DNA damage can result from metabolic processes, hydrolysis, or exogenous sources and can lead to various human diseases if left unrepaired. Defects in the cellular response to repair DNA damage can cause cancer, inflammation, cell aging, and neurodegeneration. Neurodegeneration involves the death of neurons and is associated with diseases like Huntington's, Parkinson's, and Alzheimer's. Neurons are post-mitotic cells that are susceptible to DNA damage from endogenous and exogenous agents. If the damage is not repaired, unrepaired DNA accumulates in neurons and can cause cell cycle reentry and apoptosis, leading to neurodegeneration. Chronic inflammation from infection or other sources can also cause DNA damage through reactive oxygen species
A complementation test (sometimes called a "cis-trans" test) can be used to test whether the mutations in two strains are in different genes. By taking an example of Benzer's work, complementation has been explained.
A complementation test (sometimes called a "cis-trans" test) can be used to test whether the mutations in two strains are in different genes. By taking an example of Benzer's work, complementation has been explained.
The sequencing of the human genome has been compared to putting a man on the moon, and it will certainly change health care, but the most important work lies ahead, in determining how to put the information to medical use. In this context, applications such as gene therapy are being explored. What was once seen as a science fiction dream is now becoming a real possibility.
Gene therapy is a new form of drug delivery that leads the patient's own cells to produce a therapeutic agent. It could potentially eliminate the need for repeated administration of proteins or drugs. Applications of gene therapy not only include rare inherited diseases but extend to common acquired disorders, including tumours (predominantly malignant melanoma) and haematological disorders, cardiovascular disease, and the acquired immunodeficiency syndrome. Gene therapy therefore could be a key element of medical practice in the future. Gene therapy is the insertion of genes into an individual's cells and tissues to treat a disease, and hereditary diseases in which a defective mutant allele is replaced with a functional one. Although the technology is still in its infancy, it has been used with some success. Antisense therapy is not strictly a form of gene therapy, but is a genetically-mediated therapy and is often considered together with other methods.
DNA Repair and its cause of emergence. Mutation and its types. Various repair mechanisms in living organisms with its distinctive types along with two common examples: Progeria and Multiple Sclerosis(MS).
The DNA damage response (DDR) is a multifaceted system of genes that are responsible for detecting and reacting to various forms of DNA damage. This intricate network encompasses specific mechanisms that facilitate DNA repair, regulate the cell cycle, respond to replication stress, and induce apoptosis.
Impairments in the DDR can lead to genomic instability in cells, which can contribute to the initiation and progression of cancer by promoting the accumulation of mutations. However, these defects also create exploitable vulnerabilities that are relatively specific to cancer cells, and can be targeted for clinical benefit through the use of DDR inhibitors.
Radiobiology (also known as radiation biology, and uncommonly as actinobiology) is a field of clinical and basic medical sciences that involves the study of the action of ionizing radiation on living things, especially health effects of radiation.
The action is very complex, involving physics, chemistry, and biology
– Different types of ionizing radiation
– Energy absorption at the atomic and molecular level
leads to biological damage
– Repair of damage in living organisms
Mutation Repair and DNA Replication.pptxhamzalatif40
In this Presentation Chapter 7 & 8 from the book Advanced Molecular Biology are discussed. Focus has been given to the mutation, its types, mutation repair, Different Repairing mechanisms and DNA Replication is explained with details.
A mitochondrion (singular of mitochondria) is part of every cell in the body that contains genetic material.
Mitochondria are responsible for processing oxygen and converting substances from the foods we eat into energy for essential cell functions.
The mitochondria of the zygote come from the oocyte, that is, from the mother and almost never from the sperm, form of transmission is called maternal inheritance
Which mitochondrial gene is mutated.
The extent of replicative segregation of the mutant mitochondrial genome during the early stages of embryonic development.
The abundance of the mutant mitochondrial gene in a particular tissue.
The threshold level of mutant mitochondrial DNA required in a tissue before an abnormality is evident clinically
Mitochondrial disease affects tissues most highly dependent on ATP production
*Nerves
*Muscles
Endocrine
Kidney
Low energy-requiring tissues are rarely directly affected, but may be secondarily
Lung
Connective tissue
Symptoms can be intermittent
Increased energy demand (illness, exercise)
Decreased energy supply (fasting)
Common feature
myoclonus epilepsy, deafness, blindness, anemia, diabetes, seizures and loss of cerebral blood supply (stroke).
Myoclonic epilepsy and ragged-red fiber disease (MERRF)
MERRF is a member of a group of disorders called mitochondrial encephalomyopathies that feature mitochondrial defects with altered brain and muscle functions.
The term “ragged red fibers” refers to large clumps of abnormal mitochondria that accumulate mostly in muscle cells and are stained red by a dye that is specific for complex II of the electron transport chain.
rare, maternally inherited, heteroplasmic, (point mutation in tRNA lysine gene)
Mutation is MTTK*MERRF8344G.
MT means mitochondrial gene is mutated
T means transfer RNA gene
K means the single-letter amino acid designation for lysine
MERRF means the clinical features
8344G means the mutant nucleotide is guanine (G) at nucleotide position 8344
If 90% of the mitochondria in nerve and muscle cells carry the MTTK*MERRF8344G mutation, then the defining symptoms of MERRF are present.
Maternally inherited mitochondrial disease
The MTTL1*MELAS3243G mutation accounts for more than 80% of the cases of MELAS.
This base substitution is in one of the two mitochondrial transfer RNALeu genes.
the A3243G mutation occurs in thetRNALeu(UUR) gene
When this mutation is present in ≥90% of the mitochondrial DNA of muscle tissue, there is an increased likelihood of recurrent strokes, dementia, epilepsy, and ataxia.
When heteroplasmy for the A3243G mutation
is ~40% to 50%, chronic progressive external ophthalmoplegia (CPEO), myopathy, and deafness are likely to occur.
Other MELAS mutations occur at sites 3252, 3271, and 3291 within the tRNALeu(UUR) gene and in the mitochondrial tRNAVal (MTTV) and COX III (MTCO3) genes.
Reduced activities in Complexes I and IV are established
ION EXCHANGE CHROMATOGRAPHY
ByM.Vharshini
B.Sc. Bio Medical Science
Sri Ramachandra University
ION EXCHANGE CHROMATOGRAPHY
Ion-exchange chromatography is a process that allows the separation of ions and polar molecules based on their affinity to the ion exchanger.
It can be used for almost any kind of charged molecule including large proteins, small nucleotides and amino acids.
Cations or Anions can be separated using this method.
PRINCIPLE
It is based on the reversible electrostatic interaction of ions with the separation matrix (i.e.)
The separation occurs by reversible exchange of ions between the ions present in the solution and those present in the ion exchange resin.
CLASSIFICATION OF RESINS
According to the chemical nature they classified as-
1. Strong cation exchange resin
2. Weak cation exchange resin
3. Strong anion exchange resin
4. Weak anion exchange resin
According to the Source they can -
Natural resins : Cation - Zeolytes, Clay
Anion - Dolomite
Synthetic resins: Inorganic & Organic resins
◘Organic resins are polymeric resin matrix.
The resin composed of –
Polystyrene (sites for exchangeable functional groups)
Divinyl benzene(Cross linking agent)-offers stability.
Ion exchange resin should have following requirements
»It must be chemically stable.
»It should be insoluble in common solvents.
» It should have a sufficient degree of cross linking.
»The swollen resin must be denser than water.
»It must contain sufficient no. of ion exchange groups.
Physical properties of ion exchange resins
Cross linking:
It affects swelling & strength & solubility
Swelling:
When resin swells, polymer chain spreads apart
Polar solvents → swelling
Non-polar solvents → contraction
Swelling also affected electrolyte concentration.
Particle size and porosity
Increase in surface area & decrease in particle size will increase the rate of ion exchange.
Regeneration
Cation exchange resin are regenerated by treatment with acid, then washing with water.
Anion exchange resin are regenerated by treatment with NaOH, then washing with water until neutral.
EXPERIMENTAL SETUP OF ION EXCHANGE CHROMATOGRAPHY
Metrohm 850 Ion chromatography system
Instrumentation of ion exchange chromatography
PRACTICAL REQUIREMENTS
1.Column
» glass, stainless steel or polymers
2.Packing the column
» Wet packing method:
A slurry is prepared of the eluent with the stationary phase powder and then carefully poured into the column. Care must be taken to avoid air bubbles.
3.Application of the sample
After packing, sample is added to the top of the stationary phase, use syringe or pipette.
This layer is usually topped with a small layer of sand or with cotton or glass wool to protect the shape of the organic layer from the velocity of newly added eluent.
4.Mobile phase
Acids, alkalis, buffers…
6.Stationary phase
The ionic
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
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.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
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.
(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.
1. Diseases caused by DNA
damage
By
M.Vharshini
B.Sc. Biomedical sciences
Sri Ramachandra University
2. • DNA damage is an alteration in the chemical structure
of DNA, such as a break in a strand of DNA, a base
missing from the backbone of DNA, or a chemically
changed base such as 8-OHdG.
• Damage to DNA that occurs naturally can result
from metabolic or hydrolytic processes.
• DNA damage induces sequential responses to either
repair the damage or activate apoptosis.
Introduction
5. Defects in this critical response to DNA damage leads
to wide array of human pathologies that include :
Cancer predisposition,
Inflammation responses,
Cell Ageing and
Neurodegeneration.
8. Neurodegeneration is the common feature of
many nervous system and aging diseases, such
as
• Huntington Disease (HD),
• Parkinson’s disease (PD) and
• Alzheimer’s disease (AD)
Neurodegeneration and DNA damage
9. After completing the normal development processes,
neurons enter a post-mitotic state and stay in a
resting status.
A numerous endogenous and exogenous agents can
cause DNA damage.
Activation of DNA damage sensing protein which
trigger the cascade reactivation of repair system.
If the damaged DNA was not completely repaired or
the ability of repair was deficiency, the unrepaired DNA
would be accumulated in the neuron which will be
provoked to re-enter into cell cycle *
Reactivation of the cell cycle in neurons can induce
apoptosis , lead to neuronal degeneration.
10. • Infections and chronic inflammations have been
recognized as important risk factors for carcinogenesis
and malignancies.
• Inflammation can be induced not only by chronic infection
but also endogenous and exogenous factors.
• Chronic inflammation accounts for approximately 25% of
human cancers.
• Under inflammatory conditions, reactive oxygen
species(ROS) & reactive nitrogen species(RNS) are
generated from inflammatory & epithelial cells.
• ROS can induce the formation of oxidative DNA lesion
products which is considered to be mutagenic
DNA damage in chronic inflammation
11. • Deletion of DNA segments is the predominant form of
radiation damage in cells that survive irradiation.
• It may be caused by any of two reasons:
1)Mispair of two separate double strand breaks in
DNA molecule with join of the two outer ends and
loss of the fragment between the breaks.
2)The process of cleaning (enzyme digestion of
nucleotides- the component molecules of DNA)
of the broken ends before rejoining to repair one
double strand break.
DNA damage caused my Ionising
radiation