Module 1 Flashcards
what does a microbiome contain
- mostly micro-organisms beneficial to health
- small proportion of MO that can cause disease (pathogens)
pathogens
organisms causing disease to its host
immune system
organization of cells, tissues and organs within the body that have their own personal role in fighting infection
2 components of the immune system
- innate (occurs first)
- adaptive
- work together to protect the body
microbes
BAD
- immune system tries to keep them out of the body because the human body provides the ideal environment for them
what happens if the IS fails to keep microbes out of the body?
the IS must find and destroy them
immune response
reaction of immune cells to microbes or danger signals in the body
types of immune response
- innate
- adaptive
- implicate different types of immune cells
functions of the IS
- discriminate
- eliminate
discriminate
recognize self cells from non-self cells
eliminate
destroy non-self (pathogen) and altered self-cells (ex. cancer)
dysfunctions of the IS
- autoimmunity/hypersensitivity
- immunodeficiency
autoimmunity/hypersensitivity
misdirected or overly reactive IS
immunodeficiency
underactive IS (ex. AIDS)
antigen
foreign protein that induces an immune response, usually including production of antibodies
- antigens cause you IS to produce antibodies against it
antigen name origin
antibody genderation= anti-gen
antibody
protein that is produces in response to and counteracting a specific antigen
antibody binding
antibodies bind to antigens in the body and provide a signal for their elimination
lymphatic system
vital system often considered to be part of the circulatory system
- also has role in immunity
what do immune and lymphatic systems share?
lymphoid organs
B-cells and T-cells
commonly found in lymph “lymphocytes”
- cells of the adaptive IS
efficient filtering system in the body consists of…
- lymphatic system
- circulatory system
- immune system
lymphatic system coordination
network of vessels that drain fluid, called LYMPH
lymph
colourless fluid containing white blood cells that bathes the tissues and drains through lymphatic system into the bloodstream
interstitial space
fluid filled areas that surround the cells of a given tissue
lymph and interstitial space connection
lymph is filtered from blood in capillaries and enters surrounding tissues (interstitial space)
circulatory system coordination
where lymph comes from and goes after being filtered
- lymph vessels pick up lymph around the body and carry it towards heart to re-enter CS
immune system coordination
cells of IS travel between CS and LS
lymphoid organs and tissues
immune function
what do lymphoid organs tissues act as sites for?
- immune cell generation
- training
- sites of action
bone marrow structure
- flexible tissue
- 2 types: yellow and red marrow
- filled with hematopoietic cells
red bone marrow function
- important for IS
- site of hematopoiesis
- site of B-cell development
yellow bone marrow function
- some leukocyte development
- produce fat and cartilage
location of bone marrow
central cavity inside the bones
hematopoietic cells
cells lodges within the bone marrow and which are responsible for producing blood circulating cells (red and white blood cells and platelets)
hematopoiesis
formation and differentiation of blood cells
- origin of all immune cells
lymph nodes structure
- small (1-25mm)
- bean-shaped
- numerous (~600)
- divided into 3 roughly concentric regions (cortex, paracortex and medulla)
- filled with lymphocytes, macrophages and dendritic cells
lymph nodes function
- filters lymph
- often it is the first organized lymphoid structure that foreign molecules encounter when first entering the body
lymph nodes location
grounded along the lymphatic vessels
lymphocytes
white blood cells which arise from lymphoid progenitor lineage during hematopoiesis
- refers to B- and T-cells
MALT
mucosal associated lymphoid tissue
MALT structure
- refers to combined SA of various areas in the body including BALT, GALT, lamina propria of intestinal villi. peyers patch, tonsils, appendix
- filled with various types of immune cells depending on location
MALT function
initiates immune response to specific antigens encountered along all mucosal surfaces
MALT location
mucous membrane lining digestive, respiratory and urogenital systems
BALT
bronchus-associates lymphoid tissue
BALT meaning
lymphoid structure part of MALT located in lungs and bronchus
GALT
gut-associated lymphoid tissue
GALT meaning
lymphoid structure part of MALF located in the gut
lamina propria of intestinal villi
thin layer of CT rich in immune cells located into the lumen of the small intestine
peyers patch
small masses of lymphatic tissue found throughout the ileum region of the small intestine
tonsils
collection of lymphoid tissue facing the aerodigestive tract, mainly located into the pharynx
appendix
small pouch-like sac of tissues located in first part of the colon (cecum) in lower right abdomen
- harbours bacteria and aids in immune function
spleen structure
1, large, ovoid
2. divided into 2 compartments; white and red pulp
function of spleen red pulp compartment
filters blood
function of spleen white pulp compartment
site of development of immune responses against antigens found in the bloodstream
spleen location
situated in the left abdominal cavity
white pulp
filled with macrophages, lymphocytes, T-cells, B-cells and red blood cels
what is the most important compartment of the spleen in the context of immunity?
the white pulp
red pulp
composed of cords of billroth and splenic sinuses that are filled with blood
billroth
consists of fibrils and CT cells with a large population of monocytes and macrophages
thymus structure
- flat
- bi-lobed - each lobe is divided into lobules which are organized each into 2 compartments (cortex & medulla)
- filled with thymocytes, epithelial cells, DCs and macrophages
function of thymus
site of T-cell development and maturation
location of thymus
above the heart
thymocytes
T-cells found in the thymus
classification on lymphoid organs and tissues
classified as either PRIMARY or SECONDARY according to immune function
primary lymphoid organs - tissues/organs
- thymus
- bone marrow
secondary lymphoid organs - tissues/organs
- spleen
- lymph nodes
- MALT
functions of primary lymphoid organs
site of lymphocyte maturation into an immunocompetent cell
1. B-cell = bone marrow
2. T-cell = thymus
functions of secondary lymphoid organs
site of lymphocyte activation into an effector cell
- through interactions with trapped antigens
immunocompetent cell
denoting a mature lymphocyte that is capable of recognizing a specific antigen and mediating an immune response
effector cell
denoting a mature lymphocyte that has been activated and mediates an immune response against a specific antigen
infection
body is attacked by a foreign invader (bacteria or virus)
- usually in the blood (infection stays localized)
process of ridding the invading pathogen
- B and T-cells react to the specific invader and are more powerful thsn macrophages
- body sweeps infection towards nearest lymph node so B and T-cells react
- lymph vessel continues to carry filtered fluid back to blood
- lymph node filtered blood to rid of bacteria before re-entering blood
2 major roles of the immune system
- discrimination
- elimination
discrimination
recognize self cells from non-self cells
major histocompatibility complex class 1 (MCH1)
presents a “sample of proteins found inside the cell”
- immune cells are then able scan their area and recognize if there are abnormalities presented via MHC protein
what if there is abnormalities in MHC protein?
immune response can be initiated
elimination
destroy non-self (pathogen) and altered self cells (ex. cancer)
- occurs through the ability of immune cells to initiate an immune response
MCH II
present on special cells of immune system such as macrophages, dendritic cells, and B-cells
innate immune system
consists of physical, soluble, and cellular barriers that are scattered throughout the body to prevent entry of infectious agents and respond non-specifically
adaptive immune system
consists of cells and soluble components capable of recognizing and responding to specific pathogens
- can be further divided into antibody-mediated humoral immunity (B-cell) and cell-mediated immunity (T-cell)
components of innate immunity
- first line of defence against foreign agents
- physical, soluble, and cellular barriers
functions of innate immunity
- immediate recognition and response to invading pathogens
- recognizes general patterns not specific for any one antigen
(limits type of immune response initiated)
how fast is the immune response for innate immunity?
response occurs within minutes or hours
components of adaptive immunity
- humoral immunity
- cell-mediated immunity
what is humoral immunity mediated by?
B-cells
what is cell-mediated immunity mediated by?
T-cells
functions of adaptive immunity
- longer time required to initiate a response to invading pathogens
- capable of recognizing and responding to specific antigens (wide range of responses)
- results in an immunological memory
how fast in the immune response for adaptive immunity?
response occurs within days
immunological memory
allows for a quick response upon second infection with the same pathogen
what is the most ancient immune structure?
amebocyte
amebocyte
mobile cell in the body of invertebrates
- move by pseudopodia
- believed to have given rise to a phagocyte (in human body)
pseudopodia
cell membrane protrusions that extend from motile and phagocytosing cells
phagocytosis
the ingestion of bacteria or other material by phagocytes and ameboid protozoans
principle of parsimony
the explanation requiring the fewest assumptions is most likely to be correct
- with all things being equal the simplest explanation tends to be the right one
evolution of the lymphoid tissue
as the immune system evolved from the earliest vertebrates to mammals, the tissues (thymus) were repaired
- new tissue was also developed to assist in immunity (lymph nodes)
evolutionary distribution of lymphoid tissue
- GALT
- bone marrow
- thymus/spleen
- lymph nodes
GALT - evolution
most vertebrates have GALT
bone marrow - evolution
not many vertebrates generate lymphocytes in BM
- specifically sharks and rays are earliest example of organisms with B and T-cells
thymus/spleen - evolution
most vertebrates have some sort of thymus or spleen
lymph nodes - evolution
not all vertebrates have lymph nodes indicating they’re more a recent evolutionary traits
evolution of the innate immune system
- found in vertebrates, invertebrates and plants
- fruit fly is preferred model organism for biological research cause of its well-developed innate immune system
evolution of the adaptive immune system
- found only in subphylum vertebra which includes all animals with a backbone
- only more complex organism within this subphylum have a well-developed adaptive immune system
ex. B and T-cells are only found in jawed vertebrates, not un-jawed
pregnancy and immunity statistics
- over 50% DNA is self
- under 50% DNA is non-self
flux state of pregnancy and immunity
early on in pregnancy there is an activation of the immune system with specific cells (neutrophils, B-cells, etc.) bring recruited to site of implantation
what happens if the specific cells involved in flux state of pregnancy are not recruited?
there will be no implantation
after 12 weeks of pregnancy what happens?
the immune system changes and enters a state of immune dampening
what happens at the end of pregnancy?
immune system changes again and enters another flux where its not as inflammatory as in the beginning
where does every immune cell originate from?
pluripotent hematopoietic stem cells (HSC) in the fetal live and bone marrow
- occurs via hematopoiesis
pluripotent
cells capable of giving rise to several different cell types
where do B and T-cells reach maturity?
- B-cells reach maturity in bone marrow
- T-cells must travel to thymus to complete development
2 lineages of hematopoiesis
- myeloid
- lymphoid
hematopoietic stem cells (HSC)
where every blood cell arises from
blood cell types
- erythrocytes (red bc)
- platelets
- leukocytes (white bc)
HSC characteristics
- self-renewal
- pluripotent (or multipotent)
self-renewal
ability to divide itself to replace “older” cells to keep the pool of stem cells constant
pluripotent in HSC
once a stem cell commits to lineage, it loses it’s ability of self-renewal and becomes a myeloid or lymphoid progenitor cell
myeloid progenitor
cells that have the ability to differentiate into 4 different groups of myeloid cells
- generates the majority of the cells of innate immune system
4 groups of myeloid cells
- granulocyte
- monocyte
- erythrocyte (red bc)
- thrombocyte (platelete)
types of granulocytes
- neutrophil
- eosinophil
- basophil
- mast cell
type of monocyte
macrophage
dendritic cells (DCs)
can arise from either myeloid or lymphoid progenitor cells
- part of both innate and adaptive IS
main function of DCs
capture and engulf antigens that evaded innate IS and present them to adaptive immune cells (T-cells) allowing an adaptive IR to be initiated
what do DCs link?
bridge between innate and adaptive IS as they help communication between branches of IS
what is the most common subset of DCs?
Langerhans DCs
Langerhand DCs
located under the surface epithelium of the skin in the mucus membrane
what were the first cells discovered of the IS?
DCs in 1868
lymphoid progenitor cells
have the ability to differentiate into the 2 major types of cells of the adaptive IS (B-cells and T-cells)
- also has ability to differentiate into NKCs (innate IS)
2 major cell types of the adaptive IS?
B-cells and T-cells
types of B-cells
- plasmocyte (effector B-cell)
- memory B-cell
types of T-cells
- helper T-cells
- cytotoxic T-cells
- memory T-cells
plateletes
- a central contributor to process of coagulation, wound healing and fibrinolysis
- have inflammatory functions that can influence both innate and adaptive IR
what do platelets participate in?
- intervention against microbial threats
- recruitment and promotion of innate effector cell functions
- modulating antigen presentation
- enhancement of adaptive IR
monocytes
phagocytes located in the blood
functions of monocytes
- travel outside the circulatory system by moving across the blood vessel walls
- when they penetrate the tissues, they become macrophages and undergo changes
changes a monocyte undergos to become a macrophage
- cell gets bigger
- increase number and complexity of intracellular structures (pseudopodia, phagosome, lysosome)
- acquire better phagocytic abilities
macrophages
phagocytes located in the tissues
“BIG EATERS”
- most efficient phagocytes
phagocyte
capable of phagocytosis
- ingests and destroys foreign particles, bacteria and cell debris
phagosome
vacuole in cytoplasm of a cell containing a phagocytosed particle enclosed within a part of the cell membrane
lysosome
vacuole containing enzymes that digest particles
what is a lysosome fused with a phagosome called?
phagolysosome
mast cell
granulocytes located in the tissues with large granules containing histamine and other pharmacologically active substances
function of the mast cells
role in development of allergens
***similar to basophils
granulocytes
group of white blood cells characterized by secretory granules in their cytoplasm
neutrophils
most abundant type of leukocyte in the human body
- process characteristics of both granulocytes and phagocytes
granulocyte characteristics of neutrophils
- have polymorphic nucleus
- have granules containing lytic enzymes (peroxidase, lysozyme, etc.) which aid the elimination of infectious agents
phagocytic characteristics of neutrophils
have the ability to engulf and absorb (kill) bacteria
what is the first to arrive at site of inflammation?
neutrophils
lifespan of neutrophils
a few days
dead neutrophils
- opaque yellowish colour
- called pus
- produced in infected tissue
- their sticky DNA forms kind of a net that catches bacteria and cell debris
basophils
- non-phagocytic granulocytes
- have the largest granules
- the least common type of granulocyte
granulocyte characteristics of basophils
- have a polymorphic nucleus
- have granules containing pharmacologically active substances (ex. heparin, histamine)
function of basophils
role in development of allergens
- susceptibility of staining by basic dyes
heparin
a compound that inhibits blood coagulation
eosinophils
phagocytic granulocytes
granulocyte characteristics of eosinophils
- have a polymorphic nucleus
- have granules able to damage parasitic membranes
phagocytic characteristics of eosinophils
phagocytic role is minor in comparison to other phagocytes like neutrophils
function of eosinophils
role in defence against multicellular parasites like helminths
- susceptibility of staining by an acidic red-colour dye called eosine
natural killer cells (NK cells)
- granular lymphocytes
- have granules which contain perforin and granzymes
function of NK cells
- ability to recognize tumour or virus-infected cells despite lacking antigen-specific receptors
- distinguish abnormal cells and destroy them
natural killer T-cells (NKT cells)
share properties of both T-cells and NK cells
perforin
protein released by cytoplasmic granules. that destroys targeted cells by creating lesions like pores in their membranes
granzymes
proteases released by cytoplasmic granules that induce programmed cell death in the target cells
T-cells (T-lymphocytes)
- key players of cell-mediated immunity
- “T” cells mature in the “T”hymus
- non-phagocytic cells that have specific receptors at their cells surface called T-cell receptors (TCR)
characteristics of T-cells
- specificity
- diversity
specificity of T-cells
one T-cell expressed many TCR that recognize the same antigen or epitope
diversity of T-cells
every T-cell in the body recognizes a different antigen through their TCR specificity
T-cell subsets
- helper T-cells (CD4+ T-cells)
- cytotoxic T-cells (CD8+ T-cells)
- regulatory T-cells
regulatory T-cells
play a key role in controlling activation of the IS and prevent development of autoimmune disease
helper T-cells (Th cells)
specialized T-cells that express CD4 co-stimulatory molecule on their cell surface (called CD4+ T-cells)
when do helper T-cells become activated?
when T-cells recognize an antigen - MHC class II complex
effector cells of helper T-cells
when activated, T-cells play a key role in activation of other immune cells such as B-cells, cytotoxic T-cells and macrophages
memory cells of helper T-cells
- generated by activated CD4+ T-cells
- recognize the same specific antigen
- IF the pathogen reinfects the body, these cells display a quicker and stronger response to eliminate threat
MHC class II
cell surface proteins essential for adaptive immunity to recognize foreign molecules
cytotoxic T-cells (Tc-cells or cytotoxic T-lymphocytes)
specialized T-cells that express the CD8 co-stimulatory molecule on their cell surface (called CD8+ T-cells)
when do cytotoxic T-cells become activated?
when they recognize an antigen-MHC class I complex
effector cells of cytotoxic T-cells
when activated, cytotoxic T-cells play a key role in monitoring the cells of the body and eliminating any cells that display foreign antigen complexed with MHC class I (virus infected cells)
memory cells of cytotoxic T-cells
- generated by CD8+ T-cells
- recognize the same specific antigen
- IF the pathogen reinfects the body, these cells display a quicker and stronger response to eliminate threat
B-cells (B-lymphocytes)
- key players of humoral immunity
- non-phagocytic cells that have specific receptors at their cell surface called B-cell receptors (BCR)
- “B”-cells mature in the “B”one marrow
B-cell receptors (BCR)
the membrane-bound form of antibodies
characteristics of B-cells
- specificity
- diversity
specificity of B-cells
one B-cell expressed many BCR that recognize the same antigen or epitope
diversity of B-cells
every B-cell in the body recognizes a different antigen through their BCR specificity
epitope
part of an antigen that is recognized by the IS, specifically by antibodies, B-cells or T-cells
plasmoctyes (plasma cells)
the effector form of the activated naive cells
function of plasmocytes
produce and secrete highly specialized antibodies which have the ability to bind free pathogens or foreign molecules
memory cells of plasmocytes
- generated by the activation of B-cells
- recognize the same specific antigen
- have membrane-bound antibodies (or BCR) that have the same specificity as the mother cell
- IF the pathogen reinfects the body, these cells display a quicker and stronger response to eliminate threat
naive cells
immunocompetent (mature) cells are considered “naive” until they interact with a foreign antigen for the first time
components of the innate IS
- neutrophils
- eosinophils
- basophils
- monocytes
- natural killer cells
- mast cells
components of the adaptive IS
- memory B-cell
- plasmocyte
- helper T-cell
- cytotoxic T-cell
- memory T-cell
components of both the innate and adaptive IS
- macrophages
- dendritic cells
1796
- edward jenner noticed that COWPOX can produce cross-immunity to small pox, through observation that milkmaids were generally immune to smallpox
- milkmaids received blisters from milking dairy cows, and the pus protected them from smallpox since these 2 diseases are similar
pasteurization
- invented by louis pasteur
- demonstrated that pathogens were responsible for spoiling beverages (beer, wine, milk)
- introduced the concept of heat to destroy pathogens
vaccination
pasteurs frist discovery was with a disease called chicken cholera, where he accidentally exposed chickens to attenuated form of the virus and th chickens became immune to the disease
attenuated
less pathogenic form
complement system
tightly regulated network of proteins in the body that has an important role in defence against pathogens and inflammatory response
- “aid” or “complement” killing of bacteria
phagocytic theory
- by elie metchikoff
- hypothesized that the basis of inflammation and major defence mechanism against bacterial infection was a cellular reaction where cells are able to move or migrate in order to reach and internalize solid particles within intracellular vesicles
father or humoral immunity
paul enrich
paul enrich
- introduced concept of transferring blood serum to treat and counteract diphtheria
- recognized presence of bactericidal soluble substances in blood, lead to antibodies
bactericidal
kill bacteria
1913 - charles richet
charles and paul portier discovered anaphylaxis through studies involving dogs
anaphylaxis
state of an organism in which it is rendered hypersensitive, instead of being protective no
1972 - gerald M. edelman and rodney R. porter
- chemical structure of antibodies
- structure allows us to better understand how IS reacts during infection
1987- susumu tonegava
determined mechanism by which IS generated an almost limitless variety of antibodies
2011 - jules hoffman and bruce beutler
- toll-like receptors (TLRs)
- created a better understanding of the component of innate immunity and their complexity
TLR identification
- first was identified in 1994, but role wss unknown
- 1996, TLRs play essential role in fly’s immunity to fungal infection
- 1998, discovered lipopolysaccharides (LPS) are ligand for TLR-4
lipopolysacharrides (LPS)
large molecules found in outer membrane of gram-negative bacteria
- elicit a strong immune response
5 major types of infectious agents
- bacteria
- viruses
- fungi
- protozoa
- helminths
bacteria
unicellular, prokaryotic organisms that have no organized internal membranous structures such as nuclei, mitochondria, or lysosomes
genomes of bacteria
genomes are circular, double-stranded DNA that do not code for as many proteins as eukaryotic genomes
characteristics of cholera
acute, diarrheal illness caused by infection of the intestine with bacterium vibro cholerae
symptoms of cholera
- often mild
- 1 in 10 infected persons will have severe disease characterized by profuse watery diarrhea, vomiting and leg cramps
transmission of cholera
contracted by eating or drinking foods contaminated with the bacterium
diagnosis of cholera
can be diagnosed via a stool sample and rectal swabs
treatment of cholera
can be life-threatening if not treated properly through rehydration therapy and if needed antibiotic treatment
viruses
- can infect a variety of organisms from fungi and bacteria to plants and animals
- are NOT considered organisms because they rely on host cell for metabolism and reproduction
what is a virus particle composed of?
a viral genome or nucleic acid (DNA or RNA) that is surrounded by a protein coat called a CAPSID
- many viruses that infect animals are surrounded by an outer lipid envelope
viral genome
may be double-or-single-stranded (dsDNA, ssDNA, dsRNA, ssRNA)
characteristics of influenza
cause a contagious respiratory illness varying in severity
- 3 main types designated by A, B, and C
symptoms of influenza
- fever
- cough
- sore throat
- headaches
- running or stuffy nose
- muscle or body aches
transmission of influenza
- types A and B are responsible for seasonal flu epidemics every year
- they spread via droplets of saliva from infected people coughing, sneezing or talking
diagnosis of influenza
can be confirmed by quick lab tests on respiratory specimens
treatment of influenza
- most often treated with simple bed rest or antiviral medication
- flu vaccination is a preventative measure that is recommended for everyone over age of 6 months to get annually
fungi
eukaryotic, heterotrophic organisms that have rigid cellulose or chitin-based cell walls
how do fungi primarily reproduce?
forming spores
- these spores cause infection on skin or in lungs
- divided into molds and yeasts
molds
multicellular
yeasts
unicellular
when are people most vulnerable to fungal infections?
when their IS is weakened or if they are taking antibiotics
characteristics of a vaginal yeast infection (vulvovaginal candidiasis (VVC))
- occurs with overgrowth of yeast (candida) in the vagina
- common as nearly 75% have had it once
symptoms of vaginal yeast infection (vulvovaginal candidiasis (VVC))
women= genital itching
men= itchy rash on the penis
transmission of vaginal yeast infection (vulvovaginal candidiasis (VVC))
candida is always present in and on the body in small amounts , but when imbalance in IS occurs, candida can multiply
diagnosis of vaginal yeast infection (vulvovaginal candidiasis (VVC))
- visual examination by a doctor
- confirmed via lab testing of cells collected from vaginal walls
treatment of vaginal yeast infection (vulvovaginal candidiasis (VVC))
antifungal cream, ointment, tablets or suppository
protozoa
- unicellular, heterotrophic eukaryotes
- do not have cell walls so they are capable of a variety of rapid and flexible movements
example of protozoas
amoeba and paramecium
characteristics of malaria
mosquito-borne disease cause by a protozoan parasite in genus plasmodium
symptoms of malaria
- fever
- chills
- flu-like illness
***if left untreated it could lead to death
transmission of malaria
- when a female anopheles mosquito (the vector) infected with the protozoan parasite bites a human, an infection begins that develops into malaria
- comes from travellers from sub-saharan africa and south asia
diagnosis of malaria
identified in blood by microscopic analysis
treatment of malaria
can be prevented by taking preventative drugs when travelling
helminths
- parasitic worms
- simple invertebrates, some of which are infectious parasites
- multicellular and have differentiated tissues
why are helminths difficult to treat?
because drugs that kill helminths are very toxic to human cells
characteristics of schistosomiasis
disease caused by parasitic worms or helmints
symptoms of schistosomiasis
- most people show no symptoms during early phase of infection
- when adult worms present, they produce eggs that travel to intestine, liver, bladder causing inflammation or scarring
- fever
- chills
- lymphoid organ enlargement
- abdominal pain
- diarrhea
***symptoms caused by body’s reaction to eggs produced by worms, not worms themselves
transmission of schistosomiasis
- parasites are found in some types of freshwater snails
- when infectious form of parasite emerges from snail, it infects the water surrounding it
- this water affects humans by infecting skin causing disease
diagnosis of schistosomiasis
- stool or urine sample
- blood sample can confirm if signs of infection
treatment of schistosomiasis
short course of a medication called praziquantel which kills worms
prions
- infectious agent consisting of only protein
- linked yo degenerative disorders of the CNS
protein priors (PrPc)
are and function as normal proteins
what happens IF protein prions (PrPc) misfold?
they are classified as the infectious particles called prions (PrPsc)
normal prions vs abnormal prions
normal prions: can be degraded
abnormal prions: accumulate in brain tissue as they are resistant to degradation
- this causes rapid degeneration of healthy brain tissue and decline in the brain function
simple definition of prions
proteins folded incorrectly
characteristics of bovine spongiform encephalopathy (BSE)
- also mad cow disease
- fatal neurodegenerative disease of cows due to prions
- prions attack the CNS of cows
symptoms of bovine spongiform encephalopathy (BSE)
- nervousness or aggressive behaviour
- difficulty with coordination
- trouble standing up
- reduced milk production
- weight loss
***symptoms not seen immediately - once present cow declines quickly
transmission of bovine spongiform encephalopathy (BSE)
- originated from food fed to cows that contained sheep products infected with scrape (prion disease in sheep)
- humans can become infected with prions by eating contaminated meat
diagnosis and treatment of bovine spongiform encephalopathy (BSE)
not very much prevalent anymore
characteristics of crutzfeldt-jakob disease (CJD)
most common prion human disease
early symptoms of crutzfeldt-jakob disease (CJD)
- loss of muscle coordination
- impaired memory and decision making
- visual disturbances
later symptoms of crutzfeldt-jakob disease (CJD)
- rapidly progressing dementia
2 involuntary muscle jerks - coma and death
transmission of vcrutzfeldt-jakob disease (CJD)
- exposure to brain tissue or spinal fluid from an infected individual
- inheriting mutated prion protein (PRNP) gene (autosomal dominant)
diagnosis of crutzfeldt-jakob disease (CJD)
ruling out other diseases using EEG, cerebrpospinal fluid-based tests or MRI
treatment of crutzfeldt-jakob disease (CJD)
- no specific treatment
- treatments are focused on symptoms, alleviating pain and involuntary movements
