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chemotherapy

use of a chemical substance to treat different aspects of disease

Chemotherapeutic agent

any chemical substances used in medical practice to treat disease (a.k.a drugs)

antimicrobial agent

agent used to treat diseases caused by microbes

antibiotics

chemical substance produced by microorganisms; have capacity to inhibit growth of bacteria; used in dilute solutions or it can be toxic

synthetic drugs

drugs made by man in a lab

ancient remedies

molded bread on open wounds, plants for external treatment, Karaway seed used in India to treat cancer

Ehrlich

first to use chemical to treat the whole body from disease; coined the term chemotherapy; treated syphilis

Domagk

discovered that prontosil dye prohibits the growth of gram + cells

Flemming

discovered penicillin; noticed that mold from a "spoiled" experiment inhibited the growth of germs; he made a broth that could be effective on wounds

Penicillin

best against Gram + bacteria

selective toxicity

harms the microbes without significantly harming the host

spectrum of activity

the range of microbes that the antibiotic can fight against; an antimicrobial agent refers to the variety of microorganisms sensitive to the agent.

narrow spectrum

those that are effective against only a small number of microorganisms or a single taxonomic group (agents attack only a few different organisms)

broad spectrum

agents that effective against a great number of microorganisms from a wide range of taxonomic groups, including Gram-positive and Gram-negative bacteria; tetracylcines (agents attack many different organims)

5 Drug Mechanisms of Action

-Inhibition of Cell Wall Synthesis
-Disruption of Cell Membrane Function
-Inhibition of Protein Synthesis
-Inhibition of Nucleic Acid Synthesis
-Action of Antimetabolites

inhibition of cell wall synthesis

allow the membrane of the affected microbe to rupture and release the cell contents.

-does not hurt animal cells because they lack a cell wall; best for gram +; i.e. penicillin

disruption of cell membrane function

dissolve the membrane or interfere with the movement of substances into or out of cells.

-act as detergents that distort the lipid cell membrane; best for gram -; i.e. polymixins

inhibition of protein synthesis

prevent growth of microbes by disrupting ribosomes or otherwise interfering with the process of translation.

-inhibits protein synthesis so they cannot produce proteins; i.e. streptomycin

inhibition of nucleic acid synthesis

interfere with synthesis of RNA (transcription) or DNA (replication) or disrupt the information these molecules contain.

-binds to RNA polymerase to stop RNA synthesis by stopping nucleic acid formation

antimetabolites

substances that affect the utilization of metabolites and therefore prevent a cell from carrying out necessary metabolic reactions.
FUNCTION:
-affect normal metabolites by competitively inhibiting microbial enzymes
-or by being erroneously incorporated into important molecules such as nuclei acids

Kinds of Side Effects

side effects antimicrobial agents on the host include toxicity, allergy, and disruption of normal microflora.

-allergic reactions to antimicrobial agents occur when the body reacts to the agent as a foreign substance.

-many antimicrobial agents attack not only the infectious organism but also normal microflora.

-superinfections with new pathogens can occur when the defensive capacity of normal microbiota is destroyed.

sulfanilamide

mimics PABA to inhibit normal cell functions

toxicity

the chemicals could be toxic to the human system

allergy

rashes, itching, anaphylactic shock

anaphylactic shock

body can't regulate itself

disruption of Microflora

kills the good bacteria in the body making it more susceptible to infection

resistance drugs

acquire via genetic change or non-genetic mechanisms or evasion if bacteria live in areas where ab can't reach

natural selection

genetic changes leading to abnormal resistance; occurs spontaneously

chromosomal

mutation in drug receptor

plasmid borne

R plasmid via conjugation, transduction, and transformation

antibiotic resistance

ability to grow in the presence of antibiotics

first/second/third line drugs

how many times its been recreated because of resistance

cross resistance

resistance to 2 or more drugs

pathogen

a parasite capable of causing disease

host

an organism that harbors another organism

symbiosis

"living together"

mutualism

both organisms benefit

commensalism

one organism benefits and the other neither benefits nor is harmed; microbial competition

parasitism

one organism benefits and the other is harmed; antagonism

contamination

microorganisms are present

infection

pathogens invade the body

infestation

presence of worms or arthropods in or on the body

disease

pathogens or other factors disturb the state of health such that the body cannot perform its normal functions

pathogenicity

the ability of the organism to cause disease; certain strains/species can be higher in this ability;bigger picture then virulence

virulence

disease causing power of a pathogen (specific factors)

avirulence

loss of its disease causing power

attenuation

virulence has slightly changed

in vivo

animal passage

in vitro

in culture

en utero

getting microorganisms in our body in birth through the birth canal

teratogenic

harmful to baby

immunocompromised

failure of the host's natural defenses

multiplicity of infection

the more pathogens in system the higher risk for disease

resident microflora

not usually found on our internal organs or deep tissue or blood, or brain, or urine

transient microflora

present temporarily and under certain conditions

opportunists

resident or transient microflora that can cause disease under certain conditions or certain locations of the body

infectious agents

cause infectious diseases; i.e. bacteria, viruses, fungi, protists, and helminths

noninfectious agents

inherited, degenital (born with it), immunological, mental, nutritional deficient

communicable

contagious infectious disease that can be spread from one host to another

non communicable

can't be spread form host to host and may be acquired in soil, water, or contaminated foods

endotoxin

part of the cell wall of Gram - bacteria and are released when cells divide or are killed; highly inflammatory

exotoxin

produced by and released from bacteria; proteins secreted by Gram + (mostly); powerful; i.e. hemolysins

productive infection

leads to the release of a virus progeny

abortive infection

does not produce infectious progeny

latent disease

a disease characterized by periods of inactivity either before symptoms appear or between attacks

persistent infection

the continued production of the infectious parasite within the host over many months or years

sign

observable effect of a disease; swelling, fever, rash

symptom

an effect of a disease felt by the infected person; pain, nausea

syndrome

a group of signs and symptoms that occur together

sequelae

abnormal condition that is a side effect of a disease; pox mark-chicken pox, paralysis-polio

acute disease

a disease that develops rapidly and runs its course quickly

chronic disease

a disease that develops more slowly, is usually less severe, and persists for a long indeterminate period

subacute disease

a disease that is intermediate between an acute and a chronic disease

local infection

an infection confined to a specific area of the body

focal infection

an infection confined to a specific area from which pathogens can spread to other areas

systemic infection

an infection that affects the entire body (generalized infection)

septicemia

an infection caused by rapid multiplication of pathogens in the blood; blood poisoning

bacteremia

an infection in which bacteria are transported in the blood but do not multiply in transit; spreading of bacteria infection

viremia

an infection in which viruses are transported in the blood but do not multiply in transit; spreading of virus infection

primary infection

an initial infection in a previously healthy person

superinfection

a secondary infection from the removal of normal microbiota, allowing colonization by pathogenic, and often antibiotic resistant, microbes

mixed infection

an infection caused by several species of organisms present at the same time

inapparent infection

an infection that fails to produce symptoms, either because too few organisms are present or because host defenses effectively combat the pathogens

incubation period

the time between infection and the appearance of signs and symptoms of a disease; most severe signs and symptoms

prodromal phase

the stage during which pathogens begin to invade tissues; it is marked by early nonspecific symptoms

invasive phase

the period during which the individual experiences the typical signs and symptoms of the disease

acme

during the illness phase of the disease process, the time of most intense signs and symptoms

decline phase

the stage during which host defenses overcome pathogens; signs and symptoms subside during this phase, and secondary infections may occur

convalescence period

the stage during which tissue damage is repaired and the patient regains strength; recovering individuals may still transmit pathogens to others

disease

deviation or interruption of the normal structure of a living organism, accompanied by a set of signs; infectious and non; parasite and disease NOT interchangeable

epidemiology

study of factors and mechanisms in the spread of disease in a population

etiology

the cause of disease

prevalence

number of infected/ total number in population; usually higher number

incidence

number of new infections in some time period/ number of hosts in population

intensity

number of parasites in one host

transmission

move from one infected individual to another (possibly via a vector or direct contact: skin, ingest, transfusion, transplant)

epidemic

affecting a significantly large number of people at the same time

endemic

expected or normal incidence indigenous to a geographical area or population

pandemic

epidemic over a wide geographic area and affecting a large proportion of the population

sporadic

occasional cases occur in irregular intervals at unlikely locations

morbidity

the number of cases compared to the total population

mortality

number of deaths compared to the total population

common source outbreak

spread by a contaminated substance

propagated epidemic

spread by person to person contamination

descriptive

concerned with the physical aspects of an existing disease and disease spread

index case

first case of the disease

analytical

looking and focusing on finding the cause-effect relationship on the occurrence of diseases in a population

experimental

tests a hypothesis often about the value of a particular treatment

reservoirs of infection

sites where organisms can persist and maintain there ability to infect; could be animal or human

portals of entry

sites where microorganisms enter body; open orifice:nose, ears, mouth, etc

portals of exit

sites where organisms leave the body

zoonoses

diseases passed from animal to human

fomites

an object that carries infectious diseases

vehicles

non living carriers

vectors

living object that carries disease; fleas, ticks, mosquitos

horizontal transfer

spreading from one human to another

vertical transfer

passed from mother to child

acute carriers

individuals within incubation period

chronic carriers

...

herd immunity

immunity enjoyed by a large portion of a population that reduces disease transmission among non-immune individuals

isolation

the patient is separated from the general population

quarantine

the seperation of "healthy" population from infected people

notifiable disease

diseases which must be reported to the CDC

nosocomial infections

commonly spread diseases in the hospital; most easily spread are staphylococcus aureus and e. coli

infection control

best way is HANDWASHING

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