WEEK 5 - Malignancies

Natural programmed cell death

Cell death due to injury or disease progression

The division of one parent cell into two daughter cells Consists of interphase and the mitotic phase

G1 = growth phase, new daughter cells grow to adult size and duplicate organelles S = DNA synthesis phase, DNA replicates G2 = 2nd growth phase, cells grow and more organelles are added to the cytoplasm

Nuclear division such that each daughter cell has the same DNA as the parent cell

Uncontrolled reproduction of cells that can arise from ANY cell type

Incidence of gene mutations via epigenetic and genetic mechanisms increases

Environmental factors that can turn genes on or off - changes how genes are read but does not change the actual gene itself

A new growth, swelling or tumour, may be benign (well differentiated) or malignant (poorly differentiated)

A cancer arising from the glandular epithelium

Cancer arising from connective tissue

Cancer arising from lymphatic tissue

Cancer of white blood cells, proliferation of cancerous WBCs

• Have autonomy, ca produce their own growth factors and blood vessels, survive independently • Have an unlimited life span - vary in size and shape (pleomorphic), lack apoptosis due to telomerase • Are anaplastic - loss of differentiation, lack organisation, internal structure is not recognisable

Substances produced by neoplastic cells, can also be produced by benign cells.

• Confined to tissue of origin • Locally invasive - poorly differentiated cells present • Spreads to regional structures such as lymph nodes • Metastasis to distant sites

The transformation of healthy cells to malignant cells. Triggered by gene mutations as a result of risk factors, mutations stimulate growth promoting pathways and inhibit host antigrowth signals

• Chronic inflammation • Viruses and bacteria • Smoking • Alcohol • Radiation • Obesity • Physical inactivity

• Pain • Fatigue - unknown mechanism • Weight loss - altered metabolism, loss of fat stores and muscle • Infections - decreased granulocytes and lymphocytes • Blood dyscrasias - anaemia (chronic bleeding), thrombocytopenia (cancer in bone marrow), leukopenia (cancer in bone marrow)

Stimulation of nociceptors under the dermis and within deep tissues Mediated by substance P, PGs, histamines and bradykinin Arises from actual or potential tissue damage

ALWAYS with opioid and narcotic analgesics

Acts on mu-receptors in the CNS = reduces pain transmission, slow onset Longer duration than fentanyl due to high water solubility

Mainly acts on mu-receptors in the CNS, more potent than morphine due to high lipid solubility Short onset and duration of analgesia

Morphine analogue Rapidly converted to morphine, greater lipid solubility, can cross the BBB