Inflammation and Immune Response

Inflammation

• Occurs in response to tissue injury to prevent and limit infection and further damage, and to initiate healing and adaptive immune response
• Characterized by localized vasodilation and increased capillary permeability, leading to movement of WBCs, complement, and plasma proteins to the site of injury
• 5 signs: heat, redness, swelling, pain, and loss of function

Mast Cells

• Cellular bags of granules located in loose connective tissue close to blood vessels, skin, digestive lining, and respiratory tract
• Activation: physical injury, chemical agents, immunologic processes
• Leads to degranulation and synthesis of lipid-derived chemical mediators

Phagocytosis

• Process by which cells ingest and dispose of foreign material

Neutrophils

• Most abundant white cells with a lifespan of 4-8 hours in circulation and 4-5 days in tissues
• Major defense against bacterial infection
• Diapedesis: neutrophils and monocytes squeeze through pores in blood capillaries to enter tissues, moving by amoeboid motion
• Chemotaxis: neutrophils move towards the source of certain chemicals (chemo-attractants)

Microorganisms

• Classes: bacteria, viruses, fungi, protozoa, parasitic worms
• Healthcare-acquired infections: direct, droplet, indirect, airborne/aerosol, vector-dependent, faecal-oral

Process of Infection

• Colonization, infection, spread
• Factors for infection: mechanism of action, infectivity, pathogenicity, virulence, immunogenicity, toxigenicity

Host Defenses

• Classes of infectious microorganisms: viruses, bacteria, fungi, protozoa, helminths

Bacteria

• Gram staining: distinguishes between gram-positive and gram-negative bacteria
• Bacterial toxins: exotoxins (enzymes released during bacterial growth) and endotoxins (lipopolysaccharides from outer membrane of dead gram-negatives)

Viral Replication

• DNA or RNA
• Protein receptor-binding site
• Viral DNA enters nucleus and is transcribed into mRNA
• Clinical symptoms reflect alteration of infected cell function

Cellular Effects of Viruses

• Inhibition of host cell DNA, RNA, or protein synthesis
• Disruption of lysosomal membranes
• Promotion of apoptosis
• Transformation of host cells into cancerous cells

Fungi

• Moulds or yeast
• Diseases caused by fungi are called mycoses
• Dermatophytes: fungi that invade the skin

Vaccines

• Induction of long-lasting protective immune responses
• Types: attenuated organism, killed/inactive organism, extracts of antigens, toxins

Immune System

• Lymphatic system: tonsils, thymus gland, lymph nodes, spleen, appendix
• Circulatory system: bone marrow, lymphocytes/white blood cells, phagocytic cells, dendritic cells, thrombocytes, complement proteins

Types of Immunity

• Non-specific (innate): present from birth, includes blood cells, physical barriers, chemical and mechanical barriers
• Specific (acquired/adaptive): develops in response to exposure to infectious organisms, includes humoral immunity (B cell-mediated) and cell-mediated immunity (T cell-mediated)

Urinary Tract Obstruction

• Urethral obstruction in men can lead to bacterial infection and increase the risk of prostatitis and prostatic hypertrophy.
• Urinary tract obstruction can also be caused by calculi or tumours.
• Renal calculi (stones in the urinary tract) are a common cause of upper urinary tract obstruction.

Chronic Kidney Disease (CKD)

• CKD is an irreversible loss of renal function that affects all organ systems.
• Can be caused by a variety of pathophysiological conditions, including systemic diseases (diabetes, hypertension) and renal diseases (chronic glomerulonephritis).
• CKD can lead to a decline in GFR (glomerular filtration rate) and tubular functions.

GFR

• Measurement of GFR is a good indicator of kidney function.
• GFR can be calculated by measuring the clearance of a substance by the kidneys over a period of time.
• Creatinine is a breakdown product of muscle that is normally cleared from the blood by the kidneys; increased levels in the blood indicate kidney dysfunction.

eGFR

• Estimated glomerular filtration rate is based on creatinine, age, body size, gender, and race.

Renal Failure

• Acute renal failure is a sudden, reversible decline in renal function.
• Chronic renal failure is a gradual, irreversible decline in renal function over time.

Glomerular Diseases

• Acute glomerulonephritis is characterized by large, inflamed glomeruli with decreased capillary lumen and rapid onset of haematuria and proteinuria.
• Chronic glomerulonephritis is characterized by glomerular scarring and eventual loss of functioning nephrons, leading to gradual development of uremia.
• Clinical manifestations of glomerulonephritis include hypertension, renal failure, haematuria, and proteinuria.

Tubular Diseases

• Tubular diseases result in decreased excretion/reabsorption of certain substances or reduced concentrating capability.
• Renal tubular acidosis is a disorder affecting acid-base balance.

Urinary Tract Infection

• Urinary tract infection is an inflammation of the urinary epithelium caused by bacteria from gut flora.
• Common pathogens include Escherichia coli and Staphylococcus saprophyticus.

Pyelonephritis

• Acute pyelonephritis is an acute infection of the renal pelvic, commonly caused by Escherichia coli and Proteus Mirabilis.
• Ascends from the lower urinary tract.

Evaluation of CKD

• Evaluation is based on risk factors, history, and presenting signs and symptoms.
• Elevated serum creatinine and serum urea concentrations are consistent with CKD.
• Markers of kidney damage include urine protein, albumin, and examination of urine sediment.

Management of CKD

• Dietary control, fluid evaluation, and restriction of sodium, potassium, and phosphate are important.
• Adequate kilojoule intake, management of dyslipidaemias, and iron, folic acid, and erythropoietin replacement therapy as needed are also important.
• Angiotensin-converting enzyme (ACE) inhibitors or receptor blockers are often used to provide renal protection and control systemic hypertension.

Alzheimer's Disease

• Alzheimer's disease is the most common type of dementia.
• The risk of developing Alzheimer's disease increases with age.
• Pathophysiological characteristics include death of pyramidal cells, neuritic plaques, and neurofibrillary tangles in the hippocampus, temporoparietal, and front cortices.

Dementia

• Dementia is a set of symptoms that include gradual loss of memory, mood change, and problems with communication and reasoning.
• Can lead to mood swings and violent outbursts.