Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 193
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
BMC Cancer ; 24(1): 176, 2024 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-38317094

RESUMEN

BACKGROUND: This study aimed to evaluate the efficacy and side effects of first-line afatinib treatment in a real-world setting in Vietnam. METHODS: This retrospective study was conducted across nine hospitals in Vietnam. Advanced epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) patients who received afatinib as first-line therapy between April 2018 and June 2022 were included, and patient medical records were reviewed. Key outcomes were overall response rate (ORR), time-to-treatment failure (TTF), and tolerability. RESULTS: A total of 343 patients on first-line afatinib were eligible for the study. EGFR exon 19 deletion (Del19) alone was detected in 46.9% of patients, L858R mutation alone in 26.3%, and other uncommon EGFR mutations, including compound mutations, in 26.8%. Patients with brain metastases at baseline were 25.4%. Patients who received 40 mg, 30 mg, and 20 mg as starting doses of afatinib were 58.6%, 39.9%, and 1.5%, respectively. The ORR was 78.1% in the overall population, 82.6% in the Del19 mutation subgroup, 73.3% in the L858R mutation subgroup, and 75.0% in the uncommon mutation subgroup (p > 0.05). The univariate and multivariate analyses indicate that the ORR increased when the starting dose was 40 mg compared to starting doses below 40 mg (83.9% vs. 74.3%, p = 0.034). The median TTF (mTTF) was 16.7 months (CI 95%: 14.8-18.5) in all patients, with a median follow-up time of 26.2 months. The mTTF was longer in patients in the common EGFR mutation subgroup (Del19/L858R) than in those in the uncommon mutation subgroup (17.5 vs. 13.8 months, p = 0.045) and in those without versus with brain metastases at baseline (17.5 vs. 15.1 months, p = 0.049). There were no significant differences in the mTTF between subgroups based on the starting dose of 40 mg and < 40 mg (16.7 vs. 16.9 months, p > 0.05). The most common treatment-related adverse events (any grade/grade ≥ 3) were diarrhea (55.4%/3.5%), rash (51.9%/3.2%), paronychia (35.3%/5.0%), and stomatitis (22.2%/1.2%). CONCLUSIONS: Afatinib demonstrated clinical effectiveness and good tolerability in Vietnamese EGFR-mutant NSCLC patients. In our real-world setting, administering a starting dose below 40 mg might result in a reduction in ORR; however, it might not have a significant impact on TTF.


Asunto(s)
Afatinib , Neoplasias Encefálicas , Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Afatinib/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/secundario , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Estudios de Cohortes , Receptores ErbB/genética , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Mutación , Inhibidores de Proteínas Quinasas/uso terapéutico , Estudios Retrospectivos , Vietnam/epidemiología
2.
Bioorg Med Chem Lett ; 98: 129566, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38008338

RESUMEN

In this study, new indol-fused pyrano[2,3-d]pyrimidines were designed and synthesized. These products were obtained in moderate to good yields and their structures were assigned by NMR, MS, and IR analysis. Afterwards, the biological important of the products was highlighted by evaluating in vitro for α-glucosidase inhibitory activity as well as acetylcholinesterase (AChE) inhibitory activity. Eleven products revealed substantial inhibitory activity against α-glucosidase enzyme, among which, two most potent products 11d,e were approximately 93-fold more potent than acarbose as a standard antidiabetic drug. Besides that, product 11k exhibited good AChE inhibition. The substituents on the 5-phenyl ring, attached to the pyran ring, played a critical role in inhibitory activities. The biological potencies have provided an opportunity to further investigations of indol-fused pyrano[2,3-d]pyrimidines as potential anti-diabetic agents.


Asunto(s)
Inhibidores de la Colinesterasa , Inhibidores de Glicósido Hidrolasas , Acetilcolinesterasa/metabolismo , alfa-Glucosidasas/metabolismo , Inhibidores de Glicósido Hidrolasas/farmacología , Inhibidores de Glicósido Hidrolasas/química , Hipoglucemiantes/farmacología , Simulación del Acoplamiento Molecular , Piranos/farmacología , Piranos/química , Pirimidinas/farmacología , Pirimidinas/química , Relación Estructura-Actividad , Inhibidores de la Colinesterasa/química , Inhibidores de la Colinesterasa/farmacología
3.
Bioorg Med Chem Lett ; 104: 129714, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38522589

RESUMEN

A series of new fluorinated dihydrofurano-napthoquinone compounds were sucessfully synthesized in good yields using microwave-assisted multi-component reactions of 2-hydroxy-1,4-naphthoquinone, fluorinated aromatic aldehydes, and pyridinium bromide. The products were fully characterized using spectroscopic techniques and evaluated for their anti-inflammatory activity using lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. Among 12 new compounds, compounds 8b, 8d, and 8e showed high potent NO inhibitory activity in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells with IC50 values ranging from 1.54 to 3.92 µM. The levels of pro-inflammatory cytokines IL-1ß and IL-6 in LPS-stimulated RAW264.7 macrophages were remarkably decreased after the application of 8b, 8d, 8e and 8k. Molecular docking simulations revealed structure-activity relationships of 8b, 8d, and 8e toward NO synthase, cyclooxygenase (COX-2 over COX-1), and prostaglandin E synthase-1 (mPGES-1). Further physicochemical and pharmacokinetic computations also demonstrated the drug-like characteristics of synthesized compounds. These findings demonstrated the importance of fluorinated dihydrofurano-napthoquinone moieties in the development of potential anti-inflammatory agents.


Asunto(s)
Antiinflamatorios no Esteroideos , Naftoquinonas , Animales , Ratones , Ciclooxigenasa 2/metabolismo , Citocinas/metabolismo , Lipopolisacáridos/farmacología , Simulación del Acoplamiento Molecular , Naftoquinonas/síntesis química , Naftoquinonas/química , Naftoquinonas/farmacología , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II , Células RAW 264.7 , Antiinflamatorios no Esteroideos/síntesis química , Antiinflamatorios no Esteroideos/química , Antiinflamatorios no Esteroideos/farmacología , Macrófagos/efectos de los fármacos
4.
Fish Shellfish Immunol ; 144: 109293, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38104696

RESUMEN

Asian seabass (Lates calcarifer) holds significant economic value in fish farming in the Asia-Pacific region. Vibriosis caused by Vibrio harveyi (Vh) is a severe infectious disease affecting intensive farming of this species, for which prevention strategies by vaccination have been developed. This study investigated an alternative approach to injectable vaccination to prevent vibriosis in Asian seabass juveniles. The strategy begins with an immersion prime vaccination with a heat-inactivated Vh vaccine, followed by two oral booster doses administered at 14- and 28-days post-vaccination (dpv). Expression of five immune genes TNFα, IL1ß, CD4, CD8, and IgM in the head kidney and spleen, along with investigation of anti-Vh antibody response (IgM) in both systemic and mucosal systems, was conducted on a weekly basis. The efficacy of the vaccines was assessed by a laboratory challenge test at 43 dpv. The results showed that the immunized fish displayed higher levels of mRNA transcripts of the immune genes after the immersion prime and the first oral booster dose compared to the control group. The expression levels peaked at 14 and 28 dpv and then declined to baseline at 35 and 42 dpv. Serum specific IgM antibodies were detected as early as 7 dpv (the first time point investigated) and exhibited a steady increase, reaching the first peak at 21 dpv, and a second peak at 35 dpv. Although the antibody levels gradually declined over subsequent weeks, they remained significantly higher than the control group throughout the experiment. A similar antibody response pattern was also observed in the mucosal compartment. The laboratory challenge test demonstrated high protection by injection with 1.65 × 104 CFU/fish, with a relative percent of survival (RPS) of 72.22 ± 7.86 %. In conclusion, our findings highlight the potential of an immersion prime-oral booster vaccination strategy as a promising approach for preventing vibriosis in Asian seabass.


Asunto(s)
Vacunas Bacterianas , Lubina , Enfermedades de los Peces , Perciformes , Vibriosis , Animales , Enfermedades de los Peces/prevención & control , Inmersión , Inmunidad , Inmunoglobulina M , Vacunación/métodos , Vacunación/veterinaria , Vacunas de Productos Inactivados , Vibriosis/prevención & control , Vibriosis/veterinaria , Vacunas Bacterianas/administración & dosificación
5.
Fish Shellfish Immunol ; 149: 109557, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38608847

RESUMEN

Immersion vaccination, albeit easier to administer than immunization by injection, sometimes has challenges with antigen uptake, resulting in sub-optimal protection. In this research, a new strategy to enhance antigen uptake of a heat-inactivated Vibrio harveyi vaccine in Asian seabass (Lates calcarifer) using oxygen nanobubble-enriched water (ONB) and positively charged chitosan (CS) was explored. Antigen uptake in fish gills was assessed, as was the antibody response and vaccine efficacy of four different combinations of vaccine with ONB and CS, and two control groups. Pre-mixing of ONB and CS before introducing the vaccine, referred to as (ONB + CS) + Vac, resulted in superior antigen uptake and anti-V. harveyi antibody (IgM) production in both serum and mucus compared to other formulas. The integration of an oral booster (4.22 × 108 CFU/g, at day 21-25) within a vaccine trial experiment set out to further evaluate how survival rates post exposure to V. harveyi might be improved. Antibody responses were measured over 42 days, and vaccine efficacy was assessed through an experimental challenge with V. harveyi. The expression of immune-related genes IL1ß, TNFα, CD4, CD8, IgT and antibody levels were assessed at 1, 3, and 7-day(s) post challenge (dpc). The results revealed that antibody levels in the group (ONB + CS) + Vac were consistently higher than the other groups post immersion immunization and oral booster, along with elevated expression of immune-related genes after challenge with V. harveyi. Ultimately, this group demonstrated a significantly higher relative percent survival (RPS) of 63 % ± 10.5 %, showcasing the potential of the ONB-CS-Vac complex as a promising immersion vaccination strategy for enhancing antigen uptake, stimulating immunological responses, and improving survival of Asian seabass against vibriosis.


Asunto(s)
Vacunas Bacterianas , Quitosano , Enfermedades de los Peces , Vacunación , Vibriosis , Vibrio , Animales , Vibrio/inmunología , Enfermedades de los Peces/prevención & control , Enfermedades de los Peces/inmunología , Quitosano/administración & dosificación , Vibriosis/veterinaria , Vibriosis/prevención & control , Vibriosis/inmunología , Vacunas Bacterianas/inmunología , Vacunas Bacterianas/administración & dosificación , Vacunación/veterinaria , Oxígeno , Lubina/inmunología , Vacunas de Productos Inactivados/inmunología , Vacunas de Productos Inactivados/administración & dosificación
6.
J Fish Dis ; 47(8): e13964, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38798108

RESUMEN

Asian seabass, Lates calcarifer, is an important aquatic species in mariculture. Intensive farming of this species has faced episodes of bacterial diseases, including those due to vibriosis, scale drop, and muscle necrosis disease, big belly disease, photobacteriosis, columnaris, streptococcosis, aeromoniasis, and tenacibaculosis. Vaccination is one of the most efficient, non-antibiotic, and eco-friendly strategies for protecting fish against bacterial diseases, contributing to aquaculture expansion and ensuring food security. As of now, although numerous vaccines have undergone laboratory research, only one commercially available inactivated vaccine, suitable for both immersion and injection administration, is accessible for preventing Streptococcus iniae. Several key challenges in developing vaccines for Asian seabass must be addressed, such as the current limited understanding of immunological responses to vaccines, the costs associated with vaccine production, forms, and routes of vaccine application, and how to increase the adoption of vaccines by farmers. The future of vaccine development for the Asian seabass industry, therefore, is discussed with these key critical issues in mind. The focus is on improving our understanding of Asian seabass immunity, including maternal immunity, immunocompetence, and immune responses post-vaccination, as well as developing tools to assess vaccine effectiveness. The need for an alignment of fish vaccines with state-of-the-art vaccine technologies employed in human and terrestrial animal healthcare is also discussed. This review also discusses the necessity of providing locally-produced autogenous vaccines, especially for immersion and oral vaccines, to benefit small-scale fish farmers, and the potential benefits that might be extended through changes to current husbandry practices such as the vaccination of broodstock and earlier life stages of their off-spring.


Asunto(s)
Vacunas Bacterianas , Enfermedades de los Peces , Vacunación , Animales , Enfermedades de los Peces/prevención & control , Vacunación/veterinaria , Vacunas Bacterianas/inmunología , Vacunas Bacterianas/administración & dosificación , Acuicultura/métodos , Infecciones Bacterianas/prevención & control , Infecciones Bacterianas/veterinaria , Lubina/inmunología
7.
Chem Biodivers ; : e202401329, 2024 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-39363736

RESUMEN

Vietnamese ginseng (Panax vietnamensis Ha & Grushv.) represents one of the famous Panax spp. for valuable applications in both traditional and modern medicine; in which, its rhizome part has mainly been used as the medicinal materials based on the bioactive ginsenosides such as ginsenoside Rb1, ginsenoside Rg1, ginsenoside Rd, and majonoside R2. In modern medicine, the development of medicinal materials and utilization of medicinal plants are crucially based on standard bioactive ingredients, so this study to evaluate the leaves of Vietnamese ginseng as source of bioactive ginsenoside led to the identification of seven ginsenosides (1-7). Of them, ginsenoside Rd (2) and pseudoginsenoside RS1 (5) showed inhibitory effects on acetylcholinesterase in vitro with the IC50 values of 47.13 and 79.58 µM and supported by molecular docking analysis, in which ginsenoside Rd (2) and pseudoginsenoside RS1 (5) could play as allosteric inhibitors with high binding affinity (-8.5 and -9.4 kcal/mol) as evidenced by hydrogen bonding and hydrophobic interactions. The findings provided the scientific evidence for using the leaves of Vietnamese ginseng as an alternative source to the roots to enhance memory in traditional medicine as well as for further research on the anti-dementia effects of 2 and 5.

8.
Fish Shellfish Immunol ; 138: 108802, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37178986

RESUMEN

Early disease prevention by vaccination requires understanding when fry fish develop specific immunity to a given pathogen. In this research, we explored the immune responses of Asian seabass (Lates calcarifer) at the stages of 35- and 42- days post-hatching (dph) to an immersive heat-killed Streptococcus iniae (Si) vaccine to determine whether fish can produce specific antibodies against the pathogen. The vaccinated fish of each stage (V35 and V42) were immersed with the Si vaccine at 107 CFU/ml for 3 h, whereas the control groups (C35 and C42) were immersed with tryptic soy broth (TSB) in the same manner. Specific antibodies were measured by enzyme-linked immunosorbent assay (ELISA) before and post-immunization (i.e., 0, 7, and 14 days post-immunization, dpi). Expression of innate (TNFα and IL-1ß) and adaptive (MHCI, MHCII, CD4, CD8, IgM-like, IgT-like, and IgD-like) immune-related genes were evaluated at the same time points with the addition of 1 dpi. The results showed that a subset of immunized fish from both V35 and V42 fry could elicit specific antibodies (IgM) against Si at 14 dpi. All tested innate and adaptive immune genes upregulated at 7 dpi among fish in V35 group. Interestingly, 42 dph fish appeared to respond to the Si vaccine faster than that of 35 dph, as a significant increase in transcripts was observed in CD4, IL-1ß, IgM-like, and IgD-like at 1 dpi; and specific antibody titers of some fish, although not all, were higher than a threshold (p = 0.05) since 7 dpi. In conclusion, this study reveals that 35-42 dph Asian seabass fry can elicit specific immunity to Si immersion vaccine, suggesting that early vaccination of 35 dph fry Asian seabass is feasible.


Asunto(s)
Enfermedades de los Peces , Perciformes , Animales , Streptococcus iniae , Vacunas de Productos Inactivados , Calor , Inmersión , Inmunización , Vacunación/veterinaria , Vacunas Bacterianas , Inmunoglobulina M , Enfermedades de los Peces/prevención & control
9.
Fish Shellfish Immunol ; 139: 108854, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37253409

RESUMEN

Nervous necrosis virus (NNV) has spread throughout the world, affecting more than 120 freshwater and marine fish species. While vaccination effectively prevents disease outbreaks, the difficulty of producing sufficient viruses using cell lines continues to be a significant disadvantage for producing inactivated vaccines. This study, therefore, explored the application of synthetic peptides as potential vaccine candidates for the prevention of NNV in Asian seabass (Lates calcarifer). Using the epitope prediction tool and molecular docking, three predicted immunogenic B cell epitopes (30-32 aa) derived from NNV coat protein were selected and synthesised, corresponding to amino acid positions 5 to 34 (P1), 133 to 162 (P2) and 181 to 212 (P3). All the predicted peptides interact with Asian sea bass's MHC class II by docking. The antigenicity of these peptides was determined through ELISA and all peptides were able to react with NNV-specific antibodies. Subsequently, the immunogenicity of these synthetic peptides was investigated by immunisation of Asian seabass with individual peptides (30 µg/fish) and a peptide cocktail (P1+P2+P3, 10 µg each/fish) by intraperitoneal injection, followed by a booster dose at day 28 post-primary immunisation. There was a subset of immunised fish that were able to induce upregulation of immune genes (IL-1ß, TNFα, MHCI, MHCII ß, CD4, CD8, and IgM-like) in the head kidney and spleen post immunization. Importantly, antibodies derived from fish immunised with synthetic peptides reacted with whole NNV virions, and sera from P1 group could neutralise NNV in an in vitro assay. Taken together, these findings indicate that synthetic linear peptides based on predicted B cell epitopes exhibited both antigenic and immunogenic properties, suggesting that they could be potential vaccine candidates for the prevention of NNV in fish.


Asunto(s)
Enfermedades de los Peces , Perciformes , Animales , Epítopos de Linfocito B , Simulación del Acoplamiento Molecular , Péptidos , Peces , Necrosis
10.
Fish Shellfish Immunol ; 143: 109191, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37890736

RESUMEN

Oxygen nanobubble (NB-O2) technology has been introduced to the aquaculture industry in recent years. This treatment usually results in a tremendously high level of dissolved oxygen (DO) in the water. However, little is known about the possible negative effects of hyperoxia due to NB-O2 treatment (hyper-NB-O2) on farmed fish. Here, we investigated i) the effect of short-term hyper-NB-O2 exposure (single treatment) on the innate immunity in Nile tilapia, Oreochromis niloticus, and ii) the effect of long-term hyper-NB-O2 exposure (26-day treatments) on survival, growth performance, gill histology, and gut microbiome in Nile tilapia. A single treatment with NB-O2 for 10 min in 50 L of water resulted in 24.2 ± 0.04 mg/L DO (approximately 2-3 × 107 nanoscale oxygen bubbles/mL). This treatment did not result in differences in expression of several immune-related genes (e.g., TNF-α, LYZ and HPS70) in various tissues (e.g., gill, head kidney, and spleen) compared to the non-treated control. Over a 26-day period of exposure, no significant differences were observed in survival and growth performance of the fish, but minor histological changes were occasionally noted on the gills. Analysis of the gut microbiome revealed a significant increase in the genera Bosea, Exiguobacterium, Hyphomicrobium, and Singulisphaera in the group receiving NB-O2. Moreover, no signs of "gas bubble disease" were observed in the fish throughout the duration of the experiment. Overall, these results suggest that both short- and long-term hyper-NB-O2 exposure appears to be benign and has no obvious adverse effects on fish.


Asunto(s)
Cíclidos , Enfermedades de los Peces , Microbioma Gastrointestinal , Hiperoxia , Animales , Branquias , Inmunidad Innata , Oxígeno , Agua
11.
J Nat Prod ; 86(10): 2270-2282, 2023 10 27.
Artículo en Inglés | MEDLINE | ID: mdl-37792632

RESUMEN

Persea americana Mill. (Lauraceae), commonly known as avocado, is a well-known food because of its nutrition and health benefits. The seeds of avocado are major byproducts, and thus their phytochemicals and bioactivities have been of interest for study. The chemical components of avocado seeds were investigated by using UPLC-qTOF-MS/MS-based molecular networking, resulting in the isolation of seven new oxindole alkaloids (1-7) and two new benzoxazinone alkaloids (8 and 9). The chemical structures of the isolated compounds were identified by the analysis of NMR data in combination with computational approaches, including NMR and ECD calculations. Bioactivities of the isolated compounds toward silent information regulation 2 homologue-1 (SIRT1) in HEK293 cells were assessed. The results showed that compound 1 had the most potent effect on SIRT1 activation with an elevated NAD+/NADH ratio with potential for further investigation as an anti-aging agent.


Asunto(s)
Alcaloides , Persea , Humanos , Persea/química , Oxindoles/farmacología , Benzoxazinas/análisis , Espectrometría de Masas en Tándem , Sirtuina 1 , Células HEK293 , Semillas/química , Alcaloides/farmacología , Alcaloides/análisis , Extractos Vegetales/química
12.
J Fish Dis ; 46(12): 1391-1401, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37723600

RESUMEN

Streptococcus iniae is a bacterial pathogen that causes streptococcosis, leading to significant losses in fish aquaculture globally. This study reported a newly developed probe-based quantitative polymerase chain reaction (qPCR) method for the detection of S. iniae. The primers and probes were designed to target the lactate oxidase gene. The optimized method demonstrated a detection limit of 20 copies per reaction and was specific to S. iniae, as evidenced by no cross-reactivity when assayed against genetic materials extracted from 23 known aquatic animal pathogens, and fish samples infected with Streptococcus agalactiae or Streptococcus dysgalactiae. To validate the newly developed qPCR protocol with field samples, fish specimens were systematically investigated following the Food and Agriculture Organization of the United Nations & Network of Aquaculture Centres in Asia-Pacific three diagnostic levels approach, which integrated basic and advanced techniques for disease diagnosis, including observation of gross signs (level I), bacterial isolation (level II), qPCR and 16S rDNA sequencing (level III). The result showed that 7/7 affected farms (three Asian seabass farms and four tilapia farms) experiencing clinical signs of streptococcosis were diagnosed positive for S. iniae. qPCR assays using DNA extracted directly from fish tissue detected S. iniae in 11 out of 36 fish samples (30.6%), while 24 out of 36 samples (66.7%) tested positive after an enrichment step, including apparently healthy fish from affected farms. Bacterial isolation of S. iniae was only successful in a proportion of clinically diseased fish but not in healthy-looking fish from the same farm. Overall, the newly developed qPCR protocol combined with enrichment would be a useful tool for the diagnosis and surveillance of S. iniae infections in fish populations, thereby aiding in the disease control and prevention.


Asunto(s)
Enfermedades de los Peces , Infecciones Estreptocócicas , Tilapia , Animales , Streptococcus iniae , Enfermedades de los Peces/microbiología , Streptococcus agalactiae/genética , Infecciones Estreptocócicas/diagnóstico , Infecciones Estreptocócicas/veterinaria , Infecciones Estreptocócicas/microbiología , Tilapia/microbiología
13.
J Fish Dis ; 46(10): 1125-1136, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37410863

RESUMEN

Widespread distribution of a highly pathogenic Edwardsiella ictaluri strain in farmed tilapia in northern Vietnam has recently been reported. The subsequent investigation noticed a disease outbreak occurred at five nearby tilapia farms with floating cages, in which the clinical signs of both edwardsiellosis and columnaris diseases were observed on the same infected fish and caused 65% to 85% fish mortality. Naturally diseased fish (n = 109) were sampled from the five infected farms for bacterial identification and conducting challenge tests. The two bacteria Edwardsiella ictaluri and Flavobacterium oreochromis were identified by a combination of biochemical tests, PCR and 16SrRNA sequencing methods. Experimental challenge tests on Nile tilapia resulted in the median lethal dose (LD50 ) of E. ictaluri and F. oreochromis at 70 CFU/fish by intraperitoneal (i.p.) injection and 3.6 × 106 CFU/mL by immersion, respectively. The experimentally co-infected challenged fish exposed to LD50 doses resulted in 83% ± 6% mortality, with the infected fish exhibiting clinical signs of both edwardsiellosis and columnaris diseases, mimicking the naturally diseased fish. This finding suggests that the co-infection of E. ictaluri and F. oreochromis may interact in a synergistic manner, to enhance the overall severity of the infection and elevates the need for efficient methods to control both pathogens.


Asunto(s)
Cíclidos , Infecciones por Enterobacteriaceae , Enfermedades de los Peces , Tilapia , Animales , Edwardsiella ictaluri/genética , Flavobacterium , Infecciones por Enterobacteriaceae/epidemiología , Infecciones por Enterobacteriaceae/veterinaria , Infecciones por Enterobacteriaceae/microbiología , Enfermedades de los Peces/microbiología
14.
J Bus Res ; 156: 113468, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36437847

RESUMEN

The literature on the imperativeness of government support for firm survival since the onset of COVID-19 is vast, but scholars have scarcely considered the impact of such assistance on managers' time, nor the extent to which support measures induce resilience and export activity. Accordingly, this study assesses the impact of government support on (1) bureaucracy and (2) resilience using data from 535 Moroccan SMEs. It further evaluates the influence of resilience on direct versus indirect exports, and espouses the institutional voids, resource-based and strategy-creation view to explain the associations through a contingency lens. The results demonstrate that (1) government support increases bureaucracy which, (2) surprisingly triggers and enhances resilience. Furthermore, (3) resilience has a positive impact on direct exports but (4) adversely affects indirect exports. Theoretically, the findings acquiesce extant calls for measurement specificity in export performance. Practically, stakeholders' attention is drawn to the value of managers' time well spent.

15.
Fish Shellfish Immunol ; 123: 229-237, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35288305

RESUMEN

Nanobubble technology has shown appealing technical benefits and potential applications in aquaculture. We recently found that treatment with ozone nanobubbles (NB-O3) activated expression of several immune-related genes leading to effective response to subsequent exposure to fish pathogens. In this study, we investigated whether pre-treatment of Nile tilapia (Oreochromis niloticus) with NB-O3 can enhance specific immune responses and improve efficacy of immersion vaccination against Streptococcus agalactiae. Spleen and head kidney of fish in the vaccinated groups showed a substantial upregulation in expression levels of pro-inflammatory cytokine genes (IL-1ß, TNF-α, IL-6) and immunoglobulin classes (IgM, IgD, IgT) compared with the unvaccinated control groups. The mRNA transcript of pro-inflammatory cytokine genes was greatest (approx. 2.8-3.3 folds) on day 7 post-vaccination, whereas the relative expression of immunoglobulin genes was greatest (approx. 3.2-4.1 folds) on day 21 post-immunization. Both systemic and mucosal IgM antibodies were elicited in vaccinated groups. As the result, the cumulative survival rate of the vaccinated groups was found to be higher than that of the unvaccinated groups, with a relative percent survival (RPS) ranging from 52.9 to 70.5%. However, fish in the vaccinated groups that received pre-treatment with NB-O3, bacterial antigen uptakes, expression levels of IL-1ß, TNF-α, IL-6,IgM, IgD, and IgT, as well as the specific-IgM antibody levels and percent survival, were all slightly or significantly higher than that of the vaccinated group without pre-treatment with NB-O3. Taken together, our findings suggest that utilizing pre-treatment with NB-O3 may improve the immune response and efficacy of immersion vaccination in Nile tilapia.


Asunto(s)
Cíclidos , Enfermedades de los Peces , Ozono , Infecciones Estreptocócicas , Animales , Calor , Inmersión , Inmunoglobulina D , Inmunoglobulina M , Interleucina-6 , Infecciones Estreptocócicas/prevención & control , Infecciones Estreptocócicas/veterinaria , Streptococcus agalactiae , Factor de Necrosis Tumoral alfa , Vacunas de Productos Inactivados
16.
J Nat Prod ; 85(1): 70-82, 2022 01 28.
Artículo en Inglés | MEDLINE | ID: mdl-35040315

RESUMEN

The cumulative effects of cell damage result in aging, which gradually decreases human function in various aspects and leads to multiple age-related chronic diseases. To overcome the adverse effects of aging, silent mating type information regulation 2 homologue (SIRT1) activators are promising bioactive compounds that mimic calorie restriction to improve quality of life and prevent aging. In this study, 11 new flavonostilbenes (1-11) and three known compounds (12-14) were purified from stems of Rhamnoneuron balansae. The structures of the new compounds were determined using extensive data from spectroscopic methods, including NMR and HRESIMS. Their absolute configurations were deduced by ECD calculations with coupling constant analysis. All of the isolated new compounds (1-11) were evaluated for their effects on SIRT1 deacetylase activity, the NAD+/NADH ratio, and the AMP-activated protein kinase activation level in cell-based assays. The results showed that rhamnoneuronal D (1) exhibits promising biological activity in several in vitro models related to SIRT1 and suggest it is a potential natural-product-based antiaging agent.


Asunto(s)
Tallos de la Planta/química , Sirtuina 1/efectos de los fármacos , Estilbenos/aislamiento & purificación , Adenilato Quinasa/metabolismo , Animales , Espectroscopía de Resonancia Magnética con Carbono-13 , Activación Enzimática , Humanos , NAD/metabolismo , Espectroscopía de Protones por Resonancia Magnética , Espectrometría de Masa por Ionización de Electrospray , Estilbenos/farmacología , Thymelaeaceae/química
17.
Appetite ; 176: 106142, 2022 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-35724748

RESUMEN

The purchase and consumption of conventional vegetables from wet markets in Vietnam are like two sides of a coin: perceived food safety risks and perceived benefits. Drawing on a sample of 463 Hanoi consumers, this study employed a risk-benefit approach to analyze the purchase intention and consumption frequency of conventional vegetables at traditional markets. A confirmatory factor analysis examined the links among risk perception, perceived utilitarian benefits, perceived hedonic benefits, and trust. Finally, generalized ordered and Poisson regressions were performed on these psychological constructs and their identified links. We found that perceived hedonic benefits, trust in wet market actors, and the presence of homegrown vegetables determined purchase intention and consumption frequency. The joint influence of perceived hedonic and utilitarian benefits on purchase intention implies that consumers considered both benefit dimensions when thinking of their future purchase of conventional vegetables. The significant interaction between perceived risk and perceived hedonic benefits on consumption frequency supports the risk-benefit approach. The effect of perceived hedonic benefits and income on purchase intention and consumption frequency are evidence of wet markets' social and cultural relevance.


Asunto(s)
Comportamiento del Consumidor , Verduras , Inocuidad de los Alimentos , Humanos , Renta , Intención
18.
J Fish Dis ; 45(9): 1323-1331, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35638102

RESUMEN

Tilapia parvovirus (TiPV) is an emerging virus reportedly associated with disease and mortality in farmed tilapia. Although previous descriptions of histopathological changes are available, the lesions reported in these are not pathognomonic. Here, we report Cowdry type A inclusion bodies (CAIB) in the pancreas as a diagnostic histopathological feature found in adult Nile tilapia naturally infected with TiPV. This type of inclusion body has been well-known as a histopathological landmark for the diagnosis of other parvoviral infections in shrimp and terrestrial species. Interestingly, this lesion could be exclusively observed in pancreatic acinar cells, both in the hepatopancreas and pancreatic tissue along the intestine. In situ hybridization (ISH) using a TiPV-specific probe revealed the intranuclear presence of TiPV DNA in multiple tissues, including the liver, pancreas, kidney, spleen, gills and the membrane of oocytes in the ovary. These findings suggest that although TiPV can replicate in several tissue types, CAIB manifest exclusively in pancreatic tissues. In addition to TiPV, most diseased fish were co-infected with Streptococcus agalactiae, and presented with multifocal granulomas secondary to this bacterial infection. Partial genome amplification of TiPV was successful and revealed high nucleotide identity (>99%) to previously reported isolates. In summary, this study highlights the usefulness of pancreatic tissue as a prime target for histopathological diagnosis of TiPV in diseased Nile tilapia. This pattern may be critical when determining the presence of TiPV infection in new geographic areas, where ancillary testing may not be available. TiPV pathogenesis in this landmark organ warrants further investigation.


Asunto(s)
Cíclidos , Enfermedades de los Peces , Parvovirus , Infecciones Estreptocócicas , Tilapia , Animales , Cíclidos/microbiología , Enfermedades de los Peces/microbiología , Páncreas/patología , Parvovirus/genética , Streptococcus agalactiae/genética
19.
J Fish Dis ; 45(1): 77-87, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34580880

RESUMEN

Sixteen countries, including Bangladesh, have reported the presence of tilapia lake virus (TiLV), an emerging tilapia pathogen. Fish polyculture is a common farming practice in Bangladesh. Some unusual mortalities reported in species co-cultivated with TiLV-infected tilapia led us to investigate whether any of the co-cultivated species would also test positive for TiLV and whether they were susceptible to TiLV infection under controlled laboratory experiments. Using 183 samples obtained from 15 farms in six districts across Bangladesh, we determined that 20% of the farms tested positive for TiLV in tilapia, while 15 co-cultivated fish species and seven other invertebrates (e.g. insects and crustaceans) considered potential carriers all tested negative. Of the six representative fish species experimentally infected with TiLV, only Nile tilapia showed the typical clinical signs of the disease, with 70% mortality within 12 days. By contrast, four carp species and one catfish species challenged with TiLV showed no signs of TiLV infection. Challenged tilapia were confirmed as TiLV-positive by RT-qPCR, while challenged carp and walking catfish all tested negative. Overall, our field and laboratory findings indicate that species used in polycultures are not susceptible to TiLV. Although current evidence suggests that TiLV is likely host-specific to tilapia, targeted surveillance for TiLV in other fish species in polyculture systems should continue, in order to prepare for a possible future scenario where TiLV mutates and/or adapts to new host(s).


Asunto(s)
Cíclidos , Enfermedades de los Peces , Virus ARN , Tilapia , Animales , Bangladesh/epidemiología , Enfermedades de los Peces/epidemiología
20.
J Fish Dis ; 45(9): 1355-1371, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35675521

RESUMEN

This study describes the etiological agent of Vibriosis along with its distribution and antimicrobial resistance profiles among farmed Asian sea bass (Lates calcarifer) in Thailand. The study isolated 283 Vibrionaceae from 15 Asian sea bass farms located around the provinces of the Andaman Sea and Gulf of Thailand coasts to uncover the distribution and antimicrobial resistance profiles. Bacterial identification based on a combination of the biochemical characteristics, Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS) analysis, and the species-specific PCR demonstrated the predominant Vibrionaceae were Vibrio harveyi (n = 56), Photobacterium damselae (n = 35), and V. vulnificus (n = 31), respectively. According to a laboratory challenge experiment, among the six isolates, only V. harveyi was found to cause clinical signs of muscle necrosis and scale loss in Asian sea bass. Antibiotics resistance test results exhibited high resistance to antibiotics such as metronidazole (100%), streptomycin (97%), clindamycin (96%), colistin sulphate (70%) and amoxicillin (59%). Remarkably, 100% of Vibrionaceae isolates are susceptible to florfenicol. The 28 of 29 resistance profiles were multidrug resistances (MDR), with V. vulnificus having the highest MAR value (0.66). The findings of this study advise that a surveillance program, as well as preventive and control measures, be developed for Vibrionaceae to reduce production loss, pathogen proliferation, and antibiotic abuse, whereas AMR data indicate substantial health problems for aquatic animals and humans.


Asunto(s)
Lubina , Enfermedades de los Peces , Perciformes , Vibrionaceae , Animales , Antibacterianos/farmacología , Lubina/microbiología , Farmacorresistencia Bacteriana , Granjas , Enfermedades de los Peces/epidemiología , Enfermedades de los Peces/microbiología , Humanos , Prevalencia , Tailandia/epidemiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA