World without Cats

  Autoclave: A type of sterilizer that kills microbes using steam under pressure.

  B-cells: (Also called B-lymphocytes.) Lymphocytes which, when properly stimulated, manufacture antibodies that enter the blood.

  BSL-1, 2, 3, & 4: Biosafety levels. Each designation refers to specifications for laboratory design in which microorganisms of potential danger are to be investigated:

  a) BSL-1 labs—Those where any microbes to be investigated are considered not dangerous. Access to the labs is not limited to trained personnel. A high-school science lab is an example.

  b) BSL-2 labs—Those where potentially dangerous organisms might be investigated. Example: a clinical microbiology laboratory in a hospital. Access to the lab is limited to trained personnel. Protective clothing, such as laboratory coats, are worn by lab personnel. Many procedures are carried out in biological safety cabinets equipped with HEPA filters.

  c) BSL-3 labs—Labs where dangerous pathogens, such as the tuberculosis bacterium, pose a danger to others if spread through the air or by objects. Access to the lab is limited to highly trained personnel. Protective clothing, such as smocks, scrub suits, or coveralls, is worn by the lab personnel. Almost all work is conducted in biological safety cabinets.

  d) BSL-4 labs—Labs where the most dangerous pathogens (Ebola, anthrax, etc.) are investigated. All air leaving the lab is HEPA-filtered. Entry to the lab is by means of an airlock. The lab is maintained under negative air pressure so that when a portal is opened, air does not readily leave the lab. Access to the lab is limited to highly trained personnel. Street clothing is removed in a changing room. Personnel wear special protective clothing. They decontaminate the protective clothing on exiting the lab and shower before donning their street clothes. All work is done in biological safety cabinets. These labs are generally in separate buildings dedicated to their use.

  Bacterium: A type of microbe whose cells lack most of the membranous structures found in cells of higher organisms. Examples: E. coli; Staphylococcus aureus.

  Buffer: An aqueous solution that resists changes in acidity. Example: human plasma.

  Calicivirus: A type of virus responsible for upper respiratory infections and mouth ulcers in cats.

  Capacitation: Changes in spermatozoa by which they become capable of fertilizing ova.

  cDNA: Single-stranded DNA complementary to a sequence of RNA. cDNA is a normal intermediate in the replication of retroviruses. It is also commonly synthesized in the laboratory as a research tool.

  Clone: A group of cells descended from a single ancestral cell.

  DNA (deoxyribonucleic acid): A polynucleotide having a specific sequence of nucleotides that, when decoded by cellular machinery, determines all the hereditary traits of an organism.

  dsRNA (double-stranded RNA): Most RNA in the cell is single-stranded. Most DNA is double-stranded. However, a small amount of dsRNA is found in cells, where it acts as a regulator of gene function. It is also produced by many, perhaps all, retroviruses. dsRNA plays an important role in RNA interference (RNAi).

  Ebola: A virus causing a severe, generally fatal, hemorrhagic disease (Ebola hemorrhagic fever—EHF) of primates, including humans.

  Electrophoresis: A lab technique by which dissimilar substances can be separated from one another by the different rates of movement of their molecules in an electric field.

  Endemic: Of a disease that is always found in a distinct geographical area. For example, malaria is endemic in Kenya.

  ELISA (Enzyme-linked immunosorbent assay): A sensitive immunological test for identifying antigens or antibodies. Its many uses include identification of viruses (HIV, Ebola, etc.) in human or animal fluids.

  Envelope: Outer membranous capsule surrounding some viruses. The membrane is acquired during development of the virus when it exits the host cell and a portion of that cell is budded off, enclosing the viral particle.

  Enzyme: A protein capable of speeding up a specific biochemical reaction. There are thousands of different enzymes in living organisms.

  Epidemic: An outbreak of a disease in a human population characterized by a significant increase in the number of cases over the normal (endemic) level.

  epithelium (plural: epithelia): A type of tissue forming the lining of all body surfaces. examples: cells comprising the skin or lining the mouth and digestive tract.

  Epizootic: An outbreak of a disease in an animal population characterized by a significant increase in the number of cases over the normal level.

  Escherichia coli (E. coli): A common intestinal bacterium. Often used as a research tool because it’s genome has long been known. This microbe has occasionally achieved notoriety owing to the fact that some strains are pathogenic and can cause food poisoning.

  Feline AIDS: An AIDS-like disease of cats caused by the Feline Immunodeficiency Virus (FIV)

  Feline hemorrhagic fever (FHF): A fictional infectious hemorrhagic disease of cats characterized by sudden onset, rapid progression and death within hours or days.

  Feline leukemia: A contagious viral disease of cats clinically similar to leukemia (a cancerous proliferation of leukocytes) in other animals and characterized by gradual loss of weight, malaise, and, eventually, death.

  Feline Leukemia virus (FeLV): The causative agent of feline leukemia.

  Felis catus: The scientific name of the domestic cat.

  Fermentor: A vat capable of providing optimal conditions for the growth of industrial microbes used for producing vitamins, antibiotics, and other biochemical compounds.

  FIV: See Feline AIDS.

  Follicle-stimulating hormone (FSH): A pituitary hormone that stimulates egg maturation in females.

  Gene: A portion of DNA responsible for a single (or closely related group of) function(s).

  Genome: The entire complement of genes of an organism.

  Globin: Any of several polypeptide chains that make up hemoglobin. In the adult mammal, hemoglobin contains two alpha-globin and two beta-globin subunits.

  Gonadotropin: Name given to several hormones secreted by the anterior lobe of the pituitary gland. These hormones play a vital role in coordinating functions of the reproductive organs.

  Granulocytes: White blood cells containing intracellular granules.

  Hemoglobin: The protein found in red blood cells responsible for binding to oxygen and transporting it to all parts of the body. Adult hemoglobin is made up of four polypeptide chains, two of alpha-globin and two of beta-globin, as well as four iron-containing heme units.

  HEPA filter (High Efficiency Particulate Air filter): An extremely efficient air filter capable of removing particles no smaller than 0.3 µm in diameter. This includes almost all bacteria, many viruses, as well as pollen, mold spores, and other particles found in dust.

  Heterozygous: The state of having two different alleles (forms) of a given gene, one of which came from the male, and the other from the female parent.

  In vitro: From Latin meaning in glass. Any process or experiment that is performed outside the living organism, such as DNA synthesis in a test tube.

  Laparoscope: A surgical instrument allowing the observation and manipulation of structures inside the abdomen. A small surgical incision is made in the abdominal wall and the laparoscope, and a thin fiber-optic viewing device, is inserted through the hole. Additional surgical probes and instruments can be inserted through the same opening. In this way, surgical procedures are carried out inside the body without the necessity of a large incision.

  Leukocytes: White blood cells.

  Lymphocytes: Small white blood cells that play a key role in immunity by reacting to foreign substances in the body. There are two broad classes:

  B-lymphocytes—Cells that secrete antibodies into body fluids.

  T-lymphocytes—Cells that attack other cells infected with a microbe, and which interact with B-lymphocytes, modulating t
heir activity.

  Macroerythrocytic feline anemia (MEFA): A fictional hereditary disease of cats caused by a mutation in the alpha-globin gene and characterized by swollen red blood cells.

  Messenger RNA (mRNA): A class of specific RNA molecules, each of which is coded for by a specific gene. mRNA functions to carry genetic information from DNA to the sites where proteins are synthesized.

  Micromanipulator: A mechanical device consisting of motors and controls used to position tiny tools and pipettes extremely precisely as the user peers through a microscope.

  Morula: An early stage in embryonic development consisting of a ball of cells.

  Nucleotide: The basic subunit of DNA and RNA. A nucleotide is made up of a sugar molecule (ribose in RNA and deoxyribose in DNA), a phosphate molecule, and a nitrogen-containing organic base. DNA contains the four bases adenine, guanine, cytosine, and thymine. RNA contains the first three, but has uracil instead of thymine.

  Oocyte (pronounced oh-oh-cyte): immature egg cell.

  Panleukopenia (feline): A contagious disease of cats characterized by sudden onset, lack of appetite, and vomiting, generally resulting in death of the cat.

  Plasmids: Small, circular, replicating pieces of DNA found in bacteria and in the nuclei of some higher organisms. They are separate from the organism’s chromosome and carry a limited number of genes.

  Polymerase chain reaction (PCR) A laboratory procedure for replicating DNA. It is commonly used with tiny quantities of DNA samples (such as might be found at a crime scene) to amplify the samples, allowing them to be analyzed and subjected to further experimentation that would be impossible with the original, minute quantities of DNA.

  Polynucleotide: A chain of nucleotides in a specific order. The two important polynucleotides, DNA and RNA, carry information in the sequence of the bases in their nucleotides. That sequence in DNA comprises the genetic information passed from generation to generation. RNA obtains its base sequence as it is copied off of a DNA template and is the means by which the information in genes is used to carry out cellular functions such as protein synthesis.

  Polypeptide chain: A chain of amino acids bonded to each other in a unique sequence. A protein molecule is made up of one or more such chains.

  Promoter: A sequence of nucleotides on DNA that signals where the copying of a molecule of RNA is to start.

  Pronucleus: A fertilized ovum has two nuclei, one from the ovum itself, and the other from the spermatozoon that fertilized it. These two nuclei are referred to as pronuclei at this stage. After they fuse and the DNA of the pronuclei undergo recombination, the resulting zygote contains only one nucleus.

  Provirus: A viral genome integrated into the host chromosome and passed on to succeeding cell generations as the chromosome is replicated. Example: FeLV in cats is often present as a provirus.

  Protein: A molecule consisting of one or more polypeptide chains. Proteins have diverse, important functions in living organisms. Most enzymes are made of protein as are muscle fibers, antibodies, and many structural components of skin, connective tissue, and many other components of the organism.

  Recombinant DNA: DNA formed by the breaking of DNA strands from different sources (such as different chromosomes or different parents), and their reconnection into new sequences. Formed naturally in the process of fertilization or artificially in the laboratory.

  Retrovirus: A virus with an RNA genome. In the course of their reproduction such viruses use this RNA to make DNA copies (cDNA) using an enzyme called reverse transcriptase.

  Reverse transcriptase: An enzyme found in retroviruses that catalyzes the synthesis of cDNA from an RNA template.

  Rhinotracheitis (feline): An infectious upper-respiratory-tract disease, not unlike a severe cold in humans. Caused by a variety of viruses, including caliciviruses and Feline Viral Rhinotracheitis Virus (FVR).

  RNA: (ribonucleic acid) A polynucleotide having a specific sequence of nucleotides, whose sequence of bases is copied from a DNA template.

  RNA interference (RNAi): The destruction of messenger RNA (mRNA) by a complex process that involves small-interfering RNA (siRNA), double-stranded RNA (dsRNA), and several enzymes. RNAi is thought to play an important role in regulation of cellular function as well as in defense against retroviruses.

  Small interfering RNA (siRNA): Short segments of RNA about 22 nucleotides long. The siRNA is derived from partial digestion of dsRNA by an enzyme named dicer. It is an intermediate in the process known as RNA interference (see above).

  Stem cells: Certain undifferentiated cells found in multicellular organisms having the potential to differentiate into any of a wide variety of cells. Two broad categories of stem cells are embryonic stem cells and adult stem cells. In the course of embryonic development, stem cells play a seminal role, as they differentiate into the various types of cells comprising the organism—muscle, epithelia, nerve cells, etc. In the adult (here, meaning the organism at any age after birth), the primary function of stem cells is to replace cells that die and to repair damaged tissue.

  T-cells: (Also called T-lymphocytes.) See lymphocyte.

  Transfer RNA (tRNA): A class of specific RNA molecules, each of which binds to a specific amino acid and, by pairing with three bases on mRNA, brings the amino acid to its correct position in a growing polypeptide chain.

  Vector: In the context of molecular biology, any agent that can carry a piece of DNA into a cell. It can function in either of two ways:

  a) Cloning vector—used for reproducing the DNA fragment.

  b) Expression vector—used for making a gene product (e.g. a polypeptide chain) from the imported gene. Examples: plasmids, bacterial viruses, and retroviruses.

  Virogene: One or more genes found on the host’s chromosome with the information to synthesize a virus or its components.

  Virus: A particle composed of nucleic acid and protein (and, for some viruses, lipid), capable of infecting a cell and using the cell’s biochemical apparatus to reproduce itself. A virus is incapable of reproduction in the absence of a host cell.

  Wright’s stain: A staining procedure used to help distinguish different parts of a cell and to differentiate diverse types of cells. It is commonly used to stain blood smears, allowing the observer to make out the various types of white blood cells.