Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
1.
Animals (Basel) ; 14(4)2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-38396598

RESUMEN

Despite significant advances in vaccination strategies and antibiotic therapy, bovine respiratory disease (BRD) continues to be the leading disease affecting the global cattle industry. The etiology of BRD is complex, often involving multiple microbial agents, which lead to intricate interactions between the host immune system and pathogens during various beef production stages. These interactions present environmental, social, and geographical challenges. Accurate diagnosis is essential for effective disease management. Nevertheless, correct identification of BRD cases remains a daunting challenge for animal health technicians in feedlots. In response to current regulations, there is a growing interest in refining clinical diagnoses of BRD to curb the overuse of antimicrobials. This shift marks a pivotal first step toward establishing a structured diagnostic framework for this disease. This review article provides an update on recent developments and future perspectives in clinical diagnostics and prognostic techniques for BRD, assessing their benefits and limitations. The methods discussed include the evaluation of clinical signs and animal behavior, biomarker analysis, molecular diagnostics, ultrasound imaging, and prognostic modeling. While some techniques show promise as standalone diagnostics, it is likely that a multifaceted approach-leveraging a combination of these methods-will yield the most accurate diagnosis of BRD.

2.
Int J Mol Sci ; 24(22)2023 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-38003300

RESUMEN

Herpesviruses are large DNA viruses that have long been used as powerful gene therapy tools. In recent years, the ability of herpesviruses to stimulate both innate and adaptive immune responses has led to their transition to various applications as vaccine vectors. This vaccinology branch is growing at an unprecedented and accelerated rate. To date, human herpesvirus-based vectors have been used in vaccines to combat a variety of infectious agents, including the Ebola virus, foot and mouth disease virus, and human immunodeficiency viruses. Additionally, these vectors are being tested as potential vaccines for cancer-associated antigens. Thanks to advances in recombinant DNA technology, immunology, and genomics, numerous steps in vaccine development have been greatly improved. A better understanding of herpesvirus biology and the interactions between these viruses and the host cells will undoubtedly foster the use of herpesvirus-based vaccine vectors in clinical settings. To overcome the existing drawbacks of these vectors, ongoing research is needed to further advance our knowledge of herpesvirus biology and to develop safer and more effective vaccine vectors. Advanced molecular virology and cell biology techniques must be used to better understand the mechanisms by which herpesviruses manipulate host cells and how viral gene expression is regulated during infection. In this review, we cover the underlying molecular structure of herpesviruses and the strategies used to engineer their genomes to optimize capacity and efficacy as vaccine vectors. Also, we assess the available data on the successful application of herpesvirus-based vaccines for combating diseases such as viral infections and the potential drawbacks and alternative approaches to surmount them.


Asunto(s)
Herpesviridae , Vacunas Virales , Virosis , Humanos , Herpesviridae/genética , Simplexvirus/genética , Vectores Genéticos/genética
3.
Trop Anim Health Prod ; 55(5): 317, 2023 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-37737938

RESUMEN

Haemonchus contortus (H. contortus) is one of the most prevalent gastrointestinal nematodes, causing health problems and economic losses in ruminants. Nanotechnology holds great promise as a field of science, with potential applications in veterinary medicine. This study investigated the in vitro anthelmintic activity of silver nanoparticles (AgNPs), selenium nanoparticles (SeNPs), and pomegranate peel extract (Punica granatum; PPE) on different stages of H. contortus: eggs, larvae, and adults. The in vitro anthelmintic efficacy was evaluated using the egg hatching inhibition assay (EHA), the third larval stage paralysis assay (LPA), and the adult worm motility inhibition assay (WMI). Six dilutions of PPE were utilized for EHA, LPA, and WMI, ranging from 0.25 to 6 mg/ml. AgNPs dilutions ranged from 0.00001 to 1.0 µg/ml for EHA and LPA and 1 to 25 µg/ml for WMI. SeNPs were utilized at dilutions of 1, 5, 10, and 15 µg/ml for EHA, LPA, and WMI. The results showed that the lowest concentration of AgNPs, SeNPs, and PPE significantly inhibited egg hatching. To further assess larvicidal activity, AgNPs at the highest concentration of 1 µg/ml induced a strong larvicidal effect, as did SeNPs at the lowest concentration. On the contrary, PPE displayed a significant larvicidal effect at 1 mg/ml compared to the control. The percentage mortality of adult H. contortus was measured as follows (mortality (%) = the number of dead adult H. contortus/total number of adult H. contortus per test × 100). The death of the adult H. contortus was determined by the absence of motility. Adult H. contortus mortality percentage was also significantly affected by all three agents when compared to the control. The AgNPs, SeNPs, and PPE have effective antiparasitic activity on gastrointestinal parasitic nematodes. These results provide evidence of the excellent antiparasitic properties of AgNPs, SeNPs, and PPE, demonstrating their effectiveness in controlling eggs, larvae, and adult H. contortus in vitro.


Asunto(s)
Antihelmínticos , Antiinfecciosos , Haemonchus , Nanopartículas del Metal , Granada (Fruta) , Selenio , Animales , Antiparasitarios , Selenio/farmacología , Plata/farmacología , Óvulo , Antihelmínticos/farmacología , Antihelmínticos/uso terapéutico , Larva , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico
4.
Animals (Basel) ; 13(3)2023 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-36766413

RESUMEN

COVID-19 is one of the deadliest epidemics. This pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but the role of dogs in spreading the disease in human society is poorly understood. This review sheds light on the limited susceptibility of dogs to COVID-19 infections which is likely attributed to the relatively low levels of angiotensin-converting enzyme 2 (ACE2) in the respiratory tract and the phylogenetic distance of ACE2 in dogs from the human ACE2 receptor. The low levels of ACE2 affect the binding affinity between spike and ACE2 proteins resulting in it being uncommon for dogs to spread the disease. To demonstrate the role of dogs in spreading COVID-19, we reviewed the epidemiological studies and prevalence of SARS-CoV-2 in dogs. Additionally, we discussed the use of detection dogs as a rapid and reliable method for effectively discriminating between SARS-CoV-2 infected and non-infected individuals using different types of samples (secretions, saliva, and sweat). We considered the available information on COVID-19 in the human-dog interfaces involving the possibility of transmission of COVID-19 to dogs by infected individuals and vice versa, the human-dog behavior changes, and the importance of preventive measures because the risk of transmission by domestic dogs remains a concern.

5.
Biosensors (Basel) ; 12(12)2022 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-36551061

RESUMEN

Paper-based biosensors are microfluidic analytical devices used for the detection of biochemical substances. The unique properties of paper-based biosensors, including low cost, portability, disposability, and ease of use, make them an excellent tool for point-of-care testing. Among all analyte detection methods, nucleic acid-based pathogen detection offers versatility due to the ease of nucleic acid synthesis. In a point-of-care testing context, the combination of nucleic acid detection and a paper-based platform allows for accurate detection. This review offers an overview of contemporary paper-based biosensors for detecting nucleic acids from pathogens. The methods and limitations of implementing an integrated portable paper-based platform are discussed. The review concludes with potential directions for future research in the development of paper-based biosensors.


Asunto(s)
Técnicas Biosensibles , Técnicas Analíticas Microfluídicas , Ácidos Nucleicos , Pruebas en el Punto de Atención , Técnicas Biosensibles/métodos , Dispositivos Laboratorio en un Chip , Sistemas de Atención de Punto
6.
Nat Prod Res ; 36(4): 994-998, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33121282

RESUMEN

COVID 19; an infectious disease; firstly identified in December 2019 in Wuhan, China and has since spread globally, resulting in an ongoing pandemic. Searching for protease inhibitors is a challenging task in controlling COVID 19. Genus Ficus is known to be a rich source of phenolic compounds. Metabolic profiling of leaves methanolic extract of Ficus microcarpa (Moraceae) revealed nine compounds (1-9) mainly phenolics. Docking studies concerning these compounds against SARS-CoV-2 main protease showed that quercetin 3,7-O-α-L-dirhamnoside (1) and rutin (3) possessed significant binding stability at the N3 binding site in different activity degrees, which is comparable with COVID-19 main protease inhibitor, darunavir. Our study suggests that compounds quercetin 3,7-O-α-L-dirhamnoside and rutin might be potential candidates for the development of therapies against SARS-CoV-2.


Asunto(s)
Antivirales , Tratamiento Farmacológico de COVID-19 , Proteasas 3C de Coronavirus/antagonistas & inhibidores , Ficus , Extractos Vegetales , Antivirales/química , Antivirales/farmacología , Ficus/química , Humanos , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Extractos Vegetales/química , Extractos Vegetales/farmacología , SARS-CoV-2/efectos de los fármacos
7.
Future Virol ; 0(0)2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34745316

RESUMEN

Aim: The severity of COVID-19 has raised a great public health concern evoking an urgency for developing multitargeted therapeutics. Phlomis species was ethno-pharmacologically practiced for respiratory ailments. Materials & methods: An array of 15 phytoligands previously isolated from Phlomis aurea were subjected to molecular docking to explore their potential SARS-CoV-Spike-angiotensin-converting enzyme 2 complex inhibition, that is essential for virus entry to host cell. Results: Acteoside (11) showed the most potent in silico inhibition with an additional merit, over hesperidin (16), of not binding to angiotensin-converting enzyme 2 with well proven in vivo pulmonary protective role in acute lung injury, followed by chrysoeriol-7-O-ß-glucopyranoside (12) and luteolin-7-O-ß-glucopyranoside (14). Conclusion: Phytoligands (11, 12 and 14) were posed as promising candidates with potential prophylactic action against COVID-19. These phytoligands were prioritized for further biological experimentation because of their acceptable predicted ADME and drug-likeness parameters. Moreover, they could aid in developing multitargeted strategy for better management of COVID-19 using phytomedicines.

8.
Parasitol Res ; 120(11): 3883-3893, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34515863

RESUMEN

Parasitic gastroenteritis (PGE) is one of the most important parasitic diseases that causes economic losses and health problems in ruminants. PGE causes a drop in milk, meat, and wool production in addition to decreasing animal fertility and sometimes leading to animal death. Conventional anthelmintics used for animal treatment are expensive, especially for farmers in developing countries. Moreover, the concern of anthelmintic resistance to these synthetic drugs is rising. Therefore, this study aimed to evaluate the anthelmintic activity of plant extract pomegranate (Punica granatum L) peel extract (PPE) against PGE infestations among ruminants. A total of 120 ruminants of different species (20 cattle, 12 buffalos, 68 sheep, and 20 goats) were examined for PGE eggs in their fecal samples. The animals under experiment were divided into four groups: the first group (negative control) was not given any drugs, the second group was given ivermectin (0.5 ml/25 kg bwt) (positive control 1), the third group was given albendazole (2.5 mg active principle/kg bwt) (positive control 2), and the fourth group was given PPE (200 mg/kg bwt). Fecal egg count (FEC) was performed on day 0 prior to the 1st dose of treatment. On day 15, an additional treatment (with the same doses) was administered and FEC was performed on days 7 and 21. Our results showed that on the 7th day of the experiment, there was an increase in FEC in the negative control group by 5%, while in the second, third, and fourth groups, there was a decrease in FEC with 95%, 90%, and 85% respectively. On the 21st day (7 days from the second dose), there was an increase in FEC in the control group by a 10% and 100% reduction in FEC in both the second and third groups. While in the fourth group, there was a decrease in FEC by 97%. In conclusion, PPE could be used as a safe, cheap, and effective natural anthelmintic against PGE.


Asunto(s)
Antihelmínticos , Nematodos , Granada (Fruta) , Enfermedades de las Ovejas , Animales , Antihelmínticos/uso terapéutico , Búfalos , Bovinos , Heces , Cabras , Recuento de Huevos de Parásitos , Extractos Vegetales/farmacología , Ovinos , Enfermedades de las Ovejas/tratamiento farmacológico
9.
RSC Adv ; 11(22): 13537-13544, 2021 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-35423847

RESUMEN

Several studies are now underway as a worldwide response for the containment of the COVID-19 outbreak; unfortunately, none of them have resulted in an effective treatment. Salvadora persica L. (Salvadoraceae), commonly known as meswak, is one of the popular plants used by Muslims as an oral hygiene tool. It is documented that the meswak possesses antiviral activity, but no report discusses its use for coronavirus treatment. Herein, a mixture of 11 flavonoids prepared from the aqueous plant extract and its liposomal formulation were shown to inhibit SARS-CoV-2 in an in vitro A549 cell line culture and a RT-PCR test almost as well as the FDA-approved anti-COVID-19 agent, remdesivir. Encapsulation within liposomal formulation led to a highly significant increase in the percentage of inhibition of viral replication from 38.09 ± 0.83 to 85.56 ± 1.12% in a flavonoid mixture and its liposomal preparation, respectively, and this figure approached that obtained for remdesivir (91.20 ± 1.71%). Preliminary tests were also performed, including a total flavonoid assay, a molecular docking study, a 3CL-protease inhibition assay and a cytotoxicity study. It was worthy to find a cheap, readily available, safe natural source for promising anti-SARS-CoV-2 agents, that leak their phytochemicals into the aqueous saliva during regular use as a brushing agent.

10.
Trop Anim Health Prod ; 52(6): 3173-3185, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32647966

RESUMEN

Escherichia coli field isolates from calves were characterized and categorized into the most significant diarrheagenic pathotypes using polymerase chain reaction (PCR) assays with different specific primers. The used PCR systems were designed to detect sequences representing the group-specific virulence genes encoding fimbriae f5 (K99), Shiga toxins (stx1 and stx2), heat-stable enterotoxins (st), heat-labile enterotoxins (lt), intimin (eae), hemolysin (hylA), and EAEC heat-stable enterotoxin (astA). In the present work, a total of 150 E. coli field isolates were recovered from 150 fecal swabs collected from 100 diarrheic and 50 apparently healthy in-contact cattle and buffalo calves under 3 months old. Out of these 150 isolated E. coli, 106 isolates from 77 diarrheic and 29 in-contact calves harbored one or more of the investigated virulence genes. The pathotyping of the isolates could classify them into shigatoxigenic E. coli (STEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), and enteroaggregative E. coli (EAEC) with a 30.7, 2.7, 12.7, and 7.3% distribution, respectively. Meanwhile, the detection rates of f5, stx1, stx2, st, lt, eae, hylA, and astA genes were 17.3, 27.3, 6.7, 10, 37.3, 17.7, 9.3, and 20.7%, respectively. These virulence genes were found either single or in different combinations, such as stx/eae, stx/st/f5, eae/st/f5, or st/lt/f5. Four attaching-effacing shigatoxigenic E. coli isolates (AE-STEC) harboring stx/eae were retrieved from diarrheic calves. Although none of the stx-or eae-positive isolates was verified as O157:H7, STEC isolates detected in apparently healthy calves have potential pathogenicity to humans highlighting their zoonotic importance as reservoirs. Atypical combinations of ETEC/STEC and ETEC/EPEC were also detected in percentages of 14.7 and 2.7%, respectively. Most of these atypical combinations were found more in buffalo calves than in cattle calves. While STEC and EPEC isolates were detected more in cattle calves than in buffalo calves, ETEC isolates were the same in the two species. The pathogenic E. coli infection in calves was recorded to be higher in the first weeks of life with the largest numbers of virulence factor-positive isolates detected at the age of 4 weeks. Histopathological examination of five intestinal samples collected from four dead buffalo calves revealed typical attaching and effacing (AE) lesion which was correlated with the presence of intimin encoding virulence gene (eae). Other lesions characterized by hemorrhagic enteritis, shortening and fusion of intestinal villi and desquamation of the lining epithelium of intestinal mucosa had also been detected.


Asunto(s)
Búfalos , Enfermedades de los Bovinos/epidemiología , Diarrea/veterinaria , Escherichia coli Enteropatógena/genética , Escherichia coli Enterotoxigénica/genética , Infecciones por Escherichia coli/veterinaria , Escherichia coli Shiga-Toxigénica/genética , Animales , Bovinos , Enfermedades de los Bovinos/microbiología , Diarrea/epidemiología , Diarrea/microbiología , Egipto/epidemiología , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Femenino , Masculino , Prevalencia
11.
RSC Adv ; 10(33): 19570-19575, 2020 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-35515460

RESUMEN

In December 2019, an outbreak of coronavirus disease 2019 (COVID-19) commenced in Wuhan, China and affected around 210 countries and territories in a matter of weeks. It has a phylogenetic similarity to SARS-CoV and it was named coronavirus 2 (SARS-CoV-2) and caused severe acute respiratory syndrome that could lead to death. One of the promising therapeutic strategies for virus infection is the search for enzyme inhibitors among natural compounds using molecular docking in order to obtain products with minimal side effects. COVID-19 virus main protease plays a vital role in mediating viral transcription and replication, introducing it as an attractive antiviral agent target. Metabolic profiling of the aqueous extract of Salvadora persica L. (Salvadoraceae) aerial parts dereplicated eleven known flavonol glycosides using LC-HRESIMS. All the annotated flavonoids exhibited significant binding stability at the N3 binding site to different degrees, except isorhamnetin-3-O-ß-d-glucopyranoside, when compared with the currently used COVID-19 main protease inhibitor, darunavir. Structural similarity between the identified flavonoids enabled the study of the relationship between their structure and interactions with the receptor in the N3 binding site of the COVID-19 main protease. The results indicate that the basic flavonol nucleus possesses activity itself. Moreover, the presence of a rutinose moiety at the 3 position of ring C and absence of an O-methyl group in ring B of the flavonol structure could increase the binding stability. This study provides a scientific basis for the health benefits of the regular use of S. persica as it leaches bioactive flavonoids in the aqueous saliva.

12.
RSC Adv ; 10(60): 36920-36929, 2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-35517980

RESUMEN

Metabolic profiling of the crude methanolic extract of Ficus benghalensis leaves has revealed the presence of different phenolic and nitrogenous compounds including cerebrosides and tetrapyrrole pigments. A phytochemical study of the ethyl acetate fraction resulted in the identification of three known compounds, namely carpachromene (1), alpha amyrine acetate (2), and mucusoside (3) together with one new fatty acid glycoside, named 2-O-α-l-rhamnopyranosyl-hexacosanoate-ß-d-glucopyranosyl ester (4). The compounds were identified using 1D, 2D NMR, and HR-ESIMS techniques as well as via comparison to other literature. Studies on the acetylcholinesterase inhibition potential and antioxidant activity were carried out on the total methanolic leaf extract, ethyl acetate fraction, and the isolated compounds. The results revealed the potent acetylcholinesterase inhibition of mucusoside alongside a new compound. Docking studies were also performed to confirm the possible interaction between the isolated compounds and acetylcholinesterase accompanying Alzheimer's disease progress.

13.
Bioorg Med Chem ; 27(17): 3954-3959, 2019 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-31324567

RESUMEN

Three new cyclic heptapeptides (1-3) together with three known compounds (4-6) were isolated from a solid rice culture of the soil-derived fungus Clonostachys rosea. Fermentation of the fungus on white beans instead of rice afforded a new γ-lactam (7) and a known γ-lactone (8) that were not detected in the former extracts. The structures of the new compounds were elucidated on the basis of 1D and 2D NMR spectra as well as by HRESIMS data. Compounds 1 and 4 exhibited significant cytotoxicity against the L5178Y mouse lymphoma cell line with IC50 values of 4.1 and 0.1 µM, respectively. Compound 4 also displayed cytotoxicity against the A2780 human ovarian cancer cell line with an IC50 value of 3.5 µM. The preliminary structure-activity relationships are discussed.


Asunto(s)
Antineoplásicos/farmacología , Gliocladium/química , Péptidos Cíclicos/farmacología , Animales , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Fermentación , Gliocladium/metabolismo , Humanos , Ratones , Estructura Molecular , Péptidos Cíclicos/química , Péptidos Cíclicos/aislamiento & purificación , Relación Estructura-Actividad
14.
Planta Med ; 85(6): 503-512, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30699456

RESUMEN

A new cyclic pentapeptide, cotteslosin C (1: ), a new aflaquinolone, 22-epi-aflaquinolone B (3: ), and two new anthraquinones (9: and 10: ), along with thirty known compounds (2, 4:  - 8, 11:  - 34: ) were isolated from a co-culture of the sponge-associated fungus Aspergillus versicolor with Bacillus subtilis. The new metabolites were only detected in the co-culture extract, but not when the fungus was grown under axenic conditions. Furthermore, the co-culture extract exhibited an enhanced accumulation of the known constituents versicolorin B (14: ), averufin (16: ), and sterigmatocyctin (19: ) by factors of 1.5, 2.0, and 4.7, respectively, compared to the axenic fungal culture. The structures of the isolated compounds were elucidated on the basis of 1D and 2D NMR spectra and mass spectrometry as well as by comparison with literature data. The absolute configuration of compounds 3, 9: , and 10: was determined by ECD (electronic circular dichroism) analysis aided by TDDFT-ECD (time-dependent density functional theory electronic circular dichroism) calculations. Compounds 15, 18:  - 21: , and 26: exhibited strong to moderate cytotoxic activity against the mouse lymphoma cell line L5178Y, with IC50 values ranging from 2.0 to 21.2 µM, while compounds 14, 16, 31, 32: , and 33: displayed moderate inhibitory activities against several gram-positive bacteria, with MIC values ranging from 12.5 to 50 µM.


Asunto(s)
Aspergillus/metabolismo , Bacillus subtilis/metabolismo , Animales , Antraquinonas/aislamiento & purificación , Antraquinonas/metabolismo , Antraquinonas/farmacología , Antibacterianos/aislamiento & purificación , Antibacterianos/metabolismo , Antibacterianos/farmacología , Línea Celular Tumoral/efectos de los fármacos , Dicroismo Circular , Técnicas de Cocultivo , Citotoxinas/aislamiento & purificación , Citotoxinas/metabolismo , Citotoxinas/farmacología , Relación Dosis-Respuesta a Droga , Bacterias Grampositivas/efectos de los fármacos , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Ratones , Pruebas de Sensibilidad Microbiana , Péptidos Cíclicos/aislamiento & purificación , Péptidos Cíclicos/metabolismo , Péptidos Cíclicos/farmacología , Quinolonas/aislamiento & purificación , Quinolonas/metabolismo , Quinolonas/farmacología
15.
Ophthalmic Res ; 60(2): 69-79, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29969774

RESUMEN

PURPOSE: To determine the efficacy of eugenol for the treatment of Candida keratitis in an experimental model. METHODS: The in vitro antifungal activity of eugenol and fluconazole was tested against C. albicans strains via the microbroth dilution method. An experimental model of Candida albicans keratitis was used. Rabbits were classified into those that received no treatment (control; group 1) and those that started eugenol treatment immediately (group 2) or after 4 days (group 3) of keratitis induction (n = 12-16 rabbits/group). The 2 treatment groups were assigned to 50 µL of 4 mg/mL eugenol drops hourly for 15 days, while the control group received saline. Corneal penetration of eugenol was measured using HPLC, and corneal toxicity was evaluated clinically and histopathologically. RESULTS: The in vitro minimum inhibitory concentrations of eugenol and fluconazole against C. albicans were 2 and > 0.4 mg/mL, respectively. A 4-mg/mL preparation of eugenol in propylene glycol was the maximum nontoxic dose on rabbit corneas as suggested by clinical and histopathologic findings. At least 75% of all eugenol-treated eyes recovered from keratitis, with improvement in the remaining 25% of the eyes compared to controls. CONCLUSIONS: Eugenol can act as a natural, safe, and effective treatment for fungal keratitis, regardless of whether treatment is started immediately or after 4 days of keratitis induction.


Asunto(s)
Antifúngicos/farmacología , Candida albicans/efectos de los fármacos , Eugenol/farmacología , Infecciones Fúngicas del Ojo/tratamiento farmacológico , Queratitis/tratamiento farmacológico , Animales , Córnea/efectos de los fármacos , Úlcera de la Córnea/tratamiento farmacológico , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Pruebas de Sensibilidad Microbiana , Conejos
16.
Fitoterapia ; 128: 258-264, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29778575

RESUMEN

Chemical investigation of a freshwater sediment-derived fungus, Penicillium sp. (S1a1), led to the isolation of three new tanzawaic acid derivatives, including penitanzchroman (1), tanzawaic acids Y (2) and Z (3), along with six known tanzawaic acid analogues (4-9), three known isochromans (10-12) and two known benzoquinones (13 and 14). The structures of the new compounds were established based on high-resolution mass spectrometry, and detailed analysis of one- and two-dimensional NMR spectroscopy. The relative configuration of the new compounds was assigned on the basis of NMR spectroscopic data including ROESY spectra. The absolute configuration was determined based on the specific optical rotation, in addition to biogenetic considerations in comparison with related co-isolated known metabolites. Penitanzchroman (1) constitutes a hitherto unprecedented skeleton, formed of tanzawaic acid A (5) and (3S)-6-hydroxy-8-methoxy-3,5-dimethylisochroman (10) linked by a CC bond. Moreover, all compounds were evaluated for their antibacterial and cytotoxic activities.


Asunto(s)
Ácidos Grasos Insaturados/aislamiento & purificación , Sedimentos Geológicos/microbiología , Penicillium/química , Animales , Benzoquinonas/aislamiento & purificación , Línea Celular Tumoral , Agua Dulce/microbiología , Ratones , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Microbiología del Agua
17.
Z Naturforsch C J Biosci ; 73(5-6): 199-210, 2018 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-29353267

RESUMEN

Fifteen pyrrole alkaloids were isolated from the Red Sea marine sponge Stylissa carteri and investigated for their biological activities. Four of them were dibrominated [(+) dibromophakelline, Z-3-bromohymenialdisine, (±) ageliferin and 3,4-dibromo-1H-pyrrole-2-carbamide], nine compounds were monobrominated [(-) clathramide C, agelongine, (+) manzacidin A, (-) 3-bromomanzacidin D, Z-spongiacidin D, Z-hymenialdisine, 2-debromostevensine, 2-bromoaldisine and 4-bromo-1H-pyrrole-2-carbamide)] and finally, two compounds were non-brominated derivatives viz., E-debromohymenialdisine and aldisine. The structure elucidations of isolated compounds were based on 1D & 2D NMR spectroscopic and MS studies, as well as by comparison with literature. In-vitro, Z-spongiacidin D exhibited a moderate activity on (ARK5, CDK2-CycA, CDK4/CycD1, VEGF-R2, SAK and PDGFR-beta) protein kinases. Moreover, Z-3-bromohymenialdisine showed nearly similar pattern. Furthermore, Z-hymenialdisine displayed a moderate effect on (ARK5 & VEGF-R2) and (-) clathramide C showed a moderate activity on AURORA-A protein kinases. While, agelongine, (+) manzacidin A, E-debromohymenialdisine and 3,4-dibromo-1H-pyrrole-2-carbamide demonstrated only marginal inhibitory activities. The cytotoxicity study was evaluated in two different cell lines. The most effective secondary metabolites were (+) dibromophakelline and Z-3-bromohymenialdisine on L5178Y. Finally, Z-hymenialdisine, Z-3-bromohymenialdisine and (±) ageliferin exhibited the highest cytotoxic activity on HCT116. No report about inhibition of AURORA-A and B by hymenialdisine/hymenialdisine analogs existed and no reported toxicity of ageliferin existed in literature.


Asunto(s)
Alcaloides/aislamiento & purificación , Poríferos/química , Pirroles/aislamiento & purificación , Alcaloides/química , Alcaloides/farmacología , Animales , Línea Celular , Supervivencia Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Células HCT116 , Humanos , Océano Índico , Estructura Molecular , Pirroles/química , Pirroles/farmacología
18.
IEEE Trans Neural Netw Learn Syst ; 29(6): 2278-2293, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-28436895

RESUMEN

This paper proposes a new online learning algorithm which is based on adaptive control (AC) theory, thus, we call this proposed algorithm as AC algorithm. Comparing to the gradient descent (GD) and exponential gradient (EG) algorithm which have been applied to online prediction problems, we find a new form of AC theory for online prediction problems and investigate two key questions: how to get a new update law which has a tighter upper bound on the error than the square loss? How to compare the upper bound for accumulated losses for the three algorithms? We obtain a new update law which fully utilizes model reference AC theory. Moreover, we present upper bound on the worst-case expected loss for AC algorithm and compare it with previously known bounds for the GD and EG algorithm. The loss bound we get in this paper is a time-varying function, which provides increasingly accurate estimates for upper bound. The AC algorithm has a much smaller loss only if the number of the samples meets certain conditions which can be seen in this paper. We also performed experiments which show that our update law is reasonably feasible and our upper bound is quite tight on both simple artificial and real data sets. The main contributions of this paper are twofold. First of all, we develop a new online algorithm called AC algorithm, and second, we obtain improved bounds, see Theorems 2-4 in this paper.

19.
Nat Prod Res ; 32(20): 2452-2456, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29281899

RESUMEN

Although the various folk medicine uses and the biological activity of Forsskaolea tenacissima L., few chemical constituents of this plant have been reported, this provoked us to make our study. Forsskamide, a new ceramide was isolated from aerial parts of F. tenacissima L. (Urticaceae). The chemical structure was established by different spectroscopic methods (1H, 13C-NMR, HMBC, HSQC, ROESY, FAB-MS and HR-FAB-MS). Forsskamide showed a moderate cytotoxic activity by (MTT) method against human colorectal carcinoma cell line (HCT-116) with IC50 33.25 µM in comparison with 5-fluorouracil IC50 26.42 µM. While, it did not show any activity against human hepatocarcinaoma cell line (HepG-2).


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Ceramidas/farmacología , Urticaceae/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Ceramidas/aislamiento & purificación , Egipto , Células HCT116 , Células Hep G2 , Humanos , Estructura Molecular , Componentes Aéreos de las Plantas/química
20.
IEEE Trans Med Imaging ; 33(6): 1390-400, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24893261

RESUMEN

Quantitative ultrasound (QUS) spectroscopic techniques in conjunction with maximum mean discrepancy (MMD) have been proposed to detect, and to classify noninvasively the levels of cell death in response to cancer therapy administration in tumor models. Evaluation of xenograft tumor responses to cancer treatments were carried out using conventional-frequency ultrasound at different times after chemotherapy exposure. Ultrasound data were analyzed using spectroscopic techniques and multi-parametric QUS spectral maps were generated. MMD was applied as a distance criterion, measuring alterations in each tumor in response to chemotherapy, and the extent of cell death was classified into less/more than 20% and 40% categories. Statistically significant differences were observed between "pre-" and "post-treatment" groups at different times after chemotherapy exposure, suggesting a high capability of proposed framework for detecting tumor response noninvasively. Promising results were also obtained for categorizing the extent of cell death response in each tumor using the proposed framework, with gold standard histological quantification of cell death as ground truth. The best classification results were obtained using MMD when applied on histograms of QUS parametric maps. In this case, classification accuracies of 84.7% and 88.2% were achieved for categorizing extent of tumor cell death into less/more than 20% and 40%, respectively.


Asunto(s)
Muerte Celular/efectos de los fármacos , Neoplasias Experimentales , Análisis Espectral/métodos , Ultrasonografía/métodos , Algoritmos , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Procesamiento de Imagen Asistido por Computador , Ratones , Ratones SCID , Neoplasias Experimentales/diagnóstico por imagen , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/patología , Medicina de Precisión/métodos , Ensayos Antitumor por Modelo de Xenoinjerto
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...