Integrated analysis of fish intestine biomarkers: Complementary tools for pollution assessment.

The gastrointestinal tract and its enteric nervous system are the first routes of food and xenobiotics uptake. Considering the importance of this organ, this study evaluated intestinal biomarkers of Sphoeroides testudineus integrating the data to generate tools for pollution assessment. The fish were collected in three sites of São Paulo Coast and their intestines were analyzed for biochemical, histology, and neuronal density and morphometry biomarkers. To evaluate the differences among the data, a PERMANOVA was applied, followed by a FA/PCA. The PERMANOVA indicated differences (P < 0.001) between the regions (RA, A1, and A2). Four factors were extracted from the FA/PCA (62% cumulative), showing that the animals from A2 presented severe alterations, mainly in intestinal morphometry and neuronal density. A1 alterations refer mainly to the increase of neuronal metabolism. Our results also evidence a gradient of environmental quality related to the protection level (AR > A1 > A2).

Assessment of nutrients effect on the bioaccessibility of Cd and Cu in contaminated soil.

Soil is considered as a sink for heavy metals. Human health is severely affected by the continuous intake of toxic heavy metals even in a very low concentration. In the present experiment, we determined the influence of nutritional status including control (fasted condition), glucose (fed state), plant protein (fed state), animal protein (fed state) and calcium (fed state) on soil cadmium (Cd) and copper (Cu) bioaccessibility using physiologically-based extraction test (PBET) method together with simulator of the human intestinal microbial ecosystem (SHIME) model. The bioaccessibility of Cd was 1.06-73.58%, 0.44-54.79% and 0-17.78% and Cu was 3.81-67.32%, 4.98-71.14%, and 0-17.54% in the phase-I, phase-II and Phase-III respectively (in this study gastric phase, small intestinal phase and colon phase were considered as phase-I, phase-II and Phase-III respectively). The outcomes showed that, the average Cd bioaccessibility was higher with animal protein addition compared with other treatments in different phases. So, the effect of animal protein on Cd bioaccessibility was higher than other treatments in the phase-I, phase-II and phase-III. Due to the addition of plant protein, the higher average bioaccessibility of Cu was noticed in phase-I and phase-II in comparison to other treatments. However, in phase-III, the higher average bioaccessibility of Cu was found due to control treatment comparing with other treatments. Therefore, the influence of plant protein was higher than other nutrients on Cu bioaccessibility in the phase-I and phase-II. Moreover, other nutrients showed variable influence on Cd and Cu bioaccessibility. So, nutritional status has a significant effect on bioaccessibility as well as human health risk assessment.

Assessment of the long-acting ivermectin formulation in sheep: Further insight into potential pharmacokinetic interactions.

The aim of the current study was to evaluate the in vivo pharmacokinetic of ivermectin (IVM) after the administration of a long-acting (LA) formulation to sheep and its impact on potential drug-drug interactions. The work included the evaluation of the comparative plasma profiles of IVM administered at a single therapeutic dose (200 µg/kg) and as LA formulation at 630 µg/kg. Additionally, IVM was measured in different gastrointestinal tissues at 15 days posttreatment with both IVM formulations. The impact of the long-lasting and enhanced IVM exposure on the disposition kinetics of abamectin (ABM) was also assessed. Plasma (IVM and ABM) and gastrointestinal (IVM) concentrations were analyzed by HPLC with fluorescent detection. In plasma, the calculated Cmax and AUC0-t values of the IVM-LA formulation were 1.47- and 3.35-fold higher compared with IVM 1% formulation, respectively. The T1/2ab and Tmax collected after administration of the LA formulation were 2- and 3.5-fold longer than those observed after administration of IVM 1% formulation, respectively. Significantly higher IVM concentrations were measured in the intestine mucosal tissues and luminal contents with the LA formulation, and in the liver, the increase was 7-fold higher than conventional formulation. There was no drug interaction between IVM and ABM after the single administration of ABM at 15 days post-administration of the IVM LA formulation. The characterization of the kinetic behavior of the LA formulation to sheep and its potential influence on drug-drug interactions is a further contribution to the field.

Assessment of exposure to metals, As and Se in water and sediment of a freshwater reservoir and their bioaccumulation in fish species of different feeding and habitat preferences.

The concentrations of metals (Ag, Al, Ba, B, Be, Bi, Cd, Co, Cr, Cu, Fe, Ga, Hg, Li, Mn, Mo, Ni, Pb, Rb, Sr, Tl, U, V, Zn), As and Se were analyzed in water and sediments from three sites of Río Tercero Reservoir (Córdoba, Argentina) during the wet and the dry season. The dynamics of metals in six fish species (Hoplias malabaricus, Oligosarcus jenynsii, Rhamdia quelen, Bryconamericus iheringii, Astyanax fasciatus and Odontesthes bonariensis) from the reservoir were investigated to discover the possible differential influence of habitat and diet on metal accumulation in the fish. In the abiotic matrix, the highest heavy metal concentrations were observed in sediment. The concentrations of Al, Cu and Pb in water exceeded the limits considered as hazardous for aquatic life. Potential ecological risk analysis of metal concentrations in sediment indicated a low ecological risk in Río Tercero Reservoir in all sampling periods. The enrichment factor indicated that Cu, Pb, Zn and Hg come from anthropogenic sources. Among five different organs, the highest metal levels were found in gills and intestine. Rhamdia quelen and Oligosarcus jenynsii were the species with the highest values of metal accumulation in the whole body. Our study showed that the accumulation pattern of these multi-elements in the different fish species did not respond to diet or habitat, but seemed to be related to the detoxification mechanisms and the metabolism of each organism.

Potential human health risk assessment of heavy metals via the consumption of tilapia Oreochromis mossambicus collected from contaminated and uncontaminated ponds.

Fish tilapia Oreochromis mossambicus were collected from a contaminated Seri Serdang (SS) pond potentially receiving domestic effluents and an uncontaminated pond from Universiti Putra Malaysia (UPM). The fish were dissected into four parts namely gills, muscles, intestines, and liver. All the fish parts were pooled and analyzed for the concentrations of Cd, Cu, Fe, Ni, Pb, and Zn. Generally, the concentrations of all metals were low in the edible muscle in comparison to the other parts of the fish. It was found that the levels of all the heavy metals in the different parts of fish collected from the SS were significantly (P<0.05) higher than those from UPM, indicating greater metal bioavailabilities in the SS pond. The sediment data also showed a similar pattern with significantly (P<0.05) higher metal concentrations in SS than in UPM, indicating higher metal contamination in SS. Potential health risk assessments based on provisional tolerable weekly intake (PTWI) and the amount of fish required to reach the PTWI values, estimated daily intake (EDI), and target hazard quotient (THQ) indicated that health risks associated with heavy metal exposure via consumption of the fish's muscles were insignificant to human. Therefore, the consumption of the edible muscles of tilapia from both ponds should pose no toxicological risk of heavy metals since their levels are also below the recommended safety guidelines. While it is advisable to discard the livers, gills, and intestines of the two tilapia fish populations before consumption, there were no potential human health risks of heavy metals to the consumers on the fish muscle part.

Assessment of tissue distribution and concentration of ß-cryptoxanthin in response to varying amounts of dietary ß-cryptoxanthin in the Mongolian gerbil.

There is a general lack of knowledge regarding the absorption and tissue storage of the provitamin A carotenoid ß-cryptoxanthin. The present study investigated the whole-body tissue distribution of ß-cryptoxanthin in an appropriate small animal model, the Mongolian gerbil (Meriones unguiculatus), for human provitamin A carotenoid metabolism. After 5 d of carotenoid depletion, five gerbils were euthanised for baseline measurements. The remaining gerbils were placed in three weight-matched treatment groups (n 8). All the groups received 20 µg/d of ß-cryptoxanthin from tangerine concentrate, while the second and third groups received an additional 20 and 40 µg/d of pure ß-cryptoxanthin (CX40 and CX60), respectively, for 21 d. During the last 2 d of the study, urine and faecal samples of two gerbils from each treatment group were collected. ß-Cryptoxanthin was detected in the whole blood, and in twelve of the fourteen tissues analysed. Most tissues resembled the liver, in which the concentrations of ß-cryptoxanthin were significantly higher in the CX60 (17·8 (sem 0·7) µg/organ; P= 0·004) and CX40 (16·2 (sem 0·9) µg/organ; P= 0·006) groups than in the CX20 group (13·3 (sem 0·4) µg/organ). However, in intestinal tissues, the concentrations of ß-cryptoxanthin increased only in the CX60 group. Despite elevated vitamin A concentrations in tissues at baseline due to pre-study diets containing high levels of vitamin A, ß-cryptoxanthin maintained those vitamin A stores. These results indicate that ß-cryptoxanthin is stored in many tissues, potentially suggesting that its functions are widespread.

Pharmacokinetic/pharmacodynamic assessment of the effects of parenteral administration of a fluoroquinolone on the intestinal microbiota: comparison of bactericidal activity at the gut versus the systemic level in a pig model.

Classical pharmacokinetic/pharmacodynamic studies of antimicrobial agents performed by combining plasma concentrations and minimum inhibitory concentrations (MICs) are often predictive of the activity of a drug against targeted pathogens located at infectious sites closely connected to circulating blood. However, these studies do not predict the impact of parenteral antimicrobial treatment on intestinal bacteria, which could be responsible for transmission of resistance between species or in the environment. The aim of this study was to assess the differential antibacterial activity of a fluoroquinolone against lung and gut bacteria. Plasma and intestinal concentrations of marbofloxacin were assessed in pigs following intramuscular administration, and the in vitro relationship between marbofloxacin concentrations and mean bacterial inoculum growth in standard broth and in sterilised intestinal contents was modelled. It was shown that the increased intestinal exposure to marbofloxacin compared with plasma in pigs was compensated by reduced marbofloxacin activity against Escherichia coli in the contents of the digestive tract compared with in broth. These results showed that marbofloxacin doses used to target pathogens at the lung level would similarly affect the bacterial population of the same size and with a similar MIC located in the small intestine. However, it was shown that the bactericidal activity of marbofloxacin was increased 4- to 7-fold with low (10(5)CFU/mL) compared with high (10(8)CFU/mL) inoculum sizes. This result suggests that much lower marbofloxacin doses than those classically used would potentially eradicate low pulmonary pathogenic inocula while having a minimal impact on the large gut microbiota.

Health risk assessment for consumption of fish originating from ponds near Dabaoshan mine, South China.

Mining effluents are a potential source of toxic metals in the surrounding aquatic ecosystem and pose a potential health risk to humans from fish consumption. The objective of this paper is to assess the impact of the long-term Dabaoshan mining operation on heavy metal accumulation in different fish species. Heavy metal accumulation (lead (Pb), cadmium (Cd), zinc (Zn), and copper (Cu)) in four tissues (liver, muscle, intestine, and gills) of five carp species (Hypophthalmichthys molitrix, Ctenopharyngodon idellus, Megalobrama amblycephala, Aristichthys nobilis, and Carassius auratus auratus) from two fishponds exposed to effluent waters from Dabaoshan mine, South China. The bioaccumulation factor (BAF) and target hazard quotients were calculated to assess potential health risks to local residents through fish consumption. Levels of heavy metals varied depending on the analyzed tissues. C. auratus auratus accumulated the higher Pb, Cd, Zn, and Cu in the intestine compared with other fish species. Liver of all five species contained high concentrations of Pb, Cd, Zn, and Cu. The BAF for the studied metals showed a descending order of Cd>Zn>Cu>Pb for fishpond 1 and Zn>Cd>Cu>Pb for fishpond 2. Risk assessments suggested that potential human health risk may be present due to high Pb and Cd concentration in the muscle of some fish species exceeding the national and international limits, although the target hazard quotients were less than one.

Assessment of the expression of IRß, IRS-1, IRS-2 and IGF-IRß in a rat model of intrauterine growth restriction.

OBJECTIVE: To investigate glomerular development and expression of insulin and insulin-like growth factor receptors in an experimental model of intrauterine growth restriction (IUGR). MATERIAL AND METHODS: We studied three groups of Sprague-Dawley fetuses: IUGR - restricted by ligation of the right uterine artery; C-IUGR - left horn controls, and EC - external controls (non-manipulated). Body and organs were weighed, and glomerular number and volume were analyzed. Expression of IRß, IRS-1, IRS-2 and IGF-IRß was analyzed in liver, intestine and kidneys by immunoblotting. RESULTS: Organ/body weight ratios were similar. In IUGR, glomerular number and volume were increased compared to C-IUGR and EC (p<0.001). In the IUGR liver, increases were found in IGF-IRß compared to C-IUGR and EC; IRß compared to EC, and IRS-2 compared to C-IUGR. However, decreases in IRß were noted in IUGR compared to C-IUGR; IRS-1 compared to C-IUGR and EC, and IRS-2 compared to EC. In IUGR intestine, increases were detected in IRß, IRS-1 and IGF-IRß compared to C-IUGR and EC. In IUGR kidneys, increases were observed in IRß and IGF-IRß compared to C-IUGR and EC, and IRS-1 compared to EC. Decreased IRS-2 in the intestine and kidney were noticed in IUGR compared to C-IUGR and EC. CONCLUSION: IUGR fetuses had less glomeruli and alterations in insulin receptors, which may be associated with an increased risk of disease occurrence in adulthood.

Assessment of four commonly employed in vitro arsenic bioaccessibility assays for predicting in vivo relative arsenic bioavailability in contaminated soils.

Currently, a number of in vitro methods are in use worldwide to assess arsenic (As) bioaccessibility in soils. However, a dearth of research has been undertaken to compare the efficacy of the in vitro methods for estimating in vivo relative As bioavailability. In this study, As bioaccessibility in contaminated soils (n = 12) was assessed using four in vitro assays (SBRC, IVG, PBET, DIN). In vitro results were compared to in vivo relative As bioavailability data (swine assay) to ascertain which methodologies best correlate with in vivo data. Arsenic bioaccessibility in contaminated soils varied depending on the in vitro method employed. For the SBRC and IVG methods, As bioaccessibility generally decreased when gastric-phase values were compared to the intestinal phase. In contrast, extending the PBET and DIN assays from the gastric to the intestinal phase resulted in an increase in As bioaccessibility for some soils tested. Comparison of in vitro and in vivo results demonstrated that the in vitro assay encompassing the SBRC gastric phase provided the best prediction of in vivo relative As bioavailability (R(2) = 0.75, Pearson correlation = 0.87). However, relative As bioavailability could also be predicted using gastric or intestinal phases of IVG, PBET, and DIN assays but with varying degrees of confidence (R(2) = 0.53-0.67, Pearson correlation = 0.73-0.82).

Simultaneous assessment of lipid classes and bile acids in human intestinal fluid by solid-phase extraction and HPLC methods.

The purpose of the study reported here was to develop a method for the determination of lipid classes in intestinal fluids, including bile acids (BAs). A solid-phase extraction (SPE) method using C18 and silica columns for the separation of BAs, phospholipids (PLs), and neutral lipids (NLs), including free fatty acids, has been developed and validated. Fed-state small intestinal fluid collected from humans was treated with orlistat to inhibit lipolysis and mixed with acetic acid and methanol before SPE to maximize lipid recoveries. BAs, PLs, and NLs were isolated using lipophilic and polar solvents to promote elution from the SPE columns. The different lipid classes were subsequently analyzed using three separately optimized HPLC methods with evaporative light-scattering detectors. High recoveries (>90%) of all lipids evaluated were observed, with low coefficients of variation (<5%). The HPLC methods developed were highly reproducible and allowed baseline separation of nearly all lipid classes investigated. In conclusion, these methods provide a means of lipid class analysis of NLs, PLs, and BAs in human fed-state small intestinal fluid, with potential use in other fluids from the intestinal tract and animals.

Assessment of iron stores in children with transfusion siderosis by biomagnetic liver susceptometry.

To investigate the applicability of noninvasive Superconducting Quantum Interference Device (SQUID) biomagnetic liver susceptometry and its limitations in thalassemic children, 23 patients with beta-thalassemia major and other iron loading anemias (age: 4-16 years) and 16 age-related normal children were studied. Liver iron concentrations ranged from 600 to 11,000 microg/g(liver) for thalassemic patients and from 60 to 340 microg/g(liver) for normal patients. Measuring the respective organ volumes by sonography, liver and spleen iron stores, accounting for 80% of total body iron stores, were estimated. Nonliver contributions from the lung or intestine to the measured SQUID signals in the small-sized patients were not observed. Moreover, livers in thalassemia were found to be enlarged by 18% per 1,000 microg/g (r = 0.75, P < 10(-3)). Serum ferritin values correlate significantly with iron stores (r = 0.64, P < 10(-3)), but predict iron stores only within large error intervals of 4,000 microg/g(liver). Analyzing the experimental data from biomagnetometry and from related transfusion and chelation treatment data within the framework of a two-compartment model, we were able to derive additional information on total body iron elimination and chelation therapy efficacy. The exponential decline of iron stores allows forecast of steady-state conditions of the final iron load for a particular transfusion and chelation therapy regimen.

Assessment of protein quality in heat-treated soybean products using the growth responses of lambs and calves and a nylon bag-rooster assay.

Three studies were conducted to evaluate N and amino acid (AA) availability from processed soybean (SB) products. In Exp. 1 and 2, treatments consisted of corn-cottonseed hull basal diets plus SB products including SB meal (SBM); ground, raw SB (RSB); or extruded SB (ESB). In Exp. 1, 15 Suffolk (28.6 kg) and 15 Louisiana native breed (16.3 kg) ewe lambs were used in a 35-d growth trial. Although breed affected (P < .10) DMI and ADG of lambs, the diets did not (P > .10). In Exp. 2, 12 Suffolk wether lambs (34.0 kg) were used in a 3 x 3 multiple-square Latin square design N metabolism trial. Lambs fed RSB tended (P = .13) to retain more N than those fed ESB, but N retained by lambs fed RSB and ESB was similar (P > .10) to that of lambs fed SBM. In Exp. 3, four crossbred steer calves (240 kg) were used in a 4 x 4 Latin square design N metabolism trial with the above treatments plus heat-damaged SB (HDSB). Calves fed RSB and ESB retained similar (P > .10) amounts of N. Compared with calves fed RSB and ESB, calves fed SBM retained more (P < .10) N. Calves fed HDSB retained less (P < .10) N than those fed other diets. The individual SB products and the total mixed diets used in Exp. 3 were incubated intraruminally in nylon bags and the residual DM recovered and precision-fed to cecectomized roosters to estimate its intestinal AA digestibility. Digestibility of residual AA seemed to be relatively uniform across AA.(ABSTRACT TRUNCATED AT 250 WORDS)