The Hall voltage across a conductor in a 55 mT magnetic field is 1.9 mV. When used with the same current in a different magnetic field, the voltage across the conductor is 2.8 mV. What is the strength of the second field?
Chapter 20 What is the difference between narrow and broadspectrum antibiotics When are each prescribed and what are the consequences of each Narrow spectrum antibiotics Consequences only kills microbe causing infection When If you know the microbe causing infection patient is not seriously sick Broad spectrum antibiotics Consequences you can kill many microbes at once affect normal microbes of the patient When If the patient is gravely ill cause of infection is not known What are the five major ways that an antibiotic acts on a bacterial cell Identify modes of action of the following antimicrobial drugs; a. inhibition of cell wall synthesis Betalactams (natural penicillins, semisynthetic penicillins) b. inhibition of protein synthesis (these drugs target the prokaryotic ribosomes and eukaryotic mitochondrial ribosome specifically) streptomycin tetracycline chloramphenicol c. inhibition of metabolic pathways sulfonamides affect synthesis of folic acid (a precursor for DNA/RNA by competitive inhibition) d. inhibition of nucleic acid synthesis Quinolones (like cipro) Describe characteristics you should consider when selecting an antibiotic to treat a disease: a. efficacy (Minimum Inhibitory Concentration MIC/Minimum Bactericidal Concentration MBC) b. route of administration c. safety – toxicity (therapeutic index), allergies, disruption of normal microbiota, side effects d. Cost e. chemical stability What is the difference between bactericidal/bacteriostatic How are the MIC and MBC determined experimentally Bactericidal: kills all microbes Bacteriostatic: inhibits the growth of microbes How do bacteria resist antimicrobial drugs Betalactamase entry of the drug efflux pumps synergism How do we prevent the spread of antibiotic resistant bacteria Chapter 14 Define pathology, etiology, infection, and disease. ● Pathology concerned with interactions between host and pathogen ● Infection the ability of an agent to enter, survive and multiply in the host. ● Disease occurs when the infectious agent actually causes symptoms, and the body is no longer able to function normally ● Etiology what causes the disease Compare commensalism, mutualism, and parasitism. ● Commensalism: one organism benefits and the other is unaffected. ● Mutualism: both organisms benefit ● Parasitism: one organism benefits at the expense of the other List Koch’s postulates. Explain some exceptions to Koch’s postulates. ● The bacterium must be present in every case of the disease ● The bacterium must be isolated from the diseased host and grown in pure culture ● The specific disease must be reproduced when a pure culture of the bacterium is inoculated into a healthy susceptible host ● The bacterium must be recoverable from the experimentally infected host. Exceptions ● Some pathogens can’t be cultured ● Some diseases can involve any number of several pathogens ● Some pathogens can cause several diseases ● Ethically, you can’t reinoculate a human to prove a microbe causes a disease ● Some humans have microbes but no disease Describe the importance of normal microbiota and microbial antagonism. How do normal microbiota become opportunistic pathogens Normal microbiota protect the host via microbial antagonism ● Microbial antagonism where microbes compete with one another for an ecological niche ● Opportunistic pathogens normal microbiota that cause disease under certain circumstances. 1. Immune suppression 2. Changes in normal microbiota 3. Introduction to new site Put the following in proper sequence according to the normal pattern of disease progression: period of decline, period of convalescence, period of illness, prodromal period, incubation period. 1. Incubation period 2. Prodromal period 3. Period of illness 4. Period of decline 5. Period of convalescence Define reservoir of infection. Contrast human, animal, and nonliving reservoirs, and give one example of each. Reservoir: the ecological niche of the pathogen that provides a continual source of infection Human: those that have the disease or those that carry the diseasecausing pathogen but do not have symptoms of the disease Example: salmonella typhi Animal: animals that can also carry a pathogen and transmit that pathogen to humans. These are termed zoonoses. Nonliving: includes soil and water Explain different methods of disease transmission; contact transmission (direct, indirect, droplet),vehicle transmission (waterborne, airborne), mechanical transmission (by vectors), and biological transmission (by vectors). Direct: requires close association between infected and susceptible host Indirect: spread by fomites Droplet: transmission via airborne droplets (that travel less than 1 meter) Vehicle: via air, water (travels more than 1 meter) or food Vector: arthropods, especially fleas, ticks, and mosquitoes Mechanical transmission: arthropod carries pathogen on feet Biological transmission: pathogen reproduces in vector Be able to define the following terms associated with disease progression; acute, chronic, and latent diseases, local, systemic, and focal infections, sepsis, communicable, contagious, and noncommunicable infections. ● Acute disease: symptoms develop rapidly (food poisoning) ● Chronic disease: disease develops slowly (tuberculosis) ● Latent disease: disease with a period of no symptoms when the causative agent is inactive (shingles) ● Local infection: pathogens are limited to a small area of the body ● Systemic infection: an infection throughout the body ● Sepsis: toxic inflammatory condition caused by spread of microbes throughout the body, especially bacteria or their toxins. ● Communicable disease: a disease that is spread from one host to another ● Contagious disease: a disease that is easily spread from one host to another ● Noncommunicable disease: a disease that is not transmitted from one host to another The difference between symptoms and signs. ● Symptoms: subjective characteristics of disease felt only by the patient ● Signs: objective manifestations of disease observed or measured by others What is epidemiology What is prevalence and incidence of a disease ● Epidemiology: the study of occurrence and transmission of disease in a population ● Incidence: # of new cases during a specific time period ● Prevalence: # of cases total at a given time Be able to define endemic, sporadic, epidemic, and pandemic. ● Endemic: disease always present at normal range ● Sporadic Not normally present Rarely occurs ● Epidemic Not normally present Large # of cases in one region ● Pandemic Not normally present Large # of cases in several regions What is the difference between morbidity and mortality Mortality: deaths from notifiable diseases Morbidity: incidence of a specific notable disease Define healthcare associated infections and explain the interacting factors that result in nosocomial infections. How can nosocomial infections be prevented ● Presence of microorganisms in hospital environment ● Immunocompromised patients ● Transmission of pathogens between staff and patients and among patients Infections ● Urinary tract infections ● Surgical site infections ● Lower respiratory infections ● Cutaneous infections How they can be prevented ● Handwashing ● Limiting use of catheters/IVs ● Limiting use of broad spectrum antibiotics Chapter 16 What are the defining properties of innate immunity First line of defense ● Intact skin ● Mucous membranes and their secretions ● Normal microbiota Second line of defense ● Phagocytes, such as neutrophils, eosinophils, dendritic cells, and macrophages ● Inflammation ● Fever ● Antimicrobial substances