Animals Strains Selection
Mostrando 25-36 de 36 artigos, teses e dissertações.
-
25. A stochastic mechanism controls the relative replication of equally competent ribosomal RNA gene sets in individual dipteran polyploid nuclei.
The endoreplication of the two nucleolar organizers (NOs) of the diploid genome has been examined in individual polyploid nuclei of the dipteran Calliphora erythrocephala. Crosses between two strains with diagnostic nontranscribed spacer polymorphisms in their rRNA genes were used to provide progeny with distinguishable NOs, and single nuclei of two highly p
-
26. R-plasmic transfer from Serratia liquefaciens to Escherichia coli in vitro and in vivo in the digestive tract of gnotobiotic mice associated with human fecal flora.
It was shown that a strain of Serratia liquefaciens harbors a conjugative R-plasmid responsible for reistance to the following 14 antibiotics: ampicillin, carbenicillin, cephalothin, butirosin, neomycin, paramomycin, kanamycin, lividomycin, gentamicin, tobramycin, streptomycin, tetracycline, sulfonamide, and chloramphenicol, which belong to five families, th
-
27. Intestinal intraepithelial lymphocytes include precursors committed to the T cell receptor αβ lineage
The majority of T cells develop in the thymus and exhibit well characterized phenotypic changes associated with their maturation. Previous analysis of intestinal intraepithelial lymphocytes (IEL) from nude mice and a variety of experimentally manipulated models led to the view that at least a portion of these cells represent a distinct T cell population that
The National Academy of Sciences.
-
28. Two related strains of feline infectious peritonitis virus isolated from immunocompromised cats infected with a feline enteric coronavirus.
Two groups of cats were experimentally infected orally with the cat-passaged RM strain of feline enteric coronavirus (FECV-RM). One group of cats (n = 19) had been chronically infected with feline immunodeficiency virus (FIV) for over 6 years, while a second control group (n = 20) consisted of FIV-naive siblings. Fecal virus shedding of FECV occurred in both
-
29. Persistent infection with mouse hepatitis virus 3 in mouse lymphoid cell lines.
The sensitivity of mice to mouse hepatitis virus 3 (MHV3) varies according to strain, age, and immune status of the animals. In semisusceptible strains, mice surviving the acute phase of infection develop a chronic disease characterized by the occurrence of paralysis, virus persistence, and immunodeficiency. Persistent MHV3 infections established in vitro in
-
30. Mutant Selection Window in Levofloxacin and Moxifloxacin Treatments of Experimental Pneumococcal Pneumonia in a Rabbit Model of Human Therapy
For some pneumococci the fluoroquinolone MICs are low but the mutant prevention concentrations (MPCs) are high; this difference defines in vitro the mutant selection window (MSW). We investigated in vivo the bacterial reduction and the occurrence of resistant mutants with moxifloxacin (MFX; 400 mg once daily) or levofloxacin (LVX; 500 mg twice daily) in trea
American Society for Microbiology.
-
31. Contribution of Adhesion to Bacterial Persistence in the Mouse Urinary Tract
The affinity of uropathogenic Escherichia coli to kidneys and bladders of experimentally infected mice was shown to be determined in part by the adhesive properties of the infecting bacteria. Mice were infected with various pairwise combinations of two homogeneic sets of bacteria: (i) mutants derived from a human pyelonephritis E. coli isolate which were sel
-
32. Successive generations of mice produced from an established culture line of euploid teratocarcinoma cells
The possibility of utilizing mouse teratocarcinoma stem cells as intermediaries for production of new strains of mice with preselected mutant or foreign genes requires that, after propagation in culture (to allow for genetic manipulation and selection), the cells be capable of normalization and orderly development in carrier embryos and, ultimately, of germ-
-
33. Characterization of Chloramphenicol Resistance in Beta-Hemolytic Escherichia coli Associated with Diarrhea in Neonatal Swine
Ninety beta-hemolytic Escherichia coli isolates associated with diarrhea in neonatal pigs from multiple farms in Oklahoma were investigated for known associated disease serotypes, virulence factors, ribotypes, and antimicrobial susceptibility phenotypes. Fifteen different serotypes were observed, with 58% of isolates belonging to groups that produce one of t
American Society for Microbiology.
-
34. In Vitro and In Vivo Stability a Cryptococcus neoformans Glucuronoxylomannan Epitope That Elicits Protective Antibodies
The monoclonal antibody (MAb) 2H1 defines an epitope in Cryptococcus neoformans capsular glucuronoxylomannan (GXM) that can elicit protective antibodies. In murine models of cryptococcosis, MAb 2H1 administration prolongs survival and reduces fungal burden but seldom clears the infection. The mechanism by which C. neoformans persists and escape antibody-medi
American Society for Microbiology.
-
35. Lethal and Amanitin-Resistance Mutations in the Caenorhabditis Elegans Ama-1 and Ama-2 Genes
Mutants of Caenorhabditis elegans resistant to α-amanitin have been isolated at a frequency of about 1.6 X 10(-6) after EMS mutagenesis of the wild-type strain, N2. Four new dominant resistance mutations have been studied genetically. Three are alleles of a previously identified gene, ama-1 IV, encoding the largest subunit of RNA polymerase II. The fourth m
-
36. Streptococcus pneumoniae Response to Repeated Moxifloxacin or Levofloxacin Exposure in a Rabbit Tissue Cage Model
The role of moxifloxacin and levofloxacin pharmacokinetics (PK) in antimicrobial efficacy and in the selection of fluoroquinolone-resistant Streptococcus pneumoniae strains was investigated using the rabbit tissue cage abscess model. A rabbit tissue cage was created by insertion of sterile Wiffle balls in the dorsal cervical area. Animals orally received a r
American Society for Microbiology.