This presentation was given by me during my M.pharm.
It contains description, classification, mechanism of actions and therapeutic uses of Neuromuscular blockers.
This presentation was given by me during my M.pharm.
It contains description, classification, mechanism of actions and therapeutic uses of Neuromuscular blockers.
An overview of muscarinic receptor agonists and antagonists. This presentation was delivered to 2nd year pharmacy students enrolled in a pharmacology & toxicology class and accompanies Goodman & Gilman's (12e) chapter 9.
The parasympathetic division typically acts in opposition to the sympathetic autonomic nervous system through negative feedback control.
This action is a complementary response, causing a balance of sympathetic and parasympathetic responses.
Overall, the parasympathetic outflow results in the conservation and restoration of energy, reduction in heart rate and blood pressure, facilitation of digestion and absorption of nutrients, and excretion of waste products.
These are drugs that produce actions similar to that of Acetylcholine hence known as parasympathomimetics.
They act either by directly interacting with cholinergic receptors or by increasing the availability of Acetylcholine at these sites.
Parasympatholytics are the drugs that block or inhibit the actions of acetylcholine at postganglionic nerve endings and cholinergic receptors. They are also referred to as anticholinergics or cholinergic blocking agents or antispasmodics.
Anticholinergic drugs include atropine and related drugs- atropine is the prototype. Atropine is obtained from the plant Atropa belladonna. Atropine and scopolamine (hyoscine) are the belladonna alkaloids. They compete with acetylcholine for muscarinic receptors and block this receptors-they are muscarinic antagonists.
An overview of muscarinic receptor agonists and antagonists. This presentation was delivered to 2nd year pharmacy students enrolled in a pharmacology & toxicology class and accompanies Goodman & Gilman's (12e) chapter 9.
The parasympathetic division typically acts in opposition to the sympathetic autonomic nervous system through negative feedback control.
This action is a complementary response, causing a balance of sympathetic and parasympathetic responses.
Overall, the parasympathetic outflow results in the conservation and restoration of energy, reduction in heart rate and blood pressure, facilitation of digestion and absorption of nutrients, and excretion of waste products.
These are drugs that produce actions similar to that of Acetylcholine hence known as parasympathomimetics.
They act either by directly interacting with cholinergic receptors or by increasing the availability of Acetylcholine at these sites.
Parasympatholytics are the drugs that block or inhibit the actions of acetylcholine at postganglionic nerve endings and cholinergic receptors. They are also referred to as anticholinergics or cholinergic blocking agents or antispasmodics.
Anticholinergic drugs include atropine and related drugs- atropine is the prototype. Atropine is obtained from the plant Atropa belladonna. Atropine and scopolamine (hyoscine) are the belladonna alkaloids. They compete with acetylcholine for muscarinic receptors and block this receptors-they are muscarinic antagonists.
Increasing the efficacy of drugs and at the same time reducing the chances of adverse reaction should be the aim of drug development, which can be achieved by using 3D printing to fabricate personalized medications
Drugs with narrow therapeutic index can easily be prepared using 3D printing; and, by knowing the patient’s pharmacogenetic profile and other characteristics like age, race etc., optimal dosage can be given to the patient.
3D printing technology is a valuable and potential tool for the pharmaceutical sector, leading to personalized medicine focused on the patients’ needs. It offers numerous advantages, such as increasing the cost efficiency and the manufacturing speed. 3D printing has revolutionized the way in which manufacturing is done. It improves the design manufacturing and reduces lead time and tooling cost for new products.
Nanoparticles are sub-nanosized colloidal structures composed of synthetic or semi synthetic polymers.
The drug is dissolved, entrapped, encapsulated or attached to a nanoparticle matrix.
Hyphenated Techniques - coupling of a separation technique and an on-line spectroscopic detection technology.
Advantages of hyphenated techniques;
1. Fast and accurate analysis.
2. Higher degree of automation.
3. Higher sample throughput.
4. Better reproducibility.
5. Reduction of contamination due to its closed system.
6. Separation and quantification achieved at same time.
Bioanalytical Method Development and Validation..
Bioanalytical method validation include all the procedure that demonstrate that a particular method used for quantitative measurement of analyte in given biological matrix are reliable and reproducible for intended use.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
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.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
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 .
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.
Richard's entangled aventures in wonderlandRichard 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.
7. • Impulse Conduction:
• Sudden entry of Na+ (conductance)
• Depolarization
• Refractory period
• Transmission Release:
• Transmitter store in prejunctional nerve
• Nerve impulse promotes fusion of vesicular and axonal
membrane through Ca+ entry.
• Noradrenaline, dopamine
Steps in Neurohumoral Transmission
7
8. • Transmitter action on postjunctional membrane:
• EPSP : increase permeability of cations (ca+ and Na+
influx) , Efflux of K+ (depolarization), excitation
• IPSP: increase permeability of anions, cl- moves,
hyperpolarize, Inhibition
• Postjunctional Activity:
• Contraction of muscle, secretion of glands
• Terminate of transmitter action:
• Locally Degrade (Ach)
• Taken by presynaptic neuron (NA)
8
9. • Neuromuscular-blocking drugs block neuromuscular transmission at
the neuromuscular junction.
• Causing paralysis of the affected skeletal muscles.
• This is accomplished either by acting pre-synaptically via the
inhibition of acetylcholine (ACh) synthesis or release, or by acting
post-synaptically at the acetylcholine receptors of the motor nerve
end-plate.
• While some drugs act presynaptically (such as botulinum toxin and
tetanus toxin), those of current clinical importance work
postsynaptically.
Neuro-muscular blocking agents
9
11. Site of Release: Ach. and NA
• NM receptor: Location & Function
• Neuromuscular junction: depolarization of muscle end plate –
contraction of skeletal muscle
11
12. • Non-depolarizing blocking agents:
Example - tubocurarine, pancuronium, vecuronium and
atracurium, Gallamine
• Depolarizing blocking agents:
Example - succinylcholine (suxamethonium), decamethonium
rarely used clinically.
Classification of Neuro-muscular blocker
12
13. • They inhibit neuron transmission to muscle by competitively blocking
the binding of ACh to its nicotinic receptors, and block the ionotropic
activity of the ACh receptors.
• Each ACh-receptor has two receptive sites and activation of the
receptor requires binding to both of them. Each receptor site is located
at one of the two α- subunits of the receptor.
Non-depolarizing blocking agents
13
14. Mechanism of action
• Quaternary muscle relaxants bind to the nicotinic acetylcholine
receptor and inhibit or interfere with the binding and effect of ACh to
the receptor.
• They are reversible competitive antagonists combine with the nicotinic
ACh receptor at the end plate and thereby competitively block the
binding of ACh.
BlockerBlocker
14
15. • A decrease in binding of acetylcholine leads to a decrease in its effect
and neuron transmission to the muscle is less likely to occur.
• Non-depolarising blocking agents also block facilitatory presynaptic
autoreceptors, and thus inhibit the release of ACh during repetitive
stimulation of the motor nerve resulting in the phenomenon of tetanic
fade.
15
16. • Action: Tubocurarine occupies muscular cholinergic receptor
site thus preventing Ach from reacting with receptor; no
activation of muscle cells, results in muscle paralysis.
• IV route: Onset 6 min. Duration 25-90 min
• Metabolized in the tissues but excreted unchaged in the urine
• Indication: General anesthesia, Skeletal muscle relaxant
Tubocurarine
16
18. Drug
Clinical
Use
Onset of
Time
Duration
of Action
Side Effect
Tubocurarine Rarely 300 Sec.
60-120
Min.
Hypotension(Ganglionic
block),
Bronchoconstriction
Mivacurium Rarely 90 Sec.
12-18
Min.
Transient hypotension
Atracurium Widely 90 Sec. 30 Min or less
Transient hypotension,
renal failure
Vecuronium Widely 60 Sec.
30-40
Min.
Few, prolong paralysis
Pancuronium Widely 90 Sec. 90 Min Tachycardia
18
19. Depolarizing blocking agents
• A depolarizing neuromuscular blocking agent is a form of
neuromuscular blocker depolarizes the motor end plate.
• An example is Succinylcholine.
• Depolarizing blocking agents work by depolarizing the plasma
membrane of the muscle fiber, similar to acetylcholine.
• These agents are more resistant to degradation by acetylcholinesterase,
the enzyme responsible for degrading acetylcholine, and can thus more
persistently depolarize the muscle fibers. This differs from
acetylcholine, which is rapidly degraded and only transiently
depolarizes the muscle.
19
20. Drug bind with nicotinic receptor
↓
Opening of Na+ and Ca++
channels
↓
Excitation
↓
Depolarization
↓
Paralysis of muscles results in stop
the induction
⟹
⟹
Phase I
(depolarizing phase),
Phase II
(desensitizing phase)
Mechanism of action
20
22. • There are two phases to the depolarizing block.
• During Phase I (depolarizing phase), they cause muscular
fasciculation (muscle twitches) while they are depolarizing the
muscle fibers.
• Eventually, after sufficient depolarization has occurred, Phase
II (desensitizing phase) sets in and the muscle is no longer
responsive to acetylcholine released by the motor neurons, and
full neuromuscular block has been achieved.
22