. chagasi infection in endemic area and preventing the high morbidity of severe AVL cases.
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The objectives of this study were to identify individuals with symptomatic and/or asymptomatic infection due to Leishmania (L.) infantum chagasi; to study the two types of infection, both clinically and immunologically, and to determine the prevalence rate of infection at the beginning of the study. This was a cross-sectional study with a cohort of 946 individuals, of both genders, from the age of 1 year, living in the municipality of Barcarena, PA, Brazil, an area endemic for American visceral leishmaniasis (AVL). The leishmanin skin test (LST) and the indirect fluorescent test (IFAT), were used for the diagnosis of infection. One hundred and twenty cases of infection were diagnosed, with a prevalence rate of 12.6%; eight cases showed high seroreactivity (1280-10240, IgG) in IFAT and no LST reaction; four of these cases were typical AVL and four had subclinical oligosymptomatic infection. Using two immunological methods with a clinical examination of the infected individuals enabled the identification of five clinical-immunological profiles which may promote a better understanding of the interaction between L. (L.) i. chagasi and the human immune response: asymptomatic infection (AI) 73.4%; subclinical resistant infection (SRI) 15%; subclinicat oligosymptomatic infection (SOI) 3%; symptomatic infection (AVL) 3% and indeterminate initial infection (III) 5%. (C) 2009 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.
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HTLV-I seroprevalences of 3.63% (02/55), 12.19% (10/82) and 13.88% (10/72) were demonstrated among Tiryio, Mekranoiti and Xicrin Amazonian Indians, respectively, by the Western blotting enzyme assay (WBEI). By indirect immuno electron microscopy (IIEM), 2 Tiriyo, 9 Mekranoiti and 6 Xicrin Amerindians were reactive. Of 44 serum samples from Japanese immigrants, none reacted by any of the techniques before mentioned. One, 8 and 6 serum samples from Tiryio, Mekranoiti and Xicrin Indians, respectively, were both WBEI and IIEM positive. Our results strongly suggest that HTLV-I and/or an HTLV-I antigenic variant circulate (s) among populations living in the Amazon region of Brazil.
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Canine visceral leishmaniasis (CVL) is recognizable by characteristic signs of disease and is highly lethal. The infection, however, may be quite inapparent in some seropositive dogs, and this has raised the polemic question as to whether or not such animals can be a source of infection for Lutzomyia longipalpis, the vector of American visceral leishmaniasis (AVL). In this study we have examined 51 dogs with acute CVL from an AVL area in Pará State, northern Brazil, and compared the parasite density, amastigotes of Leishmania (L.) infantum chagasi, in the skin, lymph node and viscera of symptomatic with that of nine asymptomatic but seropositive dogs (IFAT-IgG). Post-mortem biopsy fragments of these tissues were processed by immunohistochemistry, using a polyclonal antibody against Leishmania sp. The X² and Mann Whitney tests were used to evaluate the means of infected macrophage density (p < 0.05). There was no difference (p > 0.05) in the skin (10.7/mm² x 15.5/mm²) and lymph node (6.3/mm² x 8.3/mm²), between asymptomatic and symptomatic dogs, respectively. It was higher (p < 0.05), however, in the viscera of symptomatic (5.3/mm²) than it was in asymptomatic (1.4/mm²) dogs. These results strongly suggest that asymptomatic or symptomatic L. (L.) i. chagasi-infected dogs can serve as a source of infection, principally considering the highest (p < 0.05) parasite density from skin (10.7/mm² x 15.5/mm²), the place where the vetor L. longipalpis takes its blood meal, compared with those from lymph node (6.3/mm² x 8.3/mm²) and viscera (1.4/mm²x 5.3/mm²).
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This study examined the susceptibility of peritoneal macrophage (PM) from the Neotropical primates: Callithrix jacchus, Callithrix penicillata, Saimiri sciureus, Aotus azarae infulatus and Callimico goeldii to ex vivo Leishmania (L.) infantum chagasi-infection, the etiological agent of American visceral leishmaniasis (AVL), as a screening assay for evaluating the potential of these non-human primates as experimental models for studying AVL. The PM-susceptibility to infection was accessed by the PM-infection index (PMI) at 24, 72 h and by the mean of these rates (FPMI), as well as by the TNF-α, IL-12 (Capture ELISA) and Nitric oxide (NO) responses (Griess method). At 24h, the PMI of A. azarae infulatus (128) was higher than those of C. penicillata (83), C. goeldii (78), S. sciureus (77) and C. jacchus (55). At 72h, there was a significant PMI decrease in four monkeys: A. azarae infulatus (128/37), C. penicillata (83/38), S. sciureus (77/38) and C. jacchus (55/12), with exception of C. goeldii (78/54). The FPMI of A. azarae infulatus (82.5) and C. goeldii (66) were higher than C. jacchus (33.5), but not higher than those of C. penicillata (60.5) and S. sciureus (57.5). The TNF-a response was more regular in those four primates which decreased their PMI at 24/72 h: C. jacchus (145/122 pg/mL), C. penicillata (154/130 pg/mL), S. sciureus (164/104 pg/mL) and A. azarae infulatus (154/104 pg/mL), with exception of C. goeldii (38/83 pg/mL). The IL-12 response was mainly prominent in A. infulatus and C. goeldii which presented the highest FPMI and, the NO response was higher in C. goeldii, mainly at 72 h. These findings strongly suggest that these New World primates have developed a resistant innate immune response mechanism capable of controlling the macrophage intracellular growth of L. (L.) i. chagasi-infection, which do not encourage their use as animal model for studying AVL.
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El proyecto propone realizar estudios multidisciplinarios para profundizar el conocimiento sobre las peculiaridades morfolgicas, sistemáticas y evolutivas en géneros americanos -con especial referencia a los que crecen en nuestro país- de la familia <i>Solanaceasi>. Los géneros a estudiar desde el punto de vista taxonómico son: <i>Larnax Miersi>, <i>Grabowskiai> Schlecht., <i>Hawkesiophytoni> Hunz., <i>Cestrumi> L., <i>Sesseai> R. et P. y <i>Nicotianai> L. El polen se analizará en representantes de <i>Latuai> Phil., <i>Nierembergiai> R. et P., <i>Bouchetia Dunal</i> y <i>Salpiglossisi> R.et P. Además, se profundizará en el conocimiento de las estructuras estaminales en las tribus <i> Jaboroseae Miersi>, <i>Datureaei> Rchb., <i>Juanulloeaei> Hunz., <i>Francisceaei> G. Don y <i>Browallieaei> Hunz. Con la informacin obtenida, se apuntará a ratificar o rectificar -mediante estudios micromorfolgicos comparativos- los sistemas clasificatorios vigentes.
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FUNDAMENTO: O tramadol é um analgésico de ação central cujo mecanismo de ação envolve a ativação de um receptor opioide. Anteriormente, mostramos que o tramadol e seus enantimeros apresentavam um efeito inotrópico negativo sobre o músculo papilar no qual o (+)-enantimero era mais potente que (-)- e (±)-tramadol. OBJETIVO: No presente trabalho, investigamos os efeitos do tramadol e seus enantimeros na corrente de cálcio tipo L (I Ca-L). MÉTODOS: Os experimentos foram realizados em micitos ventriculares isolados de ratos Wistar utilizando a técnica de patch-clamp com configuração de célula inteira. RESULTADOS: O tramadol (200 µM) reduziu a amplitude de pico do I Ca-L em potenciais de 0 a +50 mV. Em 0 mV, a I Ca-L foi reduzida em 33,7 ± 7,2%. (+)- e (-)-tramadol (200 µM) produziram uma inibião semelhante da I Ca-L, na qual a amplitude do pico foi reduzida em 64,4 ± 2,8% e 68,9 ± 5,8%, respectivamente a 0 mV (P > 0,05). O tramadol, (+)- e (-)-tramadol mudaram a inativação de estado estacionário de I Ca-L para potenciais de membrana mais negativos. Alm disso, tramadol e (+)-tramadol alteraram significativamente a curva de recuperação dependente de tempo da I Ca-L para a direita e reduziram a recuperação de I Ca-L da inativação. A constante de tempo foi aumentada de 175,6 ± 18,6 a 305,0 ± 32,9 ms (P < 0,01) para o tramadol e de 248,1 ± 28,1 ms para 359,0 ± 23,8 ms (P < 0,05) para o (+)-tramadol. O agonista do receptor µ-opioide (DAMGO) não tem nenhum efeito na I Ca-L. CONCLUSÃO: A inibião da I Ca-L induzida por tramadol e seus enantimeros não teve relação com a ativação de receptores opioides e poderia explicar, pelo menos em parte, seu efeito inotrópico negativo cardíaco.
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Estudi elaborat a partir d’una estada al Stony Brook University al juliol del 2006. El RbTiOPO4 (RTP) monocristall és un material d' òptica no lineal molt rellevant i utilitzat en la tecnologia lser actual, químicament molt estable i amb unes propietats físiques molt destacades, entre elles destaquen els alts coeficients electro-òptics i l'alt llindar de dany òptic que presenta. En els últims anys s’està utilitzant tecnolgicament en aplicacions d'òptica no lineal en general i electro-òptiques en particular. En alguns casos ja ha substituït, millorant prestacions, a materials tals com el KTP o el LNB(1). Dopant RTP amb ions lantànids (Ln3+) (2-4), el material es converteix en un material lser auto-doblador de freqüència, combinant les seves propietats no lineals amb les de matriu lser. El RTP genera radiaci de segon harmònic (SHG) a partir d’un feix fonamental amb longituds d’ona inferiors a 990 nm, que és el lmit que presenta el KTP.La determinaci de la ubicaci estructural i lestudi de l'entorn local del ions actius lser és de fonamental importància per a la correcta interpretaci de les propietats espectroscòpiques d’aquest material. Mesures de difracci de neutrons sobre mostra de pols cristall mostren que els ions Nb5+ i Ln3+ només substitueixin posicions de Ti4+ (8-9). Estudis molt recents d'EPR (electron paramagnetic resonance) semblen indicar que quan la concentraci d'i Ln3+ es baixa, aquest i presenta la tendència a substituir l'i alcal present a l'estructura (10).Després dels resultats obtinguts en el present treball a partir de la tècnica EXAFS a la installaci sincrotò del Brookhaven National Laboratory/State University of New York (Stony Brook) es pot concloure definitivament que els ions Nb s’ubiquen en la posici Ti (1) i que els ions Yb3+ es distribueixen paritariament en les dues posicions del Ti (1 i 2). Aquests resultats aporten una valuosa informaci per a la correcta interpretaci dels espectres, tant d’absorci com d’emissi, del material i per la avaluaci dels paràmetres del seu comportament durant l'acci lser.
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En aquest estudi es realitzà eliminaci biolgica simultània de fòsfor i nitrogen en un Reactor Discontinu Seqüencial (SBR), el qual conté una biomassa enriquida amb Organismes Desnitrificadors Acumuladors de Fòsfor (DPAO) que utilitzen com a única font de carboni làcid propinic i com acceptors d’electrons: nitrit en la fase anòxica i oxigen en laeròbica. LSBR opera amb cicle de 8 h alternant fase anaeròbica, anòxica i aeròbica. El seguiment del sistema es realitzà mitjançant mesures on-line (titrimetria) i off-line (quantificaci d’àcid propinic, nitrit i fòsfor), utilitzant lHPLC per quantificar làcid propinic i cromatografia inica per les mesures de nitrit i fòsfor. Amb aquest sistema es pretén augmentar la captaci de fòsfor en la fase anòxica fet que s’aconseguí realitzant diferents canvis al reactor per tal de maximitzar el consum de nitrit en aquesta fase, ja fos allargant el temps de fase o augmentant la concentraci de biomassa. Aquest experiment ha suposat un augment de la captaci de fòsfor (33 mg P-PO4 3-/L), de leliminaci neta de fòsfor (17 mg P-PO4 3-/L) i de consum de nitrit (27 mg N-NO2-). Per altra banda, es pretenia veure els efectes a curt termini de leliminaci de la fase aeròbica a partir del seguiment de 2 cicle puntuals i d’un cicle de 32 h sense fase aeròbica. En ambdós casos s’aconseguí una eliminaci neta de fòsfor.
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Forty-tree (31.4%) out of 137 serum samples obtained from two Indian communities living in the Amazon region were found to be positive for HTLV-I antibody, as tested by enzyme-linked immunosorbent assay (Elisa). Eighty-two sera were collected from Mekranoiti Indians, yielding 39% of positivity, whereas 11 (20.0%) or the 55 Tiriyo serum samples had antibody to HTLV-I. In addition, positive results occurred in 10 (23.2%) out of 43 sera obtained from patients living in the Belem area, who were suffering from cancer affecting different organs. Five (16.7%) out of 30 Elisa positive specimens were also shown to be positive by either Western blot analysis (WB) or indirect immunogold electron microscopy (IIG-EM).
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Aquest estudi multicèntric, fase IV analitza leficàcia i la seguretat del tractament amb dosi ajustada d’EPOCH amb Rituximab en infusi continua, en pacients no tractats prèviament amb mal pronòstic diagnosticats de limfomes B de cèl.lula gran. Material i mètodes. S’inclogueren 81 pacients, 68 d’aquests diagnosticats de Limfoma B difús de cèl.lula gran, 7 de Limfoma fol.licular grau III i 6 de Limfoma B primari de mediastí. Eren pacients de mal pronòstic segons IPI2 o IPIae≥1, ECOG/PS 0-4, estadi II-IV (estadi I si malaltia voluminosa al diagnòstic). Resultats. La edat mitjana era de 52 anys (rang, 21-77 anys), 92,5% d’alt risc segons lIPIae. Es va obtenir resposta completa (RC i RCi) en el 79% dels pacients, la supervivència global i la supervivència lliure d’esdeveniment, a la mediana del temps de seguiment (34,3 mesos) va ser de 68% i 63,2%, respectivament. La supervivència lliure de malaltia als 5 anys va ser de 72,2% pels pacients que van assolir RC/RCi. Cap dels factors de risc de lIPI o IPIae, ni els índexs per ells mateixos van resultar amb associaci estadísticament significativa a la OS o PFS. Només es va obtenir associaci entre els nivells de ß2 microglobulina (&3,5mg/l) i la PFS i OS (p=0,075 i p=0,015, respectivament). Es van reportar 54 episodis de neutropènia febril (11,5% dels cicles); i es van morir 27 pacients, 15 (55,5%) degut a progressi de la malaltia i 9 (33,3%) degut a sepsi o infecci grau 4. Conclusions. Els resultats aconseguits amb la combinaci de Rituximab i DA-EPOCH mostren uns resultats prometedors i amb nivells de toxicitat molt acceptables en els pacients d’alt risc diagnosticats de Limfomes B de cèl.lula gran no tractats prèviament.
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Lexpansi amb albúmina disminueix la incidència d’insuficincia renal i la mortalitat dels pacients cirròtics amb peritonitis bacteriana espontània (PBE). Però no està ben establert si caldria administrar-la a tots aquests pacients. Aquest estudi determina la incidència i evoluci de la insuficincia renal i mortalitat en una sèrie no seleccionada de pacients cirròtics amb PBE i baix risc de mortalitat (urea&11mmol/l i bilirrubina&68µmol/l) no tractats amb albúmina. La baixa mortalitat i la bona evoluci de la funci renal observades en els pacients amb PBE i baix risc de mortalitat no tractats amb albúmina, suggereixen que en aquests pacients no caldria administrar albúmina.