Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Hum Vaccin Immunother ; 19(2): 2263228, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37843437

RESUMO

Rotavirus remains a major cause of diarrhea among 5-y-old children, and vaccination is currently the most effective and economical measure. We conducted a randomized, double-blind, placebo-controlled phase II clinical trial designed to determine the dosage, immunogenicity, and safety profile of a novel hexavalent rotavirus vaccine. In total, 480 eligible healthy infants, who were 6-12 weeks of age at the time of randomization were randomly allocated (1:1:1) to receive 105.5 focus-forming unit (FFU) or 106.5FFU of vaccine or placebo on a 0, 28 and 56-d schedule. Blood samples were collected 28 d after the third dose to assess rotavirus immunoglobulin A (IgA) antibody levels. Adverse events (AEs) up to 28 d after each dose and serious adverse events (SAEs) up to 6 months after the third dose were recorded as safety measurements. The anti-rotavirus IgA seroconversion rate of the vaccine groups reached more than 70.00%, ranging from 74.63% to 76.87%. The postdose 3 (PD3) geometric mean concentrations (GMCs) of anti-rotavirus IgA among vaccine recipients ranged from 76.97 U/ml to 84.46 U/ml. At least one solicited AE was recorded in 114 infants (71.25%) in the high-dose vaccine group, 106 infants (66.25%) in the low-dose vaccine group and 104 infants (65.00%) in the placebo group. The most frequently solicited AE was fever. The novel oral hexavalent rotavirus vaccine was safe and immunogenic in infants support the conclusion to advance the candidate vaccine for phase 3 efficacy trials.


Assuntos
Infecções por Rotavirus , Vacinas contra Rotavirus , Rotavirus , Humanos , Lactente , Anticorpos Antivirais , Método Duplo-Cego , População do Leste Asiático , Imunogenicidade da Vacina , Imunoglobulina A , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/efeitos adversos , Vacinas contra Rotavirus/uso terapêutico , Vacinas Atenuadas , Vacinas Combinadas
2.
Hum Vaccin Immunother ; 17(7): 2311-2318, 2021 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-33545015

RESUMO

Background Rotavirus infections, prevalent in human populations, are caused mostly by group A viruses. Immunization against rotaviruses in infancy is currently the most effective and economical strategy to prevent rotavirus infection. This study evaluated the safety of a novel hexavalent rotavirus vaccine and analyzed its dose and immunogenicity.Methods This randomized, double-blinded, placebo-controlled phase I clinical trial enrolled healthy adults, toddlers, and infants in Zhengding County, Hebei Province, northern China. 40 adults and 40 children were assigned in a 2:1:1 ratio to receive one vaccine dose, placebo 1, and placebo 2, respectively. 120 6-12 week old infants were assigned equivalently into 3 groups. The infants in each group were assigned in a 2:1:1 ratio to receive three doses of vaccine, placebo 1, and placebo 2, at a 28-day interval. Adverse events (AEs) until 28 days after each dose and serious adverse events (SAEs) until 6 months after the third dose were reported. Virus shedding until 14 days after each dose in infants was tested. Geometric mean concentrations (GMCs) and seroconversion rates were measured for anti-rotavirus IgA by using an enzyme-linked immunosorbent assay (ELISA).Results The solicited and unsolicited AE frequencies and laboratory indexes were similar among the treatment groups. No vaccine-related SAEs were reported. The average percentage of rotavirus vaccine shedding in the infant vaccine groups was 5.00%. The post-3rd dose anti-rotavirus IgA antibody geometric mean concentrations (GMC) and seroconversion rate were higher in the vaccine groups than in the placebo groups.Conclusions The novel oral hexavalent rotavirus vaccine was generally well-tolerated in all adults, toddlers and infants, and the vaccine was immunogenic in infants.


Assuntos
Infecções por Rotavirus , Vacinas contra Rotavirus , Rotavirus , Adulto , Anticorpos Antivirais , China , Método Duplo-Cego , Humanos , Imunogenicidade da Vacina , Lactente , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/efeitos adversos , Vacinas Atenuadas/efeitos adversos , Vacinas Combinadas
3.
Food Chem ; 161: 376-82, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-24837965

RESUMO

Sensory evaluation is regarded as a necessary procedure to ensure a reproducible quality of beer. Meanwhile, high-throughput analytical methods provide a powerful tool to analyse various flavour compounds, such as higher alcohol and ester. In this study, the relationship between flavour compounds and sensory evaluation was established by non-linear models such as partial least squares (PLS), genetic algorithm back-propagation neural network (GA-BP), support vector machine (SVM). It was shown that SVM with a Radial Basis Function (RBF) had a better performance of prediction accuracy for both calibration set (94.3%) and validation set (96.2%) than other models. Relatively lower prediction abilities were observed for GA-BP (52.1%) and PLS (31.7%). In addition, the kernel function of SVM played an essential role of model training when the prediction accuracy of SVM with polynomial kernel function was 32.9%. As a powerful multivariate statistics method, SVM holds great potential to assess beer quality.


Assuntos
Cerveja/análise , Máquina de Vetores de Suporte , Algoritmos , Cerveja/normas , Etanol/análise , Análise dos Mínimos Quadrados , Modelos Teóricos , Análise Multivariada , Redes Neurais de Computação
4.
Pest Manag Sci ; 66(12): 1273-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20672333

RESUMO

BACKGROUND: The tobacco cutworm, Spodoptera litura (F.), is one of the most destructive polyphagous pests worldwide. The susceptibility of S. litura larvae reared on tobacco, Chinese cabbage, cowpea and sweet potato to phoxim, chlorfenapyr, methomyl, fenvalerate and emamectin benzoate under laboratory conditions was determined. RESULTS: Spodoptera litura larvae reared on tobacco were most tolerant to all insecticides, whereas those that fed on sweet potato were most susceptible. When larvae were reared on each host plant for three generations, the susceptibilities to phoxim of larvae that fed on Chinese cabbage and cowpea were similar, whereas the susceptibility of larvae that fed on sweet potato decreased by the third generation, and on tobacco the susceptibility decreased in each consecutive generation. When nicotine was added to their diet for three consecutive generations, the tolerance of larvae to phoxim increased twofold, and to emamectin benzoate 3.1-fold, but the tolerance of larvae to fenvalerate and chlorfenapyr did not change. The acetylcholinesterase activities of the larvae that fed on sweet potato and cowpea were greater than the activities of those that fed on Chinese cabbage and tobacco. In contrast, the carboxylesterase activities of the larvae that fed on tobacco and Chinese cabbage were greater than the activities of those that fed on sweet potato and cowpea. The glutathione S-transferase activities of larvae were highest when they fed on tobacco, followed by Chinese cabbage and cowpea, and the lowest activities were observed when larvae fed on sweet potato. CONCLUSION: Feeding on tobacco or with nicotine added to the diet, the larvae became more tolerant to insecticides, especially to phoxim and emamectin benzoate.


Assuntos
Esterases/metabolismo , Interações Hospedeiro-Parasita , Proteínas de Insetos/metabolismo , Inseticidas/toxicidade , Doenças das Plantas/parasitologia , Spodoptera/efeitos dos fármacos , Verduras/parasitologia , Animais , Brassica/parasitologia , Resistência a Medicamentos , Fabaceae/parasitologia , Glutationa Transferase/metabolismo , Controle de Insetos , Ipomoea batatas/parasitologia , Larva/efeitos dos fármacos , Larva/enzimologia , Larva/fisiologia , Spodoptera/enzimologia , Spodoptera/fisiologia , Nicotiana/parasitologia
5.
J Insect Sci ; 10: 22, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20578886

RESUMO

Effects of four host plants, tobacco, Chinese cabbage, cowpea and sweet potato, on larval and pupal development and survival, and longevity and fecundity of adults of Spodoptera litura (F) (Lepidoptera: Noctuidae), were studied under laboratory conditions (26 degrees C, 60-80% RH), as was the utilization of the four host plants and adaptation on tobacco. All of the biological parameters included in the study were affected by the host plants. In a choice test, S. litura females oviposited most on Chinese cabbage, least on tobacco, and intermediate on cowpea and sweet potato. S. litura larvae developed differently on the four host plants, from shortest to longest in the following order: Chinese cabbage, cowpea, sweet potato, and tobacco. Pupal development was shorter on cowpea than on the other three host plants, and males generally developed longer than females. More females than males were found among emerged adults, and male adults lived 1-2 d longer than females. Larvae survived best on cowpea (81.6%), followed by Chinese cabbage (75.5%), then sweet potato (66.1%), and worst on tobacco (49.2%). Pupal survival rates were relatively high (91.4-95.9%) in all four host plant treatments, although that on sweet potato was lower than those on the other three host plants. Pupal weights on tobacco and sweet potato were similar, but both were lower than those on Chinese cabbage and cowpea. Generally, male pupae weighed less than female pupae. Numbers of eggs oviposited by female S. litura were highest on sweet potato, followed by those on cowpea, Chinese cabbage, and lowest on tobacco. Relative food consumption rate was highest on sweet potato, followed by that on cowpea, Chinese cabbage, and lowest on tobacco. In contrast, S. litura larvae that fed on tobacco had higher efficiency of conversion of digested food, highest efficiency of conversion of ingested food, and lowest approximate digestibility as compared with larvae that fed on other host plants. The potential causes for S. litura outbreaks on tobacco are discussed.


Assuntos
Produtos Agrícolas/parasitologia , Interações Hospedeiro-Parasita , Oviposição , Spodoptera/crescimento & desenvolvimento , Animais , Peso Corporal , Brassica/parasitologia , Fabaceae/parasitologia , Comportamento Alimentar , Feminino , Ipomoea batatas/parasitologia , Larva , Longevidade , Masculino , Pupa , Razão de Masculinidade , Nicotiana/parasitologia
6.
Environ Entomol ; 39(3): 883-91, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20550802

RESUMO

Myzus persicae and Bemisia tabaci are serious pests of tobacco and can occur simultaneously on the same plant. We found that tobacco plants infested by whiteflies had fewer aphids than those without whiteflies. To determine whether B. tabaci feeding could induce plant defense against aphids locally and systemically, we determined the effects of B. tabaci on several biological parameters of M. persicae on tobacco. Infestation of B. tabaci nymphs reduced survival rates of M. persicae by 30.0%. In three generations, M. persicae populations increased 1,091-fold on uninfested plants compared with 222-fold on the plants with whiteflies. On the upper leaves with systemic damage but uninfested B. tabaci, the survival rate of aphids was 9.3-fold lower than that on plants that were never been infested by whitefly. Survival rates of M. persicae on leaves with whiteflies present or with whiteflies removed were also lower than those on uninfested leaves. Fecundity of M. persicae was not different on leaves with whiteflies, with whiteflies removed or uninfested leaves; however, fecundity on leaves with systemic damage was lower than on uninfested leaves. Growth rates of M. persicae on the leaves with whiteflies, or with whiteflies removed, were higher than on uninfested leaves, whereas it was lower on systemically damaged leaves than on uninfested leaves. The development of M. persicae was approximately 1 d longer on systemic leaves with whiteflies than on uninfested leaves. These results indicate that feeding of B. tabaci induced a defense in tobacco plants against M. persicae, both locally and systemically, although other mechanisms may also be involved.


Assuntos
Afídeos/crescimento & desenvolvimento , Comportamento Competitivo , Nicotiana/parasitologia , Oviparidade , Animais , Feminino , Longevidade , Ninfa/crescimento & desenvolvimento , Folhas de Planta/parasitologia , Dinâmica Populacional , Nicotiana/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...