The apparent non-host resistance of Ethiopian mustard to a radish-infecting strain of Turnip mosaic virus is largely determined by the C-terminal region of the P3 viral protein.

Two different isolates of Turnip mosaic virus (TuMV: UK 1 and JPN 1) belonging to different virus strains were tested on three different Brassica species, namely turnip (Brassica rapa L.), Indian mustard (Brassica juncea L.) and Ethiopian mustard (Brassica carinata A. Braun). Although all three hosts were readily infected by isolate UK 1, isolate JPN 1 was able to establish a visible systemic infection only in the first two. Ethiopian mustard plants showed no local or systemic symptoms, and no virus antigens could be detected by enzyme-linked immunosorbent assay (ELISA). Thus, this species looks like a non-host for JPN 1, an apparent situation of non-host resistance (NHR). Through an experimental approach involving chimeric viruses made by gene interchange between two infectious clones of both virus isolates, the genomic region encoding the C-terminal domain of viral protein P3 was found to bear the resistance determinant, excluding any involvement of the viral fusion proteins P3N-PIPO and P3N-ALT in the resistance. A further determinant refinement identified two adjacent positions (1099 and 1100 of the viral polyprotein) as the main determinants of resistance. Green fluorescent protein (GFP)-tagged viruses showed that the resistance of Ethiopian mustard to isolate JPN 1 is only apparent, as virus-induced fluorescence could be found in discrete areas of both inoculated and non-inoculated leaves. In comparison with other plant-virus combinations of extreme resistance, we propose that Ethiopian mustard shows an apparent NHR to TuMV JPN 1, but not complete immunity or extreme resistance.

Association of Exclusive Breastfeeding Duration With Systemic Inflammation Markers in Adolescents: A Cross-Sectional Study.

BACKGROUND: Breastfeeding duration has been associated with less low-grade inflammation in healthy adolescents, but there is scarce information regarding obese subjects. This study aimed to evaluate whether exclusive breastfeeding is related to serum concentrations of inflammatory markers in a population of Spanish adolescents. METHOD: A cross-sectional study was performed on 1,001 adolescents (13.2 ± 1.2 years) randomly recruited from schools in southeast Spain. Data on breastfeeding duration were collected via a parental questionnaire. Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were determined by enzyme-linked immunosorbent assay. C-reactive protein (CRP) was determined by solid-phase chemiluminescent immunometric assay. RESULTS: Nonadjusted and adjusted multivariate correlation analyses confirmed a strong association ( p < .001, 95% confidence interval) between the three markers of inflammation and exclusive breastfeeding duration. No significant differences were observed for IL-6, TNF-α, and CRP serum concentrations among normal weight, overweight, and obese adolescents, except for IL-6 between normal weight and obese subjects. Likewise, no significant association was found between these markers of inflammation and body mass index (BMI) z-score. CONCLUSIONS: We found a possible association between inflammatory markers and exclusive breastfeeding duration in adolescents, regardless of their BMI. This finding suggests that increased body weight or obesity might not mediate the association between breastfeeding and inflammation. These results contribute to the understanding of the relationship between breastfeeding and inflammatory markers in adolescents.

Predictive value of ceruloplasmin for metabolic syndrome in adolescents.

The metabolic syndrome (MetS) is precisely defined and the cardiovascular risk associated with the clustering of its components has been demonstrated in adults. However, data on children and adolescents are still scarce, in part, because of difficulties in transposing the definition from adults. The identification of risk factors for the development of MetS at an early age is essential for prevention purposes with low-grade inflammation acting as a determinant for the association among the MetS components. The aim of this study was to investigate the associations of the MetS with systemic markers of inflammation and ceruloplasmin in a population of adolescents. The present is a cross-sectional study whose sample population consisted of 976 adolescents, 13.2 ± 1.2 years of age. Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were determined by ELISA. High-sensitivity C-reactive protein (hs-CRP) was determined by a solid-phase chemiluminiscent immunometric assay. Ceruloplasmin was measured by immunoturbidimetry. MetS adolescents exhibited higher levels of TNF-α, IL-6, CRP, and ceruloplasmin compared to non-MetS individuals. TNF-α, IL-6, and CRP showed strong correlations with the MetS components and insulin resistance but not relevant predictive values according to ROC curves (AUC values 0.544- 0.555). In contrast, ceruloplasmin only showed significant correlations in non-Mets individuals, but exhibited a very high predictive value (AUC=0.941, P < 0.001). The determination of serum ceruloplasmin in adolescents might be a useful tool to identify patients with the highest risk of future cardiovascular disease.

Brief Communication: Discordant ability of the triglyceride to apolipoprotein B ratio to predict triglyceride-rich lipoprotein particle size in normal-weight and obese men.

The atherogenicity of triglyceride-rich lipoproteins (TRLs) is dependent of their particle size as it determines their metabolic fate. Since TRL possess a single apolipoprotein B (Apo B) molecule per particle, the triglyceride (TG)/Apo B ratio has been used as a convenient method to estimate TRL size. The aim of this study was to validate this approach by correlating the serum TG/Apo B ratio, and the TRL particle size measured by dynamic light scattering (DLS). Twenty-four male volunteers (12 normal-weight and 12 obese individuals) received a high-fat meal. Preprandial (0 h) and postprandial (2 and 4 h) serum samples were collected after meal ingestion, and TRLs were isolated. Serum TG and Apo B levels were quantified, and the TG/Apo B ratio was plotted against TRL particle size measured by DLS for correlation. A strong association between TRL particle size and serum TG/Apo B ratio for normal-weight subjects (P ≤ 0.001) was observed but not for obese subjects (P = 0.6116). TG/Apo B ratio correlates with particle size in healthy normal-weight males but not in obese individuals. Whether this ratio is useful to estimate TRL size in females and in other dyslipidemic patients should be subject of future investigations.

Postprandial phase time influences the uptake of TAG from postprandial TAG-rich lipoproteins by THP-1 macrophages.

Postprandial TAG-rich lipoproteins (TRL) can be taken up by macrophages, leading to the formation of foam cells, probably via receptor-mediated pathways. The present study was conducted to investigate whether the postprandial time point at which TRL are collected modulates this process. A meal containing refined olive oil was given to nine healthy young men and TRL were isolated from their serum at 2, 4 and 6 h postprandially. The lipid class and apoB compositions of TRL were determined by HPLC and SDS-PAGE, respectively. The accumulation of lipids in macrophages was determined after the incubation of THP-1 macrophages with TRL. The gene expression of candidate receptors was measured by real-time PCR. The highest concentrations of TAG, apoB48 and apoB100 in TRL were observed at 2 h after the consumption of the test meal. However, excessive intracellular TAG accumulation in THP-1 macrophages was observed in response to incubation with TRL isolated at 4 h, when their particle size (estimated as the TAG:apoB ratio) was intermediate. The abundance of mRNA transcripts in macrophages in response to incubation with TRL was down-regulated for LDL receptor (LDLR), slightly up-regulated for VLDL receptor and remained unaltered for LDLR-related protein, but no effect of the postprandial time point was observed. In contrast, the mRNA expression of scavenger receptors SRB1, SRA2 and CD36 was higher when cells were incubated with TRL isolated at 4 h after the consumption of the test meal. In conclusion, TRL led to excessive intracellular TAG accumulation in THP-1 macrophages, which was greater when cells were incubated with intermediate-sized postprandial TRL isolated at 4 h and was associated with a significant increase in the mRNA expression of scavenger receptors.