Retinoblastoma

• autosomal dominant 
• tumor suppresor gene
• gene carrier shows 10,000 fold increased risk (other gene needs to mutate?)
• bilateral
• risk for other malignancies (osteosarcoma)
• Knudson's 2 hit for retinoblastoma
• sporadic cases inherit both defective alleles

Familial Cancers of Uncertainty 

• colon, breast, ovary, and brain cancer
• early age of onset, tumors in 2 or more first degree relatives, metastisized or bilateral tumors
• Breast uncertainty is not BRCA1 or 2 

Acquired Preneoplastic Lesions

• increased likelihood, but most do not progress to cancer
• often arise in chronic tissue injury or inflamation (stimulation continues regenerative proliferation)
• removal or reversal may prevent cances
• Bronch squamous meta and displasia in smokers airways
• endometrial hyperplasia in women w/ unopposed estrogenic stimulation
• leukoplakia of oral cavity, uvula
• adenomas of colon (50% malignant)
• cervical dysplasia

Genetic Lesions in Cancer

• balanced translocations
• gene amplification
• He-2/Neu breast cancer (20% of cases)
• epigenic modifications: reverse changes in gene expression that occur w/o mutation such as hypermethylation

Balanced Translocations

• genetic lesions in cancer
• Burkitt lymphoma (8:14) MYC gene and Ig Heavy Chain
• folicular lymphoma: overexpression of BCL2 (anti-apoptopic) - also available in an immunostain
• CML Ph: chromosoma BCR-ABL fusion
• ewing sarcoma

He-2/Neu Breast cancer 

• 20% of breast cancer cases
• targed Ab therapy/heceptin
• all invasive breast cancers are analyzed for Her 2 amplification by immunohistochemisitry or FISH

P53 Tumor Suppressor 

• most common mutated gene in cancers ( >70%)
• detects stressed cells (DNA damage/anaxia) and sends to one of 3 pathways: temorary cycle arrest to repair, permanent cell cycle arrest or apoptosis (for cells w/ irreversible cell damage

PET positive

• cells that are glucose hungry cells
• might mean a tumor
• Warburg effect: cancer cells have high rate of glycolysis followed by lactic acid production

Genomic Instability

• HNPCC (lynch syndrome) - MSI
• sporadic MSI colon adenocarcinomas
• xeroderma pigmentosome (from sun damage)
• PCR or imunohistochemistry can be used to assess colon cancers for MSI
• prognastic  and therapeutic implications

Tumor Immunity

• cell mediated mechanisms can have anti-tumor action: NK cells and macrophages, monoclonal Ab-rituximab (CD20)
• immunosuppressed patients have inc risk for development of cancers
• tumors develop ways to avoid immune system: ant-negative clones, secretion of immunosuppressive mediators, etc

Paraneoplastic Syndromes

• symptom complexes that cannot be readily explained by local or distant spread of tumor or by elaboration of hormones not indogenous to tumor tissue origin
• polycytheria w/ RCCa is not a paraneoplastic syndr
• hypercalcemia from bone metastasis is not a paraneoplastic syndrome
• occurs in 10-15% of patients with cancer

Lab Diagnosis of Cancer

• evaluation is only as good as specimen submited
• specimen must be adequate, representative and properly preserved
• clinical and radio info are invaluable
• tissue spec.: cytology, biopsy or surgical resections, frozen section (routine histo and imunohisto for diagnosis and prognosis)
• Blood and/or body fluids: cytology, tumor markers, flow cytometry
• molc testing: MSI, translocations, FISH, Her-2, BRAF, ALK/EGFR/ROS-1, ocnotype breast or prostate

Serum tumor markers

• used for screening and/or monitoring response to therapy/recurance
• not used for diagnosis
• tend to lack sensitivity and specificity
• PSA-Prostate cancer
• AFP - hepatocellular carcinoma and germ line cells
• hCG - Germ Cell Tumors
• CA19-9 - Pancreatic and gastric carcinoma
• CA15-3 - Breast cancer
• Ca125 - Ovarian cancer

Therapeutic Decision Making

• oncotype - BRAF
• Her-2 - KRAS
• EGFR/ALK/ROS1
• all of these allow more targeted, personalized cancer treatment

Pathogen Stains

• Silver stains: fungi, some bacteria, pneumocystis
• Periodic Acid Schiff: Fungi and amebae
• Mucicarmine: Cryptococcus (indian ink??)
• Giemsa: some bacteria, leishmariae, malaria

Biofilms

• layer of extracellular polysac. secreted by bacteria: aids in adherence to tissues or devices and immune/drug evasion
• important in endocarditis, artificial joint infections and resp infections in Cystic Fibrosis

Bacterial Exotoxins

• enzymes: s. aureus exfoliative toxins separate keratinocytes from dermis
• alternating intracellular signaling and reg pathways (cholera results in disregulation of A/C)
• Superantigens: Staph Toxic Shock Syndrome (strep too)
• Neurotoxins: C botulinum and C tetani
• Enterotoxins

Infection in Immunocompromised Host

• patients w/ Ab deficiences: bacteria and some viruses
• T cell deficiency: intracellular organisms
• Complement Def: S. pneumo, HiB, and N meningitidis
• Neutrophil function: s aureus, some gram neg and some fungi

Supportive (Purulent) Inflammation

• response to acute tissue injury, composed predominantl of neutrophils
• Pus = neutrophils and liquified, necrotic tissue
• usually due to bacteria

Granulomatous Inflamation

• Inflammatory infiltrate composed predominantly of histiocytes (tissue macrophages)
• most commonly associated w/ mycobacterial and fungal infections; sometimes with parasites or viruses

Cytopathic/Cytoproliferative Reactions

• usually sparse inflammation
• cells develop inclusions, die, become architecturally abnormal and/or replicate
• usually done by viruses
• CMV/HPV inclusions
• generally detect/confirm viruses in tissue w/PCR, ISH and IHC

Tissue Necrosis

• organisms produces tissue death so rapidly that infammatory cells dont have time to accumulate
• may be caused by c perfringens, herpes (enceph), entamoeba histolytica (gay bowel)

Chronic Inflammation and Scarring

• exhibited by many infections: maye lead to complete healing or extensive scarring
• almost any inflammatory response, if secure enough and sufficient duration may result in chronic inflam and scarring

Xenobiotics

• exogenous chemicals in the environment
• absorbed by: inhalation, ingestion or skin contact

Reactive Oxygen Species

(ROS)

• can be produced by the detoxification and activation functions of the cytochrome p450 system
• sources are mitochondrial respiration and phagocytosis
• rate and removal = damage determination
• lipid peroxidation of membranes
• cross-linking and other changes in proteins
• DNA damage (ssDNA breaks) 

Phase I reactions

• hydrolysis, reduction, oxidation
• detoxification, elimination and protection
• turns a Xenobiotic into a primary metabolite

Phase II Reactions

• Glucuronidation, sulfation, methylation, and conjugation
• turns a primary metabolite into a secondary metabolite
• after secondary metabolite there is elimination in the urine, bile or feces

Lead (Pb) - Metal poisoning

• air, food, and pica (eating objects): paints, gasoline, mines, foundries, batteries, and spray paint
• flaking "old" paint - 15sq cm = 175ug of lead
• children: can cross BBB and lead to brain damage
• Absorption of lead in bones (competes w. Ca): 80-85% bones (20-30 yr half life), 5-10% stored in blood (diagnosit tests for this), and 5-10% in soft tissue
• neurologic tissue - most resistant
• high lvls of lead for prolonged periods of time can even affect the neruo tissue
• Central effects: children low IQ: sens, motor, intellectual and psychiological impairments
• peripheral effects: adults-neuropathies 
• kids can get a lead line at epiphysies 

Metals and other Occupational Exposure

• organic: solvents, plycyclic hydrocarbons
• organochlorines (DDT, PCBs, Dioxin)
• dust 

Tobacco

(environment factor)

• most common exogenous cause of human cancers (90% of lung cancers)
• most preventable cause of human death
• Carcinogens: tar, plolycyclic aromatic hydrocarbons, benzopyrene, nitrosamines
• carbon monoxide causes impaired oxygen transport
• Nicotine = tumor promotion??; addiction
• most common disease: epmphysema, chronic bronchitis, lung cancer
• many other organs effected (atherosclerosis)
• multiplicative effects with alcohol (esophageal cancer

Alcohol (environment agent)

• 5-10% of western adults chronic alcoholism (binge drinking counts)
• absorbed in stomach and small intestine (unaltered)
• most metabolized CYP450, alcohol dehydrogenase, and catalase
• alcohol oxidation = decrease in NAD+ (NAD req for FA oxidation, fat accumulation)
• acetaldehyde - toxic effects (esp in asians)
• CYP2E1 metabolism of EtOH - ROS
• liver main site of chronic injury 
• chronic effects: liver, GI, nerves, vitamins/nutrients, heart, and malignancies

Radiation

• non-ionizing (UV): moves atoms or causes vibrations but does not displace electrons
• Ionizing (Xrays, gama, alpha (2 prots and 2 neutrons) and beta particles): energy to remove tightly bound electrons
• 18% of radiation in US is from environment
• Curie - disintegrations per second
• Gray (Gy): energy absorbed by target tissue
• Sievert (Su): abs x biologic effectiveness
• biological effects: rate of delivery, field size, cell proliferation, hypoxia, vasc damage, and DNA damage
• indirect effect is free radical formation
• fibrosis and cancer late effects

Malnutrition

• healthy diet: sufficient energy, essential AA, and vitamins and minerals
• Primary Malnutrition: one or all missing
• Secondary (conditional) Malnutriton: intake is good, malabsorption, impaired utilization/storage, excess losses, or increased requirements 
• causes: poverty, ignorance, chronic alcohol, acute or chronic illness, drugs, therapy and malabsorption

Marasmus

• weight levels fall to 60% of normal for sex, height and age
• protein AND total calories are reduced
• loss of muscle mass (somatic): adaptive (provides body w/ AA as a source of energy where no intake)
• visceral protein compartment spared
• serum albumin is normal
• fat stores are depleted

Kwashiorkor

• protein deprivation is relatively greater than reduction in total calories
• loss of visceral protein
• liver is affected and albumin lvls decrease
• loss of weight (overall) is masked by edema
• multiple other lesions
• fatty liver, skin disease, hair changes, and immune defects
• two ends of a spectrum or primary malnutrition?

Vitamin A

• retinol, retinal, retinoic acid
• Liver, fish, eggs, milk and butter
• carrots, squash and spinach
• B-carotene -most important carotenoid
• fat soluble
• functions: normal vision in reduced light, specialized epithelial cells (mucous secreting), enhanced immunity to infections

Vitamin A Deficiency

• night blindnes (Vit A is part of rhodopsin)
• specialized epithelium: metaplasia and keratinization; eye, respiratory system
• immunity

Vitamin A Toxicity

• short or long term excess of Vit A produces effects
• Acute: headache, dizziness, vomiting, stupor and blurred vision
• Chronic: weight loss, anorexia, nausea, vomiting, bone and joint paint, retinoic acid stim osteoclast production and activity; fractures common
• synthetic retinoids (skin disease) are not associated with these complications

Diet Diseases

• hypertension and Na+
• dietary fiber and colon diverticulosis and cancer
• caloric restriction (fasting) and increased lifespan
• garlic and heart disease

Diet and Cancer

• exogenous carcinogens: aflatoxin and many others (saccharinyaspartate)
• endogenous carcinogen (syn of carcinogens from dietary compenents): nitrosamine/amides; gastric carcinoma (sodium nitrite-nitrite/preservatives), and nitrates from foods/metabolized
• High fat-low fiber: bacteria, bulk, carcinogens/promters; colon carcinoma
• Protective factos: vit C, E, beta-carontenes, selenium, and anti-oxidant (protective) properties

Hypertorphy

• increase in cell size
• large diameter of the cells, especially in heart muscle cells from hypertension (work induced hypertrophy)
• heart it selve eventually enlarges and causes degenerative changes to hypertrophic myocyes (fragmentation and loss of myofibril contractile elements)
• it is an adaptive mechanism for cells that cant divide easily
• not always pathological:  uterus undergoes hypertrophy and hyperplasia, muscle from excercise undergoes hypertrophy

Hyperplasia

Pathological Hyperplasia

• seen in response toe excessive hormonal, growth factors, or other stimulation
• endometrial hyperplasia due to estrogen/progesterone imbalance (cause abnormal menstration)
• ganulation tissue for wound repair due to factors elaborated by WBC and connective tissue
• benign hyperplastic polyps of the colon

Atrophy

• downsizing cell shrinkage
• due to: disuse (muscle), denervation (muscle in ALS), diminished blood supply (atherosclerosis), diminshed nutrition (diet), hormonal loss (menopause), aging 
• Retreat to a smaller size where survival is possible because reduced protein sythesis
• Catabolism via ubiquitin- proteasome pathway can increase
• or cells can undergo autophagy (eat itself)

Metaplasia

• change to a more adaptive cell type
• reversible change of one cell type to another
• must reprogram stem cells
• example: in smokers glandular epithelium in the airways change to rugged squamous ep but they lose mucociliary elevator thus cant remove harmful particles
• barretts intestinal metaplasia in the esophagus due to gastric reflux (gastric mucose to intestinal to cancer)

Cell Injury Changes

• reversible injury: cellular swelling, fatty changes and mild cytoplasmic eosinophilia (redness)
• Irreversible injury: marked cytoplasmic eosinophilia and nuclear changes: pryknosis (irr condensation of chromatin), karyorrhexis (fragmentation of nucleus), and keryolysis (complete dissolution of chromatin), with cellular fragmentation

Necrosis Types

• coagulative (mummification)
• Liquefactive
• Gangrenous: more clinical or gross term; may be coag or liquifactive due to superimposed bacterial infection
• Caseous (cheesy; TB)
• Fat necrosis
• Fibrinoid: pink stuff in vessel walls due to leakage of plasma protein into damaged vesssel walls (vasculitis, necrotizing arteriolitis)

Coagulative Necrosis

• mummification, leaves ghostly outline of cells that once were infarct
• White infarcts: pale in picture due to blockage of arterial blood supply (found in spleen)
• Red Infarcts: can occur when blood re-enters an infarcted area (reperfusion), when blood outflow (venous) is blocked , or in torsion of ovary or testis
• coagulative necrosis can be dry gangrene 

Liquefactive Necrosis

• enzymes and phagocytosis liquefy and remove dead tissue (CNS, infarct, lung abscess) eventually leave empty cavity
• may have macrophages or neutrophils present
• typical of tissue with lots of lipids
• Old Middle Cerebral Artery infarct can cause a chunk of the brain to be gone
• in pancreatitis there is fat necrosis and liquefactive necrosis due to auto digestion by other escaped pancreatic enzymes (protease and elastase)
• can cause wet gangrene

Caseous Necrosis

• cells turned to cheesy debris (TB, fungus)
• example: granuloma in the lung
• picture shows a cheesy center, with pink amorphous debris, surrounded by giant cells with a sprinkling of lymphocytes

Fat Necrosis

• Enzymatic: acute pancreatitis and calcium saponification (process that produces soap)
• powerful enzyme (lipase) release damges fat by the production of soaps and these appear grossly as soft, chalky white areas (fat cells have vague outline, lost their peripheral nuclei, cytoplasm pink necrotic)
• Traumatic: breast with calcification

Mitochondria Damage

• can be damaged by hypoxia, radiation, infarct, reprfusion and certain toxins
• loss of ATP leads to ATP pump failure (cells take on Na/H2O.Ca and lose K swelling cell), lactic acidosis (due to anaerobic glycolysis), ribosomal detachment (reduced protein synthesis)
• ROS production by mit causes necrosis/inflammation
• Mit damage leads to mitochondrial permeability transition pore MPTP opening leading to apoptosis

Reactive Oxygen Species (ROS)

Specifics

• increasing order of reactivity: H2O2 -> O2- -> HOCL -> ONOO- -> OH radical
• normally produced in cell signaling, oxidative phosphorylation, and respiratory burst
• superoxide dismutase, catalase, and glutathione peroxidase decompose ROS to protect the cell
• Cause injury by liquid peroxidation of membrane, cross-linking proteins and DNA damage
• radicals are increased by ionizing radiation, metabolism of chemical/poisons, inflamation

Ischemia vs Hypoxia

• Hypoxia is low oxygen in the blood or decreased ATP
• Ischemia is blocking the blood supply seen in heart attack, stroke: Hypoxia + no waste removal or nutrient delivery
• Without coninuous O2 then mitochondrial damage, membrane damage, ROS accumulation, massive Ca influx (bad), and necrosis
• If increase in intracell Ca than activation of phospholipase, protease, endonuclease, ATPase and apoptosis

Mitochondrial (intrinsic) Apoptosis

Pathway

• Injury: growth factor loss, DNA damage, misfolded protein
• Sensed by BH3 proteins of the Bcl-2 which inhibit pro-life protein BCL-2 and Bcl-xl (keep pore closed)
• Pro-death bax and bak are activated (promote pore opening)
• they dimerize and open the MPTP
• cytochrome c leaks out and activates caspase 9

Death Receptor (extrensic) Apoptosis

Pathway

• cytotoxic T cells carry FasL which will cross link Fas on the surface of the cell
• leads to activation of death domain on Fas which binds adapter proteins
• which initiates caspases 9 which activate execution caspases (3, 6, and 7)
• these cleave targets leading to nuclear and cytoskeletal breakdown
• FLIP is an antogonist that ordinarily blocks caspases

Intracellular Accumulation

• Russel Bodies: accumulation of Ig in plasma cells forming intracytoplasmic protein globules
• Mallory bodies: acc of intermediate filaments (keratin) in hepatocytes (seen in alcoholic liver)
• Iron seen as brownish pigment in liver cells
• Fatty liver in diabetes, alcoholism and malnutrition
• Alzheimers, amloidosis, alpha 1 antitripson deficiency
• Storage disease: glycogenoses, Gauchers, Taysachs
• Pulmonary anthrosillicosis, absestosis (ingestion of indigestible materials; silica crystals in polarized light)

Alzheimers, amyloidosis, alpha 1 antitripson deficiency

Intracellular Accumulation

• defect in protein folding transport
• pink globs are alpha 1 antitrypsin
• amyloid results from deposition of certain misfolded protein fibrils containing a beta pleated sheet structural conformation: appears as apple green birefringence when stained w. congo red

Storage Disease

Intracellular Accumulation

• GLycogenoses, Gaucher's, Tay-Sachs
• Lack of enzyme
• glycogen accumulation makes liver cells appear clear
• Gaucher's disease with cytoplasmic accumulation of glucocerobroside in bone marrow macrophages: inherited enzyme deficiency of beta-glucocerebrosidase

Dystrophic Calcification

• cuased by necrotic tissue or abnormal degeneration of tissue forming mineral deposits 
• blood levels of Ca remain normal during this 
• causes a brittle (hardening)
• occurs in areas of fat necrosis

Metastatic Calcification

• depostion of calcium salts in otherwise normal tissue because of elevated Ca Levels
• Hypercalcemia

Acute Inflammation

• response rapidly delivers neutrophils and plasma proteins to sites of injury: once there neutrophils clear the invaders, digest and get rid of necrotic tissue (2 parts to acute inflam)
• Vascular Changes: vasodilation and changes in vessel wall that permit plasma proteins to leave circulation. In addition, endothelial cells are activated, resulting in adhesion and migration through vessel walls
• Cellular Events: emigration of leukocytes from circ, accumulation in focus of injury, followed by activation of the cells, enabling them to do their job
• stimuli for acute inflam: infections, trauma, tissue necrosis, foreign bodies

Inflammasome

• multi protein cytoplasmic complex that recognizes components of dead cells (cahnges in K, ROS, crystals)
• upon activation, activates caspace -1 which cleaves precursor forms of IL-1B

Increasing Vascular Permeability

• endothelial cell contraction by bradykinin/histamine; sustained by TNF and IL-1
• endothelial cell injury results in fluid leakage
• increased transcytosis
• increased lymph drainage (can lead to lymphangitis)
• histmine, IL-1, TNFα also upregulate selectins on endothelial cells (cause rolling)  

Firm Adhesion of Leukocytes

• firm adhesion is mediated by integrins expressed on leukocytes and ligands of endothelial cells
• integrin up regulation is mediated again by chemokines and cytokines as well as up regulation of ligands from endothelial cells to be made
• Ligands include I-CAM-1, V-CAM-1
• binding of ligand to integrin receptor leads to changes in cytoskeleton that promotes firm adhesion

Transmigration

• leukocytes migrate through blood vessel wall primarily by squeezing btw cells at intercellular junctions (due to contraction of endothelial cells)
• use collagenase to break through vessels
• the extravasation of leukocytes is called diapedesis and it occurs in venules of circulation
• PECAM-1 (expressed on both cells) binding promotes collagenases - which break through vascular basement membrane

Genetic Disorders

Leukocyte Adhesion

• deficit in leukocyte adhesion 
• Leukocyte Adhesion Deficiency - 1 (LAD-1) due to defective synthesis of a subunit (CD18) in integrin production
• LAD-2, there is defect in fucose metabolism (thus, problem with selectin) and as a result, no adhesion

Chediak-Higashi Syndrome

• autosomal recesssive disorder in which defective fusion of lysosomes with phagosomes as well as inability to secrete cytolytic granules by T cells
• neutropenia
• giant granules in leukocytes (due to fusion of granules arising form the golgi)
• Defective primary hemostasis (due to abnormal dense granules in platelets
• Peripheral neuropathy

Morphological Patterns of 

Acute Inflammation

• Serous Inflammation: outpouring of watery, protein poor fluid that derives from plasma or from secretions of body cavities (fluid in a serous cavity is effusion)
• Fibrinous Inflammation: occurs as consequence of more severe injuries when large vasodilation results in large proteins leaving circulation such as fibers - resulting in fibrogenesis and fibrosis and scarring formation
• Suppurative (purulent) inflammation and abscess formation: collecltion of pus (dead neutrophils) and is called pyogenic
• Ulcer: Local Defect or excavation of surface of an organ or tissue that is produced by necrosis of cells and sloughing of the necrotic and inflammatory cells (seen in GI tract, mouth and other places with surfaces)

Arachidonic Acid Metabolites

• Bound in membrane and released by phospholipase
• Cyclooxygenase stimulates production of prostaglandin and thromboxanes
• Lipoxygenase stimulates production of luekotriens and lipoxins
• Thromboxanes: platelent aggregating agent and vasoconstrictor
• Prostoglandins: contribute to pain and fever that accompany inflammation (vasodilate)
• Luekotrienes: increase vascular permeability and chemokine for neutrophils, can cause brochoconstriction
• Lipoxins: produced after cells are at site of infection and inh neutrophil chemotaxis and adhesion (vasodilate)

Nitric Oxide

• synthesized from arginine, oxygen and nitric oxide synthase
• Type 1, Neuronal NOS: no significant role in inflammation (constitutively expressed)
• Type 2, inducible NOS: induced by macrophages and other cytokines (ind)
• Type 3, Endothelial NOS: synthesized in endothelium
• NO is a cytotoxic agent in activated macrophages
• when NO is produced in endothelial cells it does Vasodilation

Complement System Regulation

• inhibitors protect cels from inappropriate damage
• C1 inhibitor blocks C1 activation and causes angioedema (excess edema)
• Decay-accelerating factor (DAF) limits formation of C3 and C5 and causes lysis of RBC's 
• Factor H limits convertase activity and causes various diseases (alternative pathway)

Macrophage Activation

• dominant cells of chronic inflammation
• Classical: induced by microbial products, cytokine IFN-gamma and foreign substances
• Alternative pathway: cytokines such as IL-4 and 13, and these macrophages main purpose is tissue repair (not phagocytosis)

Granulomatous Inflammation

• aggregates of activated macrophages with scattered lymphocytes
• form under three conditions:
• 1) persistant T cell repsonses to microbes in which the cytokines from the activated T cells are responsible for chronic macrophage act (IFN gamma from CD4 T cells
• 2)some immune mediated inflam diseases (chron's)
• 3) Diseases of unknown etiologies called sarcoidosis
• granulomas wall of the offending agent and are useful defense mechanisms
• cells in granulomas will then be referred to as epitheliod cells

Extracellular Material 

(ECM)

• regulates proliferation and differentiation of cells and is constantly being remodeled based on cell prolliferation
• Interstitial Matrix: present in spaes btw cells in CT and btw cells of other cell walls and epithelia. includes collagen, fibronectin, elastin and other elements (btw mesenchymal cells)
• Basement membrane: array of interstitial matrix CT that is organized around epithel cells forming a BM. lies beneath epithelium and is syn by overlying epithelium and underlying mesenchymal cells
• BM includes only non fibrilar Type 4 collagen and laminins

Components of ECM 

• Fibrous structural proteins: collagen and elastin that provide tensile strength
• Water hydrated gels: proteoglycan and hyaluronan: provide resilience and lubrication (consist of long chains of glycosaminoglycans linked to protein backbone
• Adhesive glycoproteins: connect matrix elements to one another: fibronectin and laminin have adhesion receptors such as CAMs (integrins, selectins, cadherins, and Igs)

Collagen and Elastin

• Collagen: composed of three chians braided like a triple helix that are cross linked to other chains to provide strength (enzyme lysl oxidase cross links chians -Vit C dependent) 
• collagen genetic diseases are due to CT malformations such as Ehlers Danlos Syndrome
• Elastin: provides recoil for cells to return to baseline structure for cells in large blood vessels as well as ligaments (defect in this can cause marfans syndrome in aorta)

Steps in Scar formation

• if replication is not possible, repair occurs by replacement of non-regenerated cells with CT, leading for scar formation
• formation of new blood vessels (angiogenesis)
• migration and proliferation of fibroblasts and deposition of CT which together with abundant vessels and leukocytes has a pink, granular appearance called granulation tissue
• maturation and reorganization of fibrous tissue (remodeling to produce stable firbous scar
• repair begins with in 24 hours of injury
• by 3 to 5 days, granulation tissue that is characteristic of healing is apparent

Steps in Angiogensis

• vasodilation occuring in response to NO and increased permeability induced by VEGF (no production and endothelial migration)
• separation of pericytes from ablumina surface
• migration of endoth cells toward area of tissue injury
• proliferation of endoth cells just behind the leading front of migrating cells
• remodeling into capillary tubes
• recruitment of periendothelial cells (pericytes for small capillaries) to form mature vessel
• suppression of endothelial proliferation and migration and deposition of the basement membrane
• involves many growth factors, cell interactions

Growth Factors invloved in 

Angiogenesis

• VEGF: inducer of angiogenesis by stimulating migration and proliferation of endothelial cells and initiating process of capillary sprouting
• FGF: Stimulates proliferation of endoth cells and migration of blank cells to site of infection
• Angiopoietins 1 and 2: growth factors that play role in angiogenesis and structural maturation of new vessels (help w/ maturation of depositing connective tissue)
• MMPs (metalloproteinases): degrade ECM to permit remodeling and extension of vascular tube

Deposition of CT in Scarring

• laying down of CT in scar occurs in two steps:
• 1) migration and prolif of fibroblasts into site injury
• 2) deposition of ECM proteins produced by these cells
• driven by growth factors PDGF (causes migration and proliferation of cells), FGF, and TGF-beta (stim production of collagen, fibronectin and proteoglycans as wella s activating MMP inh called TIMPS)
• major source of fibrous tissue is macrophages which are present at site of injury anyways

Remodeling of Connective Tissue (CT)

• Constant remodeling of CT in tissue
• MMPs degrade collagen and other eCM components
• MMPs are produced by a variety fo cells but their activity is tightly regulated
• mesenchymal cells produce TIMPS (inh of MMPs)
• during scarring, MMPs are activated to remodel the deposited ECM, but then are inh by TIMPS

Factors that influence Tissue Repair

• infection- cause of delay in healing - prolongs inflammation and increases local tissue injury
• nutrition: coauses rpofound effects on repair - Vit C helps (deficiency is harmful)
• glucocorticoids: have anti-inflammatory affects but have weak forming scars due to lack of TGF beta
• poor perfusion, increased local pressure, foreign bodies can all harm or delay process
• any abnormal development in terms of deficiency in growth factors also delays scarring and healing

Hyperemia

• results from arteriolar dilation and increased blood inflow
• results from arteriolar dilation and inc blood flow
• occurs at site of inflammation or infection, and exercising skeletal muscle
• tissue is redder than normal due to increased oxygenated blood and are warm to touch

Congestion

• is a passive process resulting from decreased blood outflow
• results from impaired outflow of venous blood
• can occur systemically in cardiac failure or locally due to isolated venous obstruction
• tissue appears abnormal blue-red color
• long standing congestion can cause inadequate tissue oxygenation and cell death

Edema

• is the accumulation of interstitial fluid w/i tissue
• edema fluid accumulating w/i body cavities is called pleural effusion (hydrothorax), pericardial efusion (hydropericardium), or peritoneal efusion (ascites)
• anasarca is severe generalize edema w. profound swelling and effusion
• causes of edema: increased hydostatic pressure (impaired venous return or arteriolar dilation), reduced plasma osmotic pressure, lymphatic obstruction, sodium retention, and inflammation

Hemorrhage

• extravasation (leakage of fluid out of its container) of blood from blood vessels
• can be external, accumulate in tissue, or in body cavities
• patterns of hemorrhage: petechia, pupura or ecchymosis
• Petechiae: minute hemorrhages in skin, mucosa or serosal surfaces (related to low platelet ocunt, platelet dysfunction or loss of vascular wall support)
• Pupura: slightly larger hemorrhages and can be from platelet problems or trauma, vascular inflam
• Eecchymosis are even larger subcutaneous hematomas (brusies) caused by trauma or coag disorders

Inflammation vs Accumulation 

Edema

• Accumulation: lyphatics drain escess edema fluid, accumulation leads to a protein poor transudate
• Inflammation Edema: is a protein rich exudate

Hemostasis

• pro-coagulant and anticoagulant forces in balance
• Dominance of anticoag forces result in hemorrhage
• Dominance of pro-coagulant forces result in thrombosis
• Virchow's triad: endothelial injury, abnormal blood flow (stasis or turbulence), hypercoagulability of the blood (pro-coag force)
• Primary hemostasis: formation of platelet plug (endoth injury also exposes Tissue Factor that works with VII in cascade) (fibrinogen cross links with IIb/IIIa to aid in aggregation of adjacent platelets)
• Secondary hemostasis: coagulation cascade that forms stable clot

Abnormal Blood Flow

• any loss of normal laminar blood flow
• turbulence: causes activation of coagulation and injures endothelium
• Stasis (slow blood flow): allows activation of platelets in contact with vascular wall, and slows washout of activated coagulation factors and entry of anticoagulants
• platelets is first thing to appear of clot

Hypercoagulability

• any alteration in the hemostatic mechanism that predisposes a patient to thormbosis
• Primary (inherited): factor V leiden, prothrombin 20210A, deficiences of protein C, protein S, AT-III, others
• Secondary (acquired): age, obesity, smoking, inactivity, cancers (environment)
• should be considered in young patients (<50) with repeated thrombosis and family history

Pathology of Thrombi

• Arterial and cardiac thrombi arise at sites of endothelial injury or turbulence
• Venous Thrombi are at sites of stasis
• both propagate toward heart
• thrombi have alternating lighter and darker layers called lines of Zahn (platelets mixed w/ fibrin are lighter, and RBC is darker)
• Thrombi in the heart chambers or aorta are called mural thrombi
• Thrombi on heart valves are called vegetations and may be related to infective endocarditis or nonbacterial thrombotic endocarditis
• Venous thrombi are common (usually in leg)
• Lines of Zahn will be there if before patient died but if aftern then will look like chicken fat or current jelly

Deep Vein Thrombosis

• in leg (usually proximal to popliteal fossa) are common and give rise to pulmonary embolism
• large embolus at bifurcation of right and left pulmonary arteries is called a saddle embolus
• small emboli will pass to the periphery of the lung causing pulm infarcts (small arteries), pulmo hemorrhage (medium arteries), sudden death (larger arteries)
• multiple emboli over time can cause pulmonary hypertension and right heart failure

Embolism

• solid, liquid, or gaseous mass that is carried by the blood to a site distant from its origin
• systemic emboli cause ischemic necrosis of downstream tissue: most arise from intracardiac mural thrombi, common embolization sites are extremities, CNS, intestine, kidney, spleen
• Pulmonary emboli: cause hypoxia, hypotension, right heart failure and sudden death

Infarction

• an area of ischemis necrosis caused by interuption of the blood supply
• most infarct are caused by arerial thormbosis or arterial embolism
• Red Hemorrhagic infarcts (venous or spongy): within venious occlusion as in torsion, in loose tissue where blood can collect in tisue, with dual circulation, or in congested tissue, where blood flow is reestablshed after infarction
• White anemic infarcts: occur in solid organs with end arterial circulation and in dense tissue
• all infarcts may be bland or septic
• factors that influence infarct development: anatomy of vascular supply, rate of occlusion, tissue vulnerability and hypoxemia

Amyloidosis

• associated with a number of inherited and inflammatory and neoplastic disorders
• Extracellular deposits of fibrillar proteins
• tissue damage and functional compromise
• produced by aggregation of misfolded proteins or protein fragments
• bind a variety of proteoglycans and glycosaminoglycans 

Amyloid Pathogenesis

• misfolded proteins normally degraded intracellularly (proteosomes) or extracellularly by macrophages but these mechanisms fail
• normal proteins that fold improperly or mutant proteins that are prone to misfolding
• Amyloid light chian (AL) protein: lambda light chain most frequently
• Amyloid associated (AA) fibrils (inflam conditions)
• AB amyloid (cerebral lesion of alzheimer disease)
• Transthyretin (TTR): normal transports thyroxin and retionl (familial amyloid plyneuropathy, and senile systemic amyloidosis)
• B-2 microglobulin MHC I molecules and AB2m (renal disease)
• Endocrine amyloid: calcitonin-medullary carcinoma of thyroid

Amyloid Classification

• localized (single organ): AB (senile cerebral) or endocrine (calcitonin)
• systemic primary-monoclonal protein (AL-light lambda chian) or secondary - chronic inflamm condition(AA) or B2
• Hereditary or familial: AA or transthyretin: familial mediterranean fever (AA proteins), familialy amyloidotic neuropathy: transthyretin), and senile systemic amyloidosis (transthyetin, dominant heart involvment)

Primary and Secondary Amyloidosis

• Primary: monoclonal protein (AL light chian lambda): usually systemic and AL (Bence-jones proteins)
• Secondary: chronic inflam condition(AA) or B2: reactive systemic amyloidosis, sene in TB, autoimmune diseases, bronchiectasis, chornic osteomyelitis 

Amyloidosis Morphology

• amyloid deposition is always extracellular and begins btw cells
• primary (AL): heart, GI, respiratory, peripheral nerves, skin, tongue
• secondary (inflam): kidney, liver, spleen, lymph nodes, adrenals, thyroid

Amyloidosis Clinical Course

• non specific symptoms
• poor prognosis, short survival of 1-3 years
• AA control the underlying condition
• AL multiple myeloma (poorer prognosis)
• Reasorption of protein is rare
• tissue injury and impair function by causing pressure on cells and tissue
• it does not evoke an inflammatory response

Labatory Evaluation of Hemostasis

• Arteriole Vasoconstriction (Neurovascular reflex): no way to measure
• Platelets (Primary Hemostasis): Platelet count and platelet function studies (PFA, bleeding time)
• Coagulation Cascade (secondary hemostasis): Prothrombin time (pT), activated thromboplastin time (aPTT), fibrinogen
• fibrin is end point for pT (extrinsic) and aPTT (intrinsic) and last is direct measure of fibrinogen in blood

Anti-Thrombin III

• anti-coagulant
• inhibits activity of : Thrombin (II), IX, X, XI, XII
• acts with heparin-like molecule on intact endothelium
• acts with heparin (drug)
• consumed with activity 

Leiden Mutation

• factor V mutation that makes it resistant to Protein C 
• hyercoaguability
• prothrombin gene mutations can also cause hypercoag

Vitamin K Dependent Coagulation Factors

• II (prothrombin)
• VII (Extrinsic pathway activator for X)
• IX (Intrinsic pathway activator for X)
• X (turns prothrombin to thormbin with help of V)
• Protein C
• Protein S (both C and S inhibit the cofactors V (for X) and VIII (for IX) and are anticoagulants)

Tissue Plasminogen Activator (tPA)

• plasminogen is stored inside blood clots
• Tissue plasminogen activator (tPA) converts plasminogen to plasmin to remove clot by proteolisis)
• this can also be done by Factor XII
• free plasmin is inactivated by alpha-2 antiplasmin
• urokinase and streptokinase can also lyse clots

Cell Mediated Adaptive Immunity

• CD3 is the transmembrane protein attached to the TCR which transmits the T cell signal and activates it
• CD4 and CD28-B7 are also involved in T cell activation
• The B cell receptor complex is composed of membrane IgM or IgD and the associated signaling B cell receptor proteins Igalpha nd Igbeta to transmit the signal
• C3d (complement) binds to the antigen and to CD21 which enhances the signal for B cell activation

TH1 Pathway

• IFN gamma and IL-12 induces this pathway for host defense against intracellular microbes
• activates macrophages (by producing IFN gamma) and IgG production 
• Immune mediated chornic inflammatory diseases (often autoimmune) 

TH2 Pathway

• this pathway is sitmulated by IL-4 and produces cytokines IL-4, IL-5 and IL-13
• stimulation of IgE production and activation of mast cells and eosinophils
• defense against Helminthic parasites
• Causes allergies (hypersensitivity type I reaction)

TH17 Pathway

• TGF-beta, IL-6, IL-1, and IL-23 induce this pathway
• it produces cytokines IL-17 and IL=22
• causes recruitment of neutrophils and monocytes
• host defense against Extracellular bacteria and fungi
• Immune mediated chronic inflammatory diseaes (often Autoimmune)

Type I: Hypersensitivity 

• activation of TH2 cell and IgE class switching in B cells
• Production of IgE
• Binding of IgE to FcRl on mast cells (must sensitive first on first exposure)
• Repeat exposure to allergen causes activation of mast cell and thus release of mediators
• Immediate response: Histamines, chemostatic factors, prostaglandins, leukotriene which cause vasodilation, vascular leakage, smooth muscle spasm 
• Late phase reaction: cytokines which include TNF and chemokine that recruite leukocytes, IL-4, IL-5 which amplify the TH2 response, also cause bronchospasm, epithelial damage (see many neutrophils, eosinophil and lymphocytes in picture

Type 2 Hypersens:

Antibody Mediated Disease

• antibody binding causes osponization, phagocytosis, inflammation, (complement cascade), and cellular dysfunction
• autoimmune hemolytic anemia
• Grave's disease is hyperthyroidism due to continuous stimulation of TSH

Type 3 Hypersensitivity

Immune complex Disease, complement Activation

• systemic lupus erythematosus (will make antibody to their DNA due to lack of self tolerance on collagen and connective tissue)
• causes vasculitis, glomerulonephritis, arthritis
• Is systemic

Rejection of Transplants

• Hyper acute rejection: mins/hours, preformed anti-door antibodies; vascular thrombosis (due to infiltrations of CD4 and CD8)
• Acute (cellular): first months; CD4 and 8 cells, HLA differences
• Acute (humoral): vasculitis, necrotizing vasculitis
• Chronic: dominated by vascular changes, interstitial fibrosis and loss of renal parenchyma (can be cellular and humoral)

Primary (Congenital) Immune

Deficiency Diseases

• ADA deficiency: shutting off T cells because cant do purine turnover
• X-Linked SCID: T/B cell immune deficiency
• Digeorge Syndrome: do not have thymus or parathyroid
• X linked agammaglobulinemia: prevent light chain resolution so no Ig (burtons tyrosine kinase def)
• Hyper-IgM syndrome: CD40L deficiency
• MHC class 2 deficiency

Secondary (acquired) Immune

Deficiency Diseases

• HIV: macrophage and T cell are the repository hosts
• Gp120 binds CD4 causing a conformational change
• Gp41 present it to the membrane
• membrane fusion
• integration of pro-virus into host cell genome
• Ultimately CD4 T cells decline and the patient develops AIDS: cd4 cells can not activate the CD8 cell that protect the individual from the virus
• macrophages that get the virus via CCR5 go to the brain

Amyloid Classification

• Systemic: AL/AA/B2
• Hereditary: AA/Transthyretin
• Localized: AB/endocrine

TNM Classification

• classification for malignant tumors (helps for therapy and treatment response predictions
• T: describes the size of the original tumor and wheter it has invaded the stroma or not
• N: describes the nearby lymph nodes that are involved
• M: describes distant metastasis (spread of cancer from one part of the body to the next)

Cancer Grades

• shows progression of cancer
• 1 - shows tubular formation that goes into the stoma nucleus are uniform and ont mitosis
• 2- cells have solid nests, nuclei pleomorphic, mitosis
• 3 - solid nests, little glands, atypical nuclei, high mitosis

Poorly Differentiated Carcinoma

• cell that can spread are large, nuclear membrane irregulation, cell necrosis, little gland formation and nuclei are pleomorphic
• Poorly differentiated are faster growing and less like the normal cells

Intrinsic Subtypes of Breast Cancer

• Luminal A: High ER related genes, low Her2 cluster genes, low proliferation cluster genes
• Luminal B: Low ER related genes, variable Her2 cluster
• Her2 Positive: high Her2 cluster, high proliferation cluster
• Her2 oncogene encodes transmembrane glycoprotein receptor, belongs to EGFR family, activates growth pathway
• Basal-like (triple negative): ER, PR, Her2 negative, high proliferation cluster

Benign Tumors

• Neoplasm that tend to remain localized (does not invade stoma)
• amenable to surgical removal
• patient generally survives
• growth is slow
• well circumscribed, may have capsule
• mitosis are rare and show normal configuration
• Ex: adenoma which is a epithelial neoplasm producing gland patterns

Malignant Tumors

• invades locally and destroys adjacent structures
• spreads systemically (metastasize)
• more rapid growth
• anaplasia (loss of structure and function of normal cells): pleomorphic nuclei, hyperchromatic nuclei (High N:C ratio), mitosis, loss of normal polarity
• Show a range of differentiation from well to poorly undifferentiated
• Sarcoma: arises from or resembles mesenchymal elements
• Carcinoma: arises from or resembles epithelial elemnts (ectoderm, mesoderm, endoderm
• exceptions are melanoma, lymphoma, and seminoma

Stroma

• supporting, host-derived, non-neoplastic
• connective tissue, blood vessels, inflammatory cells
• desmoplastic reaction from host: pervasive growth of dense fibrous tissue around the tumor

Other Types of Tumors

• mixed tumors: contains epithelial and stromal components (fibroadenoma, pleomorphic adenoma, carcinosarcoma)
• Teratoma: more than one germ cell layer, originate from totipotential germ cells
• Hamartoma: mass of disorganized tissue appropriate to the site
• Choristoma: nodule of heterotopic cells

Dysplasia

• disorderly, but pre-neoplastic proliferation
• some may regress spontaneously
• epithelial lesions: cervix and colonic tubulo adenomas
• loss of normal polarity and architecture
• basement membrane still intact (preinvasive for malignant)
• carcinoma in situ involves entire thickness of epithelium

Anaplasia

• cells lose the morphological characteristics of mature cells and their orientation with respect to each other and to endothelial cells. 
• pleomorphic nuc: variation in size, shape (bizzare)
• hyperchromatic nuc: cource clumped chromatin; inc nuc to cytoplasm ratio
• mitosis in numerous, atypical
• loss of normal polarity of cells
• presence of nucleoli

Pathways of Dissemination

• Seeding w/i body cavity: peritoneal carcinomatosis; pleural fluid/ascites (breast and lung)
• Hematogenous spread: usually invades veins (especially spreads to liver and lungs) and mostly sarcomas but can be carcinomas
• Lymphatic spread: pattern depend son site of primary tumor; inject dye/radiolabeled tracer into tumor to remove lymph node first to receive tracer; sentinel lymph node (first regional lymph node to receive lymph flow from primary cancer)

Metastasis

• secondary implants that are discontinuous w/ primary tumor and located in remote tissues
• identifies tumor as malignant
• 30% of newly diagnossed cancers present w/ clinically identifiable metastasis
• aditionally 20% have occult (unknown) metastasis
• variable based on tumor site

Vitamin D

• facilitates intestinal absorption of calcium
• facilitates phosphorus and mineralization of bone
• Deficiency syndromes: Rickets in children; osteomalacia in adults

Vitamin E 

• major antioxidant; scavenges free radicals
• Deficiency: spinocerebellar degeneration 

Vitamin C

• serves in many redox reactions and hydroxylation of collagen
• Deficiency: scurvy