Feeding behavior of yellowfin tuna around two insular regions of the western Atlantic Ocean

The yellowfin tuna is a very abundant tropical tuna species in the western equatorial Atlantic Ocean and an important fishery resource for the Brazilian tuna fleet. In this study we performed stable isotope analysis to better understand the spatial trophodynamics and dietary changes in yellowfin tuna around two insular marine protected areas in Brazil. A total of 65 yellowfin tuna specimens measuring between 47 and 138 cm LT (total length) were sampled around the archipelagos of Fernando de Noronha (FNA; n = 34) and Saint Peter and Saint Paul (SPSPA; n = 31) between July 2018 and September 2019. Bayesian mixing models and generalized additive models were used to investigate the contributions of four different prey items (zooplankton, cephalopods, fish larvae, and flying fish) to yellowfin tuna diet in each area and their potential changes in relation to predator growth. The four prey items were found to have different overall contributions between the two studied areas, with zooplankton being the most important prey in FNA, whereas flying fish was the most relevant prey to the species' diet in SPSPA. Significant changes in the species diet by size were also found, with fish smaller than 90 cm (TL) having a more generalist diet and larger animals relying more on consuming larger and more nutritious prey (i.e., flying fish). Our results suggest that these two marine protected areas play an important role in ocean dynamics, providing important and different foraging grounds for the development of this predator species.

From the light blue sky to the dark deep sea: Trophic and resource partitioning between epipelagic and mesopelagic layers in a tropical oceanic ecosystem

The connection between epipelagic and deep-sea mesopelagic realms controls a variety of ecosystem processes including oceanic carbon storage and the provision of harvestable fish stocks. So far, these two layers have been mostly addressed in isolation and the ways they connect remain poorly understood. Furthermore, both systems are affected by climate change, exploitation of resources, and increasing pervasion of pollutants. Here we use bulk isotopes of δ¹³C and δ¹⁵N of 60 ecosystem components to evaluate the trophic linkage between epipelagic and mesopelagic ecosystems in warm oligotrophic waters. Additionally, we we conducted a comparison of isotopic niche sizes and overlaps across multiple species to evaluate how environmental gradients between epipelagic and mesopelagic ecosystems shape ecological patterns of resource use and competition between species. Our database comprises siphonophores, crustaceans, cephalopods, salpas, fishes, and seabirds. It also includes five zooplankton size classes, two groups of fish larvae, and particulate organic matter collected at different depths. Through this wide taxonomic and trophic variety of epipelagic and mesopelagic species, we show that pelagic species access resources originating from different food sources, mostly autotrophic-based (epipelagics) and microbial heterotrophic-based (mesopelagics). This leads to a sharp trophic dissimilarity between vertical layers. Additionally, we show that trophic specialization increases in deep-sea species and argue that food availability and environmental stability are among the main drivers of this pattern. Finally, we discuss how the ecological traits of pelagic species highlighted in this study can respond to human impacts and increase their vulnerability in the Anthropocene.

From prey to predators: Evidence of microplastic trophic transfer in tuna and large pelagic species in the southwestern Tropical Atlantic

Plastic pollution is present in most marine environments; however, contamination in pelagic predators, including species of economic interest, is still poorly understood. This study aims to access the macro- and microplastic contamination in tuna and large pelagic species and verify whether a trophic transfer occurs from prey to tunas captured by two fleets in the Southwestern Tropical Atlantic (SWTA). We combined different methodological approaches to analyse the intake of macro- and microplastics. In addition to examining the plastics in the fish' stomachs, we investigated the contamination in the prey retrieved from the guts of predators. A low frequency of occurrence (3%) of macroplastic was detected in the tuna and large pelagic species; conversely, we observed a high frequency of microplastic in the tuna's stomachs (100%) and prey analysed (70%). We evinced the trophic transfer of microplastics by analysing the ingestion rate of particles in prey retrieved from the tuna stomachs. In the 34 analysed prey, we detected 355 microplastic particles. The most contaminated prey were cephalopods and fishes of the Bramidae family. The most frequent microplastic shapes in both prey and tuna stomachs were foams, pellets and fibres (<1 mm). A variety of polymers were identified; the most frequent were styrene-butadiene rubber (SBR), polyamide (PA), polyethylene terephthalate (PET) and polyethylene (PE). Our findings enhance scientific knowledge of how the ecological behaviour of marine species can affect microplastic intake.

Continuous enzalutamide after progression of metastatic castration-resistant prostate cancer treated with docetaxel (PRESIDE): an international, randomised, phase 3b study

BACKGROUND

Although androgen deprivation therapy is typically given long-term for men with metastatic prostate cancer, second-generation hormone therapies are generally discontinued before the subsequent line of treatment. We aimed to evaluate the efficacy of continuing enzalutamide after progression in controlling metastatic castration-resistant prostate cancer (mCRPC) treated with docetaxel and prednisolone.

METHODS

PRESIDE was a two-period, multinational, double-blind, randomised, placebo-controlled, phase 3b study done at 123 sites in Europe (in Austria, Belgium, Czech Republic, France, Germany, Greece, Italy, Netherlands, Norway, Poland, Russia, Spain, Sweden, Switzerland, Turkey, and the UK). Patients were eligible for period 1 (P1) of the study if they had histologically confirmed prostate adenocarcinoma without neuroendocrine differentiation or small-cell features, serum testosterone concentrations of 1·73 nmol/L or less, and had progressed during androgen deprivation therapy with a luteinising hormone-releasing hormone agonist or antagonist or after bilateral orchiectomy. In P1, patients received open-label enzalutamide 160 mg per day orally. At week 13, patients were assessed for either radiographic or prostate-specific antigen (PSA) progression (25% or more increase and 2 ng/mL or more above nadir). Patients who showed any decline in PSA at week 13 and subsequently progressed (radiographic progression, PSA progression, or both) were screened and enrolled in period 2 (P2), during which eligible patients were treated with up to ten cycles of intravenous docetaxel 75 mg/m² every 3 weeks and oral prednisolone 10 mg/day, and randomly assigned (1:1) to oral enzalutamide 160 mg/day or oral placebo. Patients were stratified by type of disease progression. The block size was four and the overall number of blocks was 400. Patients, investigators, and study organisers were masked to treatment assignment. The primary endpoint was progression-free survival analysed in all patients in P2. This trial is registered with ClinicalTrials.gov, NCT02288247, and is no longer recruiting.

FINDINGS

Between Dec 1, 2014, and Feb 15, 2016, 816 patients were screened for P1 of the study. 688 patients were enrolled in P1 and 687 received open-label enzalutamide. In P2, 271 patients were randomly assigned at 73 sites to receive enzalutamide (n=136) or placebo (n=135). The data cutoff for analysis was April 30, 2020. Median progression-free survival with enzalutamide was 9·5 months (95% CI 8·3-10·9) versus 8·3 months (6·3-8·7) with placebo (hazard ratio 0·72 [95% CI 0·53-0·96]; p=0·027). The most common grade 3 treatment-emergent adverse events were neutropenia (17 [13%] of 136 patients in the enzalutamide group vs 12 [9%] of 135 patients in the placebo group) and asthenia (ten [7%] vs six [4%]). The most common grade 4 treatment-emergent adverse event in P2 was neutropenia (23 [17%] of 136 patients in the enzalutamide group vs 28 [21%] of 135 patients in the placebo group). Serious treatment-emergent adverse events were reported in 67 (49%) of 136 patients in the enzalutamide group and 52 (39%) of 135 patients in the placebo group. Two (15%) of 13 deaths in the enzalutamide group (caused by septic shock and haematuria) and one (14%) of seven deaths in the placebo group (caused by actue kidney injury) were associated with docetaxel.

INTERPRETATION

PRESIDE met its primary endpoint and showed that continuing enzalutamide with docetaxel plus androgen deprivation therapy delayed time to progression compared with docetaxel plus androgen deprivation therapy alone, supporting the hypothesis that enzalutamide maintenance could control persistent androgen-dependent clones in men with mCRPC who progress after treatment with enzalutamide alone.

FUNDING

Astellas Pharma and Pfizer.

Health resource utilization, costs, and community treatment order status before and after the initiation of second-generation long acting-injectable antipsychotics in patients with schizophrenia in Alberta, Canada

Introduction

Long-acting injectable (LAI) antipsychotics and community treatment orders (CTOs) are used in patients with schizophrenia to improve treatment effectiveness through adherence.

Objectives

Understanding healthcare resource utilization (HRU) and associated costs, and medication adherence in patients with schizophrenia overall and by CTO status before and after second generation antipsychotic (SGA) LAI initiation may guide strategies to optimize health.

Methods

A retrospective observational single-arm study using administrative data from Alberta was performed. Adults with schizophrenia who initiated SGA-LAI (index date) were included. Medication possession ratio (MPR) was determined; paired t-tests were used to examine differences in HRU and costs ($CDN) between the 2-year pre-index period and 2-year post-index period. Stratified analysis by presence or absence of an active CTO during the pre-post periods was performed.

Results

Among 1,211 patients who initiated SGA-LAIs, MPR was greater post-index (0.84) compared with pre-index (0.45; 95% confidence interval [CI] 0.36, 0.41). All-cause and mental health-related HRU and costs were lower post-index versus pre-index (p<0.001); total all-cause HRU costs were $33,788 lower post- versus pre-index ($40,343 [standard deviation, SD $68,887] versus $74,131 [SD $75,941], 95% CI [-$38,993, -$28,583]), and total mental health-related HRU costs were $34,198 lower post- versus pre-index ($34,205 [SD $63,428] CDN versus $68,403 [SD $72,088] CDN, 95%CI [-$39,098, -$29,297]). Forty-three percent had ≥1 active CTO during the study period; HRU and costs varied according to CTO status.

Conclusions

SGA-LAIs are associated with improved adherence, and lower HRU and costs however the latter vary according to CTO status.

Disclosure

The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this abstract: SD and MS have no competing interest to declare. LR, SK, KW, and KM are members of the Real-World Evidence

A158 COMPARING CORTIMENT® AND PREDNISONE IN ULCERTATIVE COLITIS: A POPULATION-BASED STUDY OF OUTCOMES

Background

In August 2016 Cortiment® was approved for use in ulcerative colitis (UC) patients in Canada, but not approved for reimbursement; the Canadian Agency for Drugs and Technology in Health cited no comparable benefit for its use over other approved UC medications. Real-world data comparing Cortiment® to other UC medications is limited, especially during the COVID-19 pandemic where the use of steroids is counter-indicated for COVID-19-related outcomes.

Aims

To examine the comparative risk of hospitalization, surgery, and infection after initiation of Cortiment® or oral corticosteroids among UC patients using real-world data

Methods

Using population-based data from Alberta Canada, two cohorts were compared: 1. Patients dispensed Cortiment® and an ICD diagnostic code for UC [9: 556.X; 10: K51.X] (August 1, 2016 to October 31, 2019); and, 2. Validated (algorithm) UC patients dispensed a >30 day supply or >500mg in 24 hours of prednisone/prednisolone (April 1, 2016 to October 31, 2019). All hospitalizations, IBD-surgery, or infections (i.e., pneumonia, c.diff, sepsis, tuberculosis) that occurred 6 or 12 months from initial medication dispensing were identified. Cox-proportional hazard models, with Hazard Ratios (HR), assessed comparative outcomes. Kaplan-Meier survival curves were created, and Poisson regression (or negative binomial) used to assess the Average Monthly Percentage Change (AMPC) with associated 95% confidence intervals (CI).

Results

We identified 917 Cortiment® and 2,404 Prednisone patients. Over the study period, prednisone dispensing significantly decreased (AMPC:-2.53% [CI:-2.85,-2.21]) while Cortiment® remained stable. Dispensing of Cortiment® significantly decreased the hazard of hospitalization (all types, except surgery) at 12 months as compared to prednisone, and significantly decreased the hazard of an infection at both 6 and 12 months (Table 1, Fig 1).

Conclusions

The use of Cortiment® in a real-world setting is associated with fewer deleterious outcomes, and its use during a pandemic should be preferred, especially when it’s counterpart can exacerbate negative COVID-19-related outcomes.

Table 1

Kaplan-Meier Survival Curves of 1-year Outcomes: A) All Hospitalizations; B) IBD-Related Hospitalizations; C) IBD-Specific Hospitalizations; and, D) Any Infection.

Dashed Line

Cortiment Cohort

Solid Line

Prednisone/Prednisolone Cohort

Funding Agencies

Ferring Pharmaceuticals

A randomized, double-blind, placebo (PBO)-controlled, phase 3b study of the efficacy and safety of continuing enzalutamide (ENZA) in chemotherapy-naïve, metastatic castration-resistant prostate cancer (mCRPC) patients (pts) treated with docetaxel (DOC) plus prednisolone (PDN) who have progressed on ENZA: PRESIDE

15

Background: PRESIDE (NCT02288247) evaluated the benefit of continued ENZA + androgen deprivation therapy (ADT) with DOC + PDN in men with mCRPC who progressed on ENZA + ADT. Methods: PRESIDE (Dec 2014–Apr 2020) enrolled chemotherapy-naïve men with mCRPC and disease progression while on a luteinizing hormone-releasing hormone (LHRH) agonist/antagonist (ADT) or after bilateral orchiectomy. Pts received open-label ENZA (160 mg) + ADT in Period 1 (P1). Those with a prostate-specific antigen (PSA) response of ≥50% change from baseline to week (wk) 13 and later progression were eligible for Period 2 (P2). P2 pts received DOC (75 mg/m2), PDN (10 mg), and ADT, and were randomized to ENZA (160 mg) or PBO. The primary endpoint was progression-free survival (PFS) in P2 (from randomization to radiographic/clinical progression or death). Secondary endpoints included time to PSA progression (TTPP) [≥25% increase; absolute increase ≥2 ng/mL] and PSA response in P2. Hazard ratios (HRs) were from a Cox proportional hazards model with covariates for treatment and P1 progression. Adverse events (AEs) were recorded to assess safety. Results: 687 pts received ENZA in P1; 273 pts were randomized and 271 were treated in P2. Baseline demographics and characteristics were balanced between P2 arms. Median ENZA exposure was 62.6 wks in P1 and 36.1 and 30.1 wks in P2 with ENZA and PBO, respectively. At P2 data cut-off (Apr 30, 2020), 269 (99.3%) pts had discontinued therapy; 93 pts in each arm (ENZA, 74.4%; PBO, 75.6%) had progression. PFS was significantly improved with ENZA (HR 0.72; 95% confidence interval [CI] 0.53, 0.96; p = 0.027), with a higher median PFS with ENZA (9.53 months; 95% CI 8.25, 10.87) than with PBO (8.28 months; 95% CI 6.28, 8.71). ENZA also significantly delayed TTPP (8.44 vs. 6.24 months with PBO; HR 0.58; 95% CI 0.41, 0.82; p = 0.002) and improved PSA response at any time (ENZA, n = 76 [55.9%]; PBO, n = 50 [37.0%]). There were 46 (6.7%) deaths in P1 and 20 (ENZA, n = 13 [9.6%]; PBO, n = 7 [5.2%]) in P2. In P2, 264 (97.4%) pts had a treatment-emergent AE (TEAE) [ENZA, n = 133 (97.8%); PBO, n = 131 (97.0%)]. Grade 3/4 TEAEs were reported by 84 (61.8%) pts on ENZA and 84 (62.2%) on PBO, and 12 (8.8%) and 9 (6.7%) pts, respectively, had TEAEs leading to discontinuation. Neutropenia (ENZA, 16.9%; PBO, 20.7%) was the most common grade 4 TEAE. Drug-related TEAEs (ENZA, 46.3%; PBO, 41.5%) were similar, and 90.4% of pts in each arm reported DOC-related TEAEs. Conclusions: Continued ENZA therapy in men with mCRPC who progressed on ENZA + ADT and received post-progression DOC + PDN significantly improved PFS compared to PBO. Treatment was well tolerated and ENZA AEs were consistent with its known safety profile. Clinical trial information: NCT02288247.

Assessing trophic interactions between pelagic predatory fish by gut content and stable isotopes analysis around Fernando de Noronha Archipelago (Brazil), Equatorial West Atlantic

The objective of this study was to analyse the feeding habits and trophic interactions between four oceanic predatory fish around the Fernando de Noronha Archipelago (FNA), Brazil, in the western equatorial Atlantic (3.86°S/32.42°W), internationally recognized as an environment of high economic and ecological value. For this purpose, biological samples of yellowfin tuna (Thunnus albacares), wahoo (Acanthocybium solandri), barracuda (Sphyraena barracuda) and dolphinfish (Coryphaena hippurus) were collected for stomach content and stable isotope analysis. Values of the index of relative importance revealed varied diets, with a strong presence of teleost fishes (Diodontidae and Exocoetidae) for all species, with yellowfin tuna having a greater diversity of food items. Despite being generalists/opportunists, the feeding strategy of these predators showed a tendency towards a specialized diet in the use of the available resources around the FNA. They presented a narrow trophic niche width (Levin's index, Bi < 0.6) and low overlap between species, except between barracuda and wahoo (MacArthur and Levin's, R₀  = 0.72). Isotopic compositions had broad values of δ¹³ C and δ¹⁵ N, and were significantly different between species. Our results provide information about the four species' trophic organization and suggest that the predators avoid competition by preying on different prey, thus allowing their coexistence.

A155 REAL-WORLD USE OF CORTIMENT IN ULCERATIVE COLITIS: A POPULATION-BASED STUDY

Background

Ulcerative colitis (UC) is a relapsing and remitting disease with variable severity. BudesonideMMX (Cortiment®) was approved by Health Canada for the treatment of mild to moderate UC in July 2016. It offers the advantage of extensive first pass hepatic metabolism resulting in decreased systemic corticosteroid toxicity. Most public drug plans in Canada do not cover it, limiting its use to private insurance and self-pay.

Aims

To characterize the UC patients who use Cortiment® and explore prescribing patterns and short-term outcomes.

Methods

Population-based administrative data identified patients who were covered by the Alberta Health Care Insurance Plan and dispensed Cortiment® from August 1, 2016 to December 31, 2017. Analyses identified: age, sex, rural/urban status, Material [MDI] and Social Deprivation Indices [SDI], UC-related medications 6-months before and 10-weeks following Cortiment® dispensing, and disease exacerbation indicators (new dispense of corticosteroids, hospitalization with inflammatory bowel disease (IBD) as most responsible diagnosis, or IBD-related surgery).

Results

We identified 427 UC patients dispensed Cortiment®. The median age was 47 years (25th %: 35; 75th %: 59) and 57.4% were females. Most individuals (91.3%, n=390) resided in an urban setting, as compared to approximately 73% of all UC cases. Distribution of patients across SDI was consistent while the MDI had a higher proportion in the more well-off categories. 77.5% had a UC-related drug therapy in the 6 months prior to Cortiment® dispensing and 71.7% had a UC-related drug dispensed in the 10-weeks following. Approximately, 30% had a disease exacerbation indicators in the 10 weeks following dispensing: 24.8% new corticosteroid, 3.7% UC-related hospitalization, and &lt;2.3% UC-related surgery.

Conclusions

Despite lack of public drug coverage, Cortiment® was dispensed across socioeconomic classes. The high dispensing within urban sites suggests that rural UC patients may have less access to Cortiment®. While a quarter of Cortiment® dispensings had a new concurrent dispensing of prednisone, &lt;5% of these patients were admitted to hospital for a flare of UC.

Funding Agencies

Ferring Pharmaceuticals

Genetic diversity of the forage peanut in the Jequitinhonha, São Francisco, and Paranã River valleys of Brazil

Arachis pintoi and A. repens are legumes with a high forage value that are used to feed ruminants in consortium systems. Not only do they increase the persistence and quality of pastures, they are also used for ornamental and green cover. The objective of this study was to analyze microsatellite markers in order to access the genetic diversity of 65 forage peanut germplasm accessions in the section Caulorrhizae of the genus Arachis in the Jequitinhonha, São Francisco and Paranã River valleys of Brazil. Fifty-seven accessions of A. pintoi and eight of A. repens were analyzed using 17 microsatellites, and the observed heterozygosity (H_O), expected heterozygosity (H_E), number of alleles per locus, discriminatory power, and polymorphism information content were all estimated. Ten loci (58.8%) were polymorphic, and 125 alleles were found in total. The H_E ranged from 0.30 to 0.94, and H_O values ranged from 0.03 to 0.88. By using Bayesian analysis, the accessions were genetically differentiated into three gene pools. Neither the unweighted pair group method with arithmetic mean nor a neighbor-joining analysis clustered samples into species, origin, or collection area. These results reveal a very weak genetic structure that does not form defined clusters, and that there is a high degree of similarity between the two species.

Using the mini-VIDAS(®) Easy Salmonella protocol to assess contamination in transitional and coastal waters

Classical methodologies for Salmonella detection may be too long in time to assure public safety. Presently, one of the fastest assays for Salmonella detection using the mini-VIDAS(®) system is the Easy Salmonella protocol. This assay, developed for food matrixes analysis, was here assessed for the applicability on the detection of these bacteria in transitional and saltwaters. The presence of Salmonella was detected in 4.2 % of the samples studied. In these transitional waters, the proposed protocol presented an efficiency of 79.1 %, due to a high false positive rate (20.8 %), and a false negative rate of 0 %-implying reducing analysis time, the use of enrichment broths, and making it more cost effective. Despite the multitude of samples nature, the method here described revealed to be an efficient and promising tool for transitional waters analysis.

Does adding a dietician to the liaison team after discharge of geriatric patients improve nutritional outcome: a randomised controlled trial

Objectives:

The objective was to test whether adding a dietician to a discharge Liaison-Team after discharge of geriatric patients improves nutritional status, muscle strength and patient relevant outcomes.

Design:

Twelve-week randomized controlled trial.

Setting and subjects:

Geriatric patients (70 + years and at nutritional risk) at discharge.

Interventions:

Participants were randomly allocated to receive discharge Liaison-Team vs. discharge Liaison-Team in cooperation with a dietician. The dietician performed a total of three home visits with the aim of developing and implementing an individual nutritional care plan. The first visit took place at the day of discharge together with the discharge Liaison-Team while the remaining visits took place approximately three and eight weeks after discharge and were performed by a dietician alone.

Main measures:

Nutritional status (weight, and dietary intake), muscle strength (hand grip strength, chair-stand), functional status (mobility, and activities of daily living), quality of life, use of social services, re-/hospitalization and mortality.

Results:

Seventy-one patients were included (34 in the intervention group), and 63 (89 %) completed the second data collection after 12 weeks (31 in the intervention group). Odds ratios for hospitalization and mortality 6 months after discharge were 0.367 (0.129; 1.042) and 0.323 (0.060; 1.724). Nutritional status improved and some positive tendencies in favour of the intervention group were observed for patient relevant outcomes, i.e. activities of daily living, and quality of life. Almost 100 % of the intervention group received three home visits by a dietician.

Conclusion:

Adding a dietician to the discharge Liaison-Team after discharge of geriatric patients can improve nutritional status and may reduce the number of times hospitalized within 6 months. A larger study is necessary to see a significant effect on other patient relevant outcomes.

Morphological and molecular characteristics do not confirm popular classification of the Brazil nut tree in Acre, Brazil

In the State of Acre, the Brazil nut tree, Bertholletia excelsa (Lecythidaceae), is classified by the local population into two types according to morphological characteristics, including color and quality of wood, shape of the trunk and crown, and fruit production. We examined the reliability of this classification by comparing morphological and molecular data of four populations of Brazil nut trees from Vale do Rio Acre in the Brazilian Amazon. For the morphological analysis, we evaluated qualitative and quantitative information of the trees, fruits, and seeds. The molecular analysis was performed using RAPD and ISSR markers, with cluster analysis. Significant differences were found between the two types of Brazil nut trees for the characters diameter at breast height, fruit yield, fruit size, and number of seeds per fruit. Despite the significant correlation between the morphological characteristics and the popular classification, we observed all possible combinations of morphological characteristics in both types of Brazil nut trees. In some individuals, the classification did not correspond to any of the characteristics. The results obtained with molecular markers showed that the two locally classified types of Brazil nut trees did not differ genetically, indicating that there is no consistent separation between them.

Genetic structure in fragmented populations of Solanum lycocarpum A. St.-Hil. with distinct anthropogenic histories in a Cerrado region of Brazil

Solanum lycocarpum is a woody tree widely distributed in the Cerrado that reaches high population densities in disturbed environments. We examined the genetic diversity and population differentiation of six S. lycocarpum populations with different degrees of human disturbance in order to determine if they are negatively affected by anthropogenic activity. Three populations located in southern and three located in southeastern regions of Goiás State, Central Brazil, were genotyped with five microsatellite markers. The population located in a protected area had higher number of alleles (26) than the remaining populations (19 to 21 alleles). It indicates that extensive and continuous areas of preserved native vegetation contribute positively to the conservation of genetic diversity, even with S. lycocarpum that easily adapts to disturbed environments. The three southeastern populations, although fragmented, had preserved native vegetation and were not significantly different from each other (θp = 0.002). All other population pairs compared were significantly divergent (θp varied from 0.03 to 0.11 between pairs, P < 0.05). We found three distinct sets of allele frequencies. The three southeastern populations shared similar gene pools, as well as the two disturbed southern populations, which are secondary vegetation. The southern population located in protected area had the most dissimilar gene pool. In conclusion, populations showing a higher degree of human disturbance tends to show a larger population differentiation than expected from the isolation by distance model, which in the current scenario of the Cerrado destruction points out to a threat to the long-term conservation of the species.

Genetic structure based on nuclear and chloroplast microsatellite loci of Solanum lycocarpum A. St. Hil. (Solanaceae) in Central Brazil

Solanum lycocarpum (Solanaceae) is a woody species found in the Brazilian Cerrado. The flowers are pollinated by Xylocopa spp bees, and seeds are dispersed by mammals with distinct home range sizes. As a consequence, relative contributions of pollen and seeds to overall gene flow can vary according to different spatial scales. We studied the genetic structure of four natural populations of S. lycocarpum separated by 19 to 128 km, including individuals located along dirt roads that interlink three of the populations. A total of 294 individuals were genotyped with five nuclear and six chloroplast microsatellite markers. Significant spatial genetic structure was found in the total set of individuals; the Sp statistic was 0.0086. Population differentiation based on the six chloroplast microsatellite markers (θ(pC) = 0.042) was small and similar to that based on the five nuclear microsatellite markers (θ(p) = 0.054). For this set of populations, pollen and seed flow did not differ significantly from one another (pollen-to-seed flow ratio = 1.22). Capability for long distance seed dispersion and colonization of anthropogenic sites contributes to the ability of S. lycocarpum to maintain genetic diversity. Seed dispersion along dirt roads may be critical in preserving S. lycocarpum genetic diversity in fragmented landscapes.

Effects of novel manufacturing technology on blood and dialysate flow distribution in a new low flux "alpha Polysulfone" hemodialyzer

The main target for low flux hemodialyzers is an efficient low molecular weight solutes clearance. Such efficiency is largely dependent on the optimization of diffusion between blood and dialysis solution. The diffusion process can be impaired if there is a mismatch between blood and dialysate flow distribution in the dialyzer. Thus optimized flow distribution both in the blood and dialysate compartment becomes quintessential for the maximal efficiency of the diffusion process within the hemodialyzer. The present paper describes the distribution of the blood and dialysate flows in a new low flux polysulfone hollow fiber hemodialyzer characterized by a specific undulation of the fibers and a new cutting technology of the fibers for an improved micro-flow condition in the blood compartment headers. Twelve Diacap alpha Polysulfone LO PS 15 (1.5 sqm) (B. Braun Medizintechnologie, Melsungen Germany) were employed for the study. Six were analyzed in vitro and six were studied in vivo. Blood flow distribution was studied in vitro by dye injection in the blood compartment during experimental extracorporeal circulation utilizing human blood with hematocrit adjusted at 33%. Sequential images were obtained with a helical scanner in a fixed longitudinal section of the dialyzer 1 cm thick. Average and regional blood flow velocities were measured utilizing the reconstructed imaging sequence. The method allowed the calculation of single fiber blood flow (SF Qb) and the mass transfer zone (MTR) definition in digitally subtracted images. The patterns 20-10 and 40-30 were utilized. The same technology was used to evaluate flow distribution in the dialysate compartment after dye injection in the Hansen's connector. Regional dialysate flow was calculated in central and peripheral sample areas of 1 cm2. Six in vivo hemodialysis treatments on patients with end stage renal disease were performed at three different blood flow rates (250-350 and 450 ml/min) in order to measure urea, creatinine and phosphate clearance. Macroscopic and densitometrical analysis revealed that flow distribution was homogeneous in the blood compartment while in the dialysate compartment a slight difference between the peripheral and central regions in terms of flow velocity was observed. This however was not generating channeling phenomena. Urea creatinine and phosphate clearances were remarkably high and so were the Kt/V observed in all sessions, especially in relation to the studied blood flows. In conclusion, a significant blood to dialysate flow match with optimized countercurrent flow condition was observed in the studied hollow fiber hemodialyzers. Such optimization might be due both to the improved dialyzer design at the level of the blood header and to the specific fiber undulation that prevents dialysate channeling.

Release of microparticles in LDL apheresis

Particle contamination of blood always takes place in extracorporeal systems and few studies have been conducted to evaluate potential risks. Particle concentration was measured in the efferent blood line on original equipment for two established LDL elimination procedures (DALI) (Fresenius) and Liposorber (Kaneka). Acquired data were compared with standards for infusion solutions from European (EP) and American (USP) Pharmacopoeia. All values were well below the given limits. Even in extreme situations (>20 pump stops) particle concentration did not exceed the standards. Considering an average treated blood volume of 7.31 for the DALI-System and 17.01 for Liposorber (long term clinical studies) the absolute amount of particles infused per treatment was 167,000 (DALI) and 465,000 (Liposorber) particles > or = 2 microm.

Particle release in extracorporeal low-density lipoprotein lowering therapies

Release of microparticles into the blood during extracorporeal circulation must be kept low because of possibly serious acute and chronic adverse effects. Concentration and size distribution of microparticles were measured during simulated treatments (n = 7) on original equipment for 2 standard low-density lipoprotein (LDL) elimination procedures (DALI 750, Fresenius AG, St. Wendel, Germany and Liposorber, Kaneka Corporation, Osaka, Japan) and compared to hemofiltration solutions. For both systems as well as in hemofiltration solutions, the mean particle concentrations in 500 ml portions gathered from the efferent blood line stayed below 10% of pharmacopoeia standards for infusion solutions (United States Pharmacopoeia, European Pharmacopoeia) in all measured size classes. Although particle concentrations were comparable in all systems, the mean total number of particles > or =2 microm released per session was lowest in the DALI (167,000) compared to the Liposorber (465,000) and hemofiltration solutions (2,240,000). This was mainly due to different total processed blood volumes necessary to achieve the required LDL reduction.

In vitro antibiotic susceptibility of salmonellae

In vitro antibiotic susceptibilities were determined for 101 strains of salmonellae. Resistance to chloramphenicol and ampicillin was low. Cefamandole was active against the majority of strains and deserves further evaluation.