Concept of reversible injury
Concept of necrosis
Subcellular, cellular and gross features of necrosis
Morphological types of necrosis
Utility of tissue specific enzyme assay to detect necrosis
- Coagulative Necrosis / summarized
- Description of the GROSS appearance of Coagulative necrosis.
- Description of the MICROSCOPIC appearance of Coagulative necrosis.
Concept of reversible injury
Concept of necrosis
Subcellular, cellular and gross features of necrosis
Morphological types of necrosis
Utility of tissue specific enzyme assay to detect necrosis
- Coagulative Necrosis / summarized
- Description of the GROSS appearance of Coagulative necrosis.
- Description of the MICROSCOPIC appearance of Coagulative necrosis.
Morphology of cell injury and Intracellular accumulationspptxvaishaliwasnik
MORPHOLOGY OF REVERSIBLE CELL INJURY
Common examples of morphologic forms of reversible cell injury are as under:
Hydropic change
2. Hyaline change
3. Mucoid change
4. Fatty change (discussed under intracellular accumulations)
1. HYDROPIC CHANGE
Hydropic change means accumulation of water within the cytoplasm of the cell.
Other synonyms used are cloudy swelling (for gross appearance of the affected organ) and vacuolar degeneration (due to cytoplasmic vacuolation).
Hydropic swelling is an entirely reversible change upon removal of the injurious agent.
ETIOLOGY
This is the commonest and earliest form of cell
injury from almost all causes.
The common causes include acute and subacute cell injury from various etiologic agents such as bacterial toxins, chemicals, poisons, burns, high fever, intravenous administration of hypertonic glucose or saline etc.
PATHOGENESIS
Cloudy swelling results from impaired
regulation of sodium and potassium at the level of cell membrane.
This results in intracellular accumulation of sodium and escape of potassium.
This, in turn, is accompanied with rapid flow of water into the cell to maintain iso-osmotic
2. HYALINE CHANGE
The word ‘hyaline’ or ‘hyalin’ means glassy (hyalos = glass).
Hyalinisation is a common descriptive histologic term for glassy, homo geneous, eosinophilic appearance of proteinaceous material in haematoxylin and eosin-stained sections and does not refer to any specific substance.
Though fibrin and amyloid have hyaline appearance, they have distinctive features and
staining reactions and can be distinguished from non-specific hyaline material.
Hyaline change is seen in heterogeneous pathologic conditions and may be intracellular or extracellular.
INTRACELLULAR HYALINE
Intracellular hyaline is mainly seen in epithelial cells.
1. Hyaline droplets in the proximal tubular epithelial cells due to excessive reabsorption of plasma proteins in proteinuria.
2. Hyaline degeneration of rectus abdominalis muscle called Zenker’s degeneration, occurring in typhoid fever. The muscle loses its fi brillar staining and becomes glassy and hyaline.
3. Mallory’s hyaline represents aggregates of intermediate filaments in the hepatocytes in alcoholic liver cell injury.
4. Nuclear or cytoplasmic hyaline inclusions seen in some viral infections.
5. Russell’s bodies representing excessive immuno glo bulins in the rough endoplasmic reticulum of the plasma cell
EXTRACELLULAR HYALINE
Extracellular hyaline commonly termed hyalinisation is seen in connective tissues.
1. Hyaline degeneration in leiomyomas of the uterus.
2. Hyalinised old scar of fi brocollagenous tissues.
3. Hyaline arteriolosclerosis in renal vessels in hyper tension and diabetes mellitus.
4. Hyalinised glomeruli in chronic glomerulonephritis.
5. Corpora amylacea seen as rounded masses of concentric hyaline laminae in the enlarged prostate in the elderly, in the brain and in the spinal cord in old age, and in old infarcts of the
lung.
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
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.
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
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.
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.
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
- 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
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
263778731218 Abortion Clinic /Pills In Harare ,sisternakatoto
263778731218 Abortion Clinic /Pills In Harare ,ABORTION WOMEN’S CLINIC +27730423979 IN women clinic we believe that every woman should be able to make choices in her pregnancy. Our job is to provide compassionate care, safety,affordable and confidential services. That’s why we have won the trust from all generations of women all over the world. we use non surgical method(Abortion pills) to terminate…Dr.LISA +27730423979women Clinic is committed to providing the highest quality of obstetrical and gynecological care to women of all ages. Our dedicated staff aim to treat each patient and her health concerns with compassion and respect.Our dedicated group ABORTION WOMEN’S CLINIC +27730423979 IN women clinic we believe that every woman should be able to make choices in her pregnancy. Our job is to provide compassionate care, safety,affordable and confidential services. That’s why we have won the trust from all generations of women all over the world. we use non surgical method(Abortion pills) to terminate…Dr.LISA +27730423979women Clinic is committed to providing the highest quality of obstetrical and gynecological care to women of all ages. Our dedicated staff aim to treat each patient and her health concerns with compassion and respect.Our dedicated group of receptionists, nurses, and physicians have worked together as a teamof receptionists, nurses, and physicians have worked together as a team wwww.lisywomensclinic.co.za/
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.
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
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
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
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
3. PATHOLOGY
• the science of the causes and effects of diseases, especially the branch of
medicine that deals with the laboratory examination of samples of body tissue for
diagnostic or forensic purposes.
Histopathology : the study of changes in tissues caused by disease.
4. Inflammation
• is the response of tissue to a noxious stimulus.
• The response can be localized or generalized, and the stimulus can be infectious or
non-infectious.
• Non-infectious can be exogenous / endogenous
• Exogenous causes originate outside the eye, e.g. penetrating trauma, alkali
chemical injury, or external allergens.
• Endogenous causes originate in the eye and body such as uveitis secondary to
leaked lens matter (phacoantigenic uveitis), spread from adjacent structures (the
sinuses in orbital cellulitis), and haematogenous spread.
• Can be acute and chronic
6. Cell mediators
ACUTE
• Polymorphonuclear leukocytes (PMNs), including neutrophils, eosinophils, and
basophils
• Neutrophils(acute inflammatory cells) Multisegmented nucleus and
intracytoplasmic granules
• Eosinophils- Bilobed nuclei and prominent intracytoplasmic eosinophilic granules
• Mast cells are the tissue- bound equivalent of the blood-borne basophils.
7. Cont
CHRONIC
• Monocytes that migrate from the intravascular space into tissue are classified as
histiocytes or macrophages. Epitheloids (epithelial like histiocytes). Epithelioid
histiocytes may form a ball-like aggregate known as a granuloma.
• Multinucleated giant cell (merged epitheloid/monocytes) eg Langhan’s giant cell,
Foreign body giant cell,Touton giant cell
• Lymphocytes
• Plasma cells
• Eosinophils
17. Acute Inflammation
Five cardinal signs :
1. Rubor (Redness) - increased blood flow
2. Calor (Heat) - increased blood flow
3. Tumour (Mass) - oedema caused by leakage of fluid andcells
4. Dolor (pain)
5. Loss of function
• The triple response - refers to the behaviour of blood vessels in damaged tissue
18. Acute
• Neutrophils are the main infl ammatory cells in the acute phase of infl ammation.
They are thought to follow a chemotactic stimulus released by vascular
endothelial cells, leukocytes, mediators of complement, or even bacteria
themselves at the site of injury
• There are many chemical mediators involved in acute infl ammation. In addition to
this, those present in plasma are interrelated cascade systems, including the
clotting cascade, fibrinolysis, complement, and bradykinin systems.
• The outcome of acute inflammation is dependent on many factors, for example in
infectious cases the organism, host response, and extent of necrosis.
• Acute inflammation may resolve, repair with scarring, or progress to chronic
inflammation.
19. CHRONIC
May start as chronic or result from acute inflammation
Proliferative inflammation characterized by acellular infiltrate of lymphocytes and
plasma cells (sometimes polymorphonuclear neutrophils (PMNs) or eosinophils)
Granulomatous and non-granulomatous.
20. Granulomatous
• Granulomatous -The characteristic cell type in granulomatous inflammation is the
epithelioid or giant cell. Classic examples include tuberculosis and sarcoid
• Three patterns
• Diffuse type: sympathetic uveitis, juvenile xanthogranuloma,Vogt–Koyanagi–Harada
syndrome, toxoplasmosis. Epithelioid cells are distributed randomly against a
background of lymphocytes and plasma cells.
• Discrete type: sarcoidosis, tuberculoid leprosy, military tuberculosis. Nodules or
tubercles form due to accumulation of epithelioid or giant cells surrounded by a narrow
rim of lymphocytes and plasma cells.
• Zonal type: caseous necrosis of tuberculosis, chalazion, ruptured dermoid cyst, reaction
to suture material, rheumatoid scleritis, toxocara. A central area of necrosis surrounded
by a palisade of epithelioid cells. In addition, PMNs, Langhan’s giant cells, and
macrophages are in turn surrounded by lymphocytes and plasma cells
21. Non-granulomatous
• Cell types may includeT and B lymphocytes, plasmacytoid cells (a variation of the
plasma cell), and plasma cells with a Russell body. A Russell body is an inclusion in
a plasma cell whose cytoplasm is fi lled and enlarged with eosinophilic structures.
The nucleus is eccentric or absent.These are seen in B cell lymphomas.
• Examples include the many forms of anterior and posterior uveitis, Behcet’s
disease, multiple sclerosis, retinal vasculitis, and endocrine exophthalmos
24. CELLULARANDTISSUE REACTIONS
• Hypertrophy: an increase in size of cells, fi bres, or tissues without an increase in
number (e.g. RPE hypertrophy).
• Atrophy: a decrease in size of cells, fi bres, or tissues.
• Hyperplasia: an increase in the number of individual cells in a tissue; their size may
or may not increase. Growth will reach equilibrium and is not indefi nite (e.g. RPE
hyperplasia secondary to trauma).
• Hypoplasia: arrested development of a tissue during embryonic life (e.g. aniridia)
25. CONT
• Aplasia: lack of development of a tissue in embryonic life (e.g. aplasia of the optic
nerve).
• Metaplasia: the transformation of one type of tissue into another type (e.g. in
anterior subcapsular cataract fibrous metaplasia of the lens epithelium).This can
arise due to chronic irritation and will usually involve columnar or cuboidal
epithelium changing to squamous epithelium.
Dysplasia: abnormal growth of tissue with increased mitoses and reduced diff
erentiation (e.g. retinal dysplasia). Dysplastic tissue is not invasive and will not pass
through the basement membrane
26. Ageing, degeneration, and dystrophy
The term degeneration refers to a wide variety of tissue changes that may occur over
time. It occurs in tissue that has reached its full growth and can come in many
forms.
Not usually associated with a proliferation of cells; rather,there is often an
accumulation of acellular material or a loss of tissue mass. Extracellular deposits
may result from cellular overproduction of normal material or metabolically
abnormal material.These processes may occur in response to an injury or an
inflammatory process.
27. TYPES OF DEGENERATION
• Hyaline e.gWalls of arteriolosclerotic small vessels of the eye in ageing,benign hypertension,
and diabetes
• Amyloid e.g solitary nodule in eyelid, orbit, conjunctiva—in the cornea it can be seen in lattice
dystrophy and gelatinous drop-like dystrophy
• Hydropic e.g Infection, intoxication, anaemia, or circulatory disturbance
• Cloudy swelling e.g Mild infection, intoxication, anaemia, or circulatory disturbance
• Calcification Band keratopathy involves calcification of Bowman’s layer and the superficial
stromaThis also occurs in hyperparathyroidism, hypervitaminosis D,and sarcoidosis.
Cataracta ossea is calcification in the fibrous and degenerative cortex of the lens Bruch’s
membrane can be calcified in Paget’s disease In phthisis bulbi, ossification of the metaplastic
fibrous tissue derives from proliferation of the RPE in a hypotonic eye.Woven and lamellar
bone is located on the inner surface of Bruch’s membrane Ossification can extend into the
vitreous and choroid
28. cont
• Elastotic e.g Skin in ageing individuals, pterygia and pseudoxanthoma elasticum in
which ruptures in Bruch’s membrane expose the choroid (angioid streaks)
• Fatty change - Arcus senilis of the cornea—fatty infiltration of the
peripheralcorneal stroma Xanthelasma—lipid within clumps of macrophages in
the dermis of the eyelid seen in ageing and hypercholesterolaemia Deposition of
lipid and cholesterol in the intima of arteries, leading to atheroma, can lead to
thrombosis
• Glycogen infiltration e.g Diabetes mellitus-lacy vacuolation of iris pigment
epithelium Long-standing neural retinal detachment due to lack of nutrition and in
proliferating RPE cells
29. DYSTROPHY
• Dystrophy is a primary, inherited disorder that can occur at any age. Dystrophies
may involve a single matrix component.
• Usually bilateral, symmetric, inherited conditions that appear to have little or no
relationship to environmental or systemic factors. Eg corneal dystrophies
30. AGEING
Ageing involves:
• a decline in tissue cellularity
• a reduction in blood fl ow due to vascular disease
• atrophy of tissue
• tissue replacement with an acellular collagenous matrix.
31. NEOPLASIA
• Increase in the number of cells in a tissue; growth exceeds and is uncoordinated
with that of the normal tissues.This results in a neoplasm, which persists in an
excessive manner after cessation of the stimuli that evoked the change.
• stereotypic, monotonous new growth of a specific tissue phenotype.
• Neoplasia is caused by an upregulation of proliferation(excessive or inappropriate
oncogene action) or a failure of mechanisms that lead to cell death (tumour
suppressor genes).
• A neoplasm may be benign or malignant.
• General histologic signs of malignancy include nuclear hyperchromasia and
pleomorphism, necrosis, hemorrhage, and mitotic activity.
35. WOUND HEALING
The purpose of wound healing is to restore the anatomical and functional integrity
of an organ or tissue as quickly and perfectly as possible.
• The acute inflammatory phase may last from minutes to hours. Blood clots quickly
in adjacent vessels in response to tissue activators. Neutrophils and fluid enter the
extravascular space. Macrophages remove debris from the damaged tissues, new
vessels form, and fibroblasts begin to produce collagen
• Regeneration, the replacement of lost cells, occurs only in tissues composed of
cells capable of undergoing mitosis throughout life (eg, epithelial cells, fibroblasts)
Repair is the process of restructuring of tissues that leads to a fibrous scar.
• In the final phase, contraction causes the reparative tissues to shrink so that the
scar is smaller than the surrounding uninjured tissues.
36. CORNEA
Abrasion - Regenerates at the limbus and spreads rapidly across cornea
• Cell migration – parabasilar epithelial cells begin to migrate across the denuded area
until they touch other migrating cells; then contact inhibition stops further migration
[1hr]
• Proliferation - surrounding basal cells undergo mitosis to supply additional cells to cover
the defect
• Differentiation – restoration of the full thickness of epithelium (5–7 layers) and re-
formation of the anchoring fibrils [5 weeks]
If a thin layer of anterior corneal stroma is lost with the abrasion, epithelium
will fill the shallow crater, forming a facet
• Bowman’s layer-Does not regenerate
• Descemet’s membrane- Does not regenerate. Is elastic and can recoil at the edge of
a deficit
37. Corneal healing in a full thickness laceration
• Immediate phase: Retraction of Descemet’s membrane and stromal collagen,
anterior and posterior wound gaping of the wound, fibrin plug formation from
aqueous fibrinogen, and stromal oedema.
• Leukocytic phase: (30 min)polymorphonuclear leukocytes/ neutrophils from the
conjunctival vessels,tears and from the aqueous invade the wound. Limbal
wounds have an invasion of mononuclear cells from limbal vessels.These can
transform to fibroblasts after 12–24 hours.
• Epithelial phase: at 1 hour full thickness ingrowth is inhibited by healthy
endothelium.
• Fibroblastic phase: central corneal wound fibrocytes[fibroblast-like cells] are
derived from keratocytes.They produce collagen and mucopolysaccharides to
form an avascular matrix
• Endothelial phase: at 24 hours endothelial sliding allows for coverage of the
posterior wound.
38. Clear corneal wound. 1, Tears carry neutrophils with lysozymes to the wound within an hour. 2, Immediately after
closure of the incision, the wound edge shows early disintegration and edema.The glycosaminoglycans at the edge
are degraded.The nearby fibrocytes are activated. 3, At 1 week, migrating epithelial and endothelial cells partially
seal the wound; fibrocytes begin to migrate and supply collagen. the surrounding lamellae.The number of
fibrocytes decreases.
39. 4, Fibrocyte activity and collagen and matrix deposition continue.The endothelium, sealing the inner
wound, lays down new Descemetmembrane. 5, Epithelial regeneration is complete. Fibrocytes fill the
wound with type I collagen and repair slows. 6, The final wound contracts.The collagen fibers are not
parallel with the surrounding lamellae.The number of fibrocytes decreases.
41. Sclera
• Differs from the cornea in that its collagen fibers are randomly distributed rather
than laid down in orderly lamellae, and dermatan sulfate is its glycosaminoglycan
• Relatively avascular and hypocellular
• Scars from episcleral and uveal fibroblasts
• When stimulated by wounding, the episclera migrates into the scleral wound,
supplying vessels, fibroblasts, and activated macrophages.The final wound
contracts, creating a puckered appearance.
• Dense adhesion between the uvea and the sclera if adjacent uvea involved
• Tensile strength of wounds is less than that of the native, undisturbed tissue thus
in certain clinical situations, modifying the healing process through the use of
topical chemotherapy, such as 5-fluorouracil or mitomycin C, or via collagen cross-
linking, may be desirable
42. Uvea
• Fibrinolysins in the aqueous inhibit fibrin clot formation, hence the patency of iris
defects If the edges of a wound appose, reactive proliferation of the iris pigment
epithelium can occur
• Though richly endowed with blood vessels and fibroblasts, the iris stroma does not
produce granulation tissue to close a defect
• Migration is usually limited to the subjacent surface of the lens capsule, where
subsequent adhesion of epithelial cells occurs (posterior synechia)
• Stroma and melanocytes of the ciliary body and choroid do not regenerate after
injury.Granulation followed by scar tissue forms from fibroblasts
43. Lens
• Epithelium responds to trauma by fibrous metaplasia
• Small tears in the anterior lens capsule are sealed by nearby lenticular epithelial
cells.
• In circumstances that make the lenticular epithelium anoxic or hypoxic, such as
posterior synechiae or markedly elevated intraocular pressure (IOP), a metaplastic
response may occur, producing fibrous plaques intermixed with basement
membrane
44. RETINA
• Retina is made of terminally differentiated cells that typically do not regenerate
when injured.
• Glial cells replace damaged nerve cells,which are derived from perivascular
astrocytes and Muller cells
• RPE can become metaplastic and proliferate and form fibrous tissue, for example
preretinal membranes
• Surgical techniques to close openings in the neurosensory retina are successful
when the retina and retinal pigment epithelium (RPE) are intentionally injured (eg,
as a result of cryotherapy, photocoagulation) forming an adhesive, atrophic scar
45. Vitreous
• Vitreous has few cells and no blood vessels
• The collagen fibrils of the vitreous can provide a scaffold for glial and fibrovascular
tissue from the retina and uveal tract to grow and extend into the vitreous to
proliferate as membranes.These membranes usually have a contractile
component, which can lead to retinal traction
46. Conjunctiva
• Can form granulation tissue
• Epithelium heals by sliding and proliferation similar to skin or cornea
47. SKIN
Epidermal
• (i) Cell migration, (ii) proliferation, (iii)diff erentiation
Dermal
• Invasion of fibrin clot by buds of endothelial cells from intact vessels
• Form blood vessels within 1 week
• Macrophages and fibroblasts invade wound
• Macrophages clear clots and fi broblasts produce collagen and
glycosaminoglycans. Myofibroblasts allow wound contraction by around 1 week
48. OPTIC NERVE
• Axonal loss and demyelination with reactive proliferation of glial cells and
connective tissue cells
49. Orbit and LacrimalTissues
The eyelid and orbit are compartmentalized by intertwining fascial membranes that
enclose muscular, tendinous, fatty, lacrimal, and ocular tissues; these tissues can
become distorted by scarring. Exuberant contraction distorts the muscle action,
producing dysfunctional scars.The striated muscles of the orbicularis oculi and
extraocular muscles are made of terminally differentiated cells that do not
regenerate, but the viable cells may hypertrophy.
50. Histologic Sequelae of OcularTrauma
The anterior chamber angle structures, especially the trabecular beams, are
vulnerable to distortion of the anterior globe.
• Traumatic recession of the anterior chamber angle - tear in the ciliary body between
the longitudinal and circular muscles with posterior displacement of the iris root
• Cyclodialysis - results from disinsertion of the longitudinal muscle of the ciliary
body from the scleral spur. Leads to hypotony
• Iridodialysis- tear in the iris at the thinnest portion of the diaphragm, the iris root,
where it inserts into the supportive tissue of the ciliary body
• Vossius ring- appears when iris pigment epithelial cells are compressed against the
anterior surface of the lens, depositing a ring of melanin pigment concentric with
the pupil.
• Cataract -The epithelium of the lens may be stimulated by trauma to form an
anterior fibrous plaque just inside the capsule.
51.
52.
53.
54. Suprachoroidal hemorrhage. A, This eye developed an expulsive hemorrhage after
a corneal perforation. B, The intraocular suprachoroidal hemorrhage is dome shaped
(arrowheads),
delineated anteriorly by the insertion of the choroid at the scleral spur (arrow).
55. Iridodialysis. A, Clinical photograph of an eye showing iridodialysis, a disinsertion of
the iris root from the ciliary body. B, Gross photograph showing a posterior view of
iridodialysis (arrows).
56. Retinal dialysis.This photomicrograph illustrates the separation of the retina from
its normal attachment to the posterior edge of the nonpigmented epithelium of the pars plana
(arrowhead) at the ora serrata (asterisk). The vitreous base is still attached to the ora serrata
(arrows).
57. Cont
• Lens Displacement - lens zonular fibers are points of relative weakness; if they
rupture, lens displacement occurs, either partial (subluxation) or complete
(luxation)
• Vitreous prolapse - Focal areas of zonular rupture may allow formed vitreous to
enter the anterior chamber.
• Commotio retinae (Berlin edema) - complicates blunt trauma to the eye.Traumatic
retinopathy secondary to direct or indirect trauma to the globe. Retinopathy may
be present at areas of scleral impact (coup) and or distant sites (contrecoup)
including the macula.
• Retinal dialysis - Deformation of the eye can result in a circumferential retinal tear
at the point of attachment of the ora serrata or immediately posterior to the point
of attachment of the vitreous base
58. Anterior proliferative vitreoretinopathy (PVR). A, Traction of the vitreous base on
the peripheral retina (arrow) and ciliary body epithelium (asterisks). B, Incorporation of
peripheral retinal (arrow) and ciliary body tissue (arrowheads) into the vitreous base.
59. C, A condensed vitreous base (asterisk), adherent retina (arrow),
and RPE hyperplasia (arrowhead).
60. Cont
• Fibrocellular proliferation - Penetrating injury, may lead to
vitreous/subretinal/choroidal hemorrhage; tractional retinal detachment;
proliferative vitreoretinopathy (PVR), including anterior PVR ,hypotony; and
phthisis bulbi (discussed later)
• Sequelae of intraocular hemorrhage include hemosiderosis bulbi, cholesterolosis,
and hemoglobin spherulosis.
• Rupture of Bruch membrane or a choroidal rupture - Choroidal neovascularization,
granulation tissue proliferation, and scar formation.
A subset of direct choroidal ruptures, those usually occurring after a projectile
injury, may result in focal posttraumatic choroidal granulomatous inflammation.
This inflammation may be related to foreign material introduced into the choroid.
61. Focal posttraumatic choroidal granulomatous inflammation. A, An enucleated eye in which a projectile
caused a perforating limbal injury that extends to the posterior choroid.
B, Photomicrograph shows chronic inflammation with multinucleated giant cells (arrowheads)
in the choroid, focal RPE hyperplasia (arrow), and attenuation of photoreceptor outer segments
(asterisks).
62. Cont
• Chorioretinitis sclopetaria - Chorioretinal rupture and necrosis
• Phthisis bulbi - Atrophy, shrinkage, and disorganization of the eye and intraocular
contents.
• Atrophia bulbi without shrinkage - size and shape of the eye are maintained despite the
atrophy of intraocular tissues
• Atrophia bulbi with shrinkage - eye becomes soft because of ciliary body dysfunction and
the progressive diminution of IOP
• Phthisis bulbi - In this end stage, the size of the globe shrinks from a normal average
diameter of 23–25 mm to an average diameter of 16–19 mm. Most of the ocular
contents become disorganized. In areas of preserved uvea, the RPE proliferates, and
drusen may develop. In addition, extensive dystrophic calcification of Bowman layer,
lens, retina, and drusen usually occurs. Osseous metaplasia of the RPE with bone
formation may be a prominent feature. Finally, the sclera becomes markedly thickened,
particularly posteriorly.
63. A, Gross photograph showing a globe with irregular contour, cataractous
lens with calcification (asterisk), cyclitic membrane with adherent retina (arrowheads),
and bone formation (between green arrows). B, Photomicrograph demonstrating the histopathologic
correlation with the gross photograph shown in part A. In addition, organized ciliochoroidal
effusions are apparent histologically (yellow arrows)
64. SPECIMEN HANDLING
COMMUNICATION to pathologist
• before, during, and after surgical procedures
• relevant and reasonably detailed clinical history when submitting the specimen to
the laboratory
• Pathology request
• Previous tissue biopsy
• Need for normal tissue
• Biopsy technique
65. FIXATIVES
• 10% neutral- buffered formalin
• Formalin is a 40% solution of formaldehyde that stabilizes proteins, lipids, and
carbohydrates and prevents enzymatic destruction of the tissue (autolysis)
• glutaraldehyde for electron microscopy
• Ethyl alcohol for cytologic preparations
• Michel medium for immunofluorescence studies.
66. Cont
Because most of the functional tissue of the eye is located within 2–3 mm of the
surface, it is not necessary or desirable to open the eye.Opening an eye before
fixation may damage or distort sites of pathology, making histologic interpretation
difficult or impossible. It is generally desirable to suspend an eye in formalin in a
volume of approximately 10:1 for at least 24–48 hours prior to processing to ensure
adequate fixation. However, different institutions may use different protocols, so
preoperative consultation is critical.
67.
68. Orientation
• Once the laterality of the eye is determined, accurate location of ocular lesions is
possible. Position of attachment of the inferior oblique
70. Macroscopic photograph. Note that the posterior ciliary artery and nerve appear as a subtle blue-gray
line as they pass through the sclera.This marks the horizontal meridian of the globe. Also note that
the rectus muscle insertions are not present.The rectus muscles are typically incised at their
scleral insertion during enucleation so that they may be attached to the orbital implant
71. Gross dissection
• Prior to gross dissection, eyes are transilluminated with bright light. Identify
intraocular lesions such as tumors, which block the transilluminated light and cast
a shadow
• Shadow can be outlined with a marking pencil on the sclera
• Outline can then be used to guide the gross dissection of the globe so that the
center of the section includes the maximum extent of the area of interest
• Objective is to open the globe in such a way as to display as much of the
pathologic change as possible on a single slide
• Pupil-optic nerve (PO) section ; pupil and optic nerve are present in the same
section
73. The opened eye shows the intraocular tumor that was demonstrated by
transillumination.
The paraffin- embedded eye shows the intraocular tumor
74. The hematoxylin- eosin (H&E)–
stained section shows that the maximum extent of the tumor demonstrated
by transillumination
is in the center of the section, which includes the pupil and optic nerve
75. Cont
• The meridian, or clock-hour, of the section is determined by the unique features of
the case, such as the presence of an intraocular tumor or a history of previous
surgery or trauma. In routine cases, eyes with no prior surgery or intraocular
neoplasm are typically opened in the horizontal meridian, which includes the
macula in the same section as the pupil and optic nerve
• Globes with a surgical or nonsurgical wound should be opened such that the
wound is perpendicular to, and included in the PO section.
• Globes with intraocular tumors are opened in a way (horizontal, vertical, or
oblique) that places the center of the tumor, as outlined by transillumination, in
the PO section
• The globe can also be opened coronally with separation of the anterior and
posterior segments, allowing a clinician’s view of posterior segment pathology
76. Gross dissection of a globe. A, The goal of sectioning is to obtain a pupil–optic
nerve (PO) section that contains the maximum area of interest. B, Two caps, or calottes, are
removed to obtain a PO section. C, The first cut is generally performed from posterior to
anterior. D, The second cut yields the PO section
77. Processing and staining
Tissue processing
• infiltration and embedding process replaces most of the water in the tissue with
paraffin
• organic solvents used in this process dissolve lipids and may dissolve some
synthetic materials
• Routine processing usually dissolves intraocular lenses made of polymethyl
methacrylate (PMMA), acrylic, or silicone
• Sutures made of silk, nylon, or other synthetic materials do not dissolve during
routine processing
78. Cont
• Embedding tissue in a paraffin block mechanically stabilizes the tissue, allowing
for cutting very thin sections through the tissue.
• Rapid processing - reserved for biopsy specimens that require urgent handling
• Because the quality of histologic preparation after rapid processing is usually
inferior to that of standard processing, it should not be requested routinely.
• Surgeons should communicate directly with their pathologists about the
availability and shortcomings of these techniques
79. Tissue Staining and Slide Preparation
Sections are usually cut at 4–6 μm
• Cut section is colorless except for areas of indigenous pigmentation, and various
tissue dyes—principally hematoxylin- eosin and periodic acid–Schiff (PAS)—are
used to color the tissue for identification
• A small amount of resin is placed over the stained section and covered with a thin
glass coverslip to protect and preserve it