RESUMEN
We propose a miniaturized quad-band filter (QBF), designed using substrate-integrated coaxial cavities (SICCs). The employed SICC structure consists of two vertically stacked substrates with a large circular patch embedded in between. The embedded patch is segmented unevenly into four pieces, which are shorted to the cavity's bottom wall through one or two blind vias. This SICC structure exhibits four independently controlled resonances with frequencies much lower than the frequency of its conventional SIW cavity counterpart, thus achieving size reduction. A sample quad-band filter is designed and fabricated for experimental measurement. Reasonably good agreement between measured and simulated data is observed.
RESUMEN
This study examined the effects of substituting fish oil and fish meal with a blend of alpha-linolenic acid (ALA, 18:3 n-3) rich vegetable oils (14%, w/w) and defatted poultry meal (34%, w/w) in a formulated diet, on growth and tissue fatty acid profiles in barramundi fingerlings. Results indicated that on average, while the ALA levels of the barramundi liver and fillet increased with increasing dietary ALA, there was no corresponding increase in the levels of the omega-3 (n-3) long chain polyunsaturated fatty acid (LCPUFA). Compared to fish consuming a commercial feed, which contained fish meal and fish oil, fish on the ALA diets grew slower, had a lower feed intake and lower n-3 LCPUFA levels in the tissues. Hepatic mRNA expression of Δ6 desaturase (FADS2) and elongase (ELOVL5/2) was ~10 fold and ~3 fold higher, respectively, in all the ALA dietary groups, relative to those fed the commercial feed. However, the level of expression of the two genes was not different between fish fed differing ALA levels. These data demonstrate that increasing the ALA level of the diet is not an appropriate strategy for replacing marine sources of n-3 LCPUFA in barramundi. It was also noted, however, that within the different ALA dietary groups there was a large amount of variation between individual fish in their tissue DHA levels, suggesting a significant heterogeneity in their capacity for conversion of ALA and/or retention of n-3 LCPUFA. When dietary ALA intakes were greater than 0.8% en, tissue DHA levels were inversely related to ALA intake, suggesting that high intake of dietary ALA may inhibit DHA synthesis.
Asunto(s)
Ácidos Grasos Omega-3/química , Ácidos Grasos Omega-3/metabolismo , Perciformes/metabolismo , Ácido alfa-Linolénico/farmacología , Acetiltransferasas/genética , Alimentación Animal/análisis , Animales , Ácidos Docosahexaenoicos/química , Ácidos Docosahexaenoicos/metabolismo , Ácidos Grasos Omega-3/biosíntesis , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Linoleoil-CoA Desaturasa/genética , Hígado/efectos de los fármacos , Hígado/metabolismo , Perciformes/crecimiento & desarrollo , Fosfolípidos/química , Fosfolípidos/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ácido alfa-Linolénico/metabolismoRESUMEN
Desaturase and elongase are two key enzyme categories in the long-chain polyunsaturated fatty acid (LCPUFA) pathway that convert dietary α-linolenic acid (18:3n-3) to docosahexaenoic acid (22:6n-3). The Δ6 desaturase is considered as rate limiting in the conversion. In a previous study in barramundi we demonstrated that the desaturase had a low Δ6 activity but noted that the enzyme also possessed Δ8 ability that utilised 20-carbon fatty acids. This observation suggests that an alternative pathway may exist in the barramundi via elongases to form 20-carbon metabolites from 18:3n-3 to 20:3n-3 and then Δ6/8 desaturase to 20:4n-3. Cloning of the barramundi elongation of very long-chain fatty acid gene (ELOVL) and heterologous expression of the corresponding elongase were performed to examine activity with regard to time course, substrate concentration and substrate preference. Results revealed that the barramundi elongase showed a broad range of substrate specificity including 18-carbon PUFA (including 18:3n-3 and 18:2n-6), 20- and 22-carbon LCPUFA, with greater activity towards omega-3 (n-3) than n-6 fatty acids. The findings from this study provide molecular evidence for an alternative n-3 fatty acid elongation pathway utilising 18:3n-3 in barramundi.
Asunto(s)
Acetiltransferasas/metabolismo , Ácidos Docosahexaenoicos/biosíntesis , Perciformes/metabolismo , Ácido alfa-Linolénico/metabolismo , Acetiltransferasas/genética , Animales , Clonación Molecular , Elongasas de Ácidos Grasos , Perciformes/genética , Especificidad por SustratoRESUMEN
Barramundi is a commercially farmed fish in Australia. To examine the potential for barramundi to metabolise dietary α-linolenic acid (ALA, 18:3 n-3), the existence of barramundi desaturase enzymes was examined. A putative fatty acid Δ6 desaturase was cloned from barramundi liver and expressed in yeast. Functional expression revealed Δ6 desaturase activity with both the 18 carbon (C(18)) and C(24) n-3 fatty acids, ALA and 24:5 n-3 as well as the C(18) n-6 fatty, linoleic acid (LA, 18:2 n-6). Metabolism of ALA was favoured over LA. The enzyme also had Δ8 desaturase activity which raises the potential for synthesis in barramundi of omega-3 (n-3) long chain polyunsaturated fatty acids from ALA via a pathway that bypasses the initial Δ6 desaturase step. Our findings not only provide molecular evidence for the fatty acid desaturation pathway in the barramundi but also highlight the importance of taking extracellular fatty acid levels into account when assessing enzyme activity expressed in Saccharomyces cerevisiae.
Asunto(s)
Ácido Graso Desaturasas/metabolismo , Peces , Hígado/enzimología , Ácido alfa-Linolénico/metabolismo , Animales , Australia , Clonación Molecular , Ácido Graso Desaturasas/genética , Expresión Génica , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismoRESUMEN
Androgen receptor (AR) is the main therapeutic target for treatment of metastatic prostate cancers (PCa). As recurrent tumors restore AR activity independent of hormones, new therapies that abolish AR activity have been sought to prevent or delay the emergence of ablation-resistant disease. Here, we report that a novel abietane diterpene, 6-hydroxy-5,6-dehydrosugiol (HDHS), isolated from the stem bark of Cryptomeria japonica, was a potent AR antagonist in PCa cells. HDHS treatment of androgen-dependent LNCaP and androgen-responsive 22Rv1 cells induced apoptosis as shown by nucleosome release, activation of caspase-3 and caspase-7, and cleavage of poly(ADP-ribose) polymerase accompanied with concomitant up-regulation of tumor suppressor p53. HDHS also decreased the protein expression of cyclins (D1 and E), cyclin-dependent kinases (CDK2, CDK4, and CDK6), and retinoblastoma phosphorylation in PCa cells, which suggest cell cycle arrest in the G(1) phase. Oral administration of HDHS at 0.5 and 2.5 mg/kg once daily for 24 days to 22Rv1 PCa xenografted mice suppressed tumor growth by 22% and 39%, respectively, in association with decreased proliferation and increased apoptosis in tumor cells, which further correlated with increased levels of HDHS in plasma and tumors. Overall, our data suggest that HDHS has potential for use in chemoprevention and chemotherapy of PCa.
Asunto(s)
Abietanos/uso terapéutico , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Fitoterapia , Neoplasias de la Próstata/tratamiento farmacológico , Administración Oral , Antagonistas de Receptores Androgénicos , Animales , Cryptomeria/química , Quinasas Ciclina-Dependientes/metabolismo , Ciclinas/metabolismo , Fase G1/efectos de los fármacos , Humanos , Masculino , Ratones , Ratones Desnudos , Corteza de la Planta/química , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Receptores Androgénicos/genética , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
We identified eight diterpenes from Cryptomeria japonica (Taxodiaceae), which inhibit the activity of the androgen receptor (AR) in human prostate cancer (PCa) 22Rv1-derived 103E cells. The compounds 6,12-dihydroxyabieta-5,8,11,13-tetraen-7-one ( 2), sugiol ( 3), ferruginol ( 4), and 5-epixanthoperol ( 7) have near 100 % AR inhibition efficacy at concentrations of 10, 5, 25, and 25 microM, respectively. Because these compounds have very similar structures, analysis of their differential activity may aid in the design of inhibitors for PCa treatment.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Cryptomeria , Fitoterapia , Extractos Vegetales/farmacología , Receptores Androgénicos/metabolismo , Antineoplásicos Fitogénicos/administración & dosificación , Antineoplásicos Fitogénicos/uso terapéutico , Línea Celular Tumoral/efectos de los fármacos , Línea Celular Tumoral/metabolismo , Diterpenos/administración & dosificación , Diterpenos/farmacología , Diterpenos/uso terapéutico , Humanos , Concentración 50 Inhibidora , Masculino , Extractos Vegetales/administración & dosificación , Extractos Vegetales/uso terapéutico , Neoplasias de la Próstata/prevención & controlRESUMEN
In an outbreak of food poisoning involving a dried purple laver product (called nori), four persons had allergic-like symptoms such as inflammation and red rash on their face, mouth and belly. The causative nori was extracted and smeared on the arm-skin of five volunteers. Three out of five volunteers had a slight allergic reaction after 5 to 30 min when they were exposed to sunlight. The levels of the chlorophyll derivatives, pheophorbide a and pyropheophorbide a, measured by HPLC were 851-906 and 5,460-5,624 microg/g, respectively, in the causative samples. Judging from the high contents of pyropheophorbide a and pheophorbide a and the symptoms of patients and volunteers, the causative agents were concluded to be the photosensitizers pyropheophorbide a and pheophorbide a.