RESUMO
Lactoferrin is part of the innate immune system, with antiviral activity against numerous DNA and RNA viruses. Rhinoviruses, the leading cause of the common cold, are associated with exacerbation of respiratory illnesses such as asthma. Here, we explored the effect of bovine lactoferrin (BLf) on RV-B14 infectivity. Using different assays, we show that the effect of BLf is strongest during adhesion of the virus to the cell and entry. Tracking the internalisation of BLf and virus revealed a degree of colocalisation, although their interaction was only confirmed in vitro using empty viral particles, indicating a possible additional influence of BLf on other infection steps.
Assuntos
Antivirais/farmacologia , Enterovirus/efeitos dos fármacos , Lactoferrina/farmacologia , Internalização do Vírus/efeitos dos fármacos , Antivirais/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Efeito Citopatogênico Viral/efeitos dos fármacos , Enterovirus/fisiologia , Infecções por Enterovirus/virologia , Células HeLa , Humanos , Lactoferrina/metabolismo , Ligação Viral/efeitos dos fármacosRESUMO
Room-temperature acid (pH 2) extraction of Dictyota dichotoma thalli yielded 2.2% of sulfated polysaccharides. Further extraction with the same solvent at 70°C was conducted sequentially for nine times, with a total yield of 7.2%. Fucose was the main monosaccharide only in the room-temperature extract (EAR) and in the first 70°C extract (EAH1). The remaining fractions showed increasing amounts of mannose (the main neutral monosaccharide), xylose and uronic acids. Fractionation by means of cetrimide precipitation and redissolution in increasing sodium chloride solutions has allowed obtaining several subfractions from each extract. The fractions redissolved at lower NaCl concentrations have large amounts of uronic acids and lesser sulfate contents, whereas those redissolved at higher NaCl concentrations are heavily sulfated and have low uronic acid contents. For the fucose-rich extracts (EAR and EAH1), fractionation leads to uronoxylomannofucan-rich and galactofucan-rich fractions. The remaining extracts gave rise to complex mixtures, with mannose and uronic acid-rich polysaccharides. Moderate inhibitory effect against herpes virus (HSV-1) and Coxsackie virus (CVB3) were found for the galactofucan-rich fractions. Most of the other fractions were inactive against both viruses, although some xylomannan-rich fractions were also active against HSV-1.
Assuntos
Antivirais/química , Antivirais/farmacologia , Phaeophyceae/química , Polissacarídeos/química , Polissacarídeos/farmacologia , Enterovirus/efeitos dos fármacos , Herpesvirus Humano 1/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Concentração Inibidora 50 , TemperaturaRESUMO
Much has been learned in recent years about the mechanisms by which breastfeeding improves child health and survival. However, there has been little progress in using these insights to improve pediatric care. Factors that are important for protecting the breast fed infant might be expected to decrease the adverse effects of weaning on diarrhea, growth, and development. Lactoferrin, an iron-binding protein with multiple physiological functions (anti-microbial, anti-inflammatory, and immunomodulatory), is one of the most important proteins present in mammalian milk. Protection against gastroenteritis is the most likely biologically relevant activity of lactoferrin. Multiple in vitro and animal studies have shown a protective effect of lactoferrin on infections with enteric microorganisms, including rotavirus, Giardia, Shigella, Salmonella and the diarrheagenic Escherichia coli. Lactoferrin has two major effects on enteric pathogens: it inhibits growth and it impairs function of surface expressed virulence factors thereby decreasing their ability to adhere or to invade mammalian cells. Thus, lactoferrin may protect infants from gastrointestinal infection by preventing the attachment by enteropathogens in the gut. Recently several clinical trials in children have started to address this issue. Whether lactoferrin can prevent a significant portion of diarrheal disease remains to be determined.
Assuntos
Lactoferrina/uso terapêutico , Diarreia Infantil/tratamento farmacológico , Enterobacteriaceae/efeitos dos fármacos , Enterovirus/efeitos dos fármacos , Humanos , Lactente , Recém-Nascido , Enteropatias Parasitárias/tratamento farmacológicoRESUMO
This paper reports on the physical and chemical characteristics of agents isolated from serum samples of patients presenting with epidemic neuropathy. The behaviour of isolated enteroviruses was as described for such viruses. Mild cytopathogenic effects-producing agents behaved in a variable form regarding sensitivity to chloroform; on the other hand they were neither sensitive to phosphonoacetic acid (PAA) nor to guanidine hydrochloride (GHC1) and grew in cells previously treated with bromodeoxyuridine (BDUR). These results suggest the presence of agents resembling enteroviruses and enveloped viruses. Further studies for the characterization of such agents need to be performed.
Assuntos
Surtos de Doenças , Enterovirus/química , Neurite Óptica/virologia , Doenças do Sistema Nervoso Periférico/virologia , Aciclovir/farmacologia , Antivirais/farmacologia , Bromodesoxiuridina/farmacologia , Fenômenos Químicos , Físico-Química , Cuba/epidemiologia , Enterovirus/efeitos dos fármacos , Enterovirus/isolamento & purificação , Guanidina/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Neurite Óptica/epidemiologia , Doenças do Sistema Nervoso Periférico/epidemiologia , Ácido Fosfonoacéticos/farmacologia , TemperaturaRESUMO
The presence of 2 agents such as a Cox A9 strain and another mild cytopathogenic effect-producing strain, both isolated from patients presenting with epidemic neuropathy is reported in this paper. A mild cutopathogenic effect which was propagated in successive dilutions was developed in the dilution 10(-4) by means of the neutralization test of a Coxsackie A9 virus with its homologous hyperimmune serum. A gradient in saccharose was performed in a mild cytopathogenic effect-producing strain and a typical cytopathogenic effect of an Enterovirus developed from one of the fractions passed in tissular cultures in the presence phosphonoacetic acid (PAA). The possible pathogenic role of these viruses are discussed.
Assuntos
Enterovirus/química , Neurite Óptica/virologia , Doenças do Sistema Nervoso Periférico/virologia , Animais , Fenômenos Químicos , Físico-Química , Chlorocebus aethiops , Cuba/epidemiologia , Efeito Citopatogênico Viral , Enterovirus/efeitos dos fármacos , Enterovirus/isolamento & purificação , Enterovirus/patogenicidade , Humanos , Neurite Óptica/epidemiologia , Doenças do Sistema Nervoso Periférico/epidemiologia , Inoculações Seriadas , Células VeroRESUMO
Certain factors influencing upon the growth of the agent producer of mild cytopathogenic effect and isolated from the cerebrospinal fluid of patients presenting with epidemic neuropathy are described in this paper. It was demonstrated that a concentration of NaHCO3 was essential for the occurrence of the cytopathogenic effect. Determined concentrations of MnCl2 allowed for the visualization of the cytopathogenic effect and increased viral yields.
Assuntos
Enterovirus/crescimento & desenvolvimento , Neurite Óptica/virologia , Doenças do Sistema Nervoso Periférico/virologia , Animais , Cloretos/farmacologia , Chlorocebus aethiops , Efeito Citopatogênico Viral/efeitos dos fármacos , Relação Dose-Resposta a Droga , Enterovirus/efeitos dos fármacos , Enterovirus/isolamento & purificação , Enterovirus/patogenicidade , Humanos , Cloreto de Magnésio/farmacologia , Compostos de Manganês/farmacologia , Bicarbonato de Sódio/farmacologia , Temperatura , Células VeroRESUMO
We present the results of the in vitro action of alpha and gamma interferons and of Intacglobin and Igegam against the 47/93/IPK (Coxsackie A9) strain isolated from the cerebrospinal fluid of a patient with epidemic neuropathy. The in vitro studies showed that the two interferons inhibited the replication of this agent; they also showed the presence of antibodies to it in the Intacglobin and Igegam. The results attained demonstrated that the use of these compounds could be effective for the treatment of this entity.
Assuntos
Antivirais/farmacologia , Enterovirus/efeitos dos fármacos , Interferon-alfa/farmacologia , Interferon gama/farmacologia , Replicação Viral/efeitos dos fármacos , Animais , Chlorocebus aethiops , Infecções por Coxsackievirus/líquido cefalorraquidiano , Infecções por Coxsackievirus/epidemiologia , Cuba/epidemiologia , Enterovirus/fisiologia , Humanos , Células Vero/efeitos dos fármacosRESUMO
Foram estudadas 15 substâncias de estrutura naftoquinônica obtidas de síntese química: a própria 1,4-naftoquinona sem substituintes, um derivado com um radical hidroxila na posiçäo 2 e 13 derivados hidroxilados apresentando diferentes grupos metileno-amino na posiçäo 3. As culturas de células foram protegidas com as drogas antes da titulaçäo dos vírus (pólio 1, Coxackie B4 e ECHO 19). Pela determinaçäo do índice de inibiçäo virótico (IIV) mostrou-se que o ECHO-vírus 19 foi o mais inibido. Dos 14 compostos testados, 3 deles mostraram um IIV significativo contrao ECHO-vírus como segue: IIV de 1,75 para 2-HO-1,4-naftoquinina e 2-HO-3 (N-morfolil)-metil-1, 4-naftoquinona e IIV de 3,75 para 2-HO-3-N-benzil-N'(N-benzil-2-etilamina) -1,4-naftoquinona. Este último composto mostrou atividade virucida, em experiência paralela, significando que a droga afeta diretamente a partícula viral
Assuntos
Naftoquinonas/farmacologia , Enterovirus/efeitos dos fármacos , QuímicaRESUMO
Some derivatives obtained by chemical transformation of lapachol (a natural substance extracted from the core of plants belonging to the family Bignoniaceae) vere studied as to their posible antiviral action. Cell cultures were treated with those substances and then inoculated with poliovirus type 1, echovirus 19 and Coxsackievirus B type 4. Only ß-lapachone, succinamidyl-ß-norlapachone and intermediary of Hooker have shown a significant viral inhibition index to echovirus type 19. Those derivatives had in in vitro ion but they did not cause any harm to the viral particles studied (virucidal action)