Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
1.
J Cancer Res Clin Oncol ; 150(6): 291, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38836955

RESUMEN

PURPOSE: The neoadjuvant chemotherapy (NACT) regimen for triple negative breast cancer (TNBC) primarily consists of anthracyclines and taxanes, and the addition of platinum-based drugs can further enhance the efficacy. However, it is also accompanied by more adverse events, and considering the potential severe and irreversible toxicity of anthracyclines, an increasing number of studies are exploring nonanthracycline regimens that combine taxanes and platinum-based drugs. METHODS: The retrospective study included 273 stage II-III TNBC patients who received NACT. The AT group, consisting of 195 (71.4%) patients, received a combination of anthracyclines and taxanes, while the TCb group, consisting of 78 (28.6%) patients, received a combination of taxanes and carboplatin. Logistic regression analysis was performed to evaluate the factors influencing pathological complete response (pCR) and residual cancer burden (RCB). The log-rank test was used to assess the differences in event-free survival (EFS) and overall survival (OS) among the different treatment groups. Cox regression analysis was conducted to evaluate the factors influencing EFS and OS. RESULTS: After NACT and surgery, the TCb group had a higher rate of pCR at 44.9%, as compared to the AT group at 31.3%. The difference between the two groups was 13.6% (OR = 0.559, 95% CI 0.326-0.959, P = 0.035). The TCb group had a 57.7% rate of RCB 0-1, which was higher than the AT group's rate of 42.6%. The difference between the two groups was 15.1% (OR = 0.543, 95% CI 0.319-0.925, P = 0.024), With a median follow-up time of 40 months, the TCb group had better EFS (log-rank, P = 0.014) and OS (log-rank, P = 0.040) as compared to the AT group. Clinical TNM stage and RCB grade were identified as independent factors influencing EFS and OS, while treatment group was identified as an independent factor influencing EFS, with a close-to-significant impact on OS. CONCLUSION: In stage II-III triple TNBC patients, the NACT regimen combining taxanes and carboplatin yields higher rates of pCR and significant improvements in EFS and OS as compared to the regimen combining anthracyclines and taxanes.


Asunto(s)
Antraciclinas , Protocolos de Quimioterapia Combinada Antineoplásica , Carboplatino , Terapia Neoadyuvante , Taxoides , Neoplasias de la Mama Triple Negativas , Humanos , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/patología , Femenino , Estudios Retrospectivos , Carboplatino/administración & dosificación , Antraciclinas/administración & dosificación , Antraciclinas/uso terapéutico , Terapia Neoadyuvante/métodos , Persona de Mediana Edad , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Adulto , Taxoides/administración & dosificación , Taxoides/uso terapéutico , Anciano , Estadificación de Neoplasias
2.
Nanoscale ; 16(4): 1823-1832, 2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-38168975

RESUMEN

Here, a series of transition metal (Ni) doped iron-based perovskite oxides LaFe1-xNixO3-δ (x = 0, 0.25, 0.5, 0.75, 1) were prepared, and then the perovskite oxide with the optimized nickel-iron ratio was doped with non-metallic elements (N). Experimental and theoretical investigations reveal that the co-doping breaks the traditional linear constraint relationship (GOOH - GOH = 3.2 eV) and the theoretical overvoltage is reduced from 0.64 V (LaFeO3-δ) to 0.44 V (LaFe0.5Ni0.5O3-δ/N). Specifically, Ni-doping can accelerate electron transfer and improve the conductivity. Moreover, N-doping can reduce the adsorption energy of *OH/*O and enhance the adsorption energy of *OOH. We demonstrated that the optimized cation and anion co-doped LaFe0.5Ni0.5O3-δ/N perovskite oxide exhibits an excellent OER performance, with a low overpotential of 270.6 mV at 10 mA cm-2 and a small Tafel slope of 65 mV dec-1 in 1 M KOH solution, markedly exceeding that of the parent perovskite oxide LaFeO3-δ (300.9 mV) and commercial IrO2 (289.1 mV). It also delivers decent durability with no significant degradation after a 35 h stability test. This work reveals the internal mechanism of perovskite oxide by doping cation and anion for water oxidation, which broadens the idea for the rational design of new perovskite-based sustainable energy catalysts.

3.
BMC Med Genomics ; 16(1): 201, 2023 08 25.
Artículo en Inglés | MEDLINE | ID: mdl-37626362

RESUMEN

OBJECTIVE: To screen the possible potential signaling pathways related to enhancer of zeste homolog 2 (EZH2) based on ceRNA mechanism, and to analyze the correlation between E2H2 and depths of various immune cell infiltration depths. The relationship between different immune checkpoints were also analyzed. METHODS: First, the expression of EZH2 in pan-cancer (18 malignancies) was analyzed with the TCGA database. Hepatocellular carcinoma (HCC) tissues of 374 cases and normal tissues of 50 cases were analyzed in terms of the differential expression, overall survival (OS) and progression-free-survival (PFS). Then, we conducted GO and KEGG enrichment analysis on target gene. We also analyzed mRNA-miRNA and MicroRNA (miRNA)- long non-coding RNA (lncRNA) correlation with starbase databse, so as to determine the potential ceRNA mechanism associated with EZH2. Finally, immunoassay and drug-sensitivity analysis of EZH2 was performed. RESULTS: Seven potential EZH2-related ceRNA pathways were screened out, namely lncRNA: Small Nucleolar RNA Host Gene 1 (SNHG1), SNHG 3, and SNHG 6-miR-101-3p-EZH2; and lncRNA: Long Intergenic Non-Protein Coding RNA 1978 (LINC01978), SNHG12, Ring Finger Protein 216 Pseudogene 1 (RNF216P1), and Coiled-coil Domain Containing 18 Antisense RNA 1 (CCDC18-AS1)-let-7c-5p-EZH2. Finally, 4 potential EZH2-related ceRNA pathways were identified through qPCR.According to immune correlation analysis, EZH2 may be positively correlated with T cells follicular helper, T cells Cluster of differentiation (CD)4 memory activated, Macrophages M0, and B cells memory (P < 0.05, cof > 0.2); while be negatively correlated with T cells CD4 + memory resting (P < 0.05, cof < -0.2). And EZH2 is positively correlated with Programmed Cell Death 1 (PDCD1) (R = 0.22), CD274 (R = 0.3) and Cytotoxic T-Lymphocyte Associated Protein 4 (CTLA4) (R = 0.23). According to drug sensitivity analysis, patients in the high expression group were more susceptible to the effects of various drugs including Sorafenib, 5-Fluorouracil, Doxorubicin, Etoposide, Paclitaxel, and Vinorelbine than those with low expression. CONCLUSION: This study revealed seven potential pathways of Enhancer of Zeste Homolog 2 (EZH2)-related ceRNA mechanisms: lncRNA (SNHG3, 6) -Mir-101-3P-ezh2; lncRNA (SNHG12, RNF216P1)-let-7c-5p-EZH2. We also analyzed the immunity and drug sensitivity of EZH2. Our study proves that EZH2 still has great research prospects in HCC.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroARNs , ARN Largo no Codificante , Humanos , Carcinoma Hepatocelular/genética , Proteína Potenciadora del Homólogo Zeste 2/genética , ARN Largo no Codificante/genética , Neoplasias Hepáticas/genética , MicroARNs/genética , Inmunoensayo
4.
BMJ Open ; 12(5): e056374, 2022 05 30.
Artículo en Inglés | MEDLINE | ID: mdl-35636793

RESUMEN

INTRODUCTION: It is currently unclear which cyclin-dependent kinase 4/6 (CDK4/6) inhibitor, combined with endocrine therapy, is the preferred treatment approach in patients with hormone receptor (HR)-positive, human epidermal receptor-2 (HER2) negative metastatic breast cancer. The aim of this study was to evaluate the existing evidence for the comparative efficacy, safety and cost-effectiveness of different CDK4/6 inhibitors for metastatic breast cancer in first-line and second-line settings. METHODS AND ANALYSIS: We will systematically conduct a literature search in Embase, PubMed and the Cochrane Library and additional searches by handsearching citations of previous systematic reviews. We will also screen major conference proceedings (American Society of Clinical Oncology, European Society of Medical Oncology and San Antonio Breast Cancer Symposium). Preliminary scoping searches were conducted in July 2021, but the search will be updated when new trials are available. The primary outcome was progression-free survival. The secondary outcomes were overall survival, objective response rates, grade 3-4 haematological and non-haematological toxicities, quality-adjusted life years and incremental cost-effectiveness ratios. The risk of bias will be assessed by Cochrane risk of bias tools, and the quality of evidence will be assessed by the Grading of Recommendations Assessment, Development and Evaluation. Subgroup analyses and sensitivity analyses will be performed to further confirm our findings. In addition, one-way sensitivity analysis and probabilistic sensitivity analyses will be conducted to determine uncertainty. ETHICS AND DISSEMINATION: This study does not require ethics approval as only secondary data will be collected. The results of our study will provide an overview of the current level of CDK4/6 inhibitors for patients with HR-positive, HER2-negative metastatic breast cancer, and undertake subgroup analyses to explore variables that might affect these effects. The results of this study will be presented at an international clinical conference and published in a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42021266597.


Asunto(s)
Neoplasias de la Mama , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Análisis Costo-Beneficio , Quinasa 4 Dependiente de la Ciclina , Femenino , Hormonas/uso terapéutico , Humanos , Metaanálisis como Asunto , Metaanálisis en Red , Supervivencia sin Progresión , Revisiones Sistemáticas como Asunto
5.
Eur J Pharmacol ; 915: 174680, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34890544

RESUMEN

Most cases of pancreatic cancer develop in patients with chronic pancreatitis (CP). Berberine is natural product that exhibits anti-tumor effects in various types of cancer and is used in traditional Chinese medicine. In this study, we demonstrated that berberine inhibited the development of pancreatic intraepithelial neoplasia (PanIN) in an in vivo CP model and an in vitro acinar-to-ductal metaplasia model. As berberine may inhibit glycolysis during the development of PanIN, we measured indicators of glycolysis. Quantitative reverse transcription polymerase chain reaction and western blotting assays revealed that berberine activated the adenosine monophosphate-activated protein kinase (AMPK) pathway. This demonstrated that berberine suppressed glycolysis by targeting AMPK, a key metabolic sensor. Furthermore, berberine acted via the AMPK-hypoxia-inducible factor 1 alpha pathway to achieve suppression of PanIN. These findings show that berberine is a potential therapeutic candidate for preventing the progression of CP to PanIN.


Asunto(s)
Berberina
6.
J Dairy Sci ; 103(11): 9980-9991, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32952010

RESUMEN

Human milk is the main source of nutrition for infants and the transmission of various microorganisms. The lactic acid bacteria (LAB) in breast milk allow for the establishment of the gut microflora of infants. In this study, we aimed to assess the probiotic potential of LAB strains isolated from breast milk of healthy Chinese women. Two strains, Lacticaseibacillus rhamnosus (formerly Lactobacillus rhamnosus) LHL6 and LHL7, were selected and identified through morphology observation, Gram staining, and 16S rDNA phylogenetic analysis. Using Limosilactobacillus fermentum (formerly Lactobacillus fermentum) CECT5716 as the standard reference strain, the screened strains were characterized for aspects of growth, production of lactic acid and H2O2, antibiotic susceptibility, survival under simulated gastrointestinal conditions, and tolerance to cadmium (Cd). In de Man, Rogosa, and Sharpe (MRS) broth, LHL6 and LHL7 showed longer lag phases than CECT5716 but higher specific growth rates. For the production of lactic acid and H2O2, LHL7 performed better than LHL6 and CECT5716, indicating better antimicrobial ability. Strain LHL7 generated 9.99 mg/L H2O2, considerably higher than 1.25 mg/L for LHL6 and 2.33 mg/L for CECT5716. According to European Food Safety Authority minimum inhibitory concentrations, all of the investigated strains were resistant to chloramphenicol, streptomycin, and kanamycin. However, unlike LHL6 and CECT5716, LHL7 was susceptible to ampicillin and resistant to tetracycline. Resistance to azithromycin, cephalexin, and penicillin G were similar for all 3 strains, whereas CECT5716 was resistant to a higher concentration of roxithromycin. All 3 strains were able to survive in a simulated gastric-like solution, but a low percentage survived in the presence of 0.4% bile salt and 7% pancreatin. Encapsulation with protectants may enhance the survival rate. All 3 strains were tolerant to 500 mg/L Cd in MRS broth and to 1,000 mg/L Cd on MRS agar medium. In summary, 2 novel strains of LAB were obtained that have similar characteristics to the reference strain CECT5716. This work identified potential probiotic candidates for application in the food and pharmaceutical industries and facilitated identification of further probiotics.


Asunto(s)
Antibacterianos/farmacología , Lacticaseibacillus rhamnosus/aislamiento & purificación , Lactobacillales/aislamiento & purificación , Limosilactobacillus fermentum/aislamiento & purificación , Leche Humana/microbiología , Probióticos/farmacología , Animales , Inocuidad de los Alimentos , Humanos , Peróxido de Hidrógeno/metabolismo , Ácido Láctico/metabolismo , Lactobacillales/efectos de los fármacos , Lactobacillales/genética , Lactobacillales/crecimiento & desarrollo , Limosilactobacillus fermentum/efectos de los fármacos , Limosilactobacillus fermentum/genética , Lacticaseibacillus rhamnosus/efectos de los fármacos , Lacticaseibacillus rhamnosus/genética , Lacticaseibacillus rhamnosus/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Filogenia
7.
Cell Biol Int ; 44(7): 1447-1457, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32159250

RESUMEN

Esophageal squamous cell carcinoma (ESCC) belongs to one of the most common malignant tumors worldwide and possesses high mortality. Long non-coding RNAs (lncRNAs) have been demonstrated to be essential biological participants in the progression of ESCC. On the basis of bio-informatics prediction, forkhead box P4 antisense RNA 1 (FOXP4-AS1) and forkhead box P4 (FOXP4) were upregulated in esophageal carcinoma samples and were positively correlated with each other. The present study aimed to explore the function of FOXP4-AS1 and FOXP4 in ESCC cells. Function assays disclosed that knockdown of FOXP4-AS1 or FOXP4 efficiently suppressed cell proliferation and induced cell apoptosis. Moreover, FOXP4-AS1 positively regulated FOXP4 by interacting with insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) to stabilize FOXP4 messenger RNA. In addition, FOXP4-AS1 could upregulate the expression of FOXP4 by sponging miR-3184-5p. Finally, we found that Yin Yang 1 (YY1) is a transcription factor that can transcriptionally activate both FOXP4-AS1 and FOXP4 in ESCC cells. In a word, YY1-induced upregulation of FOXP4-AS1 and FOXP4 promote the proliferation of ESCC cells.


Asunto(s)
Proliferación Celular/genética , Neoplasias Esofágicas/patología , Factores de Transcripción Forkhead/genética , Regulación Neoplásica de la Expresión Génica/genética , Factor de Transcripción YY1/genética , Línea Celular Tumoral , Neoplasias Esofágicas/genética , Carcinoma de Células Escamosas de Esófago/genética , Carcinoma de Células Escamosas de Esófago/patología , Neoplasias de Cabeza y Cuello/genética , Humanos , Neoplasias de la Boca/genética , ARN sin Sentido/genética , ARN Largo no Codificante/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Regulación hacia Arriba , Factor de Transcripción YY1/metabolismo
8.
Dis Markers ; 2019: 6328503, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31198475

RESUMEN

Biomarkers, including DNA methylation, have shown a great potential for use in personalized medicine for BC and especially for the diagnosis of BC in developing countries. According to the bisulfite sequencing PCR in twelve specimens (BC and matched normal tissues), nine genetic probes were designed to detect the frequency of methylation of the promoters in a total of 302 paired cases of BC and matched normal breast tissues. Finally, a total of 900 serum samples were used to validate the use of these methylation biomarkers for clinical diagnosis of BC. A high frequency of promoter methylation of SFN, HOXA11, P16, RARß, PCDHGB7, hMLH1, WNT5a, HOXD13, and RASSF1a was observed in BC tissues. The methylation frequencies of HOXD13 and hMLH1 increased with the progression of BC. The methylation frequencies of HOXD13 and WNT5a were significantly higher in BC. We found that methylation modification-positive samples were most consistently associated with luminal BC. Finally, we confirmed that RASSF1a, P16, and PCDHGB7 displayed a significant sensitivity and specificity as diagnostic biomarkers for BC (P < 0.001), and a panel that combined these three genes displayed increased significance (AUC, 0.781; P < 0.001). These data suggest that epigenetic markers in serum can potentially be used to diagnose BC. The identification of additional BC-specific methylated genes would improve the sensitivity and specificity of this approach. This study could also indicate that different molecular subtypes of BC are caused by distinct genetic and epigenetic mechanisms.


Asunto(s)
Biomarcadores de Tumor/genética , Metilación de ADN , Neoplasias de la Vejiga Urinaria/genética , Adulto , Biomarcadores de Tumor/normas , Femenino , Proteínas de Homeodominio/genética , Humanos , Masculino , Persona de Mediana Edad , Homólogo 1 de la Proteína MutL/genética , Regiones Promotoras Genéticas , Factores de Transcripción/genética , Proteínas Supresoras de Tumor/genética , Neoplasias de la Vejiga Urinaria/patología , Proteína Wnt-5a/genética
9.
J Ethnopharmacol ; 219: 195-201, 2018 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-29481852

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: The Yao ethnic group in Xuefeng Mountains area have used Xuefeng cordyceps, the caterpillar-fungus complex of Ophiocordyceps xuefengensis, for treating a variety of diseases for long. Just like some other cordyceps, O. xuefengensis, which is identified as the sister taxon of O. sinensis in 2013, also seems to have broad pharmacological properties, not only enhancing human immunity, anti-bacteria, anti-virus, but also anti-tumor. However, investigation of the medicinal fugal species O. xuefengensis can be found only in few literature records since its pharmacological and therapeutic use is mainly in traditional Yao communities by local healers. AIM OF THE STUDY: The aim of this study is to collect samples of Xuefeng cordyceps and isolate the strain of O. xuefengensis, to determine bioactive components and evaluate the anti-tumor activity, to obtain the gene expression profile of O. xuefengensis and reveal its pharmacological properties by de novo transcriptome analysis. Accordingly, we attempt to provide information and give a comprehensive understanding of this mysterious medicinal fugal species from traditional Yao communities of China. MATERIAL AND METHODS: Bioactive components were determined with HPLC-DAD-Q-TOF-MS technology; in vitro anti-tumor activity against 6 cell lines was evaluated using standard MTT assay; transcriptome analysis was done by de novo sequencing; unique genes were functionally profiled basing on Gene Ontology Database and the targeted genes were examined by blast. RESULTS: Trace cordycepin, an anti-tumor agent, was detected in O. xuefengensis water extract. To some extent, the raw water extract of O. xuefengensis showed in vitro anti-tumor activity, against A549, HepG2, MCF-7, PC-3 and Raji cell lines. A total of 94,858 transcripts and 49,001 unique genes were obtained, amongst, 43.4% unique genes were matched with those of O. sinensis. Not all supposed genes related to cordycepin biosynthetic pathways were found by transcriptome analysis. CONCLUSION: According to the gene expression profile, O. xuefengensis is very close to medicinal fungus O. sinensis. Raw water extract of O. xuefengensis, to a certain degree, could inhibit the growth of tumor cells, indicating that this fungus could be a new resource for the exploration of anti-tumor drug.


Asunto(s)
Antineoplásicos/aislamiento & purificación , Antineoplásicos/farmacología , Cordyceps/genética , Perfilación de la Expresión Génica/métodos , Medicina Tradicional China/métodos , Células A549 , Animales , Proliferación Celular/efectos de los fármacos , Proliferación Celular/fisiología , Células HT29 , Células HeLa , Células Hep G2 , Humanos , Células MCF-7 , Medicina Tradicional China/tendencias
10.
Tumour Biol ; 37(10): 12969-12981, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27449047

RESUMEN

Protocadherins (PCDHs) are a group of transmembrane proteins belonging to the cadherin superfamily and are subdivided into "clustered" and "non-clustered" groups. PCDHs vary in both structure and interaction partners and thus regulate multiple biological responses in complex and versatile patterns. Previous researches showed that PCDHs regulated the development of brain and were involved in some neuronal diseases. Recently, studies have revealed aberrant expression of PCDHs in various human malignant tumors. The down-regulation or absence of PCDHs in malignant cells has been associated with cancer progression. Further researches suggest that PCDHs may play major functions as tumor suppressor by inhibiting the proliferation and metastasis of cancer cells. In this review, we focus on the altered expression of PCDHs and their roles in the development of cancer progression. We also discuss the potential mechanisms, by which PCDHs are aberrantly expressed, and its implications in regulating cancers.


Asunto(s)
Cadherinas/metabolismo , Neoplasias/metabolismo , Neoplasias/patología , Cadherinas/clasificación , Humanos
11.
Oncotarget ; 7(14): 18485-94, 2016 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-26918343

RESUMEN

Detection of breast cancer at an early stage is the key for successful treatment and improvement of outcome. However the limitations of mammography are well recognized, especially for those women with premenopausal breast cancer. Novel approaches to breast cancer screening are necessary, especially in the developing world where mammography is not feasible. In this study, we examined the promoter methylation of six genes (SFN, P16, hMLH1, HOXD13, PCDHGB7 and RASSF1a) in circulating free DNA (cfDNA) extracted from serum. We used a high-throughput DNA methylation assay (MethyLight) to examine serum from 749 cases including breast cancer patients, patients with benign breast diseases and healthy women. The six-gene methylation panel test achieved 79.6% and 82.4% sensitivity with a specificity of 72.4% and 78.1% in diagnosis of breast cancer when compared with healthy and benign disease controls, respectively. Moreover, the methylation panel positive group showed significant differences in the following independent variables: (a) involvement of family history of tumors; (b) a low proliferative index, ki-67; (c) high ratios in luminal subtypes. Additionally the panel also complemented some breast cancer cases which were neglected by mammography or ultrasound. These data suggest that epigenetic markers in serum have potential for diagnosis of breast cancer.


Asunto(s)
Neoplasias de la Mama/genética , Metilación de ADN , ADN de Neoplasias/sangre , ADN de Neoplasias/genética , Adulto , Biomarcadores de Tumor/sangre , Biomarcadores de Tumor/genética , Neoplasias de la Mama/sangre , Neoplasias de la Mama/patología , Estudios de Casos y Controles , Detección Precoz del Cáncer , Femenino , Humanos , Persona de Mediana Edad , Regiones Promotoras Genéticas
12.
Huan Jing Ke Xue ; 30(1): 91-5, 2009 Jan.
Artículo en Chino | MEDLINE | ID: mdl-19353863

RESUMEN

20 strains of bacteria were isolated from river sediment using enrichment culture medium for denitrification, and the denitrification intensity was determined. F10, one of bacteria strain, was identified having the highest denitrifying intensity, and further used to test its role in the removing of nitrogen and phosphorus from wastewater in laboratory. By checking the individual morphology, colony culture characteristics, DNA sequencing and 16S rDNA gene bank, F10 was identified as Alcaligenes faecalis, and its denitrifying intensity was 63.2%. The highest removal of TN (76.2%) and TP (93.8%) were observed in a 10 days period with an addition of F10 at a rate of 100 mg/L.


Asunto(s)
Alcaligenes faecalis/aislamiento & purificación , Sedimentos Geológicos/microbiología , Nitrógeno/metabolismo , Fósforo/metabolismo , Contaminantes Químicos del Agua/metabolismo , Alcaligenes faecalis/metabolismo , Biodegradación Ambiental , Ríos , Purificación del Agua/métodos
13.
J Med Entomol ; 45(6): 1117-25, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19058637

RESUMEN

To test the hypothesis that enzootic and epidemic Venezuelan equine encephalitis (VEE) complex alphaviruses can infect and be transmitted by Ae. aegypti, we conducted a series of experimental infection studies. One set of experiments tested the susceptibility of geographic strains of Ae. aegypti from Peru and Texas (U.S.A.) for epidemic (subtype IC) and enzootic (subtype ID) strains from Colombia/Venezuela, whereas the second set of experiments tested the susceptibility of Ae. aegypti from Iquitos, Peru, to enzootic VEE complex strains (subtypes ID, IIIC, and IIID) isolated in the same region, at different infectious doses. Experimental infections using artificial bloodmeals suggested that Ae. aegypti mosquitoes, particularly the strain from Iquitos, Peru, is moderately to highly susceptible to all of these VEE complex alphaviruses. The occurrence of enzootic VEE complex viruses circulating endemically in Iquitos suggests the possibility of a dengue-like transmission cycle among humans in tropical cities.


Asunto(s)
Aedes/virología , Virus de la Encefalitis Equina Venezolana/patogenicidad , Encefalomielitis Equina Venezolana/transmisión , Interacciones Huésped-Patógeno , Animales , Perú , Especificidad de la Especie , Texas
14.
Am J Trop Med Hyg ; 78(3): 413-21, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18337337

RESUMEN

Venezuelan equine encephalitis virus (VEEV) continues to circulate enzootically in Mexico with the potential to re-emerge and cause disease in equines and humans in North America. We infected two geographically distinct mosquito populations of eastern Psorophora columbiae form columbiae (Chiapas, Mexico and Texas, United States) and one mosquito population of western Psorophora columbiae form toltecum (California, United States) with epizootic and enzootic IE VEEV and epizootic IAB VEEV. We detected no differences between epizootic and enzootic IE viruses in their ability to infect any of the mosquito populations analyzed, which suggested that neither species selects for epizootic IE viruses. Psorophora columbiae f. columbiae (Texas) were significantly less susceptible to infection by epizootic IE than Ps. columbiae f. columbiae (Mexico). Psorophora columbiae f. toltecum populations were more susceptible than Ps. columbiae f. columbiae populations to epizootic IE and IAB viruses.


Asunto(s)
Culicidae/virología , Virus de la Encefalitis Equina Venezolana/fisiología , Insectos Vectores/virología , Animales , Chlorocebus aethiops , Cricetinae , Culicidae/clasificación , Virus de la Encefalitis Equina Venezolana/clasificación , Virus de la Encefalitis Equina Venezolana/genética , Femenino , Genotipo , Mesocricetus , Serotipificación , Células Vero
15.
J Virol ; 82(10): 4920-30, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18353963

RESUMEN

Eastern equine encephalitis virus (EEEV) causes sporadic epidemics of human and equine disease in North America, but South American strains have seldom been associated with human neurologic disease or mortality, despite serological evidence of infection. In mice, most North American and South American strains of EEEV produce neurologic disease that resembles that associated with human and equine infections. We identified a South American strain that is unable to replicate efficiently in the brain or cause fatal disease in mice yet produces 10-fold higher viremia than virulent EEEV strains. The avirulent South American strain was also sensitive to human interferon (IFN)-alpha, -beta, and -gamma, like most South American strains, in contrast to North American strains that were highly resistant. To identify genes associated with IFN sensitivity and virulence, infectious cDNA clones of a virulent North American strain and the avirulent South American strain were constructed. Two reciprocal chimeric viruses containing swapped structural and nonstructural protein gene regions of the North American and South American strains were also constructed and found to replicate efficiently in vitro. Both chimeras produced fatal disease in mice, similar to that caused by the virulent North American strain. Both chimeric viruses also exhibited intermediate sensitivity to human IFN-alpha, -beta, and -gamma compared to that of the North American and South American strains. Virulence 50% lethal dose assays and serial sacrifice experiments further demonstrated that both structural and nonstructural proteins are important contributors to neurovirulence and viral tissue tropism. Together, the results of this study emphasize the complex and important influences of structural and nonstructural protein gene regions on EEEV virulence.


Asunto(s)
Virus de la Encefalitis Equina del Este/inmunología , Virus de la Encefalitis Equina del Este/patogenicidad , Interferones/inmunología , Proteínas no Estructurales Virales/inmunología , Proteínas no Estructurales Virales/fisiología , Proteínas Estructurales Virales/inmunología , Proteínas Estructurales Virales/fisiología , Animales , Virus de la Encefalitis Equina del Este/genética , Virus de la Encefalitis Equina del Este/crecimiento & desarrollo , Encefalomielitis Equina/virología , Dosificación Letal Mediana , Ratones , Análisis de Supervivencia , Ensayo de Placa Viral , Viremia , Virulencia
16.
J Virol ; 81(24): 13552-65, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17913819

RESUMEN

The encephalitogenic New World alphaviruses, including Venezuelan (VEEV), eastern (EEEV), and western equine encephalitis viruses, constitute a continuing public health threat in the United States. They circulate in Central, South, and North America and have the ability to cause fatal disease in humans and in horses and other domestic animals. We recently demonstrated that these viruses have developed the ability to interfere with cellular transcription and use it as a means of downregulating a cellular antiviral response. The results of the present study suggest that the N-terminal, approximately 35-amino-acid-long peptide of VEEV and EEEV capsid proteins plays the most critical role in the downregulation of cellular transcription and development of a cytopathic effect. The identified VEEV-specific peptide C(VEE)33-68 includes two domains with distinct functions: the alpha-helix domain, helix I, which is critically involved in supporting the balance between the presence of the protein in the cytoplasm and nucleus, and the downstream peptide, which might contain a functional nuclear localization signal(s). The integrity of both domains not only determines the intracellular distribution of the VEEV capsid but is also essential for direct capsid protein functioning in the inhibition of transcription. Our results suggest that the VEEV capsid protein interacts with the nuclear pore complex, and this interaction correlates with the protein's ability to cause transcriptional shutoff and, ultimately, cell death. The replacement of the N-terminal fragment of the VEEV capsid by its Sindbis virus-specific counterpart in the VEEV TC-83 genome does not affect virus replication in vitro but reduces cytopathogenicity and results in attenuation in vivo. These findings can be used in designing a new generation of live, attenuated, recombinant vaccines against the New World alphaviruses.


Asunto(s)
Proteínas de la Cápside/metabolismo , Proteínas de la Cápside/farmacología , Virus de la Encefalitis Equina Venezolana/patogenicidad , Proteínas/metabolismo , Transcripción Genética/efectos de los fármacos , Animales , Proteínas de la Cápside/genética , Supervivencia Celular , Cricetinae , Efecto Citopatogénico Viral , Virus de la Encefalitis Equina Venezolana/genética , Virus de la Encefalitis Equina Venezolana/metabolismo , Encefalomielitis Equina Venezolana/mortalidad , Encefalomielitis Equina Venezolana/patología , Encefalomielitis Equina Venezolana/virología , Femenino , Inmunización , Ratones , Mutación , Proteínas/genética
17.
Vaccine ; 25(43): 7573-81, 2007 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-17904699

RESUMEN

We developed chimeric Sindbis (SINV)/eastern equine encephalitis (EEEV) viruses and investigated their potential for use as live virus vaccines against EEEV. One vaccine candidate contained structural protein genes from a typical North American EEEV strain, while the other had structural proteins from a naturally attenuated Brazilian isolate. Both chimeric viruses replicated efficiently in mammalian and mosquito cell cultures and were highly attenuated in mice. Vaccinated mice did not develop detectable disease or viremia, but developed high titers of neutralizing antibodies. Upon challenge with EEEV, mice vaccinated with >10(4) PFU of the chimeric viruses were completely protected from disease. These findings support the potential use of these SIN/EEEV chimeras as safe and effective vaccines.


Asunto(s)
Virus de la Encefalitis Equina del Este/inmunología , Encefalomielitis Equina Oriental/inmunología , Virus Sindbis/inmunología , Vacunas Atenuadas/inmunología , Vacunas Virales/inmunología , Animales , Anticuerpos Antivirales/sangre , Temperatura Corporal , Peso Corporal , Células Cultivadas , Chlorocebus aethiops , ADN Recombinante/genética , ADN Recombinante/inmunología , Virus de la Encefalitis Equina del Este/genética , Encefalomielitis Equina Oriental/prevención & control , Ensayo de Inmunoadsorción Enzimática , Femenino , Ratones , Plásmidos/genética , Plásmidos/inmunología , Embarazo , Virus Sindbis/genética , Vacunas Atenuadas/administración & dosificación , Vacunas Atenuadas/genética , Células Vero , Vacunas Virales/administración & dosificación , Vacunas Virales/genética
18.
J Environ Sci (China) ; 18(1): 201-6, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-20050573

RESUMEN

Manure odor, which results in the increasing complaints and lawsuits, has increased the tension among swine producers and surrounding residents. The effects of Lactobacillus plantarum and different rates of soluble carbohydrates additions to swine manure on odorous compounds, chemical compounds and indigenous flora were evaluated. Additions were calculated on dried manure weight basis. Variables monitored included ammonia (NH3), hydrogen sulfide (H2S), odor offensiveness, pH, ammonium nitrogen (NH4(+)-N), volatile fatty acids (VFAs), urease and indigenous flora. The results indicated that the combination of L. plantarum and soluble carbohydrates dramatically reduced manure pH. Lower pH resulted in the reduction of NH3 volatilization (34.6%-92.4%, P < 0.01), the increases of H2S (P < 0.05) and NH4(+)-N (5.3%-17.5%, P < 0.05). In addition, L. plantarum and soluble carbohydrates additions significantly reduced odor offensiveness, those VFAs related to malodor indicators (valeric acids, 12.3%-47.7%, P < 0.05; iso-valeric, 3.5%-23.8%) and the main microorganisms responsible for odor production, with the number of Eubacteria in swine manure reducing by 4.9%, 11.6%, 17.4%, 34.1% and 32.2% respectively.


Asunto(s)
Metabolismo de los Hidratos de Carbono , Lactobacillus plantarum/metabolismo , Estiércol/microbiología , Odorantes , Amoníaco/metabolismo , Animales , Ácidos Grasos/metabolismo , Sulfuro de Hidrógeno/metabolismo , Concentración de Iones de Hidrógeno , Porcinos , Compuestos Orgánicos Volátiles
19.
Am J Trop Med Hyg ; 72(6): 805-10, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15964967

RESUMEN

An epitope-blocking enzyme-linked immunosorbent assay was developed for the rapid differentiation of serologic responses to enzootic variety IE and ID versus epizootic variety IAB and IC strains of Venezuelan equine encephalitis (VEE) virus. Two monoclonal antibodies that differentially recognize epizootic versus enzootic VEE virus epitopes were used to measure the serotype-specific blocking abilities of antibodies in sera of naturally infected humans, equines, and bovines, as well as in experimentally infected equines. The assay is simple, species-independent, rapid, and sensitive, and will improve surveillance for VEE emergence. It could also be used to determine the epidemic potential of a VEE virus following an intentional introduction for bioterrorism.


Asunto(s)
Anticuerpos Antivirales/sangre , Virus de la Encefalitis Equina Venezolana/aislamiento & purificación , Animales , Bovinos , Línea Celular , Cricetinae , Virus de la Encefalitis Equina Venezolana/clasificación , Virus de la Encefalitis Equina Venezolana/inmunología , Encefalomielitis Equina Venezolana/epidemiología , Ensayo de Inmunoadsorción Enzimática , Caballos/sangre , Humanos , Sensibilidad y Especificidad , Especificidad de la Especie
20.
Emerg Infect Dis ; 10(12): 2113-21, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15663847

RESUMEN

Equine epizootics of Venezuelan equine encephalitis (VEE) occurred in the southern Mexican states of Chiapas in 1993 and Oaxaca in 1996. To assess the impact of continuing circulation of VEE virus (VEEV) on human and animal populations, serologic and viral isolation studies were conducted in 2000 to 2001 in Chiapas State. Human serosurveys and risk analyses indicated that long-term endemic transmission of VEEV occurred among villages with seroprevalence levels of 18% to 75% and that medical personnel had a high risk for VEEV exposure. Seroprevalence in wild animals suggested cotton rats as possible reservoir hosts in the region. Virus isolations from sentinel animals and genetic characterizations of these strains indicated continuing circulation of a subtype IE genotype, which was isolated from equines during the recent VEE outbreaks. These data indicate long-term enzootic and endemic VEEV circulation in the region and continued risk for disease in equines and humans.


Asunto(s)
Encefalomielitis Equina Venezolana/epidemiología , Animales , Animales Salvajes/virología , Virus de la Encefalitis Equina Venezolana/genética , Virus de la Encefalitis Equina Venezolana/aislamiento & purificación , Encefalomielitis Equina Venezolana/veterinaria , Genoma Viral , Enfermedades de los Caballos/epidemiología , Enfermedades de los Caballos/virología , Caballos , Humanos , México/epidemiología , Filogenia , ARN Viral , Factores de Riesgo , Vigilancia de Guardia , Estudios Seroepidemiológicos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA