Gisela Kristoff

• PhD
• Investigador Independiente at National Scientific and Technical Research Council

Biomphalaria straminea is a freshwater gastropod native to South America and used in toxicological assessments. Our aim was to estimate 48h-LC50 and sub-chronic effects after the exposure to low concentrations of chlorpyrifos as commercial formulation (CF) and active ingredient (AI) on B. straminea adult, embryos and juveniles. Concentrations betwe...

The study of multiple biomarkers in bioindicator species is a useful tool to evaluate water quality in addition to physicochemical analysis. The aim of this work was to study the toxicity of water samples from two sites with different anthropogenic impacts (R: near a residential area and FP: close to horticultural farms and industrial waste treatme...

Lugano Lake is located in an Ecological Reserve of Buenos Aires City. Biomonitoring of its water quality is essential due to its importance as a place for recreation and protection of native species. Biomphalaria straminea is a native hermaphrodite aquatic gastropod that inhabits different freshwater bodies of Argentina and was recently selected as...

We studied the absorption, cytotoxicity and oxidative stress markers of Paralytic Shellfish Toxins (PST) from three extracts from Alexandrium catenella and A. ostenfeldii, in middle Oncorhynchus mykiss intestine in vitro and ex vivo preparations. We measured glutathione (GSH) content, glutathione-S transferase (GST), glutathione reductase (GR) and...

Neurotoxic insecticides are ubiquitous in aquatic ecosystems, frequently as part of complex mixtures. Freshwater gastropods are generally underrepresented in neurotoxicity evaluations and cumulative toxicity testing. This study investigates the behavioural and biochemical effects of acute exposures to the carbamate carbaryl, the organophosphate chl...

Neonicotinoids emerged as an environmentally safe alternative to previous generations of insecticides becoming one of the most widely applied in modern agriculture. Nevertheless, they have been reported to affect several non-target organisms. Most toxicity studies focus on the effects on pollinators or terrestrial invertebrates and evaluate either...

In this chapter, we show the results obtained after exposing the freshwater gastropod Chilina gibbosa 7 and 14 days to the organophosphate azinphos-methyl and the carbamate carbaryl. These insecticides are applied in Argentina and found in water bodies. Chilina gibbosa is naturally distributed in our country, and the family (Chilinidae) is consider...

This work aimed to study in the freshwater gastropod Planorbarius corneus the effects of acute (2 days) and subchronic (14 days) exposures to an environmental concentration of the organophosphate azinphos-methyl on different reproductive parameters, offspring survival and B-esterase activities in gonads and in the whole organism soft tissue. The ac...

The aims of this work were: a. Determine carboxylesterase (CES) activity in homogenates of Zea mays seeds during the first eleven days of germination; b) Study the pattern of isoenzymes by native PAGE and evaluate the effects of the organophosphate azinphos methyl-oxon on CES; c. Study the tissue distribution of CES. The highest CES activity was ob...

Organophosphate insecticides (OPs) are commonly used in Argentina and around the world for pest control in food crops. They exert their toxicity through the inhibition of the enzyme acetylcholinesterase. In the present study, we aimed to evaluate biochemical and reproductive effects in Biomphalaria straminea, a freshwater gastropod naturally distri...

The use of a battery of biomarkers, especially those more closely related to species integrity, is desired for more complete ecotoxicological assessments of the effects of pesticide contamination on aquatic organisms. The phosphorodithioate azinphos-methyl has been intensively used in agriculture worldwide and have been found in the habitat of Chil...

A pesar de que sabemos que la información que recibimos se traduce en toma de decisiones que afectan nuestra realidad, la relación entre la ciencia y la sociedad continúa sin afianzarse. Esto crea la necesidad de buscar métodos de comunicación de la ciencia alternativos para que los contenidos científicos puedan ser apreciados, entendidos eficiente...

Muchas especies están expuestas en sus hábitats naturales a distintos pesticidas. Cada especie responde de una manera diferente a los contaminantes. En el laboratorio estudiamos distintos efectos tóxicos del insecticida organofosforado metilazinfos en dos gasterópodos de Argentina: Biomphalaria straminea y Chilina gibbosa. C. gibbosa resultó muy se...

The increasing worldwide contamination of freshwater systems with a wide range of chemical compounds is one of the main environmental problems that humanity faces nowadays. These contaminants, such as pesticides, disturb natural ecosystems and can have a great impact on the species that inhabit them. Traditionally, environmental monitoring programs...

Organophosphate insecticides (OPs) continue to be an important class of agrochemicals used in modern agriculture worldwide. Even though these pesticides persist in the environment for a relatively short time, they show a high acute toxicity that may represent a serious hazard for wildlife. Sub-lethal effects on non-target species are a focus in pes...

Azinphos-methyl belongs to the class of organophosphate insecticides which are recognized for their anticholinesterase action. It is one of the most frequently used insecticides in the Upper Valley of Río Negro and Río Neuquén in Argentina, where agriculture represents the second most important economic activity. It has been detected in water from...

A natural petroleum spill affects Las Minas stream (41°17’21’’S, 71°10’58’’W, Río Negro Argentina), in which the rainbow trout, Oncorhynchus mykiss, is abundant throughout the year. We assayed possible biomarkers of exposure to polycyclic aromatic hydrocarbons (PAH): carboxylesterase (CEs) activity (induced PAH in rat liver) and glutathione S-trans...

Las Minas stream is located southeast of the city of San Carlos de Bariloche in the south of Argentina (41°17’21’’ S, 71°10’58’’ O, 1001 msnm). Between 1910 and 1940 natural reserves of crude oil near to the stream were exploited commercially until the activity stopped and the source was abandoned leaving behind an oil spill that affects Las Minas...

Chlorpyrifos is an organophosphate insecticide widely used in a variety of food crops in Argentina and other countries. In a previous work, we have reported that subchronic exposure (14 days) to an environmental concentration of chlorpyrifos (5 μg L- 1 ) caused severe effects on reproduction of the freshwater hermaphrodite gastropod Planorbarius co...

Organophosphorous and carbamates insecticides are ones of the most popular classes of pesticides used in agriculture. Its success relies on their high acute toxicity and rapid environmental degradation. These insecticides inhibit cholinesterase and cause severe effects on aquatic non-target species, particularly in invertebrates. Since the properti...

In the Upper Valley of Río Negro and Río Neuquén in Argentina, agriculture represents the second most important economic activity. Azinphos-methyl has been found in water from this region throughout the year at a maximum concentration of 22.48μgL(-1) during the application period. Toxicological studies on local non-target species have been performe...

Chlorpyrifos is an organophosphate insecticide used for pest control on a number of food crops in many parts of the world. In recent years, there has been an important decrease in the number of organisms of Planorbarius corneus. Since the presence of pesticides in the water can be one of the reasons for this decrease, it is very important to study...

In this study, the cholinesterase (ChE) and carboxylesterase (CES) activities present in whole organism homogenates from Planorbarius corneus and their in vitro sensitivity to organophosphorous (OP) pesticides were studied. Firstly, a characterization of ChE and CES activities using different substrates and selective inhibitors was performed. Secon...

Cholinesterases and carboxylesterases belong to the group of B-esterases, the serine superfamily of esterases that are inhibited by organophosphorus compounds. It is now generally accepted that before using the B-esterases as biomarkers of exposure to organophosphorus and carbamates in a given species, the biochemical characteristics of these enzym...

Azinphos-methyl is an organophosphate insecticide used for pest control on a number of food crops in many parts of the world. The snail Biomphalaria glabrata is a freshwater gastropod widely distributed in South America, Central America and Africa. The aim of the present work was to investigate whether azinphos-methyl causes alterations in the repr...

In this study, the effects of sublethal concentrations of the carbamate carbaryl on the cholinesterase (ChE) and carboxylesterase (CES) activities present in the oligochaete Lumbriculus variegatus and in the pigmented Biomphalaria glabrata gastropod were investigated. The results showed that ChE activity from both species was inhibited by in vivo a...

Azinphos-methyl is an organophosphate insecticide used for pest control on a number of food crops in many parts of the world. The oligochaete Lumbriculus variegatus and pigmented and non-pigmented specimens of the gastropod Biomphalaria glabrata are freshwater invertebrates that have been recommended for contamination studies. Recently, it has been...

Paraquat is still a widely used herbicide in several countries. Its toxic action on plants occurs through a one-electron reduction interfering with the photosynthesis process. By a similar reaction, the herbicide may induce peroxidation processes in non-target animal species. Furthermore, paraquat may interfere with the cellular transport of polyam...

In this study, some biochemical features and the extent of inhibition induced by the organophosphorous pesticide azinphos-methyl on the cholinesterase (ChE) activity present in whole soft tissue of two freshwater invertebrate species, the gastropod Biomphalaria glabrata and the oligochaete Lumbriculus variegatus were investigated. Both invertebrate...

The in vivo effect of menadione bisulfite adduct on both hepatic oxidative stress and heme oxygenase induction was studied. A marked increase in lipid peroxidation was observed 1 h after menadione bisulfite adduct administration. To evaluate liver antioxidant enzymatic defenses, superoxide dismutase, catalase and glutathione peroxidase activities w...

The accumulation of compatible solutes is one of the strategies that plants have developed to tolerate salt stress. Proline and betaine are the main metabolites that accumulate in various species of higher plants in response to salt stress. In Helianthus annuus L., pre-treatment of seeds with ethanolamine led to enhanced seedling tolerance to condi...