RESUMO

Rhipicephalus sanguineus s.l. is an intra- and peridomiciliary tick of medical and veterinary importance, whose control is carried out through the application of various ixodicides, to which it can develop resistance. The objective of this work was to determine the discriminant doses (d.d.) to identify resistance against three ixodicides - fipronil, flumethrin and coumaphos - in R. sanguineus s.l. larvae originating from Mexico. Engorged ticks were collected from naturally infested dogs residing in rural communities in five Mexican states; the dogs had no history of recent treatment with ixodicides. All ticks were identified as R. sanguineus s.l. They were incubated for 25 days and their progeny was used in the larval package test (LPT) to be exposed to d.d. as determined in Rhipicephalus microplus, and those that were susceptible were analyzed using the LPT with six concentrations, for fipronil from 0.1 to 0.003125%, for flumethrin from 0.02 to 0.000625% and for coumaphos from 0.4 to 0.0125%. Mortality was analyzed with Probit methodology, to calculate the 50 and 99% lethal concentrations (LC50 and LC99). The d.d. was determined as a consensus value by multiplying the LC99 value × 2. Nine double susceptible samples (fipronil + flumethrin) and one triple susceptible sample (fipronil + flumethrin + coumaphos) were found; the d.d. determined were fipronil 0.05%, flumethrin 0.01% and coumaphos 0.43%. These doses can be used to rapidly and inexpensively identify resistant populations in samples collected in the field.

RESUMO

The brown dog tick, Rhipicephalus sanguineus s.l., is considered the most widely distributed three-host tick in the world and has medical and veterinary importance; the control of infestation is carried out with acaricides, towards which it can develop resistance. This study aimed to determine the discriminant dose (d.d) of amitraz to identify resistance in R. sanguineus s.l. larvae natives from Mexico and to evaluate its application in field-collected ticks. Engorged ticks were collected from naturally infested dogs residing in rural communities and were incubated for 25 days, and their progeny was used in a larval immersion test (LIT) to be exposed to the d.d. determined in Rhipicephalus microplus, and those that were susceptible were analyzed using the LIT in six concentrations. Mortality was analyzed through probit methodology to calculate the lethal concentration (LC) 50 and 99. The d.d. was determined as a consensus value by multiplying the LC99 × 2, and then, we proceeded to evaluate it in in-field samples by using the LIT technique. The d.d. calculated was 4 ppm. The in-field evaluation found 64% of the resistant samples to amitraz with mortality percentages between 98.3% and 0.35%. This dose can be used to rapidly and inexpensively identify resistant populations in samples collected in the field.

RESUMO

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) infections are highly prevalent in the human population and produce mild to life-threatening diseases. These viruses interfere with the function and viability of dendritic cells (DCs), which are professional antigen-presenting cells that initiate and regulate the host's antiviral immune responses. Heme oxygenase-1 (HO-1) is an inducible host enzyme with reported antiviral activity against HSVs in epithelial cells and neurons. Here, we sought to assess whether HO-1 modulates the function and viability of DCs upon infection with HSV-1 or HSV-2. We found that the stimulation of HO-1 expression in HSV-inoculated DCs significantly recovered the viability of these cells and hampered viral egress. Furthermore, HSV-infected DCs stimulated to express HO-1 promoted the expression of anti-inflammatory molecules, such as PDL-1 and IL-10, and the activation of virus-specific CD4+ T cells with regulatory (Treg), Th17 and Treg/Th17 phenotypes. Moreover, HSV-infected DCs stimulated to express HO-1 and then transferred into mice, promoted the activation of virus-specific T cells and improved the outcome of HSV-1 skin infection. These findings suggest that stimulation of HO-1 expression in DCs limits the deleterious effects of HSVs over these cells and induces a favorable virus-specific immune response in the skin against HSV-1.

RESUMO

Here we report the use of graphene quantum dots (GQDs), obtained from 3D graphene foam, functionalized with 8-hydroxyquinoline (8-HQ) for the sensitive and selective detection of Hg2+ via front-face fluorescence. The great surface area and active groups within the GQDs permitted the functionalization with 8-HQ to increase their selectivity toward the analyte of interest. The fluorescence probe follows the Stern-Volmer model, yielding a direct relationship between the degree of quenching and the concentration of the analyte. Diverse parameters, including the pH and the use of masking agents, were optimized in order to improve the selectivity toward Hg2+ down to a limit of detection of 2.4 nmol L-1. It is hereby demonstrated that the functionalized GQDs work perfectly fine under adverse conditions such as acidic pH and in the presence of a large number of cationic and anionic interferences for the detection of Hg2+ in real samples. Parallel measurements using cold vapor atomic fluorescence spectrometry also demonstrated an excellent correlation with the front-face fluorescence method applied here for real samples including tap, river, underground, and dam waters.

Assuntos

Grafite , Mercúrio , Pontos Quânticos , Pontos Quânticos/química , Grafite/química , Mercúrio/análise , Espectrometria de Fluorescência/métodos , Oxiquinolina

RESUMO

Tick-borne bacterial pathogens (TBBPs) show a worldwide distribution and represent a great impact on public health. The brown dog tick (Rhipicephalus sanguineus) is a vector of several pathogens that affect dogs and sometimes humans as well. In addition, TBBPs represent a diagnostic challenge and imply financial resources and medical treatment for long periods of time. In the present study, R. sanguineus s. l. was identified as the main tick species naturally parasitizing dogs that inhabit. Juárez City, Chihuahua, in the Paso del Norte region, Mexico-US Border, representing 99.8% of the cases. Additionally, an end-point PCR was performed to search for whether pathogens in R. sanguineus s. l. can transmit in DNA extracted from ticks and dog blood samples. This is the first molecular detection of Rickettsia rickettsi infecting domestic dogs in Mexico; however, other pathogens were also identified, such as Ehrlichia canis and Anaplasma platys in both ticks and dog blood samples, while Anaplasma phagocytophilum was identified only in dog blood samples. Moreover, co-detection in tick pools and co-infection in the analyzed dog blood samples could be found. Similarly, this research showed that dogs were found mostly parasitized by adult female ticks, increasing the possibility of transmission of E. canis.

RESUMO

Equine piroplasmosis is a disease of horses, mules and donkeys, caused by the hemoprotozoans Babesia caballi and Theileria equi and transmitted by ticks of tropical and subtropical regions. Because the clinical signs are not specific, the diagnosis of equine piroplasmosis is difficult. In Mexico, where the environmental factors are conducive to the persistence of these pathogens, there is a lack of molecular studies to evaluate the occurrence of both parasites in horses. In the present study, matching serum and whole blood samples were obtained from 269 horses residing in 24 locations with tropical or subtropical climate and the presence of ticks. Testing of serum samples by ELISA demonstrated 55.7% seroprevalence of B. caballi and 68.4% prevalence of antibodies to T. equi. Blood samples analyzed with nPCR test were 7.8% positive to B. caballi and 78.8% positive to T. equi, while a duplex qPCR showed 15.24% positive samples to B. caballi and 59.11% to T. equi. From these results, 27 samples were sequenced for T. equi and 13 for B. caballi, confirming the presence of both horse parasites that cause equine piroplasmosis and suggesting that they are widespread in Mexico. This is the first study confirming the presence of B. caballi and T. equi in Mexico using both serological and molecular diagnostic methods. This study shows a high incidence of exposure to the etiological agents of equine piroplasmosis in horses in the studied areas.

Assuntos

Babesia , Babesiose , Doenças dos Cavalos , Theileria , Theileriose , Carrapatos , Animais , Babesia/genética , Babesiose/diagnóstico , Babesiose/epidemiologia , Bovinos , Equidae/parasitologia , Doenças dos Cavalos/diagnóstico , Doenças dos Cavalos/epidemiologia , Doenças dos Cavalos/parasitologia , Cavalos , México/epidemiologia , Estudos Prospectivos , Estudos Soroepidemiológicos , Theileria/genética , Theileriose/diagnóstico , Theileriose/epidemiologia , Theileriose/parasitologia , Carrapatos/parasitologia

RESUMO

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) infections are life-long and highly prevalent in the human population. These viruses persist in the host, eliciting either symptomatic or asymptomatic infections that may occur sporadically or in a recurrent manner through viral reactivations. Clinical manifestations due to symptomatic infection may be mild such as orofacial lesions, but may also translate into more severe diseases, such as ocular infections that may lead to blindness and life-threatening encephalitis. A key feature of herpes simplex viruses (HSVs) is that they have evolved molecular determinants that hamper numerous components of the host's antiviral innate and adaptive immune system. Importantly, HSVs infect and negatively modulate the function of dendritic cells (DCs), by inhibiting their T cell-activating capacity and eliciting their apoptosis after infection. Previously, we reported that HSV-2 activates the splicing of the mRNA of XBP1, which is related to the activity of the unfolded protein response (UPR) factor Inositol-Requiring Enzyme 1 alpha (IRE-1α). Here, we sought to evaluate if the activation of the IRE-1α pathway in DCs upon HSV infection may be related to impaired DC function after infection with HSV-1 or HSV-2. Interestingly, the pharmacological inhibition of the endonuclease activity of IRE-1α in HSV-1- and HSV-2-infected DCs significantly reduced apoptosis in these cells and enhanced their capacity to migrate to lymph nodes and activate virus-specific CD4+ and CD8+ T cells. These findings suggest that the activation of the IRE-1α-dependent UPR pathway in HSV-infected DCs may play a significant role in the negative effects that these viruses exert over these cells and that the modulation of this signaling pathway may be relevant for enhancing the function of DCs upon infection with HSVs.

Assuntos

Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/imunologia , Endorribonucleases/antagonistas & inibidores , Herpes Genital/imunologia , Herpesvirus Humano 1/imunologia , Herpesvirus Humano 2/imunologia , Ativação Linfocitária , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Animais , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/virologia , Chlorocebus aethiops , Células Dendríticas/virologia , Endorribonucleases/imunologia , Feminino , Camundongos , Proteínas Serina-Treonina Quinases/imunologia , Células Vero

RESUMO

BACKGROUND: Acaricide resistance is a central problem for the control of the cattle tick Rhipicephalus microplus. The physiological effects and phenotypes of the mutations that cause acaricide resistance are not always well understood or characterized. Single nucleotide polymorphisms (SNPs) that confer cypermethrin knockdown resistance (kdr) have been reported in R. microplus. These SNPs have been associated and correlated with pyrethroid resistance although there is no direct physiological evidence that their presence does confer kdr in this organism. METHODS: Resistant and susceptible strain resistance profiles were obtained using the larval packet discriminating dose assay. The relevant genomic regions of the para-sodium channel were amplified using standard PCR; SNPs were detected by sequencing the corresponding amplicons. Ovary response to cypermethrin exposure/treatment was evaluated using videometrical analysis. RESULTS: We found that the pyrethroid resistance trait is stable in a resistant reference strain after years without selection, suggesting that the resistance conferring mutations are fixed in the population. In this strain, a change in the structure of the pre-synaptic para-sodium channel caused by the G184C, the C190A and the T2134A SNPs appears to confer resistance. These mutations are absent in the susceptible strain used as control. We demonstrate that cypermethrin blocks ovary contraction in cypermethrin-susceptible ticks. We also show that ovaries from organisms that carry the kdr associated SNPs still contract at cypermethrin concentrations that completely block ovary contraction in the susceptible strain. The configuration of the experimental system excludes a xenobiotic detoxification mechanism. CONCLUSIONS: This is the first report that presents physiological evidence that the presence of the G184C, the C190A, and the T2134A mutations in the para-sodium channel correlates with maintaining muscle contractility in R. microplus exposed to cypermethrin. These SNPs may confer cypermethrin resistance in this organism by avoiding presynaptic blockage, inhibiting the flaccid muscle paralysis characteristic of this acaricide. The videometric assay that we previously validated can be used to detect more rapidly than other assays that involve larval mortality kdr-like cypermethrin resistant tick strains, permitting to directly assay adult pre-engorged females after they are collected on the field without waiting until eggs are laid and larvae eclose.

Assuntos

Resistência a Inseticidas/genética , Piretrinas/farmacologia , Rhipicephalus , Canais de Sódio , Acaricidas/farmacologia , Animais , Bovinos , Feminino , Contração Muscular/efeitos dos fármacos , Mutação , Ovário/efeitos dos fármacos , Polimorfismo de Nucleotídeo Único , Rhipicephalus/efeitos dos fármacos , Rhipicephalus/genética , Rhipicephalus/fisiologia , Canais de Sódio/efeitos dos fármacos , Canais de Sódio/genética , Canais de Sódio/metabolismo , Sinapses/efeitos dos fármacos

RESUMO

Microbial production of carotenoids has mainly focused towards a few products, such as ß-carotene, lycopene and astaxanthin. However, other less explored carotenoids, like violaxanthin, have also shown unique properties and promissory applications. Violaxanthin is a plant-derived epoxidated carotenoid with strong antioxidant activity and a key precursor of valuable compounds, such as fucoxanthin and ß-damascenone. In this study, we report for the first time the heterologous production of epoxycarotenoids in yeast. We engineered the yeast Saccharomyces cerevisiae following multi-level strategies for the efficient accumulation of violaxanthin. Starting from a ß-carotenogenic yeast strain, we first evaluated the performance of several ß-carotene hydroxylases (CrtZ), and zeaxanthin epoxidases (ZEP) from different species, together with their respective N-terminal truncated variants. The combined expression of CrtZ from Pantoea ananatis and truncated ZEP of Haematococcus lacustris showed the best performance and led to a yield of 1.6 mg/gDCW of violaxanthin. Further improvement of the epoxidase activity was achieved by promoting the transfer of reducing equivalents to ZEP by expressing several redox partner systems. The co-expression of the plant truncated ferredoxin-3, and truncated root ferredoxin oxidoreductase-1 resulted in a 2.2-fold increase in violaxanthin yield (3.2 mg/gDCW). Finally, increasing gene copy number of carotenogenic genes enabled reaching a final production of 7.3 mg/gDCW in shake flask cultures and batch bioreactors, which is the highest yield of microbially produced violaxanthin reported to date.

Assuntos

Engenharia Metabólica , Microrganismos Geneticamente Modificados , Saccharomyces cerevisiae , Microrganismos Geneticamente Modificados/genética , Microrganismos Geneticamente Modificados/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Xantofilas/metabolismo

RESUMO

The synergy between graphene foam (Gf) and ZnO nanoparticles (NPs) allows the detection of analytes at low conentrations, which can be subsequently photocatalyzed on the hybrid surface as well as in the liquid phase upon illumination with low-power UV-vis light-emitting diode (LED) lamps. Detection of methylene blue (MB) and bisphenol A (BPA) is monitored either by graphene-enhanced Raman scattering (GERS) or molecular doping/sensing upon analyte adsorption. Using GERS, we were able to detect concentrations as low as 0.3 ppm of MB, which remained adsorbed on the graphene surface after a photocatalytic conversion of 88% (total conversion). The photocatalysis performances of BPA and MB performed in the liquid phase were lower and corresponded to 73 and 33% as indicated by gas chromatography-mass spectrometry (GC/MS) and UV-vis, respectively. The kinetics of photocatalysis was fitted with a quasi-first-order reaction, and the apparent rate constant (kapp) was calculated according to the Langmuir-Hinshelwood model. The fastest kinetics was achieved with the hybrid platform named "Gf-ZnO400", which was thermally treated at high temperatures and with most of the Ni etched away. This is consistent with the excellent electronic interaction between ZnO and graphene foam as indicated by photoelectrochemistry analysis. We mainly employed Raman scattering and UV-vis spectroscopy analyses for detection and photocatalysis applications; however, we also used other complementary techniques such as focused ion-beam scanning electron microscopy (FIB-SEM), X-ray photoelectron spectroscopy (XPS), diffuse reflectance, GC/MS, and photoelectrochemistry to explore the synergetic behavior of these two nanomaterials. This work brings about new insights into the detection of analyte molecules followed by photocatalysis performed in the solid and liquid states.

RESUMO

A preconcentration method based on a novel hybrid sorption nanomaterial consisting in a 3D graphene-Ni foam functionalized with an ionic liquid (IL) was developed for Hg species determination. The capability of different phosphonium-ionic liquids (PILs) to functionalize the hybrid material and form ion-pairs with Hg(II) chlorocomplex was evaluated. A comparative study with PILs containing the trihexyl(tetradecyl)phosphonium cation but different anions (dicyanamide and decanoate) and trihexyl(tetradecyl)phosphonium chloride was performed. Inorganic Hg (InHg) species was selectively retained forming a chlorocomplex (HgCl42-) followed by its retention in a column filled with the IL-3D graphene-Ni foam material implemented in an on-line micro solid phase extraction system (µSPE). The elution of Hg from the column was performed with SnCl2, which was also used as reducing agent for subsequent detection by cold vapor generation atomic fluorescence spectrometry (CV-AFS). Organic mercury species (OrgHg) were not retained on the sorption material of the column. The effect of several parameters determining the efficiency of the preconcentration and detection system (sample loading and elution flow rate, sample volume, instrumental conditions, etc.) was investigated. A sensitivity enhancement factor (EF) of 180 was achieved for InHg. The detection limit obtained after the preconcentration of 100 mL of sample was 3.6 ng L-1 of InHg. The relative standard deviation (RSD) was 4.1% (at 1 µg L-1 InHg and n = 10) calculated from the peak height of the absorbance signals (Gaussian form and reproducible peaks). This work reports the first application of the IL-3D graphene-Ni foam in an on-line µSPE preconcentration system for the speciation analysis of Hg in mineral, tap, and river water samples.

RESUMO

El uso indebido de los punteros láser, especialmente el recreativo en los niños, puede causar lesiones retinianas que amenazan la visión. El daño retiniano que producen no está bien caracterizado, debido a que la mayoría de las publicaciones son casos aislados o series pequeñas. El tratamiento y el pronóstico visual es variable según la morfología del daño macular que presenten. En algunos casos, no existe tratamiento, y pueden evolucionar a la curación espontánea; sin embargo, otros precisan cirugía. En una serie de 13 casos, uno requirió cirugía, mientras que el resto necesitó solo observación. De estos 13 casos, 3 pacientes se curaron en forma espontánea, con agudeza visual de 10/10.Se describen dos pacientes de 16 y 12 años con disminución de agudeza visual tras el uso indebido de punteros láser. En el fondo de ojo, presentaron alteraciones maculares. La agudeza visual de ambos se recuperó completamente sin tratamiento.

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The improper use of laser pointers, especially for recreational use in children, may cause sight-threatening retinal injuries. The retinal damage it is not well characterized because most publications are isolated cases or small series.The treatment and visual prognosis are variable according to the morphology of the macular damage. In some cases, there is no treatment, and spontaneous healing can be developed; however, others require surgery. In a series of 13 cases, 1 required surgery and the rest observation; 3 patients obtained a spontaneous healing with visual acuity of 10/10.We describe two patients aged 16 and 12 years with decreased visual acuity. Macular alterations appear in the fundus of the eye. The visual acuity of both recovered completely without treatment

Assuntos

Humanos , Masculino , Criança , Adolescente , Doenças Retinianas , Lasers/efeitos adversos , Macula Lutea/efeitos da radiação , Macula Lutea/lesões

RESUMO

The improper use of laser pointers, especially for recreational use in children, may cause sight-threatening retinal injuries. The retinal damage it is not well characterized because most publications are isolated cases or small series. The treatment and visual prognosis are variable according to the morphology of the macular damage. In some cases, there is no treatment, and spontaneous healing can be developed; however, others require surgery. In a series of 13 cases, 1 required surgery and the rest observation; 3 patients obtained a spontaneous healing with visual acuity of 10/10. We describe two patients aged 16 and 12 years with decreased visual acuity. Macular alterations appear in the fundus of the eye. The visual acuity of both recovered completely without treatment.

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El uso indebido de los punteros láser, especialmente el recreativo en los niños, puede causar lesiones retinianas que amenazan la visión. El daño retiniano que producen no está bien caracterizado, debido a que la mayoría de las publicaciones son casos aislados o series pequeñas. El tratamiento y el pronóstico visual es variable según la morfología del daño macular que presenten. En algunos casos, no existe tratamiento, y pueden evolucionar a la curación espontánea; sin embargo, otros precisan cirugía. En una serie de 13 casos, uno requirió cirugía, mientras que el resto necesitó solo observación. De estos 13 casos, 3 pacientes se curaron en forma espontánea, con agudeza visual de 10/10. Se describen dos pacientes de 16 y 12 años con disminución de agudeza visual tras el uso indebido de punteros láser. En el fondo de ojo, presentaron alteraciones maculares. La agudeza visual de ambos se recuperó completamente sin tratamiento.

Assuntos

Traumatismos Oculares/etiologia , Lasers/efeitos adversos , Doenças Retinianas/etiologia , Adolescente , Criança , Traumatismos Oculares/patologia , Humanos , Masculino , Doenças Retinianas/patologia , Transtornos da Visão/etiologia , Acuidade Visual

RESUMO

Herpes simplex viruses type 1 and type 2 (HSV-1 and HSV-2) produce lifelong infections and are highly prevalent in the human population. Both viruses elicit numerous clinical manifestations and produce mild-to-severe diseases that affect the skin, eyes, and brain, among others. Despite the existence of numerous antivirals against HSV, such as acyclovir and acyclovir-related analogs, virus variants that are resistant to these compounds can be isolated from immunosuppressed individuals. For such isolates, second-line drugs can be used, yet they frequently produce adverse side effects. Furthermore, topical antivirals for treating cutaneous HSV infections usually display poor to moderate efficacy. Hence, better or novel anti-HSV antivirals are needed and details on their mechanisms of action would be insightful for improving their efficacy and identifying specific molecular targets. Here, we review and dissect the lytic replication cycles of herpes simplex viruses, discussing key steps involved in cell infection and the processes that yield new virions. Additionally, we review and discuss rapid, easy-to-perform and simple experimental approaches for studying key steps involved in HSV replication to facilitate the identification of the mechanisms of action of anti-HSV compounds.

RESUMO

The goal of the present study was to assess the gene expression of xenobiotic metabolizing enzymes (XMEs) Cytochrome P-450 (CYP) and carboxylesterase (CE) related to detoxification of synthetic pyrethroids, plus acetylcholinesterase (AChE), in field isolates of acaricide-resistant Rhipicephalus microplus. The XMEs expression levels were assessed by mRNA measurement using quantitative reverse transcription PCR. The XME expression levels of field-isolated acaricide-resistant ticks were compared against acaricide-susceptible reference ticks used in this study as a gene expression baseline and represented as relative expression units (REU). Field isolates were subjected to toxicological bioassays and determined resistant to all the Pyr acaricides (Pyr), whereas most of them were found susceptible to organophosphorous acaricides (OP), with the exception of three isolates, which exhibited moderate resistance to Diazinon. Significantly higher levels of CYP were detected in pyrethroid-resistance ticks when compared to Su ticks (P<0.01). A linear regression analysis showed that pyrethroid acaricide resistance levels of R. microplus were proportional to the CYP expression levels (correlation coefficient (R):0.85; P<0.05). Analysis on CE expression levels showed only one isolate resistant to Pyr and OP with a statistically significant increase (P<0.01). AChE expression levels showed statistically significant (P<0.01) subexpression in all tick isolates when compared to the susceptible reference. Our results suggest that pyrethroid acaricide resistance in the cattle tick may be diagnosed by measuring the CYP expression levels using quantitative PCR.

Assuntos

Acaricidas/farmacologia , Sistema Enzimático do Citocromo P-450/metabolismo , Piretrinas/farmacologia , Rhipicephalus/enzimologia , Animais , Bovinos , Doenças dos Bovinos , Resistência a Medicamentos , Complexo IV da Cadeia de Transporte de Elétrons , Feminino , México , Reação em Cadeia da Polimerase , Rhipicephalus/patogenicidade

RESUMO

The human metapneumovirus (hMPV) is the second leading cause globally of acute infection of the respiratory tract in children, infecting the upper and lower airways. The hMPV may induce an inappropriate Th2-type immune response, which causes severe pulmonary inflammation, leading to the obstruction of airways. Despite its severe epidemiological relevance, no vaccines are currently available for the prevention of hMPV-induced illness. In this investigation, we demonstrated that immunization of mice with the recombinant hMPV nucleoprotein (hMPV-N) mixed with the AbISCO-100 adjuvant reduced viral replication in lungs following challenge with the virus. We found that immunized mice had reduced weight loss, decreased granulocytes in the lung, an increased level of specific nucleoprotein antibodies of IgG1 and IgG2a-isotypes, and a local profile of Th1/Th17-type cytokines. Our results suggest that immunization with the hMPV-N and the AbISCO-100 adjuvant induces a reduction of viral infection and could be considered for the development of an hMPV vaccine.

Assuntos

Imunização , Metapneumovirus/imunologia , Nucleoproteínas/administração & dosagem , Infecções por Paramyxoviridae/imunologia , Vacinas Virais/imunologia , Adjuvantes Imunológicos/farmacologia , Animais , Anticorpos Antivirais/sangue , Anticorpos Antivirais/classificação , Citocinas/análise , Células Dendríticas/classificação , Modelos Animais de Doenças , Expressão Gênica/efeitos dos fármacos , Granulócitos , Humanos , Pulmão/efeitos dos fármacos , Pulmão/patologia , Pulmão/virologia , Camundongos , Camundongos Endogâmicos BALB C , Nucleoproteínas/genética , Nucleoproteínas/isolamento & purificação , Infecções por Paramyxoviridae/prevenção & controle , Pneumonia/virologia , RNA Viral/análise , Vacinas Virais/farmacologia , Redução de Peso

RESUMO

Hard ticks are a perennial problem in livestock systems throughout Mexico. No data are currently available on tick prevalence, infestation intensity and population dynamics for sheep in the humid tropics of Mexico. Blackbelly sheep (n = 30) in Tabasco state, Mexico, were examined every 3 weeks for 1 year, and all Ixodidae ticks were counted and removed for analysis. Tick species were identified, infestation prevalence and intensity calculated per animal, and infestation per body zone determined. Overall infestation on the studied animals was 51.9%. Four tick species were identified (Amblyomma mixtum, A. imitator, Rhipicephalus microplus and R. annulatus), the most abundant being A. mixtum (94.9%). Prevalence was highest during the northwinds season (61.9%), followed by the dry (48.5%) and rainy (47.3%) seasons; however, the intensity (2.01-2.07 ticks/sheep) did not differ between seasons. Infestation was most frequent in certain zones including the axilla, crotch, udder, abdomen, thorax and rib area. Sheep in the humid tropics of Tabasco, Mexico, are parasitized by four hard tick species and prevalence is highest in the northwinds season. The present data constitute an important baseline for developing sustainable tick control programs for sheep in the humid tropics of Mexico.

Assuntos

Ixodidae/fisiologia , Doenças dos Ovinos/epidemiologia , Infestações por Carrapato/veterinária , Animais , Biodiversidade , México/epidemiologia , Dinâmica Populacional , Prevalência , Estações do Ano , Ovinos , Doenças dos Ovinos/parasitologia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia , Clima Tropical

RESUMO

Heme oxygenase-1 (HO-1) is an inducible enzyme that is expressed in response to physical and chemical stresses, such as ultraviolet radiation, hyperthermia, hypoxia, reactive oxygen species (ROS), as well as cytokines, among others. Its activity can be positively modulated by cobalt protoporphyrin (CoPP) and negatively by tin protoporphirin (SnPP). Once induced, HO-1 degrades iron-containing heme into ferrous iron (Fe2+), carbon monoxide (CO) and biliverdin. Importantly, numerous products of HO-1 are cytoprotective with anti-apoptotic, anti-oxidant, anti-inflammatory, and anti-cancer effects. The products of HO-1 also display antiviral properties against several viruses, such as the human immunodeficiency virus (HIV), influenza, hepatitis B, hepatitis C, and Ebola virus. Here, we sought to assess the effect of modulating HO-1 activity over herpes simplex virus type 2 (HSV-2) infection in epithelial cells and neurons. There are no vaccines against HSV-2 and treatment options are scarce in the immunosuppressed, in which drug-resistant variants emerge. By using HSV strains that encode structural and non-structural forms of the green fluorescent protein (GFP), we found that pharmacological induction of HO-1 activity with CoPP significantly decreases virus plaque formation and the expression of virus-encoded genes in epithelial cells as determined by flow cytometry and western blot assays. CoPP treatment did not affect virus binding to the cell surface or entry into the cytoplasm, but rather downstream events in the virus infection cycle. Furthermore, we observed that treating cells with a CO-releasing molecule (CORM-2) recapitulated some of the anti-HSV effects elicited by CoPP. Taken together, these findings indicate that HO-1 activity interferes with the replication cycle of HSV and that its antiviral effects can be recapitulated by CO.

RESUMO

Besides overcoming physical constraints, such as extreme temperatures, reduced humidity, elevated pressure, and natural predators, human pathogens further need to overcome an arsenal of antimicrobial components evolved by the host to limit infection, replication and optimally, reinfection. Herpes simplex virus-1 (HSV-1) and herpes simplex virus-2 (HSV-2) infect humans at a high frequency and persist within the host for life by establishing latency in neurons. To gain access to these cells, herpes simplex viruses (HSVs) must replicate and block immediate host antiviral responses elicited by epithelial cells and innate immune components early after infection. During these processes, infected and noninfected neighboring cells, as well as tissue-resident and patrolling immune cells, will sense viral components and cell-associated danger signals and secrete soluble mediators. While type-I interferons aim at limiting virus spread, cytokines and chemokines will modulate resident and incoming immune cells. In this paper, we discuss recent findings relative to the early steps taking place during HSV infection and replication. Further, we discuss how HSVs evade detection by host cells and the molecular mechanisms evolved by these viruses to circumvent early antiviral mechanisms, ultimately leading to neuron infection and the establishment of latency.

Assuntos

Antivirais/química , Herpes Simples/virologia , Herpesvirus Humano 1/metabolismo , Animais , Apoptose , Sobrevivência Celular , Quimiocinas/metabolismo , Citocinas/metabolismo , Células Epiteliais/virologia , Herpes Simples/imunologia , Humanos , Imunidade Inata , Interferons/metabolismo , Neurônios/metabolismo , Neurônios/virologia , Transdução de Sinais , Replicação Viral

RESUMO

Here, we developed a simple method for obtaining a heterojunction composed of graphene (G) and surfactant-coated Au nanoparticles (NPs) to measure film conductivity and surface enhanced Raman scattering (SERS). Monolayer G is obtained by chemical vapor deposition (CVD) and transferred via poly(methyl methacrylate) (PMMA) to microfabricated Au electrodes, glass, and silicon. Post-synthesis treatments of G with PMMA and ozone (O3) showed 1 and 6 orders of magnitude decrease in film conductivity, respectively. The heterojunction formation with Au NPs had no major effect on G conductivity. In this work is demonstrated that G quenches more than 90% of the combined photoluminescence and fluorescence of Au NPs and Rhodamine B (RhB), respectively. Signal quenching permitted quantitative analysis of SERS of RhB on various substrates including as-transferred graphene, oxidized graphene (OG), and the heterojunction. While G is mainly responsible for quenching photoluminescence and fluorescence, ∼3 orders of magnitude increase SERS activity for RhB was accomplished by the heterojunction. Finally, we wanted to correlate changes in film current during UV light sensing experiments. We found striking differences in the sensing profiles at different UV energies.