A stem cell is a "blank" cell that can give rise to multiple tissue types such as a skin, muscle, or nerve cell.
Under certain physiologic or experimental conditions, they can be induced to become tissue- or organ-specific cells with special functions.
Imagine that you have been told you have an illness that cannot be cured or what if your body has been irreversibly paralysed. There is no hope. But there is a science that could change that. It’s Called Stem Cell Research and it’s an important step in the medical revolution. But it comes with controversies as it uses Human Embryos’ as Raw Material.
But something astounding happened in the year 2006 that removed the usage of surplus embryos from the equation altogether. It’s about a brand new technology that can turn back the clock on your body cells. This is cutting edge of science where new developments are happing all the time. The iPSCs could be the potential medicine of 21st century. So what are stem cells? Why do they Matter? What are iPSCs and how it changed the biological rules?
A stem cell is a "blank" cell that can give rise to multiple tissue types such as a skin, muscle, or nerve cell.
Under certain physiologic or experimental conditions, they can be induced to become tissue- or organ-specific cells with special functions.
Imagine that you have been told you have an illness that cannot be cured or what if your body has been irreversibly paralysed. There is no hope. But there is a science that could change that. It’s Called Stem Cell Research and it’s an important step in the medical revolution. But it comes with controversies as it uses Human Embryos’ as Raw Material.
But something astounding happened in the year 2006 that removed the usage of surplus embryos from the equation altogether. It’s about a brand new technology that can turn back the clock on your body cells. This is cutting edge of science where new developments are happing all the time. The iPSCs could be the potential medicine of 21st century. So what are stem cells? Why do they Matter? What are iPSCs and how it changed the biological rules?
iPSCs are pluripotent; unlike ESC, iPSCs are not derived from the embryo, but instead created from differentiated cells in the lab through a process – cellular reprogramming.
Stem cells
Undifferentiated cells capable of self-renew and to differentiate into different cell types or tissues during embryonic development and throughout adulthood.
Have possibility to become a specialised cell.
Have the ability to divide continuously and develop into various other kinds of cells.
Have immune potential and can help to treat a wide range of medical problems.
Discovery of stem cells lead to a whole new branch of medicine known as Regenerative medicine.
youtube link : https://www.youtube.com/watch?v=da69DB6dU58&lc=z13osnvyfnnryny2z22qh3y4rs2bd3h2d
Stem cells can be defined simply as cells which are not specialized in any specific tissue or organs.
In other words, stem cells have not differentiated into other cell types to form tissues and organs.
They are the base or foundational cells to develop into cells which specialized in certain functions.
Another distinguishing characteristics of stem cells is their ability to undergo division, giving rise to more stem cells.
The significance of stem cells in their application to the human body and human health boils down to the two important characteristics of differentiation and self-regeneration.
Imagine how powerful they can be if stems cells can be developed into heart cells, especially when someone’s heart is doomed to fail Or, for someone with damaged brain cells or nerve cells, wouldn’t it be extremely great news if stem cells can develop new brain cells or nerve cells for the person.
Indeed, the potential and possibilities of exploiting stem cells for medical science and health science are enormous.
Many untreatable diseases and ailments may in the near future become curable.
Stem cells are classified into various types based on their ability to undergo differentiation into different cell types.
In other words, their classification, and hence their name, is derived from their potential to develop into one, two or several other cell types.
In my presentation I’ll discuss the principals of formation the stem cell and its applications .
What are stem cells? This presentation provides an overview of multiple different stem cells including embryonic stem cells, mesenchymal stem cells, cancer stem cells, induced pluripotent stem cells, hematopoietic stem cells and neural stem cells.
PRODUCTION AND MAINTENANCE OF EMBRYONIC STEM CELLSANKUR SHARMA
Embryonic stem cells are pluripotent stem cells and have capacity to differentiate into all type of cells arising from 3 different germ layers i.e., ecto-, meso- and endoderm. In this presentation brief information is given about different methods for production of embryonic stem cells and their maintenance
iPSCs are pluripotent; unlike ESC, iPSCs are not derived from the embryo, but instead created from differentiated cells in the lab through a process – cellular reprogramming.
Stem cells
Undifferentiated cells capable of self-renew and to differentiate into different cell types or tissues during embryonic development and throughout adulthood.
Have possibility to become a specialised cell.
Have the ability to divide continuously and develop into various other kinds of cells.
Have immune potential and can help to treat a wide range of medical problems.
Discovery of stem cells lead to a whole new branch of medicine known as Regenerative medicine.
youtube link : https://www.youtube.com/watch?v=da69DB6dU58&lc=z13osnvyfnnryny2z22qh3y4rs2bd3h2d
Stem cells can be defined simply as cells which are not specialized in any specific tissue or organs.
In other words, stem cells have not differentiated into other cell types to form tissues and organs.
They are the base or foundational cells to develop into cells which specialized in certain functions.
Another distinguishing characteristics of stem cells is their ability to undergo division, giving rise to more stem cells.
The significance of stem cells in their application to the human body and human health boils down to the two important characteristics of differentiation and self-regeneration.
Imagine how powerful they can be if stems cells can be developed into heart cells, especially when someone’s heart is doomed to fail Or, for someone with damaged brain cells or nerve cells, wouldn’t it be extremely great news if stem cells can develop new brain cells or nerve cells for the person.
Indeed, the potential and possibilities of exploiting stem cells for medical science and health science are enormous.
Many untreatable diseases and ailments may in the near future become curable.
Stem cells are classified into various types based on their ability to undergo differentiation into different cell types.
In other words, their classification, and hence their name, is derived from their potential to develop into one, two or several other cell types.
In my presentation I’ll discuss the principals of formation the stem cell and its applications .
What are stem cells? This presentation provides an overview of multiple different stem cells including embryonic stem cells, mesenchymal stem cells, cancer stem cells, induced pluripotent stem cells, hematopoietic stem cells and neural stem cells.
PRODUCTION AND MAINTENANCE OF EMBRYONIC STEM CELLSANKUR SHARMA
Embryonic stem cells are pluripotent stem cells and have capacity to differentiate into all type of cells arising from 3 different germ layers i.e., ecto-, meso- and endoderm. In this presentation brief information is given about different methods for production of embryonic stem cells and their maintenance
A seminar I gave as a PhD student reviewing the role of stem cells in the development of various different kinds of cancers, as well as emerging treatment options.
Stem cell therapy is the use of stem cells to treat or prevent a disease or condition. Bone marrow transplant is the most widely used stem cell therapy, but some therapies derived from umbilical cord blood are also in use.
The complete, compiled presentation on stem cell research. The contents include background history along with the introduction, different stem cell types, cultivation process, stem cell cloning and potential uses, the negative aspects and ethical concerns regarding stem cell therapy. Different examples of the useful work in stem cell therapy field has also been mentioned.
Blood production agency. all types of blood cellls are produced in it. to understand it is the need of this era. it also will help in the physiology of blood making mechanism.
Stem cells are unspecialized cells that are thought to be able to reproduce themselves indefinitely and under the right conditions, to develop into a wide variety of mature cells with specialized functions.
"stem cells known to be a blank or undifferentiated cells act as revolutionized medicine by bringing a prolong life to millions of people for survival and also by creating a better hope to the research field"
The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
Title: Sense of Taste
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 structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
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.
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
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- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
2. Definition of Stem Cells
• A cell that has the ability to continuously divide and
differentiate (develop) into various other kind(s) of cells/tissues
• Biological cells found in all multicellular organisms.
• Blank or Unspecialized and Undifferentiated cells.
3. What can be done with Stem Cells?
• Have immune potential and can help to
treat a wide range of Medical problems.
• Discovery of stem cells lead to a whole new
branch of medicine known as …..
Regenerative medicine
4. Historical perspectives
• 1908: The term "stem cell" was coined by Alexander Maksimov
• 1963: McCulloch and Till illustrate the presence of self-renewing cells in mouse bone marrow.
• 1968: Bone marrow transplant between two siblings successfully treats SCID.
• 1978: Haematopoietic stem cells are discovered in human cord blood.
• 2000: Several reports of adult stem cell plasticity are published.
• 2007: The Nobel Prize was awarded jointly to Mario R. Capecchi, Sir Martin J. Evans and Oliver
Smithies "for their discoveries of principles for introducing specific gene modifications in
mice by the use of embryonic stem cells".
• 2008: Development of human cloned blastocysts following somatic cell nuclear transfer with adult
fibroblasts
• 2012: The Nobel Prize was awarded jointly to Sir John B. Gurdon and Shinya Yamanaka "for the
discovery that mature cells can be reprogrammed to become pluripotent"
7. Human embryonic stem cells
Cell colonies that
are not yet
differentiated
Nerve cell
8. Properties of Stem Cells
• Self.renewal.Can regenerate into
only the specific tissue from which
they are isolated (Proliferation
and renewal)
• Potency (ES cells) : Capacity to
differentiate into specialized cell
types of stem cells.
9. Properties of Stem Cells
• Totipotent – Can differentiate into embryonic and
extra embryonic cell types. Can construct a
complete viable organism.
Ex: Cell produced
by fusion of an egg and
sperm
• Pluripotent – Can differentiate into nearly all
cells, cells derived from any of the three germ
layers.
• Multipotent : Can differentiate into a number of
cells, but only those of a closely related family of
cells.
• Oligopotent : Can differentiate into only a few
cells, such as lymphoid or myeloid stem cells.
• Unipotent : Can produce only one cell type of their
own, property of self renewal.
13. Embryonic Stem Cells
• Derived from inner cell mass of a
blastocyst or earlier morula stage.
• Blastocyst is an early stage
embryo.
• 4 – 5 days old – 50 – 150 cells.
• „ES‟ cells – Pluripotent – gives rise
all three primary germ layers.
• Do not contribute to extra
embryonic membranes or the
placenta.
14. Adult Stem Cells
• It is undifferentiated cells found among
differentiated cells in a tissue or organ after birth.
• Do not disappear following birth.
• Remain, play a role in the recovery of damaged
tissue.
• Decreased reserve and loss of vitality as with age.
• Adult stem cells can also develop into other types
of cells and are mostly recovered by bone
marrow.
• The use of Adult stem cell in research is not
controversial as the use of „ES‟ cell, as it does not
require the destruction of an embryo.
15. Adult Stem cells
Normal differentiation
• Hematopoietic stem
cells – give rise to all
types of blood cells.
• Epithelial stem cells – in
GIT – Absorptive
cells, goblet
cells, entero endocrine
cells.
• Skin stem cells.
Adult Stem Cells Plasticity/
Trans Differentiation
• Ability to differentiate into multiple cell
types is called plasticity.
• Haemopoietic stem cells – differentiate
into Brain
cells, neuron, oligodendrocytes, skelet
al muscle cells, cardiac muscle
cells, liver cells etc.,
• Bone Marrow Stem cells – into
cardiac, skeletal or muscle cells.
• Brain stem cells – into Blood cells and
skeletal muscle cells.
16. PROS AND CONS OF EACH TYPE
EMBRYONIC
•
•
•
•
CELL LINES LAST LONG
MULTIPOTENT
EASY TO FIND
ETHICAL ISSUES - WHEN
DOES LIFE BEGIN?
ADULT
•
•
•
•
CELL LINES DO NOT LAST
NOT MULTIPOTENT
HARD TO LOCATE
NO ETHICAL ISSUES
17. Nuclear reprogramming
• Development naturally progresses from totipotent fertilized eggs to pluripotent
epiblast cells, to multipotent cells, and finally to terminally differentiated cells.
• According to Waddington's epigenetic landscape, this is analogous to a ball
moving down a slope.
• The reversal of the terminally differentiated cells to totipotent or pluripotent cells
(called nuclear reprogramming) can thus be seen as an uphill gradient that never
occurs in normal conditions.
18. Nuclear reprogramming
• However, nuclear reprogramming has been achieved using nuclear
transplantation, or nuclear transfer (NT), procedures (often called
"cloning"), where the nucleus of a differentiated cell is transferred into an
enucleated oocyte
20. Dolly
Sex
Born
Died
Female
5 July 1996 (Roslin Institute)
14 February 2003 (aged 6)
Nation
United Kingdom
Known for
First mammal to be cloned from an adult somatic cell
Offspring
6 lambs
Named after Dolly Patron
22. • Dolly the sheep, first mammal to
be cloned from an adult somatic
cell
• Even though Dolly was not the
first animal to be cloned, she
gained this attention in the
media because she was the first
to be cloned from an adult cell
27. Human cloning
• Human cloning is the creation of a genetically identical copy of
an existing or previously existing human.
• The term is generally used to refer to artificial human cloning;
human clones in the form of identical twins are commonplace,
with their cloning occurring during the natural process of
reproduction.
28. • Therapeutic cloning involves cloning adult cells for use in
medicine and is an active area of research.
• Reproductive cloning would involve making cloned humans. A
third type of cloning called replacement cloning is a theoretical
possibility, and would be a combination of therapeutic and
reproductive cloning.
• Replacement cloning would entail the replacement of an
extensively damaged, failed, or failing body through cloning
followed by whole or partial brain transplant
31. Induced Pluripotent Stem Cells
• Not adult stem cells.
• Reprogrammed cells (Ex. Epithelial cells) will have pluripotent capabilities.
• Using genetic reprogramming with protein transcription factors, pluripotent stem
cells equivalent to ES cells have been derived from human adult skin tissue.
• Little is known about factors that induce this reprogramming.
• Induction of pluripotent stem cells from mouse embryonic or adult fibroblasts by
introducing four factors, Oct3/4, Sox2, c-Myc, and Klf4, under ES cell culture
conditions.
32. Nobel prize in physiology or medicine 2012 for the discovery that
“mature cells can be reprogrammed to become pluripotent"
John B Gurdon
Shinya Yamanaka
38. Heart Disease
Adult bone marrow stem cells injected into the hearts are believed
to improve cardiac function in victims of heart failure or heart
attack
39. Leukemia and Cancer
• Studies show leukemia patients treated with stem cells
emerge free of disease.
• Injections of stem cells have also reduces pancreatic
cancers in some patients.
Proliferation of white cells
41. Parkinson's disease
Major motor features of disorder results from the loss of a
single cell population i.e., dopaminergic neurons with in
stratum nigra. This suggests that cell replacement should
be adequate to treat it.
42. Type I Diabetes
• Pancreatic cells do not produce insulin
• Embryonic Stems Cells might be trained to become pancreatic
islets cells needed to secrete insulin.
45. 7) Inherited Immune System Disorders
• Ataxia-Telangiectasia
• Kostmann Syndrome
• Leukocyte Adhesion Deficiency
• DiGeorge Syndrome
• Bare Lymphocyte Syndrome
• Omenn’s Syndrome
• Severe Combined Immunodeficiency
• SCID with Adenosine Deaminase Deficiency
• Absence of T & B Cells SCID
• Absence of T Cells, Normal B Cell SCID
• Common Variable Immunodeficiency
• Wiskott-Aldrich Syndrome
• X-Linked Lymphoproliferative Disorder
Other Inherited Disorders
• Lesch-Nyhan Syndrome
• Cartilage-Hair Hypoplasia
• Glanzmann Thrombasthenia
• Osteopetrosis
• Adrenoleukodystrophy
• Ceroid Lipofuscinosis
• Congenital Erythropoietic Porphyria
• Sandhoff Disease
9) Plasma Cell Disorders
• Multiple Myeloma
• Plasma Cell Leukemia
• Waldenstrom’s Macroglobulinemia
• Amyloidosis
Abnormalities
1) Inherited Platelet Abnormalities
Congenital Thrombocytopenia
2) Inherited Erythrocyte Abnormalities
• Beta Thalassemia Major
• Sickle Cell Disease
• Blackfan-Diamond Anemia
• Pure Red Cell Aplasia
Other Malignancies
• Ewing Sarcoma
• Neuroblastoma
• Renal Cell Carcinoma
• Retinoblastoma
• Brain tumor
• Ovarian Cancer
• Small Cell Lung Cancer
• Testicular Cancer
46. Strategies for transplantation of stem cells
1. Undifferentiated or partially differentiated stem cells may be
injected directly in the target organ or intravenously.(HSC)
2. Stem cells may be differentiated ex vivo prior to injection into
the target organ. (Beta cells, Cardiomyocyte)
3. Growth factors or other drugs may be injected to stimulate
endogenous stem cell populations(EPO, GM-CSF)
49. Bone marrow transplantation was the original term used to
describe the collection and transplantation of hematopoietic stem
cells, but with the demonstration that the peripheral blood and
umbilical cord blood are also useful sources of stem
cells, hematopoietic cell transplantation has become the
preferred generic term for this process.
50. Properties of Hematopoietic stem cells
• Dies
• Self renewal
• Potency
• Plasticity
-- Apoptosis
-- Stem cell
-- Differentiated blood cells(Differentiation)
-- Neurons/ Germ cells( Trans Differentiation)
51. The procedure is usually carried out for one of two purposes:
(1) to replace an abnormal but nonmalignant lymphohematopoietic system with one from a normal donor, or
(2) to treat malignancy by allowing the administration of higher
doses of myelo suppressive therapy than would otherwise be
possible
The time it takes for hematopoietic progenitors to become mature
cells is ~10–14 days in humans,
52. In humans, transplantation replaces recipient's entire lymphohematopoietic system, including
1. all red cells,
2. granulocytes,
3. B and T lymphocytes,
4. platelets,
5. Kupffer cells of the liver,
6. pulmonary alveolar macrophages,
7. osteoclasts,
8. Langerhans cells of the skin, and
9. brain microglial cells.
53. Pre transplant
• Whole Body Irradiation to remove endogenous immune system and tumor cells
• Injection of bone marrow from a well matched donor to re-establish immune
system
• Regulation of immune response to prevent graft versus host reaction.
• Autologous donation possible if one can purify and remove tumor cells, enriching
for stem cells..
• Allogeneic donors have advantage of graft versus tumor reaction to kill any
remaining tumor cells.
• Allogeneic donors have the disadvantage of graft versus host reaction if they are
not well matched.
55. Complications of Allogeneic Transplants
• Regimen related toxicity
• Infectious complications
• Engraftment failure (resistance)
• Graft-versus-host disease
• Transplant related mortality = 10 - 15%
56.
57. Bone Marrow / Ph Blood
• Found in spongy bone where blood cells form
• Bone marrow aspirated from the posterior and anterior iliac crests has
traditionally been the source of hematopoietic stem cells for transplantation.
Typically, anywhere from 1.5 to 5 x 108 nucleated marrow cells per kilogram
• Used to replace damaged or destroyed bone marrow with healthy bone
marrow stem cells.
• Hematopoietic stem cells circulate in the peripheral blood but in very low
concentrations.
• Following the administration of certain hematopoietic growth factors, (EPO,GCSF,GM-CSF) , the concentration of hematopoietic progenitor cells in blood
increases markedly.
58. Umbilical cord Blood Stem Cells
• Also Known as Wharton‟s Jelly
• Adult stem cells of infant origin
• Less invasive than bone marrow
• Greater compatibility
• Less expensive
• Obtained from cord immediately after birth.
• Rich source of haemopoietic stem cells
• These are referred to as neonatal stem cells, less mature than those found in adults
bone marrow..
Three important functions:
1. Plasticity: Potential to change into other cell types like nerve cells
2. Homing: To travel to the site of tissue damage
3. Engraftment: To unite with other tissues
59. Benefits of banking
• Cord blood stem cells are not just for the baby, but may also helps
the whole family
• Siblings have a 25% chance of being a suitable match.
• Stem cell transplants are twice as successful when the stem cells
come from a family member rather than from a non-relative. (63%
vs. 29%)
• Once in a life time opportunity to preserve a biological resource
that could be a lifesaver for the child/ other family members.
• A lifesaving alternative to bone marrow transplants.
• The lower probability of graft Vs. host disease (GVHD) and a
greater likelihood of finding an appropriate tissue type match.
60. Cord Blood Processing
1. HLA and Infectious Disease testing.
2. Removal of RBCs
3. Addition of Dimethyl sulphoxide and Dextran.
4. Enrichment and reduction of volume to 25ml.
5. Controlled rate freezing.
6. Cryogenic storage.(Liquid nitrogen at -1960 C)
61. Process of collection and storage
• Collection is same, in vaginal or in caesarean.
• Can be done before or imm., after the delivery of the placenta.
• Procedure is short (<10 mts)
• Sterilize the umbilical cord with iodine & alcohol swabs
• Sterile needle of the bag is inserted into the maternal side of the
cord & blood is allowed to flow by gravity into bag.
• Tubing emerging from the bag is striped, clamped and sealed/
knotted twice.
• The cord blood bag is packed between the two flaps of the gel
packs to maintain the temperature
62. BONE MARROW/PERIPHERAL BLOOD
Umbilical CORD BLOOD
Requires surgery under general anesthesia. It‟s a painful and
tedious process.
Obtained from the delivered placenta and umbilical
cord. It‟s a painless procedure
Requires a quart or more of bone marrow for transplant
A few ounces can be used for transplantation.
Large dose of stem cells. Rapid engraftment.
Smaller dose of stem cells. Slower engraftment.
After a formal search is begun, takes an average of 4 months to
transplant, even if a donor is available.
When a match is found, can take only few hours for
the confirmatory and special tests.
The fate of the recipient depends on the will of donor.
Stem cells once stored is available
Shelf life ranges from hours(bone marrow) to few
months(peripheral blood).
Long periods
Latent viral infection in the donor common (CMV>50% in U.S)
Rare (iCMV<1% in U.S.)
Severe graft Vs. host disease (GvHD) common.
Rare
Generally requires a perfect match between donor and recipient
for 6/6 HLA-A, -B and –DRBI antigens. Additional HLA factors
(HLA-C, -DQ and –DP) increasingly used to improve prognosis.
HLA mismatched cord blood transplants are
possible, making it easier to find a suitable match.
64. Tissue engineering
• Tissue engineering has broad goals including
1. Organ development
2. Elimination of waiting time for transplants
3. Creation of living tissue replacements
65. • In the past several decades, the limitations of non living mechanical solutions to
organ and tissue dysfunction are now recognized and include …
1. Dialysis,
2. Mechanical heart valves,
3. Metallic orthopedic implants,
4. Non re-absorbable hernia mesh.
• Current research is focused on
1. Resorbable synthetic polymers (polyglycolic acid, polyurethanes,
polyglycerol)
2. Naturally occurring polymers(collagen, fibrin)
3. Minerals ( calcium triphosphate)
66. • The principal mechanical supporting
structure of any engineered tissue is the
SCAFFOLD.
• The ideal scaffold materials for engineered
tissues are Resorbable materials that
break down over time. During resorption,
the engineered tissue is remodeled by
normal healing processes, leaving only
living cellular tissue with natural supporting
connective tissue.
• Engineered skin substitutes were the first
true clinical success of tissue engineering.
67.
68. Key Ethical Issues
• The blastocyst used in stem cell research is microscopically small and has no
nervous system. Does it count as a “person” who has a right to life?
• What do various religions say about when personhood begins? Does science
have a view on this?
• Humans Playing God ?
The time it takes for hematopoietic progenitors to become mature cells is ~10–14 days in humans, evident clinically by the interval between cytotoxic chemotherapy and blood count recovery in patients.