Mice, Inbred BALB CBALB 3T3 Cells: Cell lines developed from disaggregated BALB/c mouse embryos. They are extremely sensitive to CONTACT INHIBITION, and highly susceptible to transformation by SV40 VIRUS and murine sarcoma virus (SARCOMA VIRUSES, MURINE).Spleen: An encapsulated lymphatic organ through which venous blood filters.Mice, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.Mice, Inbred C57BLLeishmania major: A parasitic hemoflagellate of the subgenus Leishmania leishmania that infects man and animals and causes cutaneous leishmaniasis (LEISHMANIASIS, CUTANEOUS) of the Old World. Transmission is by Phlebotomus sandflies.Neoplasm Metastasis: The transfer of a neoplasm from one organ or part of the body to another remote from the primary site.Lung Neoplasms: Tumors or cancer of the LUNG.Melanoma, Experimental: Experimentally induced tumor that produces MELANIN in animals to provide a model for studying human MELANOMA.Cell Line, Tumor: A cell line derived from cultured tumor cells.Mice, Nude: Mutant mice homozygous for the recessive gene "nude" which fail to develop a thymus. They are useful in tumor studies and studies on immune responses.Neoplasm Transplantation: Experimental transplantation of neoplasms in laboratory animals for research purposes.Melanoma: A malignant neoplasm derived from cells that are capable of forming melanin, which may occur in the skin of any part of the body, in the eye, or, rarely, in the mucous membranes of the genitalia, anus, oral cavity, or other sites. It occurs mostly in adults and may originate de novo or from a pigmented nevus or malignant lentigo. Melanomas frequently metastasize widely, and the regional lymph nodes, liver, lungs, and brain are likely to be involved. The incidence of malignant skin melanomas is rising rapidly in all parts of the world. (Stedman, 25th ed; from Rook et al., Textbook of Dermatology, 4th ed, p2445)Spores, Fungal: Reproductive bodies produced by fungi.Air Microbiology: The presence of bacteria, viruses, and fungi in the air. This term is not restricted to pathogenic organisms.Spores: The reproductive elements of lower organisms, such as BACTERIA; FUNGI; and cryptogamic plants.Air Pollution, Indoor: The contamination of indoor air.Air Pollutants: Any substance in the air which could, if present in high enough concentration, harm humans, animals, vegetation or material. Substances include GASES; PARTICULATE MATTER; and volatile ORGANIC CHEMICALS.Environment: The external elements and conditions which surround, influence, and affect the life and development of an organism or population.Ontario: A province of Canada lying between the provinces of Manitoba and Quebec. Its capital is Toronto. It takes its name from Lake Ontario which is said to represent the Iroquois oniatariio, beautiful lake. (From Webster's New Geographical Dictionary, 1988, p892 & Room, Brewer's Dictionary of Names, 1992, p391)Nelson Syndrome: A syndrome characterized by HYPERPIGMENTATION, enlarging pituitary mass, visual defects secondary to compression of the OPTIC CHIASM, and elevated serum ACTH. It is caused by the expansion of an underlying ACTH-SECRETING PITUITARY ADENOMA that grows in the absence of feedback inhibition by adrenal CORTICOSTEROIDS, usually after ADRENALECTOMY.Psychology, Experimental: The branch of psychology which seeks to learn more about the fundamental causes of behavior by studying various psychologic phenomena in controlled experimental situations.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Concept Formation: A cognitive process involving the formation of ideas generalized from the knowledge of qualities, aspects, and relations of objects.MassachusettsWord Association Tests: Lists of words to which individuals are asked to respond ascertaining the conceptual meaning held by the individual.BostonClavulanic Acid: Clavulanic acid and its salts and esters. The acid is a suicide inhibitor of bacterial beta-lactamase enzymes from Streptomyces clavuligerus. Administered alone, it has only weak antibacterial activity against most organisms, but given in combination with other beta-lactam antibiotics it prevents antibiotic inactivation by microbial lactamase.Clavulanic Acids: Acids, salts, and derivatives of clavulanic acid (C8H9O5N). They consist of those beta-lactam compounds that differ from penicillin in having the sulfur of the thiazolidine ring replaced by an oxygen. They have limited antibacterial action, but block bacterial beta-lactamase irreversibly, so that similar antibiotics are not broken down by the bacterial enzymes and therefore can exert their antibacterial effects.Amoxicillin-Potassium Clavulanate Combination: A fixed-ratio combination of amoxicillin trihydrate and potassium clavulanate.Amoxicillin: A broad-spectrum semisynthetic antibiotic similar to AMPICILLIN except that its resistance to gastric acid permits higher serum levels with oral administration.Penicillins: A group of antibiotics that contain 6-aminopenicillanic acid with a side chain attached to the 6-amino group. The penicillin nucleus is the chief structural requirement for biological activity. The side-chain structure determines many of the antibacterial and pharmacological characteristics. (Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p1065)Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.Penicillin G: A penicillin derivative commonly used in the form of its sodium or potassium salts in the treatment of a variety of infections. It is effective against most gram-positive bacteria and against gram-negative cocci. It has also been used as an experimental convulsant because of its actions on GAMMA-AMINOBUTYRIC ACID mediated synaptic transmission.Laminin: Large, noncollagenous glycoprotein with antigenic properties. It is localized in the basement membrane lamina lucida and functions to bind epithelial cells to the basement membrane. Evidence suggests that the protein plays a role in tumor invasion.Receptors, Laminin: Glycoprotein molecules on the surface of cells that react with or bind to laminin whose function allows the binding of epithelial cells to the basement membrane. The molecular weight of this high-affinity receptor is 67 kD.Macrophages: The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)Tetradecanoylphorbol Acetate: A phorbol ester found in CROTON OIL with very effective tumor promoting activity. It stimulates the synthesis of both DNA and RNA.Cell Adhesion: Adherence of cells to surfaces or to other cells.Fibronectins: Glycoproteins found on the surfaces of cells, particularly in fibrillar structures. The proteins are lost or reduced when these cells undergo viral or chemical transformation. They are highly susceptible to proteolysis and are substrates for activated blood coagulation factor VIII. The forms present in plasma are called cold-insoluble globulins.Macrophages, Peritoneal: Mononuclear phagocytes derived from bone marrow precursors but resident in the peritoneum.Lactobacillus casei: A rod-shaped bacterium isolated from milk and cheese, dairy products and dairy environments, sour dough, cow dung, silage, and human mouth, human intestinal contents and stools, and the human vagina.Listeria monocytogenes: A species of gram-positive, rod-shaped bacteria widely distributed in nature. It has been isolated from sewage, soil, silage, and from feces of healthy animals and man. Infection with this bacterium leads to encephalitis, meningitis, endocarditis, and abortion.Listeriosis: Infections with bacteria of the genus LISTERIA.Alanine Transaminase: An enzyme that catalyzes the conversion of L-alanine and 2-oxoglutarate to pyruvate and L-glutamate. (From Enzyme Nomenclature, 1992) EC 188.8.131.52.Listeria: A genus of bacteria which may be found in the feces of animals and man, on vegetation, and in silage. Its species are parasitic on cold-blooded and warm-blooded animals, including man.Probiotics: Live microbial DIETARY SUPPLEMENTS which beneficially affect the host animal by improving its intestinal microbial balance. Antibiotics and other related compounds are not included in this definition. In humans, lactobacilli are commonly used as probiotics, either as single species or in mixed culture with other bacteria. Other genera that have been used are bifidobacteria and streptococci. (J. Nutr. 1995;125:1401-12)Cytophagocytosis: The engulfment and degradation of cells by other cells.Bibliometrics: The use of statistical methods in the analysis of a body of literature to reveal the historical development of subject fields and patterns of authorship, publication, and use. Formerly called statistical bibliography. (from The ALA Glossary of Library and Information Science, 1983)Publications: Copies of a work or document distributed to the public by sale, rental, lease, or lending. (From ALA Glossary of Library and Information Science, 1983, p181)Research: Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. (Webster, 3d ed)Publishing: "The business or profession of the commercial production and issuance of literature" (Webster's 3d). It includes the publisher, publication processes, editing and editors. Production may be by conventional printing methods or by electronic publishing.Biomedical Research: Research that involves the application of the natural sciences, especially biology and physiology, to medicine.PubMed: A bibliographic database that includes MEDLINE as its primary subset. It is produced by the National Center for Biotechnology Information (NCBI), part of the NATIONAL LIBRARY OF MEDICINE. PubMed, which is searchable through NLM's Web site, also includes access to additional citations to selected life sciences journals not in MEDLINE, and links to other resources such as the full-text of articles at participating publishers' Web sites, NCBI's molecular biology databases, and PubMed Central.Academies and Institutes: Organizations representing specialized fields which are accepted as authoritative; may be non-governmental, university or an independent research organization, e.g., National Academy of Sciences, Brookings Institution, etc.