Reducing prepartum urine pH by supplementing anionic feed ingredients: Effects on physiological and productive responses of Holstein × Gir cows.

This study compared physiological and productive parameters in 3/4 Holstein × 1/4 Gir dairy cows receiving a prepartum concentrate containing ammonium chloride to reduce urine pH near 7.0 (CON; n = 17), or a commercial anionic supplement to reduce urine pH near 6.0 (SUPP; n = 17). Nonlactating, multiparous, pregnant cows were assigned to receive SUPP or CON beginning 21 d before expected date of calving. Cows were maintained in a single drylot pen with ad libitum access to corn silage, and individually received their prepartum concentrate once daily (0800 h) before calving. Cows from both treatments completely consumed their concentrate allocation within 30 min after feeding. Cow body weight and body condition score were recorded once weekly, urine pH measured every 3 d, and blood samples collected on d -21, -14, -9, -6, and -3 relative to expected calving date. After calving (d 0), cows were moved to an adjacent drylot pen with ad libitum access to water and a total mixed ration, and were milked twice daily (0600 and 1700 h). Cow body weight and body condition score were recorded once weekly and individual milk production was recorded daily until 30 d in milk (DIM). Blood samples were collected before each milking during the first 5 DIM, as well as at 6, 9, 16, 23, and 30 DIM before the morning milking. Based on actual calving dates, cows received SUPP or CON for (mean ± standard error) 19.2 ± 1.2 and 19.0 ± 0.9 d before calving, respectively. Urine pH was less in SUPP versus CON cows during the last 15 d of gestation (6.12 vs. 7.15, respectively). Milk yield during the first 5 DIM and throughout the experimental period was greater in SUPP versus CON cows (by 20 and 14%, respectively), whereas serum Ca concentrations did not differ between treatments during the first 5 DIM. Serum concentrations of fatty acids were greater in SUPP versus CON cows 3 d before and at calving (by 52 and 22%, respectively), whereas SUPP cows had lower serum glucose and cortisol concentration at calving (by 23 and 27%, respectively). Hence, the SUPP treatment decreased prepartum urine pH near 6.0 in Holstein × Gir dairy cows without depressing concentrate intake compared with CON, although total dry matter intake was not evaluated to fully investigate feed intake responses. Moreover, the SUPP treatment transiently affected serum glucose, fatty acids, and cortisol concentrations near the time of calving, and resulted in greater milk yield during the initial 30 DIM compared with CON.

Effects of supplemental calcium salts of palm oil and chromium-propionate on insulin sensitivity and productive and reproductive traits of mid- to late-lactating Holstein × Gir dairy cows consuming excessive energy.

This experiment compared insulin sensitivity, milk production, and reproductive outcomes in dairy cows consuming excessive energy during mid to late lactation and receiving in a 2 × 2 factorial design (1) concentrate based on ground corn (CRN; n = 20) or including 8% (DM basis) of Ca salts of palm oil (CSPO; n = 20), and (2) supplemented (n = 20) or not (n = 20) with 2.5 g/d of Cr-propionate. During the experiment (d 0-203), 40 multiparous, nonpregnant, lactating 3/4 Holstein × 1/4 Gir cows (initial days in milk = 81 ± 2; mean ± SE) were offered corn silage for ad libitum consumption, and individually received concentrate formulated to allow diets to provide 160% of their daily net energy for lactation requirements. From d -15 to 203, milk production was recorded daily, blood samples collected weekly, and cow body weight (BW) and body condition score (BCS) recorded on d 0 and 203. For dry matter intake evaluation, cows from both treatments were randomly divided in 5 groups of 8 cows each, and allocated to 8 individual feeding stations for 3 d. Intake was evaluated 6 times/group. Glucose tolerance tests (GTT; 0.5 g of glucose/kg of BW) were performed on d -3, 100, and 200. Follicle aspiration for in vitro embryo production was performed via transvaginal ovum pick-up on d -1, 98, and 198. Mean DMI, net energy for lactation intake, as well as BW and BCS change were similar across treatments. On average, cows gained 40 kg of BW and 0.49 BCS during the experiment. Within weekly blood samples, CRN cows had lower serum concentrations of glucose, insulin, fatty acids, and insulin-to-glucose ratio compared with CSPO cows, suggesting increased insulin sensitivity in CRN cows. During the GTT, insulin-sensitivity traits were also greater in CRN versus CSPO cows. Supplemental Cr-propionate resulted in lower serum insulin concentrations and insulin-to-glucose ratio within CRN cows only, indicating that Cr-propionate improved basal insulin sensitivity in CRN but not in CSPO cows. During the GTT, however, Cr-propionate supplementation reduced hyperinsulinemia and insulin-to-glucose ratio across CSPO and CRN cows. Milk production, as well as number of viable oocytes collected and embryos produced within each aspiration, were not affected by treatments. Hence, replacing corn by Ca salts of palm oil in the concentrate did not improve insulin sensitivity in Holstein × Gir dairy cows consuming excessive energy during mid to late lactation, whereas Cr-supplementation was effective in improving basal insulin sensitivity in cows not receiving Ca salts of palm oil.

Genetic variability analysis of Byrsonima crassifolia germplasm collected in Pará State using ISSR markers.

Native of the Amazon, the nanche (Byrsonima crassifolia) is a fruit cultivated by family farmers and used in cooking; as such, it represents an opportunity for regional agribusiness. The Embrapa Eastern Amazon set up an active germplasm bank (BAG) consisting of 22 accessions sampled in 11 municipalities of Pará State. Due to its economic potential, there is an interest to advance the genetic breeding program of this species. The aim of this study was to characterize the BAG nanche collection using inter-simple sequence repeat (ISSR) markers. Accessions were genotyped using 23 pre-selected ISSR primers resulting in 109 amplified polymorphic and 51 monomorphic bands. With eight polymorphic bands each, the most polymorphic primers were UBC 809 and UBC 848. An unweighted pair-group method with arithmetic average cluster analysis based on Jaccard's coefficient indicated that the individuals clustered into two distinct groups. Accessions Igarapé Açu-2 and Augusto Corrêa-Pl 1 were most similar. The genetic dissimilarity values ranged from 0.10 to 0.59. We conclude that the ISSR markers were efficient in detecting polymorphisms in the nanche accessions, and that it is possible to infer the genetic variability among accessions of the collection. This demonstrate the importance of using molecular markers in poorly studied species and the advantages that this information can bring to the genetic improvement of such species.

Methodology optimization to quantify microplastic presence in planktonic copepods, chaetognaths and fish larvae.

Two of the groups most impacted by microplastics (MPs) are zooplankton and fish larvae, either through MPs ingestion or absorption. Although there has been an increase of studies focusing on MPs ingestion by these organisms, there is still no standardized methodology for the quantification of MPs present in plankton. For example, some reagents normally used to digest plankton and recover MPs appear adversely to affect some plastic characteristics. This can potentially lead to underestimating the amount and types of MPs present in the organisms analyzed. Hence, this work aimed to optimize a methodology to quantify MPs present in plankton, namely zooplankton and fish larvae, and ensuring MPs integrity. Hence, the planktonic organism tissues were digested using 30% (v/v) H2O2 solution at different temperatures and incubation periods while preserving the integrity and polymer characteristics of 13 types of MPs. MPs' characteristics were register before and after the tests, by visual inspection and Fourier Transform Infrared Spectroscopy (FTIR) analysis, to evaluate the integrity and features of MPs. With this methodology, MPs recovery was above 85% for all types of plastic tested. The proposed methodology is a rapid protocol, with a maximum of 7 h of incubation, that ensures simultaneously the full digestion of the organism tissues and the complete preservation of all the plastic characteristics, namely color, size and polymer type.•A methodology was optimized to quantify microplastics present in zooplankton (copepods, chaetognaths and fish larvae).•Thirteen types of microplastics (fibers and fragments of different polymers) were used to test the efficiency of the methodology ensuring the maintenance of the integrity of plastics.•With this methodology, microplastic recovery was above 85% for all the types of microplastic tested and no changes in their characteristics were observed.

Stabilization of biomass ash granules using accelerated carbonation to optimize the preparation of soil improvers.

After the revision of the Fertilizer Regulation (EC 2019/1009), biomass ash can be used as component material for soil improvers to be placed on the EU market. This provides opportunities for large scale recycling of biomass ash. However, this material cannot be directly applied to soil without stabilization by carbonation, which also creates an opportunity for CO2 capture and storage. Here, accelerated carbonation in an atmospheric fixed-bed reactor (AFR) was applied to prepare ash granules (AG). Relative humidity of gas, temperature, reaction time and CO2 concentration were optimized and further tested in a closed high-pressure reactor (HPR). Materials resulting from both reactors were compared with those obtained after 1-year of carbonation under atmospheric conditions. This study showed that AFR accelerated tests resulted in a significant reduction of the reaction time than HPR to achieve a similar pH adjustment. Also, under 100 vol.% CO2 atmospheric conditions, pH and electrical conductivity reached target values faster than under 15 vol.% CO2 conditions. Based on results obtained here we recommend AFR operating at 25 °C and 100 vol.% CO2 for 20 h, as the optimal procedure for stabilization of AG. In this study we provide evidence that accelerated carbonation enables a much faster and cost-efficient preparation of potentially valuable soil additives than natural carbonation. Also, leaching tests revealed that plant nutrient availability (B, Mg, Mn, Mo and P) was increased under accelerated carbonation compared to natural carbonation. The present work paves the way towards the development of optimized protocols to effectively recycle biomass ashes for soil recovery.

Microplastic in marine environment: reworking and optimisation of two analytical protocols for the extraction of microplastics from sediments and oysters.

Marine sediments and sessile biota (i.e. oysters) are nowadays recognised to be affected by microplastic (MP) pollution. NOAA proposes two distinct MP extraction protocols for sandy and bed sediments, which, however, were already demonstrated to suffer from many limitations. Conversely, to what concern oysters, works already published are usually time consuming, requiring a KOH 24-48 h oxidation step. The aim of this study is to show how iterative adaptation of the NOAA protocol allows to extract MPs, included PET, from marine sediments, regardless their characteristics. The method tested on PE-LD/PET/PA/PE-HD is based on density separation and oxidation treatments which were both carefully tuned, obtaining final recoveries higher than 85% for all the micropolymers (100% for PE and PA). Furthermore, a new protocol for the extraction of MPs from oysters was assessed, highlighting its efficacy (recoveries higher than 84% for all the plastics) and time-saving peculiarity. Finally, both protocols were successfully applied in the MPs extraction from real samples from Atlantic Ocean.•The extraction of PE-LD/PET/PA/PE-HD was optimised in sediments (regardless their characteristics) and oysters.•For sediments, density separation and oxidation procedures were carefully optimised.•For oysters, oxidation times were reduced from 24 to 48 h to 1 h.

Adaptation of a laboratory protocol to quantity microplastics contamination in estuarine waters.

One of the most used protocols to extract and quantify MPs is NOAA protocol in aquatic environments. However, there is still no standardized method to extract and quantify MPs in estuarine waters. The aim of this work was to adapt the NOAA protocol to quantify microplastics in estuarine water and provide all the details and changes to improve the efficiency of the method. For that, four types of plastic (PE-LD; PET; PA; PE-HD) were used in artificial samples to test all the steps of the protocol. Several criteria were tested, namely: (i) quantities of H2O2 used for organic matter degradation; (ii) temperatures of drying samples; and (iii) density separation efficacy. With the proposed modifications, the microplastics extraction were above 90%, regardless the type of plastic, with PE-LD reaching 100% of efficiency. The new adapted protocol that we propose will allow a better efficiency in extraction and quantification of microplastics in samples from estuarine environments. •Four different types of plastic (PE-LD; PET; PA; PE-HD) were used to test the efficiency of the protocol•Details as the ideal quantity of H2O2, temperature and exact quantity of NaCl were tested and defined during the experiments•Efficiency of the microplastics extraction were above 90.

Microplastic contamination in an urban estuary: Abundance and distribution of microplastics and fish larvae in the Douro estuary.

Estuaries are productive environments used by many fish as nursery grounds. The initial stages of fishes are highly vulnerable to (a)biotic factors, and anthropogenic pressures, influencing fish larvae assemblages along the estuary. Microplastics (MPs < 5 mm) are particularly dangerous to early life stages of fishes because their ingestion can induce gut blockage, limiting food intake or exposing organisms to contamination due to MPs capacity to absorb pollutants. Present work aimed to investigate the contamination of an urban impacted estuary (Douro estuary, NW Portugal) by MPs, and study the abundance and distribution of MPs and fish larvae in this estuary. Monthly sampling surveys were performed from December 2016 to December 2017, in nine stations along the estuary. Sub-surface planktonic horizontal trawls were performed to collect fish larvae and MPs. Planktonic samples were sorted, and fish larvae identified. MPs density was determined using a protocol optimized in our laboratory. A total of 1498 fish larvae belonging to 32 taxa were collected, with a mean density of 11.66 fish larvae 100 m-3. During the spring-summer period, it was observed the typical increase in the density and diversity of the larval assemblage. Diversity was generally low, with the high dominance of very few taxa, namely the common goby, Pomatoschistus microps. Different types of MPs were found, namely fibers, soft/hard plastic, colorful/transparent plastic, in a total of 2152 particles, with a mean density of 17.06 MPs 100 m-3. Hard MPs and fibers were the most predominant types, representing 83% of the total MPs collected. In some months the number of MPs surpassed the number of fish larvae, with an average ratio of 1.0 fish larvae:1.5 MPs. Such results are concerning, highlighting that a higher availability of MPs may facilitate their ingestion by fish and therefore increase possible impacts in these communities.

Seizure suppression by asynchronous non-periodic electrical stimulation of the amygdala is partially mediated by indirect desynchronization from nucleus accumbens.

Electrical stimulation (ES) of the nervous system is a promising alternative for the treatment of refractory epilepsy. Based on the understanding that seizures are the expression of neural hypersynchronism, our group developed and tested a non-standard form of low-energy temporally unstructured ES termed NPS (Non-periodic stimulation), with pseudo-randomized inter-pulse intervals. Previous investigation demonstrated that NPS applied to the amygdala has a robust anticonvulsant effect against both acute and chronic seizures, and suggested that its therapeutic effect is based on direct desynchronization of ictogenic neural circuits. Further mechanistic investigation using functional magnetic resonance imaging has shown that NPS also activates nucleus accumbens (NAc) in seizure-free rats, raising the hypothesis of an alternative therapeutic mechanism: NPS-enhanced indirect inhibition / desynchronization of ictogenic circuits by NAc. In order to investigate this idea, here we evaluated behavior and cortical electrographic activity from animals submitted to pentylenetetrazole (PTZ) induced seizures, treated with NPS and with or without bilateral electrolytic lesion of NAc. NPS-treated animals with bilateral lesion of NAc expressed unexpected straub tail in addition to other stereotypical convulsive behavior, displayed increased susceptibility to PTZ (lower drug threshold), and had a much longer electrographic seizure, with a greater number of spikes, firing at a higher rate. Moreover, analysis of spike morphology showed an increase in amplitude and slope in these animals, suggesting that ablation of NAc results in disinhibition and/or increase of neural synchronism within ictogenic circuits. NPS had no therapeutic effect whatsoever in lesioned animals, while it displayed a mild anticonvulsant effect in those with intact brains. Results corroborate the notion that NAc has a key role in controlling aberrant epileptiform activity in ictogenic circuits through indirect polysynaptic connections that may enroll the ventral pallidum and ventral tegmental area. They also point to the possibility that NPS may enhance this effect, putatively by benefiting from the structure's property of detecting saliences.

Evaluation of a single extraction test to estimate the human oral bioaccessibility of potentially toxic elements in soils: Towards more robust risk assessment.

Intake of soil by children and adults is a major exposure pathway to contaminants including potentially toxic elements (PTEs). However, only the fraction of PTEs released in stomach and intestine are considered as bioaccessible and results from routine analyses of the total PTE content in soils, therefore, are not necessarily related to the degree of bioaccessibility. Experimental methods to determine bioaccessibility usually are time-consuming and relatively complicated in terms of analytical procedures which limits application in first tier assessments. In this study we evaluated the potential suitability of a recently developed single extract method (ISO-17586:2016) using dilute (0.43M) nitric acid (HNO3) to mimic the bioaccessible fraction of PTEs in soils. Results from 204 soils from Portugal, Brazil and the Netherlands including all major soil types and a wide range of PTEs' concentrations showed that the extraction efficiency using 0.43M HNO3 of Ba, Cd, Cu, Ni, Pb and Zn in soils is related to that of in vitro methods including the Simple Bioaccessibility Extraction Test (SBET) and Unified BARGE Method (UBM). Also, differences in the degree of bioaccessibility resulting from differences in parent material, geology and climate conditions did not affect the response of the 0.43M HNO3 extraction which is a prerequisite to be able to compare results from different soils. The use of 0.43M HNO3 as a first screening of bioaccessibility therefore offers a robust and representative way to be included in first tier standard soil tests to estimate the oral bioaccessibility. CAPSULE: The single dilute (0.43M) nitric acid extraction can be used in first tier soil risk assessment to assess both geochemical reactivity and oral bioaccessibility of PTEs.

A HAB warning system for shellfish harvesting in Portugal.

The development of sustainable shellfish aquaculture is highly dependent on the provision of reliable monitoring and predictive information on the occurrence of harmful algal blooms (HABs). The Portuguese HAB early warning system and shellfish closures presented here is a prototype, developed in the ASIMUTH project. It relies on weekly monitoring data composed of observations of HAB species and toxin concentrations within shellfish, and ocean circulation forecasts generated by an operational oceanographic model. The shellfish harvesting areas comprise coastal areas, estuaries+rías and coastal lagoons. The weekly bulletin characterizes the current shellfish closure situation and next week's forecasts for potentially impacted areas. The period analyzed ranged from 27 July 2013 to 17 March 2014, and describes the first skill assessment of the warning system. The forecast accuracy was evaluated, considering the number of forecasts that were verified to be correct the following week (85%) as well as the number of events not forecasted (false negatives, 12%) and those expected but did not occur (false positives, 3%). Variations were most visible in the first weeks of bulletin implementation and during autumn-winter months. The complementary use of field data, remote sensing and operational models led to more accurate predictions of blooms and range of the event.

Advantages and limitations of chemical extraction tests to predict mercury soil-plant transfer in soil risk evaluations.

In this study, we compared the size of the mobile Hg pool in soil to those obtained by extractions using 2 M HNO3, 5 M HNO3, and 2 M HCl. This was done to evaluate their suitability to be used as proxies in view of Hg uptake by ryegrass. Total levels of Hg in soil ranged from 0.66 to 70 mg kg(-1) (median 17 mg kg(-1)), and concentrations of Hg extracted increased in the order: mobile Hg < 2 M HNO3 < 5 M HNO3 < 2 M HCl. The percentage of Hg extracted relative to total Hg in soil varied from 0.13 to 0.79 % (for the mobile pool) to 4.8-82 % (for 2 M HCl). Levels of Hg in ryegrass ranged from 0.060 to 36 mg kg(-1) (median 0.65 mg kg(-1), in roots) and from 0.040 to 5.4 mg kg(-1) (median 0.34 mg kg(-1), in shoots). Although results from the 2 M HNO3 extraction appeared to the most comparable to the actual total Hg levels measured in plants, the 2 M HCl extraction better expressed the variation in plant pools. In general, soil tests explained between 66 and 86 % of the variability of Hg contents in ryegrass shoots. Results indicated that all methods tested here can be used to estimate the plant total Hg pool at contaminated areas and can be used in first tier soil risk evaluations. This study also indicates that a relevant part of Hg in plants is from deposition of soil particles and that splashing of soil can be more significant for plant contamination than actual uptake processes. Graphical Abstract Illustration of potential mercury soil-plant transfer routes.

Intra-amygdala blockade of the NR2B subunit of the NMDA receptor disrupts the acquisition but not the expression of fear conditioning.

The lateral nucleus of the amygdala (LA) is an essential component of the neural circuitry underlying Pavlovian fear conditioning. Although blockade of NMDA receptors in LA and adjacent areas before training disrupts the acquisition of fear conditioning, blockade before testing also often disrupts the expression of fear responses. With this pattern of results, it is not possible to distinguish a contribution of NMDA receptors to plasticity from a role in synaptic transmission. In past studies, NMDA blockade has been achieved using the antagonist d,l-2-amino-5-phosphovalerate, which blocks the entire heteromeric receptor complex. The present experiments examined the effects of selective blockade of the NR2B subunit of the NMDA receptor in LA using the selective antagonist ifenprodil. Systemic injections of ifenprodil before training led to a dose-dependent impairment in the acquisition of auditory and contextual fear conditioning, whereas injections before testing had no effect. Intra-amygdala infusions of ifenprodil mirrored these results and, in addition, showed that the effects are attributable to a disruption of fear learning rather than a disruption of memory consolidation. NMDA receptors in LA are thus involved in fear conditioning, and the NR2B subunit appears to make unique contributions to the underlying plasticity.

Soil-pore water distribution of silver and gold engineered nanoparticles in undisturbed soils under unsaturated conditions.

Release of engineered nanoparticles (ENPs) to soil is well documented but little is known on the subsequent soil-pore water distribution of ENPs once present in soil. In this study, the availability and mobility of silver (Ag) and gold (Au) ENPs added to agricultural soils were assessed in two separate pot experiments. Pore water samples collected from pots from day 1 to 45 using porous (<0.17 µm) membrane samplers suggest that both Ag and Au are retained almost completely within 24 h with less than 13% of the total added amount present in pore water on day 1. UV-Vis and TEM results showed that AuENPs in pore water were present as both homoaggregates and heteroaggregates until day 3 after which the concentration in pore water was too low to detect the presence of aggregates. A close relation between the concentration of Au and Fe in pore water suggests that the short term solubility of Au is partly controlled by natural soil colloids. Results suggest that under normal aerated soil conditions the actual availability of Ag and AuENPs is low which is relevant in view of risk assessment even though the impact of environmental conditions and soil properties on the reactivity of ENPs (and/or large ENPs aggregates) retained in the solid matrix need to be addressed further.

Testing single extraction methods and in vitro tests to assess the geochemical reactivity and human bioaccessibility of silver in urban soils amended with silver nanoparticles.

To assess if the geochemical reactivity and human bioaccessibility of silver nanoparticles (AgNPs) in soils can be determined by routine soil tests commonly applied to other metals in soil, colloidal Ag was introduced to five pots containing urban soils (equivalent to 6.8 mg Ag kg(-1) soil). Following a 45 days stabilization period, the geochemical reactivity was determined by extraction using 0.43 M and 2 M HNO3. The bioaccessibility of AgNPs was evaluated using the Simplified Bioaccessibility Extraction Test (SBET) the "Unified BARGE Method" (UBM), and two simulated lung fluids (modified Gamble's solution (MGS) and artificial lysosomal fluid (ALF)). The amount of Ag extracted by 0.43 M and 2 M HNO3 soil tests was <8% and <50%, respectively of the total amount of Ag added to soils suggesting that the reactivity of Ag present in the soil can be relatively low. The bioaccessibility of Ag as determined by the four in vitro tests ranged from 17% (ALF extraction) to 99% (SBET) indicating that almost all Ag can be released from soil due to specific interactions with the organic ligands present in the simulated body fluids. This study shows that to develop sound soil risk evaluations regarding soil contamination with AgNPs, aspects of Ag biochemistry need to be considered, particularly when linking commonly applied soil tests to human risk assessment.

Regional distribution of glutamic acid decarboxylase (GAD65 and GAD67) mRNA in the hypothalamus of male rhesus macaques before and after puberty.

Glutamic acid decarboxylase (GAD) is the rate-limiting enzyme in the gamma-aminobutyric acid (GABA) biosynthetic pathway, and is coded for by two mRNAs, GAD65 and GAD67. Using in situ hybridization, we examine the distribution pattern of both GAD mRNAs in the hypothalamus and thalamus of prepubertal and adult male rhesus macaques. Qualitatively, GAD65 and GAD67 mRNAs showed a similar wide, but highly specific distribution pattern, supporting the view that GABAergic neurons play an important role in modulating neuroendocrine function. However, no quantitative difference in the intensity of hybridization signal was detected between prepubertal and adult animals in any of the hypothalamic or thalamic nuclei. Therefore, although GABAergic neurons are anatomically well-placed to control the secretion of gonadotropin-releasing hormone (GnRH) in primates, it is unlikely that the onset of puberty and the associated increase in GnRH secretion is triggered by a change in GAD gene transcription.

Two molecular forms of gonadotropin-releasing hormone (GnRH-I and GnRH-II) are expressed by two separate populations of cells in the rhesus macaque hypothalamus.

Gonadotropin-releasing hormone represents the primary neuroendocrine link between the brain and the reproductive axis, and at least two distinct molecular forms of this decapeptide (GnRH-I and GnRH-II) are known to be expressed in the forebrain of rhesus macaques (Macaca mulatta). Although the distribution pattern of the two corresponding mRNAs is largely dissimilar, their expression appears to show some overlap in specific regions of the hypothalamus; this raises the possibility that some cells express both molecular forms of GnRH. To resolve this issue, double-label histochemistry was performed on hypothalamic sections from six male rhesus macaques, using a monoclonal antibody to GnRH-I and a riboprobe to monkey GnRH-II mRNA. In total, more than 2000 GnRH neurons were examined but in no instance were GnRH-I peptide and GnRH-II mRNA found to be coexpressed. This finding emphasizes that GnRH-I and GnRH-II are synthesized by two distinct populations of hypothalamic neurons, and suggests that they may be regulated by different neuroendocrine pathways.

[Identification of Vibrio spp bacteria on skin lesions of fisherman in the county of Raposa-MA]. / Pesquisa de bactérias do gênero Vibrio em feridas cutâneas de pescadores do município de Raposa-MA.

The study was undertaken aiming at identifying bacteria from the county of Raposa in the state of Maranhão. The clinical sample was collected by using a swab and held in a Cary-Blair transport medium. Enrichment in alkaline peptone water, isolation in TCBS selective indicator medium and biochemical coding of species were used for laboratory processing. Fifty fisherman with age varying from 12-65 years took part on the study. Vibrio bacteria isolated in 21 subjects had been identified. There was a predominance of V. alginolyticus (66.6%) followed by V. parahaemolyticus (42.8%), and V. cholerae non-O1 (9.5%). Lesions predominated on lower limbs, presenting hyperhemia, swelling, secretion, and pain. Some species of gram-negative bacteria of the Serratia, Proteus, Escherichia, Citrobacter, Enterobacter associated to the vibrios were isolated, as well as other non-fermenting bacteria (30.9) and gram-positive bacteria of the genos Staphylococcus.

Oral bioaccessibility and human exposure to anthropogenic and geogenic mercury in urban, industrial and mining areas.

The objective of this study was to characterize the link between bioaccessibility and fractionation of mercury (Hg) in soils and to provide insight into human exposure to Hg due to inhalation of airborne soil particles and hand-to-mouth ingestion of Hg-bearing soil. Mercury in soils from mining, urban and industrial areas was fractionated in organometallic forms; mobile; semi-mobile; and non-mobile forms as well as HCl-extractable Hg. The in vitro bioaccessibility of Hg was obtained by extracting soils with (1) a simulated human gastric fluid (pH1.5), and (2) a simulated human lung fluid (pH7.4). Total soil Hg concentrations ranged from 0.72 to 1.8 mg kg(-1) (urban areas), 0.28 to 94 mg kg(-1) (industrial area) and 0.92 to 37 mg kg(-1) (mining areas). Both organometallic Hg as well as 0.1M HCl extractable Hg were lower (<0.5% of total Hg) than Hg extracted by gastric fluid (up to 1.8% of total Hg) and lung fluid (up to 12% of total Hg). In addition, Hg extracted by lung fluid was significantly higher in urban and industrial soils (average 5.0-6.6% of total Hg) compared to mining soils. Such differences were related to levels of mobile Hg species in urban and industrial soils compared to mining soils. These results strengthen the need to measure site-specific Hg fractionation when determining Hg bioaccessibility. Results also show that ingestion and/or inhalation of Hg from soil particles can contribute up to 8% of adult total Hg intake when compared to total Hg intake via consumption of contaminated fish and animal products from contaminated areas.

Risk assessment for Cd, Cu, Pb and Zn in urban soils: chemical availability as the central concept.

To assess the geochemical reactivity and oral bioaccessibility of Cd, Cu, Pb and Zn in urban soils from the Porto area, four extractions were performed including Aqua Regia (AR; pseudototal), 0.43 M HNO3 (reactive), 0.01 M CaCl2 (available), and 0.4 M glycine at pH = 1.5, SBET method (oral bioaccessible pool). Oral bioaccessibility in urban soils was higher than in samples from rural, industrial and mining areas which is most likely related to sources of metals and parent materials of corresponding soils. The availability and reactivity were described well by non-linear Freundlich-type equations when considering differences in soil properties. The resulting empirical models are able to predict availability and reactivity and can be used to improve the accuracy of risk assessment. Furthermore, a close 1:1 relationship exists between results from the 0.43 M HNO3 method and the SBET method which substantially facilitates risk assessment procedures and reduces analytical costs.