Cadmium bioaccumulation and gastric bioaccessibility in cacao: A field study in areas impacted by oil activities in Ecuador

Cacao from South America is especially used to produce premium quality chocolate. Although the European Food Safety Authority has not established a limit for cadmium (Cd) in chocolate raw material, recent studies demonstrate that Cd concentrations in cacao beans can reach levels higher than the legal limits for dark chocolate (0.8 mg kg^-1, effective January 1st, 2019). Despite the fact that the presence of Cd in agricultural soils is related to contamination by fertilizers, other potential sources must be considered in Ecuador. This field study was conducted to investigate Cd content in soils and cacao cultivated on Ecuadorian farms in areas impacted by oil activities. Soils, cacao leaves, and pod husks were collected from 31 farms in the northern Amazon and Pacific coastal regions exposed to oil production and refining and compared to two control areas. Human gastric bioaccessibility was determined in raw cacao beans and cacao liquor samples in order to assess potential health risks involved. Our results show that topsoils (0-20 cm) have higher Cd concentrations than deeper layers, exceeding the Ecuadorian legislation limit in 39% of the sampling sites. Cacao leaves accumulate more Cd than pod husks or beans but, nevertheless, 50% of the sampled beans have Cd contents above 0.8 mg kg^-1. Root-to-cacao transfer seems to be the main pathway of Cd uptake, which is not only regulated by physico-chemical soil properties but also agricultural practices. Additionally, natural Cd enrichment by volcanic inputs must not be neglected. Finally, Cd in cacao trees cannot be considered as a tracer of oil activities. Assuming that total Cd content and its bioaccessible fraction (up to 90%) in cacao beans and liquor is directly linked to those in chocolate, the health risk associated with Cd exposure varies from low to moderate.

A tracer methodology for identifying ambient flows in boreholes

Identifying flows into, out of, and across boreholes is important for characterizing aquifers, determining the depth at which water enters boreholes, and determining the locations and rates of outflow. This study demonstrates how Single Borehole Dilution Tests (SBDTs) carried out under natural head conditions provide a simple and cheap method of identifying vertical flow within boreholes and determining the location of in-flowing, out-flowing, and cross-flowing fractures. Computer simulations were used to investigate the patterns in tracer profiles that arise from different combinations of flows. Field tracer tests were carried out using emplacements of a saline tracer throughout the saturated length of boreholes and also point emplacements at specific horizons. Results demonstrated that SBDTs can be used to identify flowing fractures at the top and bottom of sections of vertical flow, where there is a change in vertical flow rate within a borehole, and also where there are consistent decreases in tracer concentration at a particular depth. The technique enables identification of fractures that might be undetected by temperature and electrical conductance logging, and is a simple field test that can be carried out without pumping the borehole.

Thermodynamic and kinetic issues in the formation and oxidation of aromatic species

The chemistry of aromatic species is discussed in the context of detailed kinetic modelling of benzene and butadiene flames and stirred reactors featuring ethylene and mixed aromatic/ethylene/hydrogen fuels. The development of reliable detailed mechanisms depends on the accuracy of the underlying hydrocarbon chemistry and the present paper highlights some current issues in the formation and oxidation of aromatics. In particular, uncertainties pertaining to the rates and product distributions of a range of possible naphthalene and indene formation sequences are discussed from the basis of improved predictions of key intermediates. The naphthalene formation paths considered include initiation via C5H5 + C5H5, C6H5 + C4H4 and C7H7 + C3H3 reactions and results are assessed in the context of a number of tentative detailed and simplified sequences. It is shown that a number of possible formation channels are plausible and that their relative importance is strongly dependent upon oxidation conditions. Particular emphasis is placed on the investigation of formation paths leading to isomeric C9H8 structures. The latter are typically ignored despite measured concentrations similar to those of naphthalene. The rates of formation of C9H8 compounds are consistent with sequences initiated by C6H5 + C3H3 and C6H5 + C3H4 leading to indene through repeated isomerisation reactions. The current work also shows that reactions of the type C9H7 + CH3 and C9H7 + 3CH2 provide a mass growth source that link five and six member ring structures.

Epitope mapping of the major inner capsid protein of group A rotavirus using peptide synthesis

Three hundred and ninety-one consecutive heptapeptides derived from the VP6 protein of bovine rotavirus (397 AA) were synthesized using the "pepscan" method and were assayed on the synthesis pins with monoclonal antibodies to VP6. Heptapeptides reactive with MAbs were located in four main regions: regions AA 32-64, AA 155-167, AA 208-274, and a fourth region at the C-terminal, from AA 380 to AA 397. Among these regions, two sequences were also reactive with the MAbs when longer peptides were assayed. The sequence located between AA 58 and AA 62 (NWNFD), recognized by MAbs RV-1026, RV-50, and RV-443, was previously reported. A new site was defined in the region essential for trimerization, between AA 159 and AA 165 (PYSASFT), which was recognized by MAbs RV-133 and RV-138.

High concentrations of intrathecal interleukin-6 in human bacterial and nonbacterial meningitis

Interleukin-6 (IL-6) is multipotent cytokine that acts in a network of factors directing the inflammatory reaction of purulent bacterial meningitis (PBM). However, little is known about the role of IL-6 in aseptic or "viral" meningitis (AM). IL-6 was assayed by RIA in cerebrospinal fluid (CSF) and serum samples obtained from patients with AM (n = 65), PBM (n = 8), and lymphocytic bacterial meningitis (LBM, n = 11). Of patients with AM, 89% had detectable IL-6 in CSF, with high IL-6 titers (median, 2160 pg/mL; 95% confidence interval [CI], 1320-2540 pg/mL) compared with 100% in patients with PBM (median, 6575 pg/mL; 95% CI, 450-32,000 pg/mL) and 90.9% in patients with LBM (median, 875 pg/mL; 95% CI, 150-2180 pg/mL). There was a highly symmetrical correlation between IL-6 and the percentage of polymorphonuclear cells in CSF of patients with PBM (r = .97, P = .01) and AM (r = .49, P = .002). In conclusion, this study shows evidence that IL-6 is released into the meningeal space in aseptic meningitis and is correlated with the local acute inflammatory response.

Localization of group-specific epitopes on the major capsid protein of group A rotavirus

Chemical cleavage of the VP6 protein of bovine rotavirus showed that VP6-specific monoclonal antibodies (MAbs) reacted with the amino acid sequence between glycine 48 and asparagine 107. Furthermore, three synthetic peptides (amino acids 48 to 64, 60 to 75 and 91 to 108) containing part of this sequence and 22 consecutive overlapping heptapeptides corresponding to the region between amino acids 48 and 75 were analysed for their immunoreactivity using group-specific MAbs. The MAbs recognized peptides 48-64 and/or 60-75, and a set of overlapping heptapeptides located between residues 53 (asparagine) and 67 (glycine), which have two short sequences in common: IRNW (residues 56 to 59), recognized by MAb RV-133, and (NW)NFD (residues 58/60 to 62), recognized by MAbs RV-50, -1026 and -443. These results indicate that the sequence between amino acid residues 48 and 75 is present in one of the immunodominant sites of VP6.

Pharmacokinetics, bioavailability, metabolism, tissue distribution and urinary excretion of gamma-L-glutamyl-L-dopa in the rat

gamma-L-Glutamyl-L-dopa (gludopa) is believed to be a dopamine prodrug specific for the kidney. Its pharmacokinetics have been studied in the rat given 50 mg kg-1 intravenously (i.v.) and 60 mg kg-1 intraperitoneally (i.p.). By the i.v. route, elimination followed apparent first order kinetics and was biphasic with a t 1/2 alpha of 7 min and terminal half-life of 67 min. After i.p. administration absorption was rapid (t 1/2 ab 6 min), elimination was monophasic with a terminal half-life almost identical following i.v. dosing (65 min), and bioavailability was 40%. In tissues (liver and kidney) gludopa was biotransformed to four intact catecholic products (L-dopa, dopamine, DOPAC and gamma-L-glutamyl-dopamine) which appeared quickly (peaks at 15 min) and which were almost completely cleared by 4 h. Dopamine was the major kidney metabolite accounting for 69% of total catechol content with an AUC 31 times greater than in liver where it accounted for only 34% of total catechols. In rat urine eight major metabolites (5.7% of the dose) and at least 12 minor metabolites were detected of all of which 85% was dopamine. A higher percentage of the dose was excreted as intact catechols in man (15.7%) but fewer metabolites were detected (L-dopa, dopamine, DOPAC). It is confirmed that gludopa is kidney specific in rat but that the pharmacological effects of dopamine are likely to be short lived due to rapid clearance. Gludopa appears to be less dopamine specific in man.

Pediatric uses of opioids

It is evident that opioids are underused in infants and children, mainly owing to the erroneous belief that long-term adverse effects may result from effective use, coupled with the difficulties infants and children have in verbalizing their feelings of pain. Sufficient data exist to date on the safe use of opioids in the pediatric age group to allow pediatricians to incorporate them in a variety of protocols. Moreover, unlike most drugs in clinical use, opioids have a specific, safe antidote that can reverse their toxic effects promptly and effectively.