Visible symptoms in tree foliage can be used for stress diagnosis once validated with microscopical analyses. This paper reviews and illustrates macroscopical and microscopical markers of stress with a biotic (bacteria, fungi, insects) or abiotic (frost, drought, mineral deficiency, heavy metal pollution in the soil, acidic deposition and ozone) origin helpful for the validation of symptoms in broadleaved and conifer trees. Differentiation of changes in the leaf or needle physiology, through ageing, senescence, accelerated cell senescence, programmed cell death and oxidative stress, provides additional clues raising diagnosis efficiency, especially in combination with information about the target of the stress agent at the tree, leaf/needle, tissue, cell and ultrastructural level. Given the increasing stress in a changing environment, this review discusses how integrated diagnostic approaches lead to better causal analysis to be applied for specific monitoring of stress factors affecting forest ecosystems. Macroscopic leaf symptoms and their microscopic analysis as stress bioindications.

The present study investigates the histochemical localization of N-acetyl-β-hexozaminidase (Hex), acid phosphatase (AcP) and β-glucuronidase (β-Gus) in the digestive gland of mussels Mytilus galloprovincialis, as well as the clarification of suitable enzyme for biomarkers’ application dealing with lysosomes. The results show more intense and homogenous localization of Hex, in relation to AcP and β-Gus and, thus, Hex histochemistry is supported as more suitable procedure for the evaluation of “lysosomal membrane stability” and “morphometrical alterations of lysosomes”. The affection of lipofuscin granules on lysosomal enzymes’ activity is also discussed. Additionally, the present study examines the response of small- and large-sized mussels M. galloprovincialis by assessing the “lysosomal membrane stability”, “morphometrical alterations of lysosomes”, “lysosomal response index (LRI)” and “structural epithelial changes in digestive tubules”. The results indicate appreciable alterations of the above parameters in large-sized mussels, supporting their greater influence by the environmental factors, in relation to small-sized ones.

Studies concerning mycotoxins involve activities of relevant potential for furthering knowledge in the fields of toxicology and environmental analysis. Using bioanalytical methods (biosensors, histochemistry), the conducted research aims at contributing to raising the awareness of local, national, and international media in relation to the safety of obtaining and processing vegetal and animal foods, by analyzing the possible effects of aflatoxins and ochratoxins, promoting animal health, food hygiene, in view of ensuring animal and human health. The study using laboratory animals (mice) while being part of one of the current national research directions, also holds international priority, by its contribution to a better understanding of several fundamental mechanisms of life at molecular level and to the characterization of certain biological processes that appear in mycotoxicosis.

Bivalve mussels can concentrate pollutants which, in high amounts, can cause cellular, physiological and behavioral changes. The gill mucus is essential for many metabolic and behavioral procedures on marine mussels including the response to environmental pollution. The present work analyzed the mucous cell number in Mytella falcata gill filaments from three sites of Santos estuary (Brazil) with different levels of sediment contamination named as sites A, B, and C. Site A is located at a low impacted region of the estuary, and sites B and C are under influence of port activities, domestic sewage, and industries like a still mill located in front of site C (the most contaminated area with high amounts of polycyclic aromatic hydrocarbons). An increase in mucous cell number was detected in animals from sites B and C, when compared to site A; this increase occurred preferentially in the frontal zone and was related to sediment contamination. Mucous cell analysis can be used as an efficient biomarker. It is suggested that mucus produced in lateral and abfrontal zones is responsible for eliminating pollutants previously absorbed and mucus produced in frontal zone is responsible for pollutant arrest and elimination as pseudofeces.

Several chemicals present in the aquatic environment have the ability to alter the endocrine system of aquatic organisms, including the metals cadmium (Cd) and zinc (Zn). In males, a tool to analyze this effect is the vitellogenin (VTG) detection, a protein with defined function in the yolk production and subsequent aid to embryo-larval development. This protein is produced just by females and can be detected by simple and cheap methods such as histochemical method. Thus, this study aimed to analyze the capacity of Cd and Zn to induce VTG production in Danio rerio males and determine whether the histochemical labeling method is efficient to study estrogenic effects in this species. For this, D. rerio adult males were exposed chronically (21 days) to 0.25 and 1 μg/L of Cd and 120 and 180 μg/L of Zn, values allowed by the Brazilian and American legislation to aquatic life protection. After which, the organisms were submitted to a histological process as preparation to liver VTG marking by histochemical method and subsequent qualitative analysis of this protein in zebrafish’s liver. After analyzes, it was possible observed that Cd and Zn are capable of inducing VTG production in D. rerio males and that the histochemistry method is efficient for detection of estrogenic effects in this species.