Apolipoprotein CI causes hypertriglyceridemia independent of the very-low-density lipoprotein receptor and apolipoprotein CIII in mice

We have recently shown that the predominant hypertriglyceridemia in human apolipoprotein C1 (APOC1) transgenic mice is mainly explained by apoCI-mediated inhibition of the lipoprotein lipase (LPL)-dependent triglyceride (TG)-hydrolysis pathway. Since the very-low-density lipoprotein receptor (VLDLr) and apoCIII are potent modifiers of LPL activity, our current aim was to study whether the lipolysis-inhibiting action of apoCI would be dependent on the presence of the VLDLr and apoCIII in vivo. Hereto, we employed liver-specific expression of human apoCI by using a novel recombinant adenovirus (AdAPOC1). In wild-type mice, moderate apoCI expression leading to plasma human apoCI levels of 12-33 mg/dl dose-dependently and specifically increased plasma TG (up to 6.6-fold, P < 0.001), yielding the same hypertriglyceridemic phenotype as observed in human APOC1 transgenic mice. AdAPOC1 still increased plasma TG in vldlr(-/-) mice (4.1-fold, P < 0.001) and in apoc3(-/-) mice (6.8-fold, P < 0.001) that were also deficient for the low-density lipoprotein receptor (LDLr) and LDLr-related protein (LRP) or apoE, respectively. Thus, irrespective of receptor-mediated remnant clearance by the liver, liver-specific expression of human apoCI causes hypertriglyceridemia in the absence of the VLDLr and apoCIII. We conclude that apoCI is a powerful and direct inhibitor of LPL activity independent of the VLDLr and apoCIII.     

Decreased S-nitrosation of peptide thiols in the membrane interior

It has been proposed that autoxidation of nitric oxide (NO) stimulates S-nitrosation of thiols located in the hydrophobic milieu. We tested whether thiols located in hydrophobic membranes undergo enhanced S-nitrosation in the presence of NO/O₂. The transmembrane cysteinyl peptides C₄ (AcNH-KKACALA(LA)₆KK-CONH₂) and C₈ (AcNH-KKALALACALA(LA)₃KK-CONH₂) were incorporated into dilauroylphosphatidylcholine bilayers; their location in the membrane was determined by EPR spin labeling. The peptides, C₈ and C₄, and glutathione (GSH; 300 μM) were treated with a NO donor, DEA-NONOate, and nitrosothiol formation was determined under various O₂ levels. Surprisingly, the more hydrophobic cysteinyl peptide, C₈, did not yield any S-nitrosated product compared to GSH in the aqueous phase or C₄ peptide in the liposomes in the presence of NO/O₂. These data suggest that thiols located deeply in the hydrophobic core of the membrane may be less likely to undergo S-nitrosation in the presence of NO/O₂.     

Contribution of non-native species to soft-sediment marine community structure of San Francisco Bay,California

While non-native species (NIS) are important components in many coastal bays and estuaries, quantitative measures that characterize their effects on community structure at bay-wide scales are rare. In this study, we measure species composition and abundance for soft-sediments to assess the contribution of NIS to multiple dimensions of community structure, focusing on one of the most highly invaded bays in the world, San Francisco Bay. Benthic macrofauna was sampled in the high salinity, muddy shallow subtidal (2 m depth) across 10 sites, using replicate 0.1 m² Van Veen grabs. Invertebrates retained on a 1 mm sieve were identified, counted, and used to estimate the overall contribution of NIS to (a) abundance (b) species richness, and (c) community similarity. Soft-sediment communities were dominated numerically by NIS, which accounted for 76 % of all organisms detected and had a mean bay-wide abundance that was three and half-fold higher than native biota. Overall, NIS contributed to 36 % of observed taxa and 24–29 % of total estimated regional diversity. Native species accounted for 21 % of total abundance and 45 % of total species richness. Compared to native species, NIS occurred more frequently among samples and also explained more of the variation in community structure among sites. NIS dominate several key attributes of the soft-sediment infaunal community in San Francisco Bay. Percent contribution of NIS to species richness was at least two-fold higher than reported from two decades ago. Unique to this bay, these measures establish a quantitative baseline on the state of invasions and provide an important model for evaluating the extent of NIS in estuaries. Application of this approach across estuaries, with repeated measures over time, is critically needed to advance scientific understanding of invasions and also evaluation of efficacy and gaps in management to reduce new invasions.     

Assessment of Metal Availability in Soils from a Pb-Zn Mine Site of South-Central Spain

Heavy metal pollution of the soils around an abandoned Pb-Zn mine site located in the Alcudia Valley (South Central Spain) have been characterized by analysis of extractable and total metal concentrations in 60 samples of arable, pasture, and mine lands. The samples showed a broad range of size-particle distribution, cation exchange capacity, and pH values as well as high levels of total metal concentrations (up to 98510 mg kg^?1 of Pb, up to 20912 mg kg^?1 of Zn, and up to 61 mg kg^?1 of Cd). In order to assess the potential availability of metals the metal partitioning in two different soil size fractions (<2 mm and <63 μm) was determined using EDTA and CaCl₂ as sequestering reagents. The average contents of Pb, Zn, and Cd in the <63 μm particle size fraction for both extractions were higher than those of the <2 mm fraction due to the high metal adsorption capacity of the fine soil particles. Concentrations of heavy metals extracted by CaCl₂ were up to three orders of magnitude lower than those extracted by EDTA, because CaCl₂ only extracts the easily mobile fraction. Metal concentrations extracted by both procedures in the two granulometric fractions increased with total metal concentrations, thus increasing the potential environmental risk associated to heavy metal pollution.     

Phytoplankton biomass in the sub-Antarctic area of the Straits of Magellan (53°S), Chile during spring-summer 1997/1998

In order to provide a better understanding of the dynamics of phytoplankton in the coastal regions of high latitudes, a study was carried out to estimate the dynamics of carbon biomass of autotrophic and heterotrophic algal groups over the austral spring-summer 1997/1998 period. At a fixed station located in the central basin (Paso Ancho) of the Straits of Magellan (53°S), surface water samples were collected at least once a week from September 1997 (early spring) to March 1998 (late summer). Quantitative analysis of biomass of phytoplankton was estimated from geometric volumes, using non-linear equations, and converted to biomass. The pattern of chlorophyll a showed a strong temporal variability, with maximum values (mean 2.8 mg m⁻³) at the austral spring phytoplankton increase or bloom (October/November) and minimum values during early spring (September: <0.5 mg m⁻³) and summer (January/March: 0.5–1.0 mg m⁻³). During the spring bloom, diatoms made up to 90% of the total phytoplankton carbon (0.01–189 μg l⁻¹), followed by a maximum of thecate dinoflagellates (0.08–34 μg l⁻¹), and sporadic high biomass of phytoflagellates during summer. Heterotrophic algal groups such as Gymnodinium and Gyrodinium spp. dominated (70%, in the 5- to 25-μm size range) shortly before the main diatom bloom, and small peaks were observed within spring and early summer periods (0–0.4 μg l⁻¹). Phytoflagellates dominated earlier (spring) with higher carbon biomass (8 μg l⁻¹) and post-bloom periods (summer) when carbon biomass ranged between 1 and 4 μg l⁻¹. Accepted: 6 September 2000     

Acyl coenzyme A synthetase long-chain 1 (ACSL1) gene polymorphism (rs6552828) and elite endurance athletic status: a replication study

The aim of this study was to determine the association between the rs6552828 polymorphism in acyl coenzyme A synthetase (ACSL1) and elite endurance athletic status. We studied 82 Caucasian (Spanish) World/Olympic-class endurance male athletes, and a group of sex and ethnically matched healthy young adults (controls, n=197). The analyses were replicated in a cohort of a different ethnic origin (Chinese of the Han ethnic group), composed of elite endurance athletes (runners) [cases, n=241 (128 male)] and healthy sedentary adults [controls, n=504 (267 male)]. In the Spanish cohort, genotype (P=0.591) and minor allele (A) frequencies were similar in cases and controls (P=0.978). In the Chinese cohort, genotype (P=0.973) and minor allele (G) frequencies were comparable in female endurance athletes and sedentary controls (P=0.881), whereas in males the frequency of the G allele was higher in endurance athletes (0.40) compared with their controls (0.32, P=0.040). The odds ratio (95%CI) for an elite endurance Chinese athlete to carry the G allele compared with ethnically matched controls was 1.381 (1.015-1.880) (P-value=0.04). Our findings suggest that the ACSL1 gene polymorphism rs6552828 is not associated with elite endurance athletic status in Caucasians, yet a marginal association seems to exist for the Chinese (Han) male population.     

Minimally Invasive Electro-Magnetic Navigational Bronchoscopy-Integrated Near-Infrared-Guided Sentinel Lymph Node Mapping in the Porcine Lung

BackgroundThe use of near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) for sentinel lymph node (SN) mapping has been investigated in lung cancer; however, this has not been fully adapted for minimally invasive surgery (MIS). The aim of our study was to develop a minimally invasive SN mapping integrating pre-operative electro-magnetic navigational bronchoscopy (ENB)-guided transbronchial ICG injection and intraoperative NIR thoracoscopic imaging.MethodsA NIR thoracoscope was used to visualize ICG fluorescence. ICG solutions in a 96-well plate and ex vivo porcine lungs were examined to optimize ICG concentrations and injection volumes. Transbronchial ICG injection (n=4) was assessed in comparison to a traditional transpleural approach (n=3), where after thoracotomy an ICG solution (100μL at 100μg/mL) was injected into the porcine right upper lobe for SN identification. For further translation into clinical use, transbronchial ICG injection prior to thoracotomy followed by NIR thoracoscopic imaging was validated (n=3). ENB was used for accurate targeting in two pigs with a pseudo-tumor.ResultsThe ICG fluorescence at 10 μg/mL was the brightest among various concentrations, unchanged by the distance between the thoracoscope and ICG solutions. Injected ICG of no more than 500μL showed a localized fluorescence area. All 7 pigs showed a bright paratracheal lymph node within 15 minutes post-injection, with persistent fluorescence for 60 minutes. The antecedent transbronchial ICG injection succeeded in SN identification in all 3 cases at the first thoracoscopic inspection within 20 minutes post-injection. The ENB system allowed accurate ICG injection surrounding the pseudo-tumors.ConclusionsENB-guided ICG injection followed by NIR thoracoscopy was technically feasible for SN mapping in the porcine lung. This promising platform may be translated into human clinical trials and is suited for MIS.     

Novel Method for Enumeration of Viable Lactobacillus plantarum WCFS1 Cells after Single-Droplet Drying

Survival of probiotic bacteria during drying is not trivial. Survival percentages are very specific for each probiotic strain and can be improved by careful selection of drying conditions and proper drying carrier formulation. An experimental approach is presented, comprising a single-droplet drying method and a subsequent novel screening methodology, to assess the microbial viability within single particles. The drying method involves the drying of a single droplet deposited on a flat, hydrophobic surface under well-defined drying conditions and carrier formulations. Semidried or dried particles were subjected to rehydration, fluorescence staining, and live/dead enumeration using fluorescence microscopy. The novel screening methodology provided accurate survival percentages in line with conventional plating enumeration and was evaluated in single-droplet drying experiments with Lactobacillus plantarum WCFS1 as a model probiotic strain. Parameters such as bulk air temperatures and the carrier matrices (glucose, trehalose, and maltodextrin DE 6) were varied. Following the experimental approach, the influence on the viability as a function of the drying history could be monitored. Finally, the applicability of the novel viability assessment was demonstrated for samples obtained from drying experiments at a larger scale.