The document discusses autoimmunity, which occurs when the immune system mistakenly attacks and damages normal body tissues. It begins by explaining how self-tolerance normally prevents this but can fail. Autoimmune diseases are then caused by a variety of mechanisms, including molecular mimicry between foreign and self-antigens. Both organ-specific diseases that target single organs, as well as systemic diseases with widespread effects, are described. Specific examples like Graves' disease, systemic lupus erythematosus, and rheumatoid arthritis are outlined.
History
Introduction
Classification of grafts
The Immunology of Allogeneic Transplantation
Genetics of graft rejection
Types of rejection
Recognition of Alloantigens
Effector Mechanisms of Allograft Rejection
Prevention of graft rejection
Graft versus host reaction
History
Introduction
Classification of grafts
The Immunology of Allogeneic Transplantation
Genetics of graft rejection
Types of rejection
Recognition of Alloantigens
Effector Mechanisms of Allograft Rejection
Prevention of graft rejection
Graft versus host reaction
Autoimmunity is the system of immune responses of an organism against its own healthy cells and tissues. Any disease that results from such an aberrant immune response is termed an "autoimmune disease".
The complement system is a part of the immune system that helps or complements the ability of antibodies and phagocytic cells to clear pathogens from an organism. It is part of the innate immune system, which is not adaptable and does not change over the course of an individual's lifetime.
consists of three pathways: 1. alternative
2. classical
3. lectin pathway
Autoimmunity is the system of immune responses of an organism against its own healthy cells and tissues. Any disease that results from such an aberrant immune response is termed an "autoimmune disease".
The complement system is a part of the immune system that helps or complements the ability of antibodies and phagocytic cells to clear pathogens from an organism. It is part of the innate immune system, which is not adaptable and does not change over the course of an individual's lifetime.
consists of three pathways: 1. alternative
2. classical
3. lectin pathway
The organism possesses powerful mechanism to avoid immune auto aggression, The acquired ability of the immune system to avoid responsiveness to self antigens is defined as ‘ tolerance’ It is obtained by the cooperative efforts of central and peripheral mechanisms, which allow a rapid and efficient removal of pathogens ( Virus and Bacteria ) in the absence of self-recognition, It is a dysfunction of the immune system. The immune system protects you from disease and infection. Sometimes, though, the immune system can produce autoantibodies that attack healthy cells, tissues, and organs. This can lead to autoimmune disease.Autoimmune diseases can affect any part of the body
immunological tolerance can be divided into two parts. they are central tolerance and peripheral tolerance. this slide contains information on development of central tolerance which include both B cell and T cell central tolerance.
Autoimmunity and autoimmune diseases dr. ihsan alsaimarydr.Ihsan alsaimary
Dr. ihsan edan abdulkareem alsaimary
PROFESSOR IN MEDICAL MICROBIOLOGY AND MOLECULAR IMMUNOLOGY
ihsanalsaimary@gmail.com
mobile : 009647801410838
university of basrah - college of medicine - basrah -IRAQ
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
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Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
1. Santosh yadav
Santosh Yadav
M.Sc. Clinical Microbiology
Dept. of Microbiology
Institute of Medicine
Tribhuvan Univarsity Teaching Hospital, Nepal
AUTOIMMUNITY
3. Santosh
Introduction
Normally immune system doesnot react to self antigen due
to the protective mechanism of self tolerance.
However if there is a failure,then immune system reacts and
produces an inappropriate response to self antigens, and
this response is called autoimmunity.
Autoimmunity is the failure of an organism in
recognizing its own constituent parts as non self, which
allows an immune response against its own cells and
tissues.
Auto immune reactions can cause serious damage to
cells,organs,or tissues,which can be fatal at times.
The tissue or cellular damage could be caused by
autoantibody as well as T-cells.
4. Santosh
Autoimmunity results from a failure of the mechanisms of self-
tolerance in T or B cells, which may lead to an imbalance between
lymphocyte activation and control mechanisms.
Some of the general causes that are associated with autoimmune
reactions are the following:
l. Defects in deletion (negative selection) of T or B cells or receptor
editing in B cells during the maturation of these cells in the
generative lymphoid organs.
2. Defective numbers and functions of regulatory T lymphocytes
3. Defective apoptosis of mature self-reactive lymphocytes
4. Inadequate function of inhibitory receptors
5. Activation of APCs, which overcomes regulatory mechanisms and
results in excessive T cell activation.
5. Santosh
Mechanisms for Induction of Autoimmunity
Following possible mechanisms have been proposed to
explain the development of autoimmunity.
Release of sequestered antigen
Molecular mimicry
Inappropriare MHC-II expression
Polyclonal activation of B-cells
6. Santosh
Release of sequestered antigen
The induction of self-tolerance in T cells results from
exposure of immature thymocytes to selfantigens and
the subsequent clonal deletion of those that are self-
reactive.
Any tissue antigens that are sequestered from the
circulation, and are therefore not seen by the
developing T cells in the thymus,will not induce self-
tolerance.
Exposure of mature T cells to such normally
sequestered antigens at a later time might result in
their activation.
7. Santosh
E.g... Myelin basic protein (MBP) is an example of an
antigen normally sequestered from the immune
system, in this case by the blood-brain barrier.
sperm arise late in development and are sequestered
from the circulation. However, after a vasectomy, some
sperm antigens are released into the circulation and
can induce auto-antibody formation in some men.
Similarly, the release of lens protein after eye damage
or of heart-muscle antigens after myocardial infarction
has been shown to lead on occasion to the formation
of auto-antibodies.
8. Santosh
Molecular mimicry(cross reacting antigens)
A/C to this hypothesis, self antigens are mimicked by
some non self antigens especially those of the viral and
bacterial origin.
A number of viruses and bacteria have been shown to
posses antigenic determinant identical or similar to
normal host cell components.
Hence the autoantibodies formation induced by such
such molecules leads to autoimmunity.
E.g. Antibodies to streptococcal antigen cross react with
some heart muscle antigens and cause rheumatic fever.
Ag of Human brain & Ag of sheep brain, Streptococcal M
protein & Heart muscles, Nephritogenic strains of
Streptococci Ags & Renal glomeruli shares similar
epiotes.
9. Santosh
Inappropriate Expression of Class II MHC
Class II MHC molecules are normally expressed only on
antigen presenting cells.
The inappropriate expression of MHC-II on other cells
may serve to sensitize TH cells to peptides derived from
these cells, allowing activation of B cells or TC cells or
sensitization of TH1 cells against self-antigens.
E.g. The pancreatic beta cells of individuals with insulin-
dependent diabetes mellitus (IDDM) express high levels
of both class I and class II MHC molecules, whereas
healthy beta cells express lower levels of class I and do
not express class II at all.
Thyroid acinar cells from those with Graves’ disease
have been shown to express class II MHC molecules on
their membrane.s
10. Santosh
Polyclonal activation of B-cells
A number of viruses and bacteria can induce nonspecific
polyclonal B-cell activation.
Gram-negative bacteria, cytomegalovirus, and Epstein-
Barr virus (EBV) are all known to be such polyclonal
activators, inducing the proliferation of numerous clones
of B cells that express IgM in the absence of TH cells.
If B cells reactive to self-antigens are activated by this
mechanism, auto-antibodies can appear.
For instance,during infectious mononucleosis, which is
caused by EBV,a variety of auto-antibodies are produced,
including autoantibodies reactive to T and B cells,
rheumatoid factors, and antinuclear antibodies.
12. Santosh
Autoimmune disesase
Any disease that results from such an
aberrant immune response is termed an
autoimmune disease.
Seen in 5-7% of population.
They are broadly divisible into two groups
1.Organ specific disease , and
2.Generalized systemic disease
Organs and tissues commonly affected by autoimmune disorders include:
Blood vessels
Connective tissues
Endocrine glands such as the thyroid or pancreas
Joints
Muscles
Red blood cells
Skin
14. Santosh
1. Organ-Specific Autoimmune Diseases
In an organ-specific autoimmune disease, the immune
response is directed to a target antigen unique to a
single organ or gland, so that the manifestations are
largely limited to that organ.
The cells of the target organs may be damaged directly
by humoral or cell-mediated effector mechanisms.
Alternatively, the antibodies may overstimulate or block
the normal function of the target organ.
Some autoimmune diseases are mediated by direct
cellular damage.
Some autoimmune diseases are mediated by
15. Santosh
AUTOIMMUNE ANEMIAS
Autoimmune anemias include
pernicious anemia,
autoimmune hemolytic anemia,and
drug-induced hemolytic anemia.
Pernicious anemia is caused by auto-antibodies to
intrinsic factor, a membrane-bound intestinal protein on
gastric parietal cells.
This factor is required for vit. B12 uptake and normal
hematopoesis.
Deficincy of b12 leads to macrocytic anaemia.
16. Santosh
An individual with autoimmune hemolytic anemia
makes auto-antibody to RBC antigens, triggering
complementmediated lysis or antibody-mediated
opsonization and phagocytosis of the red blood cells.
In drug-induced hemolytic anaemia, certain drugs
such as penicillin or the anti-hypertensive agent
methyldopa interact with red blood cells, the cells
become antigenic.
Antibodies to to these RBC-drugs complex causes
hemolysis.
17. Santosh
GRAVES’ DISEASE
The production of thyroid hormones is carefully
regulated by thyroid-stimulating hormone (TSH), which
is produced by the pituitary gland.
Binding of TSH to a receptor on thyroid cells activates
adenylate cyclase and stimulates the synthesis of two
thyroid hormones, thyroxine and triiodothyronine.
A patient with Graves’ disease produces auto-
antibodies that bind the receptor for TSH and mimic
the normal action of TSH, activating adenylate cyclase
and resulting in production of the thyroid
hormones.Unlike TSH, however, the autoantibodies
are not regulated, and consequently they overstimulate
the thyroid.
For this reason these auto-antibodies are called long-
19. Santosh
2.Systemic Autoimmune Diseases
In systemic autoimmune diseases, the response is
directed toward a broad range of target antigens and
involves a number of organs and tissues.
These diseases reflect a general defect in immune
regulation that results in hyperactive T cells and B cells.
Tissue damage is widespread, both from cell-mediated
immune responses and from direct cellular damage
caused by auto-antibodies or by accumulation of
immune complexes.
These disease aremore common in female than males.
20. Santosh
Systemic Lupus Erythematosus -
Attacks Many Tissues
One of the best examples of a systemic autoimmune
disease is systemic lupus erythematosus (SLE), which
typically appears in women between 20 and 40 years of
age
The ratio of female to male patients is 10:1.
Affected individuals may produce autoantibodies to a vast
array of tissue antigens, such as DNA, histones, RBCs,
platelets, leukocytes, and clotting factors
Interaction of these auto-antibodies with their specific
antigens produces various symptoms.
Auto-antibody specific for RBCs and platelets, for example,
can lead to complement-mediated lysis, resulting in
hemolytic anemia and thrombocytopenia, respectively.
When immune complexes of auto-antibodies with various
nuclear antigens are deposited along the walls of small
blood vessels, a type III hypersensitive reaction develops.
21. Santosh
The complexes activate the complement system and
generate membrane-attack complexes and complement
split products that damage the wall of the blood vessel,
resulting in vasculitis and glomerulonephritis.
These occlusions can lead to widespread tissue
damage.
Laboratory diagnosis of SLE focuses on the
characteristic antinuclear antibodies, which are directed
against doublestranded or single-stranded DNA,
nucleoprotein, histones, and nucleolar RNA.
24. Santosh
Rheumatoid Arthritis
Attacks Joints
Rheumatoid arthritis is a common autoimmune disorder, most
often affecting women from 40 to 60 years old.
The major symptom is chronic inflammation of the joints, although
the hematologic, cardiovascular, and respiratory systems are also
frequently affected.
Many individuals with rheumatoid arthritis produce a group of
auto-antibodies called rheumatoid factors that are reactive with
determinants in the Fc region of IgG.
The classic rheumatoid factor is an IgM antibody with that
reactivity.
Such auto-antibodies bind to normal circulating IgG, forming IgM-
IgG complexes that are deposited in the joints.
These immune complexes can activate the complement cascade,
26. Santosh
Trearment of autoimmune disease
Ideally, treatment for autoimmune diseases should be
aimed at reducing only the autoimmune response while
leaving the rest of the immune system intact.
To date, this ideal has not been reached.
Using immunosuppressive drugs:-
corticosteroids,azathioprine and cyclophosphamide,etc
have been used to suppress the proliferation of
lymphocytes and immune response, they are not
preferred. They cause general reduction in immune
response and put in patient at greater risk. Newer
drugs- cyclosprin A and FK 506.
Thymectomy:- myasthenia gravis
Plasmapheresis:- SLE , graves disease, myasthenia