RESUMO
Events of catastrophic fish mortality in the lakes of the Amazonian floodplains are not uncommon. They are generally associated with thermal inversion of the water column, which is provoked by cold air masses that originate from the south of the continent. These events occur in the period of high water when the lakes are stratified. This paper reports an event of fish mortality that occurred during the low water season in a large floodplain system on the right-hand margin of the Amazon River. Information from seasoned fishers, who live in the same area where the event happened, and hydrological and satellite image analysis was used to identify the potential cause of fish mortality events. The amplitude of the flood pulse and the duration of extreme ebb showed to be the key factors responsible for the occurrence of events of fish mortality. These factors determine connectivity patterns between the floodplain lakes and the river channel, which are essential for maintaining water quality and the biota in the systems.
Assuntos
Peixes , Lagos , Animais , Rios , Biota , PercepçãoRESUMO
Events of catastrophic fish mortality in the lakes of the Amazonian floodplains are not uncommon. They are generally associated with thermal inversion of the water column, which is provoked by cold air masses that originate from the south of the continent. These events occur in the period of high water when the lakes are stratified. This paper reports an event of fish mortality that occurred during the low water season in a large floodplain system on the right-hand margin of the Amazon River. Information from seasoned fishers, who live in the same area where the event happened, and hydrological and satellite image analysis was used to identify the potential cause of fish mortality events. The amplitude of the flood pulse and the duration of extreme ebb showed to be the key factors responsible for the occurrence of events of fish mortality. These factors determine connectivity patterns between the floodplain lakes and the river channel, which are essential for maintaining water quality and the biota in the systems.
Eventos catastróficos de mortalidade de peixes em lagos de várzea da Amazônia não são incomuns, sendo, em geral, associados com a inversão térmica da coluna d'água, que é provocada por massas de ar frio que se originam no sul do continente. Esses eventos ocorrem no período de águas altas quando os lagos estão estratificados. Nesse artigo, relata-se um evento de mortalidade de peixes que ocorreu durante a estação de águas baixas em um grande sistema de várzea situado na margem direita do rio Amazonas. Usou-se o relato de pescadores residentes na área onde ocorreu o evento e com experiência na pesca, em conjunto com dados hidrológicos e imagens de satélite, para identificar potenciais causas do evento de mortalidade de peixes e propõe-se que a amplitude do pulso de inundação e a duração de secas extremas são os fatores chaves para a ocorrência dos eventos de mortalidade de peixes. Esses fatores determinam padrões de conectividade entre os lagos de várzea e o canal do rio, os quais são essenciais para a manutenção da qualidade da água e da biota nesses sistemas.
Assuntos
Ecossistema Amazônico , Caça , Mudança ClimáticaRESUMO
The corn leaf aphid, Rhopalosiphum maidis (Fitch) (Hemiptera: Aphididae), is an important pest of corn, but no corn genotypes resistant to R. maidis are commercially available. Although the ability of silicon to induce plant resistance against some insects is known, the effect of silicon on R. maidis and in corn hybrids with different levels of constitutive resistance is still unknown. This study sought to determine the constitutive resistance of corn hybrids to R. maidis and silicon resistance induction in hybrids with different degrees of constitutive resistance. Field experiments with natural infestations of aphids were conducted in three locations in Brazil (Patos de Minas, Araguari, and Tupaciguara). Greenhouse trials were also used to evaluate the effect of varietal resistance on aphid population growth and identify resistant and susceptible genotypes. Aphid resistance induced by silicon was determined with resistant and susceptible corn hybrids. In the field, the corn hybrids BM8850, AS1625PRO, and DKB310PRO had the greatest proportion of plants infested by R. maidis in all three localities. The hybrids P30F53H, STATUS VIP, BM9288, DAS2B587HX, DKB175PRO, AS1633PRO, and DKB390PRO2 were the least infested in Patos de Minas and Araguari, and P30F53H was the least infested in Tupaciguara. When antibiosis effects were evaluated by aphid population growth, the hybrids AG7088PRO3 and DKB310PRO2 were susceptible, while P30F53YH was resistant. When natural aphid infestation was evaluated, wherein the effects of antibiosis and non-preference could not be discriminated, soil applications of silicon-induced resistance to R. maidis in both susceptible and constitutively resistant corn hybrids.
Assuntos
Afídeos/efeitos dos fármacos , Afídeos/fisiologia , Silício/farmacologia , Zea mays/efeitos dos fármacos , Animais , Antibiose , Brasil , Solo , Zea mays/genética , Zea mays/crescimento & desenvolvimentoRESUMO
Bacterial wilt of common bean caused by Curtobacterium flaccumfaciens pv. flaccumfaciens is an important disease in terms of economic importance. It reduces grain yield by colonizing xylem vessels, subsequently impeding the translocation of water and nutrients to the superior plant parts. The existence of physiological races in C. flaccumfaciens pv. flaccumfaciens has not so far been reported. The objective of the present investigation was to identify physiological races, evaluate differential interaction, and select resistant genotypes of common bean. Initially, 30 genotypes of common bean were inoculated with eight isolates exhibiting different levels of aggressiveness, under controlled greenhouse conditions. Disease was assessed 15 days after inoculation. The existence of differential interactions between C. flaccumfaciens pv. flaccumfaciens isolates and common bean genotypes were identified by utilizing partial diallel analysis. The most aggressive isolates were BRM 14939 and BRM 14942 and the least aggressive isolates were BRM 14941 and BRM 14946. The genotypes IPA 9, Ouro Branco, and Michelite were selected as more resistant among the test isolates. The genotypes IAC Carioca Akytã, BRS Notável, Pérola, IAC Carioca Aruã, and Coquinho contributed more to the isolate x genotype interaction according to the ecovalence method of estimation, and were, therefore, indicated as differentials. Based on these results, it was possible to conclude that physiological races of the pathogen exist, to select resistant genotypes, and to propose a set of differentials.
Assuntos
Actinomycetales/patogenicidade , Resistência à Doença , Phaseolus/genética , Doenças das Plantas/microbiologia , Actinomycetales/genética , Genes de Plantas , Genótipo , Interações Hospedeiro-Patógeno , Phaseolus/microbiologia , Fatores de Virulência/genéticaRESUMO
Slow seed coat darkening is desirable in common bean cultivars and genetic parameters are important to define breeding strategies. The aims of this study were to estimate genetic parameters for plant architecture, grain yield, grain size, and seed-coat darkening in common bean; identify any genetic association among these traits; and select lines that associate desirable phenotypes for these traits. Three experiments were set up in the winter 2012 growing season, in Santo Antônio de Goiás and Brasília, Brazil, including 220 lines obtained from four segregating populations and five parents. A triple lattice 15 x 15 experimental design was used. The traits evaluated were plant architecture, grain yield, grain size, and seed-coat darkening. Analyses of variance were carried out and genetic parameters such as heritability, gain expected from selection, and correlations, were estimated. For selection of superior lines, a "weight-free and parameter-free" index was used. The estimates of genetic variance, heritability, and gain expected from selection were high, indicating good possibility for success in selection of the four traits. The genotype x environment interaction was proportionally more important for yield than for the other traits. There was no strong genetic correlation observed among the four traits, which indicates the possibility of selection of superior lines with many traits. Considering simultaneous selection, it was not possible to join high genetic gains for the four traits. Forty-four lines that combined high yield, more upright plant architecture, slow darkening grains, and commercial grade size were selected.
Assuntos
Phaseolus/genética , Característica Quantitativa Herdável , Sementes/genética , Cruzamentos Genéticos , Variação Genética , Genótipo , Locos de Características Quantitativas , Seleção GenéticaRESUMO
The aim of this study was to evaluate the phenotypic stability and specific and broad adaptability of common black bean genotypes for the Central and Center-South regions of Brazil by using the Annicchiarico and AMMI (weighted average of absolute scores: WAAS, and weighted average of absolute scores and productivity: WAASP) methodologies. We carried out 69 trials, with 43 and 26 trials in the Central and Center-South regions, respectively. Thirteen genotypes were evaluated in a randomized block design with three replications, during the rainy, dry, and winter seasons in 2 years. To obtain estimates of specific adaptation, we analyzed the parameters for each method obtained in the two geographic regions separately. To estimate broad adaptation, we used the average of the parameters obtained from each region. The lines identified with high specific adaptation in each region were not the same based on the Annicchiarico and AMMI (WAAS) methodologies. It was not possible to identify the same genotypes with specific or broad stability by using these methods. By contrast, the Annicchiarico and AMMI (WAASP) methods presented very similar estimates of broad and specific adaptation. Based on these methods, the lines with more specific adaptation were CNFP 8000 and CNFP 7994, in the Central and Center-South regions, respectively, of which the CNFP 8000 line was more widely adapted.
Assuntos
Adaptação Fisiológica/genética , Interação Gene-Ambiente , Modelos Genéticos , Phaseolus/genética , Brasil , Variação Genética , Genótipo , Phaseolus/crescimento & desenvolvimento , Fenótipo , Estações do AnoRESUMO
Grain yield is strongly influenced by the environment, has polygenic and complex inheritance, and is a key trait in the selection and recommendation of cultivars. Breeding programs should efficiently explore the genetic variability resulting from crosses by selecting the most appropriate method for breeding in segregating populations. The goal of this study was to evaluate and compare the genetic potential of common bean progenies of carioca grain for grain yield, obtained by different breeding methods and evaluated in different environments. Progenies originating from crosses between lines and CNFC 7812 and CNFC 7829 were replanted up to the F7 generation using three breeding methods in segregating populations: population (bulk), bulk within F2 progenies, and single-seed descent (SSD). Fifteen F8 progenies per method, two controls (BRS Estilo and Perola), and the parents were evaluated in a 7 x 7 simple lattice design, with plots of two 4-m rows. The tests were conducted in 10 environments in four States of Brazil and in three growing seasons in 2009 and 2010. Genetic parameters including genetic variance, heritability, variance of interaction, and expected selection gain were estimated. Genetic variability among progenies and the effect of progeny-environment interactions were determined for the three methods. The breeding methods differed significantly due to the effects of sampling procedures on the progenies and due to natural selection, which mainly affected the bulk method. The SSD and bulk methods provided populations with better estimates of genetic parameters and more stable progenies that were less affected by interaction with the environment.
Assuntos
Grão Comestível/genética , Variação Genética , Phaseolus/genética , Melhoramento Vegetal , Brasil , Cruzamentos Genéticos , Interação Gene-Ambiente , Genótipo , Phaseolus/classificação , Fenótipo , Seleção GenéticaRESUMO
One of the current focus of common bean breeding programs in Brazil is to increase iron (FeC) and zinc content (ZnC) in grains. The objectives of this study were to estimate genetic parameters for FeC and ZnC in common bean, verify the need for conducting multi-site evaluation tests, identify elite lines that combine high FeC and ZnC with good adaptability, stability, and agronomic potential, and examine the genetic association between FeC and ZnC. Elite lines (140) were evaluated for important agronomic traits in multiple environments. In one trial, FeC and ZnC were evaluated and genetic parameters were estimated. Based on the high heritability estimates and significant selection gains obtained, the conditions for a successful selection was favorable. Of the 140 evaluated lines, 17 had higher FeC and ZnC, and were included in the validation test (2013, five environments), specifically for the evaluation of FeC and ZnC. The line by environment interaction for FeC and ZnC was detected, but it was predominantly simple. The environmental effect strongly influenced FeC and ZnC . The environment Brasília/rainy season was selected as the best evaluation site for preliminary tests for FeC and ZnC, because it resulted in similar conclusions as the mean of the five environments. The lines CNFP 15701 and CNFC 15865 had higher FeC and ZnC and were highly adaptable and stable, and are recommended for utilization in breeding programs. The lines CNFC 15833, CNFC 15703, and CNFP 15676 showed excellent combined agronomic and nutritional traits, and were selected for the development of biofortified cultivars. Additionally, the genetic association between FeC and ZnC was detected.
Assuntos
Ferro/química , Phaseolus/genética , Característica Quantitativa Herdável , Zinco/química , Brasil , Cruzamento , Grão Comestível/química , Grão Comestível/genética , Meio Ambiente , Phaseolus/crescimento & desenvolvimento , Phaseolus/metabolismo , Fenótipo , Sementes/química , Sementes/genéticaRESUMO
Gastrointestinal health is of great importance due to the increasing consumption of functional foods, especially those concern-ing diets rich in fiber content. The common bean has been valorized as a nutritious food due to its appreciable fiber content and the fact that it is consumed in many countries. The current study aimed to evaluate and compare the genetic potential of common bean progenies of the carioca group, developed through different breeding methods, for crude fiber content. The progenies originated through hybridization of two advanced strains, CNFC 7812 and CNFC 7829, up to the F7 generation using three breeding methods: bulk-population, bulk within F2 families, and single seed descent. Fifteen F8 progenies were evaluated in each method, as well as two check cultivars and both parents, us-ing a 7 x 7 simple lattice design, with experimental plots comprised of two 4-m long rows. Field trials were conducted in eleven environments encompassing four Brazilian states and three different sowing times during 2009 and 2010. Estimates of genetic parameters indicate differences among the breeding methods, which seem to be related to the different processes for sampling the advanced progenies inherent to each method, given that the trait in question is not subject to natural selection. Variability amongst progenies occurred within the three breeding methods and there was also a significant effect of environment on the progeny for all methods. Progenies developed by bulk-population attained the highest estimates of genetic parameters, had less interaction with the environment, and greater variability.
Assuntos
Fibras na Dieta/metabolismo , Phaseolus/metabolismo , Sementes/genética , Seleção Genética/genética , Brasil , Cruzamento , Cruzamentos Genéticos , Genótipo , Phaseolus/genética , FenótipoRESUMO
The common bean is an important source of iron and zinc in humans. Increases in the contents of these minerals can combat mineral deficiencies, but these contents are influenced by environmental conditions. Thus, the objectives of this study were to investigate the interaction between common bean lines and water availability on iron and zinc contents (CFe and CZn, respectively), identify superior lines with stable CFe and CZn, and test for a genetic relationship between CFe and CZn. Six crop trials were performed using a randomized block design with three replications. The trials were performed during the winter sowing period for three different combinations of year and site in Brazil. For each combination, 53 lines were evaluated across two parallel trials; one trial was irrigated according to the crop requirements, and the other trial operated under a water deficit. Interaction was detected between lines and environments, and between lines and water availability for CFe and CZn. However, some lines exhibited high CFe and CZn in both conditions. Lines G 6492 and G 6490 exhibited high mean values, stability, and adaptability for both minerals. Other lines exhibited high CFe (Xamego) or CZn (Bambuí and Iapar 65). A moderate genetic correlation (0.62) between CFe and CZn was detected. Water availability during the common bean cycle had an effect on CFe and CZn; however, lines with high CFe and CZn in different conditions of water availability and environment were detected.
Assuntos
Variação Genética , Ferro/metabolismo , Phaseolus/genética , Phaseolus/metabolismo , Água/metabolismo , Zinco/metabolismo , Adaptação Fisiológica/genética , Algoritmos , Interação Gene-Ambiente , Genótipo , Humanos , Modelos GenéticosRESUMO
The maintenance of the light color of the grains of carioca beans is a requirement for the development of new cultivars of common beans because it enables the storage of grains for long periods so that they may be traded at a proper opportunity. Crosses of cultivar BRSMG Madrepérola, which presents slow grain darkening, were made to 10 elite lines presenting normal darkening to obtain information about the genetic control of the trait and estimates of phenotypic and genotypic parameters. Progenies at the tegument generations F3 and F4 and their parents were evaluated at the locations of Santo Antônio de Goiás and Ponta Grossa at 71, 106, and 155 days of storage for seed-coat darkening using a rank of scores ranging from 1 (very light colored grains) to 5 (very dark colored grains). Genotypic and phenotypic variances and broad-sense heritabilities were estimated for each population. The segregation ratios were subjected to the chi-square test to establish the genetic control. Some populations did not present consistent patterns of genetic control, while others presented monogenic or double-recessive digenic segregation, indicating that the trait is controlled by few genes. Six segregant populations were identified with both low means for darkening and high expected gain under selection. Despite the strong environmental influence on the expression of the traits and the occurrence of the genotype by environment interaction, the estimates of genotypic and phenotypic parameters indicate the possibility of successful selection to develop lines with slow seed-coat darkening.
Assuntos
Genes de Plantas , Phaseolus/genética , Característica Quantitativa Herdável , Sementes/genética , Cor , Cruzamentos Genéticos , Armazenamento de Alimentos , Interação Gene-Ambiente , Genótipo , Phaseolus/anatomia & histologia , Fenótipo , Sementes/anatomia & histologiaRESUMO
The synthetic peptide T-20 (enfuvirtide, EFV) represents the first compound approved by the FDA known as entry inhibitors (EIs). The resistance mutations associated with this new class of antiretroviral drug are located in the first heptad repeat (HR1) region of gp41. Amino acid changes in codons G36D/S, I37V, V38A/M/E, Q39H/R, Q40H, N42T, and N43D can confer resistance to EFV. In this work we investigated the presence of resistance mutations that occur in patients never treated with EFV and failing HAART with protease inhibitors (PIs), nucleoside reverse transcriptase (RT) inhibitors (NRTIs), and nonnucleoside RT inhibitors (NNRTIs). This knowledge can reveal whether this salvage therapy can be effective in patients failing HAART. For this, we amplified 65 samples from plasma isolates and than sequenced a fragment of 416 nt encompassing the HR1 and HR2 regions (amino acids 33-170 of gp41). The subtype distribution among the 65 isolates was 45 (69.23%) subtype B, 9 (13.85%) subtype C, 7 (10.77%) subtype F1, and 4 (6.15%) mosaics B/F1, B/C, F1/C, and C/F1/B. We found a high prevalence (7.6%) of EFV-associated mutation G36D in this cohort of patients failing HAART therapy, five isolates from subtype B (11.11% within this group). In contrast, when 1079 sequences from drug-naive patients were analyzed, only one showed the G36D substitution. This finding indicates a strong association between the selected position G36D and HAART therapy (p < 0.0001). The isolates that possess these mutations can develop resistance to EFV more rapidly. Nevertheless, more information about the impact of these mutations in salvage therapy with EFV in patients failing HAART must still be obtained.
Assuntos
Terapia Antirretroviral de Alta Atividade , Farmacorresistência Viral , Proteína gp41 do Envelope de HIV/farmacologia , Inibidores da Fusão de HIV/farmacologia , Infecções por HIV/virologia , HIV-1/genética , Mutação de Sentido Incorreto , Fragmentos de Peptídeos/farmacologia , Adulto , Sequência de Aminoácidos , Substituição de Aminoácidos/genética , Brasil , Enfuvirtida , Genótipo , Proteína gp41 do Envelope de HIV/genética , Infecções por HIV/tratamento farmacológico , HIV-1/classificação , HIV-1/efeitos dos fármacos , HIV-1/isolamento & purificação , Humanos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Alinhamento de Sequência , Análise de Sequência de DNA , Falha de Tratamento , Adulto JovemRESUMO
The antiviral effect of the CH(2)Cl(2)/MeOH-soluble fraction from the alga Dictyota menstrualis on HIV-1 replication was evaluated in vitro. The antiretroviral activity was attributed to two diterpenes: (6R)-6-hydroxydichotoma-3,14-diene-1,17-dial, named Da-1, and (6R)-6-acetoxi-dichotoma-3,14-diene-1,17-dial, named AcDa-1. Da-1 or AcDa-1 were added to the culture medium of HIV-1-infected PM-1 cells at different times post-infection or during virus adsorption/penetration. The results indicated that the compounds affected an early step of the virus replicative cycle. Virus binding and entry into the host cells were evaluated in the presence of each diterpene, but no inhibitory effect was observed. To evaluate provirus DNA synthesis/integration into the host genome, the viral protease coding sequence was amplified from total cellular DNA. Proviral DNA was not detected in infected cells incubated with the diterpenes. To investigate the effect of the diterpenes on the reverse transcription of the viral genomic RNA, the recombinant HIV-1 reverse transcriptase (RT) was assayed in vitro in the presence of each diterpene. Da-1 and AcDa-1 inhibited the RNA-dependent DNA-polymerase activity of HIV-1 RT in a dose-dependent manner. Taken together, our results demonstrate that both diterpenes inhibit HIV-1 RT and consequently virus replication.
Assuntos
Fármacos Anti-HIV/isolamento & purificação , Fármacos Anti-HIV/farmacologia , Diterpenos/isolamento & purificação , Diterpenos/farmacologia , HIV-1/efeitos dos fármacos , Phaeophyceae/química , Adsorção , Fármacos Anti-HIV/química , Brasil , Linhagem Celular , DNA Viral/biossíntese , Diterpenos/química , Transcriptase Reversa do HIV/antagonistas & inibidores , HIV-1/fisiologia , Humanos , Estrutura Molecular , Provírus/efeitos dos fármacos , Provírus/fisiologia , Inibidores da Transcriptase Reversa/química , Inibidores da Transcriptase Reversa/isolamento & purificação , Inibidores da Transcriptase Reversa/farmacologia , Replicação Viral/efeitos dos fármacosRESUMO
The aim was to investigate the performance of children with attention-deficit-hyperactivity disorder (ADHD) in tasks involving motor-memory representations. A special grip object recorded forces generated by the fingertips during a precision grip-lift task. Common objects were lifted from a linear scale. Twenty-five boys with ADHD were evaluated and grouped according to the presence (ADHD+) or absence (ADHD) of movement dysfunction using the Movement Assessment Battery for Children (Henderson and Sugden 1992). Mean group ages were 11.4 years (range 9.0 to 11.0 years) and 11.7 years (9.0 to 15.6 years), respectively. They were compared to a control group of 25 age-matched boys, mean group age 11.8 years (range 9.0 to 13.0 years). Variability of motor performance was predominant in the ADHD+ group. Several of these participants presented a higher grip-force output during the gripping movement. They also had difficulties in adapting the motor output to target different weights, suggesting deficient anticipatory parameter control based on memory representations. The results suggest that in some children motor problems are due to detrimental neural control functions rather than core symptoms of ADHD.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Força da Mão/fisiologia , Memória , Transtornos das Habilidades Motoras/etiologia , Adolescente , Transtorno do Deficit de Atenção com Hiperatividade/complicações , Criança , Feminino , Mãos/inervação , Humanos , Masculino , Transtornos das Habilidades Motoras/fisiopatologia , Fatores Sexuais , Análise e Desempenho de TarefasRESUMO
The antibiotic cerulenin, an inhibitor of lipid synthesis, was shown to suppress Mayaro virus replication in Aedes albopictus cells at non-cytotoxic doses. Cerulenin blocked the incorporation of [3H]glycerol into lipids when present at any time post infection (p.i.). Cerulenin added at the beginning of infection inhibited the synthesis of virus proteins. However, when this antibiotic was added at later stages of infection, it had only a mild effect on the virus protein synthesis. The possibility that cerulenin acts by blocking an initial step in the Mayaro virus replication after virus entry and before late viral translation is discussed.
Assuntos
Antivirais/farmacologia , Cerulenina/farmacologia , Togaviridae/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Animais , Linhagem Celular/virologia , Chlorocebus aethiops , Fatores de Tempo , Togaviridae/fisiologia , Células VeroRESUMO
Progressive multifocal leukoencephalopathy is a rare viral-induced demyelinating disease associated to immunodeficiency. A 10-year-old boy with AIDS is reported, who developed subacute cerebellar signs and symptoms with multiple cranial nerve involvement and dementia. A computed tomography scan revealed a focal nonenhancing area of low attenuation in the cerebellum. On magnetic resonance imaging high signal lesions in T2 weighted sequences were shown. The biopsy of one of those lesions showed the typical histological findings of progressive multifocal leukoencephalopathy. It seems important to consider this diagnosis in children with AIDS who present with progressive neurological features.
Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Leucoencefalopatia Multifocal Progressiva/complicações , Síndrome da Imunodeficiência Adquirida/patologia , Criança , Humanos , Leucoencefalopatia Multifocal Progressiva/patologia , Masculino , Oligodendroglia/patologiaRESUMO
Novos ribonucleosídeos derivados dos sistemas dipirazolo-piridina foram preparados e avaliados quanto à atividade polimerásica das enzimas transcriptase reversa (RT) do vírus HIV-1 e das DNA polimerases humanas alfa e epsilon. Os derivados 1b e 1d inibiram a atividade da transcriptase reversa em concentraçöes de micromolares. Entretanto, as mesmas substâncias näo foram capazes de inibir a atividade polimerase das enzimas DNA-polimerase humana alfa e epsilon.
Assuntos
DNA Polimerase II/antagonistas & inibidores , DNA Polimerase I/antagonistas & inibidores , HIV-1/enzimologia , Pirazóis/farmacologia , Piridinas/farmacologia , Inibidores da Transcriptase Reversa , Ribonucleosídeos/farmacologiaRESUMO
In 5 spontaneously breathing anesthetized dogs, sodium salicylate (250 mg/kg) was administered. Air flow, volume, and tracheal pressure were measured. The passive mechanical properties of the respiratory system, control of breathing parameters, and the postinspiratory pressure generated by the inspiratory muscles (PmusI) were computed both before and during progressive salicylate-induced hyperventilation. Resistance fell, whereas elastance and time constant were not altered with increased ventilation (VE). The relationship between PmusI and expiratory duration (TE) presented a sigmoidal decay rate, which did not vary with hyperventilation. PmusI at TE = 0 (PmusI, 0); the times for PmusI to decay to 50 (T50), 25 (T25), and 0 percent (TZ) of PmusI, 0; inspiratory (TI), expiratory (TE) and total cycle duration (TT) decreased with increasing VE. As expiration shortened more than inspiration and TI fell more than VT rose, TI/TT and VT/TI increased during hyperventilation. In conclusion, in the face of salicylic intoxication: Rrs diminished, TI and TE decreased markedly, yielding higher values of TI/TT and VT/TI, and although T50, T25, and TZ fell, the relative time profile of PmusI remained unaltered.