Effects of lead exposure on salivary glands of rats: insights into the oxidative biochemistry and glandular morphology

Environmental Science and Pollution Research - This study aimed to investigate the effects of lead (Pb) exposure on parotid and submandibular glands through morphological aspects as well as the...     

Influence of sewage sludge,as a substrate,in the plasticity of functional characteristics of plants

This work aimed to evaluate the effect of sewage sludge application as fertilizer on the plasticity of functional characteristics of species commonly found in the Caatinga. The research was developed in the nursery of the Federal Institute of Education, Science and Technology of Ceará (IFCE), Quixadá campus, located in northeastern Brazil. Three treatments were applied: raw sludge, sanitized sludge, and no manipulation. In each treatment, five species were planted, each with five individuals, totaling 75 individuals, which were tagged, and 4 months after germination, they were destroyed to obtain dry matter content (TMSF) from leaf, stem (TMSC), fine root (TMSRF), and thick root (TMSRG); leaf area; height and diameter of the seedling; and length above and below the ground. The sanitized sludge was responsible for giving higher values for leaf area, height of the seedlings, and diameter and length of stem and root. However, the dry matter content of the fine roots was higher in the treatment without manipulation. At the community level, as TMSRG increased, TMSC also increased, the same occurred between TMSRG and TMSRF, TMSC and TMSRF, and stem length and leaf area. In the treatment without manipulation, there was a positive correlation between leaf area, height and plant diameter, and negative correlation between root length and plant diameter. Thus, it can be concluded that the use of sanitized sludge is a good tool to increase the availability of soil resources, conferring to individuals’ greater dry matter content, greater leaf area, and higher height and diameter above the ground.     

Multiannual trend of microcystin production in the toxic cyanobacterium Planktothrix rubescens in Lake Garda (Italy)

Massive developments (blooms) of cyanobacteria represent a major concern in many natural and artificial waterbodies, because of the high levels of toxins that can be released into water. Microcystins, potent hepatotoxins, represent the most frequent toxins produced by cyanobacteria. The determination of the microcystins’ profile in waterbodies is important for determining the real toxic potential. We have investigated the evolution of the microcystins’ profile of Lake Garda (Italy) from both a qualitative and a quantitative point of view over a period of five years. We have also analysed possible correlations between toxin profile and selected environmental parameters. We found that a demethylated microcystin variant (RRdm) was always dominant but showing a cyclic trend, alternating periods in which it represented the only variant, and periods in which other variants were present (LRdm, HtyrRdm, RR, and LR). These changes are probably due to changes in chemotypes composition inside the resident Planktothrix rubescens population and do not seem to be exclusively linked to the considered environmental variables. Total microcystin concentrations were always low (in the ng?L^?1 scale), and showed typical peaks in the metalimnetic layer during summer–autumn time of each year.     

Restoration of flavonols and isoflavonoids in Ugni molinae subjected to a reciprocal transplant experiment in a domestication framework

Plant domestication can modify flavonoid concentration, generating a decrease in plants subjected to cultivation, but when cultivated plants are transferred to their original wild area, flavonoids can be recovered. In this framework, a native shrub from Chile, Ugni molinae, has been domesticated due to their high phenolic composition. We hypothesised that plant domestication results in a decrease of flavonoid in cultivated plants, and that when they are exposed to a reciprocal transplant experiment, the flavonoid content can be recovered. Hence, a reciprocal transplant experiment for analysing the flavonoids of cultivated plants transferred to their original wild environments was carried out. Methanolic leaf extracts from two cultivated ecotypes and their respectively wild ancestors were collected for flavonoid analysis. Four flavonols and two isoflavonoids were identified and quantified by liquid chromatography. Results showed differences in flavonoids concentrations between wild (290?µg/g) and cultivated (160?µg/g) plants. Furthermore, when wild plants were transferred to cultivated areas, a reduction in flavonoids of 80?µg/g was observed. Moreover, rutin was the most abundant compound (36.09%) detected by chromatography in Mehuín wild plants. Our results showed that cultivated plants transferred to their respective wild environment presented a capacity of recover myricetin, daidzin and genistin content.     

Do farmers need relief seed? A methodology for assessing seed systems

This article outlines a methodology to help agencies better determine whether or not relief seed is needed by farmers affected by disaster. A brief review of current seed needs assessment procedures in southern Somalia and Mozambique illustrates problems of knowing which crops and households are affected, the importance of seed access (not just availability) and the need to plan interventions earlier than at present. The development of a Seed Systems Profile (SSP) is proposed to understand better both the socio-economic and agro-ecological aspects of farmers' seed systems. A five-step framework for assessing seed systems in disaster situations is also presented. These tools are currently being tested and further refined in Mozambique. A better understanding of farmers' seed systems will allow for the development of relief and rehabilitation interventions that effectively enhance the resilience and reduce the vulnerability of these systems.     

Nectar production dynamics and sugar composition in two <Emphasis Type="Italic">Mucuna</Emphasis> species (Leguminosae,Faboideae) with different specialized pollinators

Nectar is secreted in particular rhythms throughout the lifespan of a flower, which allows determining the nectar production dynamics. This paper compares nectar features in Mucuna japira and Mucuna urens describing: dynamics of nectar production, floral response to nectar removal, resorption, nectar sugar composition, and variation in nectar sugar composition. M. japira inflorescence bears 12–21 yellow flowers, which are in anthesis for 7 days, whereas M. urens inflorescence bears 36–54 greenish flowers, but only 1–3 flowers are in anthesis simultaneously that last one night. Nectar volume and sugar concentration were measured, and the amount of sugar was estimated. Qualitative and quantitative nectar sugar composition was determined. Both species had a constant nectar sugar concentration (ca. 10% for M. japira and ca. 16% for M. urens) and secreted high volumes of nectar (ca. 340 μl per flower for M. japira and 310 μl per flower for M. urens), during 5 days for M. japira and 6 h for M. urens, but after the first removal, i.e., when flower opening mechanism is triggered, nectar production stops immediately. Nectar resorption occurred in both species. Nectar sugar composition showed some similarities between the species. Variation in nectar sugar composition occurred in both species. The Mucuna species are dependent on their pollinators to produce fruits and seeds, and they have different strategies to promote the necessary interaction with birds or bats, especially related to nectar and flower characteristics.     

Prevalence of alcohol and illicit drugs in blood specimens from drivers involved in traffic law offenses. Systematic review of cross-sectional studies

OBJECTIVE: To determine which is the reported prevalence of alcohol and illicit drugs in blood specimens from drivers involved in traffic law offenses worldwide. METHODS: The search was performed by using several international biomedical databases. In order to reduce publication bias, additional publications were identified using further sources of information. The present review includes cross-sectional studies published between 1990 and 2005 in English, Spanish, German, Portuguese, and Italian. Only studies based on the analysis of blood specimens and chromatographic quantification of drugs were included. RESULTS: Forty-nine studies fulfilled the inclusion criteria. Eighteen were excluded considering practical reasons regarding limitations for a reliable interpretation of their results. Alcohol appears to be still the predominant substance, with the consideration that among drivers primarily suspected of DUID, cannabinoids are more prevalent. Among the illicit drugs, cannabinoids are the most commonly found substance. Certain trends could be identified, e.g., very low prevalence of cocaine in reports from Nordic countries, a high prevalence of amphetamines between Norwegian and Swedish studies, and low rates of THC among Australian studies. CONCLUSION: The results of this study should be regarded as an attempt to obtain more reliable data concerning the prevalence of alcohol and illicit drugs among drivers. To obtain a better assessment of the real current role of alcohol and drugs (illicit and medications), it seems strongly necessary to update the case-control study conducted by Borkenstein et al. in 1964, including now blood analyses of the whole spectrum of substances that can impair drivers.     

Soil,water and plants contamination by total chrome and chrome VI

The chrome (Cr) is a metal utilized in various industrial sectors and its investigation in the environment is necessary, for the Cr (III) contain aessential micronutrients in the human nourishment and the Cr (VI), on the other hand, is toxic. In the present work soil contamination with Cr was realized in drainagelysimetersset in concentrations of 0, 200, 400, 600, 800 and 1000 mg kg⁻¹ of total Cr, with the intuition to determine the total Cr and Cr (VI) flux in leached water, in soil and in plants of lettuce (Lactuca sativa L.). In the lysimeters were cultivated four plants, in three cultivation circles. In the end of the cultivations was observed, that the total applied Cr leached in the soil, evidencing the Cr mobility in latossoil with simulant characteristics to the ones utilized in this paper. The Cr (VI) concentrations in the soil increased soon after the treatment applications, but tend to decrees in the time elapse, the same tendences were observed for the total Cr concentrations in the leached water. The Cr absorption by plants was related to the Cr disponibility in the soil, for the soil concentration and the plants decreased with time passing. The Cr mobility in the soil possibilitated the groundwater contamination presenting risks to the water quality and, consequently to public health.     

Toxicity testing of pesticides in zebrafish—a systematic review on chemicals and associated toxicological endpoints

The use of zebrafish (Danio rerio) has arisen as a promising biological platform for toxicity testing of pesticides such as herbicides, insecticides, and fungicides. Therefore, it is relevant to assess the use of zebrafish in models of exposure to investigate the diversity of pesticide-associated toxicity endpoints which have been reported. Thus, this review aimed to assess the recent literature on the use of zebrafish in pesticide toxicity studies to capture data on the types of pesticide used, classes of pesticides, and zebrafish life stages associated with toxicity endpoints and phenotypic observations. A total of 352 articles published between September 2012 and May 2019 were curated. The results show an increased trend in the use of zebrafish for testing the toxicity of pesticides, with a great diversity of pesticides (203) and chemical classes (58) with different applications (41) being used. Furthermore, experimental outcomes could be clustered in 13 toxicity endpoints, mainly developmental toxicity, oxidative stress, and neurotoxicity. Organophosphorus, pyrethroid, azole, and triazine were the most studied classes of pesticides and associated with various toxicity endpoints. Studies frequently opted for early life stages (embryos and larvae). Although there is an evident lack of standardization of nomenclatures and phenotypic alterations, the information gathered here highlights associations between (classes of) pesticides and endpoints, which can be used to relate mechanisms of action specific to certain classes of chemicals.     

Residues of legacy organochlorine pesticides and DDT metabolites in highly consumed fish from the polluted Guanabara Bay,Brazil: distribution and assessment of human health risk

Abstract

Organochlorine (OCP) pesticides were determined in samples of sardine (Sardinella brasiliensis), whitemouth croaker (Micropogonias furnieri), and mullet (Mugil liza) from Guanabara Bay (state of Rio de Janeiro, Brazil). OCP concentrations and fish consumption were linked with acceptable daily intake values in order to assess the human health risk for the Brazilian population. The total concentrations of OCPs (Σ OCP) was 6.6?ng/g f.w., 7.5?ng/g f.w., and 2.8?ng/g f.w. for sardines, corvina, and mullet, respectively. There was a significant difference (P?<?0.05) among the species related to o,p’-DDD and o,p’-DDT concentrations. Both DDT-related compounds were 5 and 76 times more abundant in sardines than in whitemouth croaker and mullet. Newly discovered DDT metabolite, o-Cl-DDMU, was frequently detected in the fish. None of the samples exceeded the maximum limits for acceptable levels of OCP residues. According to the data of average intake of Brazilian population, none of three species exceeded toxicological parameter. The investigated fishes are considered as safe for human consumption in regard to exposure of the studied OCPs. However, fish may be a intake source of OCP metabolites such as o-Cl-DDMU whose toxicity is still unknown.