Microsatellite diversity and effective population size in a germplasm bank of <Emphasis Type="Italic">Hymenaea courbaril</Emphasis> var. <Emphasis Type="Italic">stilbocarpa</Emphasis> (Leguminosae), an endangered tropical tree: recommendations for conservation

Deforestation in southeast Brazil has led to the extinction of Hymenaea courbaril var. stilbocarpa and ex situ conservation has been established. In this study, the levels of genetic diversity and the effective population size of H. courbaril in a germplasm bank were investigated using six nuclear microsatellite loci. A total of 79 and 91 alleles were found in 65 seed-trees and their 176 offspring, respectively. Offspring have a higher average number of alleles per locus (A = 15.2) than seed-trees (A = 13.2), but lower observed heterozygosity (offspring: H _o = 0.566; seed-trees: H _o = 0.607). The estimate of outcrossing rate shows that the study population is perfectly outcrossed (t _m  = 0.978, P > 0.05). Significant deviations from random mating were detected through mating among relatives and correlated matings. The average variance in effective population size for each family was 2.63, with a total effective population size retained in the bank of 170.1. These results confirm that the preserved population of H. courbaril retains substantial genetic variability. Moacyr Antonio Mestriner and Ana Lilia Alzate-Marin—CEEFLORUSP Members.     

Investigation of the interaction between buprenorphine and sufentanil during anaesthesia for ovariectomy in dogs

OBJECTIVE: To investigate the effect of buprenorphine pre-treatment on sufentanil requirements in female dogs undergoing ovariectomy. STUDY DESIGN: Randomized, 'blinded', prospective clinical study. ANIMALS: Thirty healthy female dogs referred for ovariectomy. MATERIALS AND METHODS: Dogs were randomly assigned to one of two pre-anaesthetic treatment groups. Those in the buprenorphine group (B) received buprenorphine 20 microg kg(-1) and acepromazine 0.03 mg kg(-1) IM. Control group (C) animals received an equal volume of NaCl 0.9% and acepromazine 0.03 mg kg(-1) IM. The anaesthetic technique was identical in both groups. Pre-anaesthetic medication consisted of intravenous (IV) sufentanil (1.0 microg kg(-1)) and midazolam (0.05 mg kg(-1)) and intramuscular atropine (0.03 mg kg(-1)). Anaesthesia was induced with propofol and maintained with a constant rate infusion of sufentanil (1.0 microg kg(-1) hour(-1)) and with oxygen-isoflurane. Ventilation was controlled mechanically. Ovariectomy was performed using a standard technique. Baseline heart rate (HR) and direct mean arterial blood pressure (MAP) were recorded before the first incision. Increases in HR and MAP of > or =20% over baseline and, or spontaneous ventilation were controlled using IV sufentanil (1.0 microg kg(-1)) repeated after 5 minutes if haemodynamic variables remained elevated or attempts at spontaneous ventilation persisted. Analysis of variance was used to determine group differences in mean and median HR and MAP and to compare the maximum HR and MAP attained during surgery. Poisson regression was used to compare the number of sufentanil injections required in both groups. RESULTS: Group B required 2.46 times more sufentanil injections (p = 0.00487) than dogs in group C to maintain haemodynamic stability and prevent spontaneous ventilation during surgery. Group B dogs also had a significantly higher (p = 0.034) marginal mean of the log maximum MAP (4.756 +/- 0.036) compared with group C (4.642 +/- 0.036). CONCLUSIONS: Pre-treatment with buprenorphine appears to negatively influence the antinociceptive efficacy of intra-operative sufentanil. CLINICAL RELEVANCE: Withholding buprenorphine therapy 6-8 hours before anaesthesia incorporating pure mu receptor agonists is probably advisable. Alternative methods of analgesia should be provided in this period.     

The microecology of dactylogyrids (Monogenea: Dactylogyridae) on the gills of wild spotted rose snapper Lutjanus guttatus (Lutjanidae) from Mazatlan Bay, Mexico

The spatial distribution and coexistence of monogenean dactylogyrids was assessed on the gills of 63 specimens of wild spotted rose snapper, Lutjanus guttatus (Steindachner), caught in the Mazatlan Bay, Sinaloa, Mexico. Five species are reported: Euryhaliotrema perezponcei Garcia-Vargas, Fajer-Avila et Lamothe-Argumedo, 2008, Euryhaliotrematoides sp., Haliotrematoides spinatus Kritsky et Mendoza-Franco, 2009, H. plectridium Kritsky et Mendoza-Franco, 2009, and H. guttati Garcia-Vargas, Fajer-Avila et Lamothe-Argumedo, 2008. All except E. perezponcei and H. guttati represent new geographical records for the Pacific coast. The most prevalent dactylogyrid species was E. perezponcei (100%), H. plectridium and H. spinatus had > 80% prevalence, and H. guttati and Euryhaliotrematoides sp. had the lowest prevalence. The mean abundance of H. plectridium and E. perezponcei was close to 60 parasites/fish, whereas Euryhaliotrematoides sp. and H. guttati had the lowest abundance. The dactylogyrid species exhibited a tendency for attachment to gill arch 2: 25% attachment occurring on gill arch 1, 30% on 2, 27% on 3 and 18% on 4, and showed a significant preference for the central sector of the gill (42%). Haliotrematoides plectridium had a preference for attachment to gill arches 2 and 3 and the central sector. Haliotrematoides spinatus tended to settle on the gill arches 2 and 3 and had a preference for the central sector. Euryhaliotrema perezponcei tended to settle on the gill arches 1 and 2 and the anterior gill sector. Euryhaliotrematoides sp. and H. guttati did not show a preference for any gill arch or sector. The intraspecific aggregation was stronger than the interspecific aggregation, indicating that all the dactylogyrid species on spotted rose snapper were aggregated, and there was no evidence of competition among the species.     

Root exudation of sugars,amino acids,and organic acids by maize as affected by nitrogen,phosphorus, potassium,and iron deficiency

Root exudates play a major role in the mobilization of sparingly soluble nutrients in the rhizosphere. Since the amount and composition of major metabolites in root exudates from one plant species have not yet been systematically compared under different nutrient deficiencies, relations between exudation patterns and the type of nutrient being deficient remain poorly understood. Comparing root exudates from axenically grown maize plants exposed to N, K, P, or Fe deficiency showed a higher release of glutamate, glucose, ribitol, and citrate from Fe‐deficient plants, while P deficiency stimulated the release of γ‐aminobutyric acid and carbohydrates. Potassium‐starved plants released less sugars, in particular glycerol, ribitol, fructose, and maltose, while under N deficiency lower amounts of amino acids were found in root exudates. Principal‐component analysis revealed a clear separation in the variation of the root‐exudate composition between Fe or P deficiency versus N or K deficiency in the first principal component, which explained 46% of the variation in the data. In addition, a negative correlation was found between the amounts of sugars, organic and amino acids released under deficiency of a certain nutrient and the diffusion coefficient of the respective nutrient in soils. We thus hypothesize that the release of dominant root exudates such as sugars, amino acids, and organic acids by roots may reflect an ancient strategy to cope with limiting nutrient supply.     

Marine Natural Products as Breast Cancer Resistance Protein Inhibitors

Breast cancer resistance protein (BCRP) is a protein belonging to the ATP-binding cassette (ABC) transporter superfamily that has clinical relevance due to its multi-drug resistance properties in cancer. BCRP can be associated with clinical cancer drug resistance, in particular acute myelogenous or acute lymphocytic leukemias. The overexpression of BCRP contributes to the resistance of several chemotherapeutic drugs, such as topotecan, methotrexate, mitoxantrone, doxorubicin and daunorubicin. The Food and Drugs Administration has already recognized that BCRP is clinically one of the most important drug transporters, mainly because it leads to a reduction of clinical efficacy of various anticancer drugs through its ATP-dependent drug efflux pump function as well as its apparent participation in drug resistance. This review article aims to summarize the different research findings on marine natural products with BCRP inhibiting activity. In this sense, the potential modulation of physiological targets of BCRP by natural or synthetic compounds offers a great possibility for the discovery of new drugs and valuable research tools to recognize the function of the complex ABC-transporters.     

Effects of soil flooding and organic matter addition on plant accessible phosphorus in a tropical paddy soil: an isotope dilution study

Plant growth experiments were conducted to reveal the mechanism by which organic matter (OM) and soil flooding enhance phosphorus (P) bioavailability for rice. It was postulated that reductive dissolution of iron‐(III) [Fe(III)] oxyhydroxides in soil releases occluded phosphate ions (PO₄), i.e., PO₄ that is not isotopically exchangeable in the original soil prior to flooding. Rice was grown in P‐deficient soil treated with factorial combinations of addition of mineral P (0, 50 mg P kg^?1), OM (0, ≈ 20.5 g OM kg^?1 as cattle manure +/– rice straw) and water treatments (flooded vs. non‐flooded). The OM was either freshly added just before flooding or incubated moist in soil for 6 months prior to flooding; nitrogen and potassium were added in all treatments. The soil exchangeable P was labeled with ³³PO₄ prior to flooding. The plant accessible P in soil, the so‐called L‐value, was determined from the ³³P/³¹P ratio in the plants. The L‐values were inconsistently affected by flooding in contrast with the starting hypothesis. The OM and P addition to soil clearly increased the L‐value and, surprisingly, the increase due to OM application was larger than the total P addition to soil. An additional isotope exchange study in a soil extract (E‐value) at the end of the experiment showed that the E‐value increased less than the total P addition with OM. This suggests that plants preferentially take up unlabeled P from the OM in the rhizosphere compared to labeled labile inorganic P. The effects of soil flooding on P bioavailability is unlikely related to an increase of the quantity of bio‐accessible P in soil (L‐value) but is likely explained by differences in P mobility in soil.     

Pharmacokinetics of an injectable long-acting formulation of doxycycline hyclate in dogs

Based on its PK/PD ratios, doxycycline hyclate (DOX-h), a time-dependant antibacterial, is ideally expected to achieve both sustained plasma drug concentrations at or slightly above the MIC level for as long as possible between dosing intervals. Pursuing this end, a poloxamer-based matrix was used to produce a long-acting injectable preparation (DOX-h-LA) and its serum concentrations vs. time profile investigated after its SC injection to dogs (≤ 0.3 mL per injection site), and results compared with the oral (PO) and IV pharmacokinetics of DOX-h, prepared as tablet or as freshly made solution. A crossover (4 x 4 x 4) study design was employed with 12 Mongrel dogs, with washout periods of 21 days, and at dose of 10 mg/kg in all cases. DOX-h-LA showed the greatest values for bioavailability (199.48%); maximum serum concentration (Cmax) value was 2.8 ± 0.3 with a time to reach Cmax (Tmax) of 2.11 ± 0.12 h and an elimination half-life of 133.61 ± 6.32 h. Considering minimum effective serum concentration of 0.5 μg/mL, a dose-interval of at least 1 week h can be achieved for DOX-h-LA, and only 48 h and 24 h after the IV or PO administration of DOX-h as a solution or as tablets, respectively. A non-painful small bulge, apparently non-inflammatory could be distinguished at injection sites. These lumps dissipated completely in 30 days in all cases.