M5

• Cell Nucleus


  Contains all genetic material that is necessary for cell reproduction and for regulation of cellular production of protein. Contains genes, or sequences of DNA, that control basic cell functions and allow for cell division
• Cell Membrane


  Thin barrier in the cell which separates the ICF from the ECF that maintain Homeostasis. It consists of: Lipoprotein - lipids and protein, Receptor sites - for neurons and muscle cells, Identifying markers - functions to identify, Channels or pores -passageway of small substance
• Focus Points: Organelles in the cytoplasm important for cellular function

  • Mitochondria produce energy for the cell
  • Endoplasmic reticulum contains ribosomes that produce proteins
  • Golgi apparatus packages proteins
  • Lysosomes contain protein-dissolving enzymes that are important for digestion and the recycling of the nature
• Cell Properties

  • Endocytosis - involves incorporation of material into the cell
  • Pinocytosis - movement of nutrients and needed substances into the cell through specific receptor sites
  • Phagocytosis - involves the destruction of engulfed proteins or bacteria
  • Exocytosis - movement of substances (waste products, hompones, neurotransmitters) out of the cell
• Types of Passive Transport

  • Diffusion - higher to lower concentration
  • Osmosis - lower to high
• Types of Solution

  • Isotonic - same concentration of solutes
  • Hypertonic - higher concentration of solutes than plasma; it draws water from cells
  • Hypotonic - lower concentration of solutes than plasma; water moves from the solution into the cell
• Phases of the Cell Cycle

  • Resting phase (G0)
  • Gathering phase (G1) - when the components needed for cell division are collected by the cell
  • Synthesizing phase (S) - when the DNA and other components are produced
  • Final gathering phase (G2) - when the last substances needed for division are collected and produced
  • M phase - when actual cell division occurs, producing two identical daughter cells
• All cells progress through a cell cycle, which allow them to reproduce
• Anti-infective therapy


  May act on the cells of the invading organisms in several different ways. The goal is interference with the normal function of the invading organisms to prevent it from reproducing and to cause cell death without affecting the host cells
• Penicillins


  Natural antibacterial agents obtained from the mold genus Penicillium
• Types of Anti-infective Activity

  • NARROW - selective in their actions; only effective in very specific metabolic pathways or enzymes
  • BROAD - interfere with biochemical reactions in many different kinds of microorganisms
• Penicillins


  • They are both bacteriostatic and bactericidal, depending on the drug and dosage
  • Bacteria can produce enzymes like beta-lactamases that can inactivate penicillin and other beta-lactam antibiotics
• Penicillin was introduced to the military and considered a "miracle drug"


  World War II
• Types of Anti-infective Activity

  • BACTERICIDAL - drugs that can cause the death of the cells they affect
  • BACTERIOSTATIC - not aggressive against invading organisms but they interfere with the ability of the cells to reproduce or divide
• Penicillin became widely used

  1945
• Gram-positive bacteria


  Stained dark blue or violet by Gram staining. Have a thick peptidoglycan layer and do not have rigid cell walls
• Beta-lactam antibiotics

  Penicillins are mainly referred to as this
• Staphylococcal infections

  Penicillin was first introduced for the treatment of
• Gram-negative bacteria


  Cannot retain the crystal violet stain, instead taking up the counterstain (safranin or fuchsine) and appearing red or pink. Have thin, insignificant peptidoglycan layers and require rigid cell walls for support and protection
• Gram-positive bacteria are able to retain the crystal violet stain because of the thick peptidoglycan layer
• Mutant strains of Staphylococcus developed

  They were resistant to penicillins G and V because of the bacterial enzyme penicillinase, which destroys penicillin
• Because gram-negative bacteria have thin, insignificant peptidoglycan layers, they require rigid cell walls for support and protection
• Penicillin V


  Food in the stomach does not significantly alter its absorption, so it should be taken after meals
• Gram Staining

  • Gram (+) Bacteria
  • Gram (-) Bacteria
• Amoxicillins


  Penicillins that are unaffected by food
• Antibiotic


  A substance produced by a microorganism, which, in minute amounts, is able to inhibit other microorganisms. Therefore, this term is properly applied only to compounds directly derived from microorganisms
• Penicillin G


  • The first penicillin administered orally and by injection
  • About one third (1/3) of the oral dose is absorbed
  • IV and intramuscular administration is more effective in achieving a therapeutic serum penicillin level
• Antibacterial agent


  Any compound - natural, synthetic or semisynthetic - that is clinically useful in the treatment of bacterial infections
• Procaine penicillin


  • A longer-acting form of penicillin produced to extend the activity of the drug
  • Procaine (an anesthetic) in the penicillin decreases the pain related to injection
• Bacteriostatic agents


  Inhibit bacterial growth (e.g. sulfonamides, chloramphenicol)
• Penicillin V


  • The next type of penicillin produced
  • Two thirds (2/3) of the oral dose are absorbed by the gastrointestinal (GI) tract
  • Less potent antibacterial drug than penicillin G
  • Effective against mild to moderate infections, including anthrax as a weapon of bioterrorism
• Bactericidal agents


  Significantly reduce (99.9%) the number of viable bacteria in the culture (killing effect). Bactericidal effect in vivo is obtained in cooperation with host's defense mechanisms
• Basic Penicillins


  • Penicillin G procaine
  • Penicillin G Benzathine
  • Penicillin G Sodium
  • Penicillin VK
• Antibacterial agent types

  • Narrow spectrum - preferentially active against either gram-negative or gram-positive bacteria
  • Broad-spectrum - active against both gram-positive and gram-negative bacteria
• Antibacterial agent types

  • Concentration dependent - the antibacterial effect depends on the achievement of high concentrations; it doesn't matter for how long this concentration lasts (e.g., gentamycin)
  • Time dependent - the antibacterial effect depends on the achievement of active concentrations according with period of time when active concentration > MIC (minimum inhibitory concentration); the raise of the dose doesn't improve the antibacterial effect (e.g., beta-lactam antibiotics)
• Broad-Spectrum Penicillins (Aminopenicillins)


  • Used to treat both gram-positive and gram-negative bacteria
  • Not as broadly effective against all microorganisms as they were once considered to be
  • Costlier than penicillin and therefore should not be used when ordinary penicillins, such as penicillin G, are effective
• Qualities of the ideal antimicrobial drug

  • Selective toxicity
  • Broad antimicrobial spectrum
  • Good diffusion in the tissues
  • Good persistence in active form
  • It should not produce hypersensitivity reactions (allergy or anaphylactic shok)
  • Bacteria should not develop resistance
  • Cheap
• Broad-Spectrum Penicillins (Aminopenicillins)


  • Effective against some gram-negative organisms such as E. coli, H. influenzae, Shigella dysenteriae, Proteus mirabilis, and Salmonella species
  • Not penicillinase resistant; readily inactivated by beta-lactamases, so ineffective against S. aureus
• Penicillinase-Resistant Penicillins (Antistaphylococcal Penicillins)


  • Used to treat penicillinase-producing S. aureus
  • Not effective against gram-negative organisms and less effective than penicillin G against gram-positive organisms
• General criteria for effective antibiotic activity

  • Microorganism: An unique and vital target (specific protein or nucleic acid), that is susceptible to low concentration of the antibacterial agent, must exist in the organism; this target must be sufficiently different from the host's target in order to minimize side effects (ex. peptidoglycan)
  • Antibacterial agent: The antibacterial agent must be able to penetrate the bacterial surface and reach the target in its active form. The antibacterial agent needs to reach the infected tissue
  • Host: Intact immune system. The immune system of the host must be able to collaborate effectively in the fight against the invading organism. The integrity of the phagocytes is particularly important. Bacterial infections are difficult to be treated in neutropenic patients and in those with primary or secondary immune-deficiencies
  • Host - Irrigation and drainage: Impaired blood supply or drainage of the infected area usually diminishes the efficiency of the antibacterial therapy. Bacterial endocarditis, osteomyelitis, and abscesses are associated with minimal irrigation of the infected tissue. Bronchi ectasia (lung disease), kidney stones, and gallbladder stones impair drainage of bronchial secretions, urine and bile, respectively; this may be the cause to extremely difficult to treat bacterial infections, unless the obstruction or anatomical abnormality is surgically removed