Definition of pest and pesticide.
Names of chemically related pesticides.
Description on carbamate insecticide, definition, history and mode of action.
symptoms of carbamate poisoning and it's treatment.
Definition of pest and pesticide.
Names of chemically related pesticides.
Description on carbamate insecticide, definition, history and mode of action.
symptoms of carbamate poisoning and it's treatment.
Toxicology is the scientific study of adverse effects that occur in living organisms due to chemicals. It involves observing and reporting symptoms that arise following exposure to toxic substances.
Ecotoxicology is the science devoted to the study of the adverse effects of chemicals on ecosystems structure, functions, and biodiversity. It is a modern discipline, just developed during the last four decades, directly associated to the need to identify, predict, control, and minimize the negative environmental consequences of the recent human industrial development. Ecotoxicology has always been connected to toxicology, and is in part an extension of human/veterinary toxicology to the investigation of effects on wildlife. In parallel, it also linked ecotoxicology to ecology, from both conceptual and methodological viewpoints.
Toxicology is the scientific study of adverse effects that occur in living organisms due to chemicals. It involves observing and reporting symptoms that arise following exposure to toxic substances.
Ecotoxicology is the science devoted to the study of the adverse effects of chemicals on ecosystems structure, functions, and biodiversity. It is a modern discipline, just developed during the last four decades, directly associated to the need to identify, predict, control, and minimize the negative environmental consequences of the recent human industrial development. Ecotoxicology has always been connected to toxicology, and is in part an extension of human/veterinary toxicology to the investigation of effects on wildlife. In parallel, it also linked ecotoxicology to ecology, from both conceptual and methodological viewpoints.
toxin
medicine
antidotes
medicolegal duties of a RMP
duties of a doctor
management of a case of poisoing
sources of poisons
gastric lavage
ideal homicidal poison
Insecticide may be defined as a substance or mixture of substances intended to kill, repel or otherwise prevent the insects.
Insecticides are the most powerful tools available for use in pest management. They are highly effective, rapid in curative action, adoptable to most situations, flexible in meeting changing agronomic and ecological conditions and economical
You can gain ideas on toxico-kinetics from this presentation. Different aspects regarding bio-concentration and bioaccumulation. In addition, demerits of different toxic chemicals from food industries are discussed with examples.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
1. Organochlorine Insecticides
Dr. Kumari Anjana
Assistant Professor
Deptt. of Veterinary Pharmacology & Toxicology
Bihar Veterinary College, Bihar Animal Sciences University, Patna
2. Contents of the chapter
• Introduction to Agrochemicals
• Introduction to Pesticides
• Pesticides Classification
• Introduction to Insecticides
• Insecticides Classification
Organochlorine compounds
• Sources of poisoning
• Classification of OCI
• Factors affecting toxicity
• Mechanism of Toxicity
• Clinical symptoms
• PM Lesions
• Diagnosis
• Treatment
3. Agrochemicals
•Agrochemicals are of two major groups:
Fertilizers
Pesticides
•Nitrate, Phosphorus and Urea are used as
fertilizers.
•A pest is an uneconomical, undesirable or
harmful species that adversely affect the
economic, desirable or beneficial species.
Pesticides are used to kill the pests.
4. Pesticides
Pesticides:are heterogeneous groups of
substances used for preventing,
destroying or repelling pests.
Pesticides are the most widely used agrochemicals of
toxicological importance.
Use – economical control of pests
or increase production of crops
6. Insecticides
• Substances which are specifically used for preventing,
destroying or repelling the insects pests.
• The use of insecticides in agriculture has grown
tremendously since world war II.
• Now a days insecticides have become an integral part
of agriculture.
• Large scale use- acute toxicities,
residues in food stuff
and environmental problem.
8. Organochlorines
• Organochlorines were the first major
class of synthetic organic chemical to
become widely used as insecticides.
• Use- contact insecticides and
ectoparaciticides.
9. Sources of poisoning
• Accidental ingestion of these products may lead
to toxicity.
• Environmental pollution.
• Residues in agricultural products.
• Consumption of freshly sprayed crop by animals.
• Improper dilution in sprays and dips may cause
toxicity.
• Spillage of insecticides into food during storage
or transport.
• Secondary poisoning in predator animals.
11. • 1874 : Dichloro diphenyltrichloro ethane (DDT) was synthesized.
1939 : Its insecticidal property was discovered by Paul Muller.
1948 : Paul Muller, a Swiss chemist who was awarded Nobel
prize for his contribution.
• However its effectiveness in controlling pests was short lived
due to its persistence in the environment for a prolonged time.
• It is also stored in the body fats of animals which is eliminated
at extremely slow rate and has biomagnifications potential.
• One of the most adverse effects of DDT due to
biomagnifications is the decline in the population of certain
birds due to thinning of their egg shells.
• Because of its persistence in the biosphere, the use of DDT has
been banned by almost all the countries including India.
• Dicofol and methoxychlor are still in use.
DDT
12. Chemical structure of OCI
• Presence of cyclic carbon chain.
• Apolarity and lipophilicity.
• Chemical unreactivity and high stability in
the environment.
• T ½ of OCl in soil - 1-12 years.
• T ½ of DDT in soil -- 3-10 years
13. Factors affecting toxicity
• Young animals- more sensitive.
• Female- more sensitive.
• Fatty and lactating animal- more
sensitive.
• Stress and illness enhance the toxicity.
• More toxic in oily vehicle then suspension
and dry powder.
14. • Cyclodiene group- more toxic
Oral LD50 - 5- 100 mg/kg cattle.
• DDT group - least toxic
Oral LD50 - 250-1000 mg/kg cattle.
• Cats are more susceptible – other domestic
animal.
• Fish > mammal > birds.
15. Properties of toxicological importance
Lipid soluble compound
+
Highly persistent in the environment
Bioaccumulation upward in food chain from
environment to animal or human hosts.
16. Toxicokinetics
• OCIs are highly lipid soluble, so readily absorbed from
skin and mucous membrane (accumulate in the body fat).
Asoption:
• Its absorption from GIT is poor except in oily solution.
• OCIs are not highly volatile – no inhalation toxicosis.
But aerosols can be absorbed.
• After absorption - in blood stream bind with serum
lipoprotein and stored in body fat.
• Organochlorines are distributed to vital organs namely
liver, kidney and brain.
17. Metabolism:
• Metabolism is mainly by liver and the
metabolite may be non toxic than the parent
compound.
• Slow metabolism from deposited fat.
Excreted
• Excreted mainly in the faeces (unchanged
form).
• From body excreted in bile, urine and in
lactating animals, it is excreted in milk.
18. Mechanism of Toxicity
• These drugs are neurotoxic.
Diphenyl OCI
• Easily enter in the nerve membrane interfere with
Na+ Channel kinetics.
• Prolong the time of sodium channel opening during
depolarization.
• Sodium inflow is enhanced and potassium outflow is
inhibited.
• Results in enhanced action potential and increased
neuronal excitability (seizures).
19. Cyclodiene and aryl hydrocarbon
• Bind to a site close to ion channel on GABAA
receptors.
• Inhibit the binding of Inhibitory NT GABA to the
receptor.
• No opening of chloride channels.
• Partial repolarization of the neuron and a state of
uncontrolled excitation.
20. Clinical symptoms
• Initial stimulation of CNS followed by depression and
death due to respiratory failure.
Behavioural symptoms- like anxiety, aggressiveness,
abnormal posturing, jumping over unseen objects, wall
climbing and madness syndrome.
• Neurological symptoms - hypersensitivity to
external stimuli, fasciculation and twitching of facial
and eyelid muscles, spasm and twitching of the fore
and hind quarter muscles, champing of the jaws,
seizures and hyperthermia.
• Cholinergic symptoms - vomiting, marked salivation,
mydriasis, diarrhoea and micturition are noticed.
21. PM Lesions
• carcass – bruised, lacerated and dirty.
• Rigor prominent.
• Chronic case- carcass emaciated and devoid
of body fat.
22. Diagnosis
• Acute toxicosis is diagnosed based on history of
exposure, appropriate clinical signs.
• Brain concentration is better then body fat
diagnosis of acute toxicosis.
• Half of the frozen brain should be submitted for
analysis.
• The other half should be fixed for histopathology to
rule out infectious degenerative, or neoplastic
diseases.
• To determine sources, specimens for analysis such as:
feed, suspected insecticidal formulation - granules,
liquid, old containers, etc., gastrointestinal tract
contents and liver.
23. Treatment
• Diazepam, phenobarbital or pentobarbital in
dogs.
Thiobarbitone in cats
Chloral hydrates, Phenobarbital or
pentobarbital in farm animals.
• Activated charcoal (1-2g/kg).
• If exposure is by dermal suspected,
scrubbed (bathe) the animal with soapy
water.
• Supportive and symptomatic therapy.
24. Methoxychlor
• It is the only insecticide of DDT group which is still
in use and is safest among the subgroup.
• The substitution of CH3O (methoxy) groups for
chlorines renders the insecticide biodegradable and
environmentally non- persistent.
• As such, it retains some of the advantages of DDT
but without most of its disadvantages.
• It is stored in adipose tissue to about 0.2% of the
extent of DDT, and hail-life in rats is only about 2
weeks (DDT=6 months).
