Subject(s)
Chromosome Mapping , Molecular Biology , Muscular Dystrophies/genetics , Base Sequence , Cloning, Molecular , DNA/genetics , Disease Models, Animal , Dystrophin , Gene Expression Regulation , Genetic Carrier Screening , Humans , Muscle Proteins/genetics , Muscular Dystrophies/diagnosis , Prenatal Diagnosis , Protein BiosynthesisABSTRACT
Detailed analysis of a large region of genomic DNA is facilitated by generating overlapping clones covering the entire region. These clones are usually obtained by bidirectional "walking" using either bacteriophage lambda or cosmid cloning vectors. This is a slow procedure when starting from a single start site. Multiple start sites are an advantage, and here we describe a method of generating clones from an extensive region of the Duchenne muscular dystrophy locus by preparative pulsed field gel electrophoresis using the chromosome of interest isolated in a cell hybrid. We have generated 12 clones mapping to an 840-kb SfiI fragment of DNA from the Xp2.1 region of the X chromosome, where the DMD gene has been localized. Further localization of these clones to the four subregions of the 840-kb fragment indicates that the clones are distributed throughout the fragment. The feasibility of using this approach to generate probes close to other loci is discussed.
Subject(s)
DNA/genetics , Genes , Muscular Dystrophies/genetics , Animals , Chromosomes, Human, Pair 21 , Cloning, Molecular , DNA/isolation & purification , Electrophoresis, Agar Gel/methods , Genetic Vectors , Humans , Hybrid Cells/cytology , Mice , Nucleic Acid Hybridization , Restriction Mapping , Saccharomyces cerevisiae/genetics , Translocation, Genetic , X ChromosomeABSTRACT
Plasmid DNA from an avian strain of Chlamydia psittaci was purified and estimated to be 7.9 kb in size using restriction endonuclease analysis. A 5.9 kb fragment of this plasmid was cloned, mapped and used to screen a range of chlamydial strains. Hybridizing DNA was absent from ovine abortion and arthritis isolates and also from the Cal 10 strain but related sequences were detected in C. psittaci strains of feline pneumonitis, guinea-pig inclusion conjunctivitis, ovine conjunctivitis and C. trachomatis serovar L2. The plasmid DNA from the feline strain was shown to have a distinct restriction endonuclease profile. Similar plasmid sequences were detected in all avian isolates tested: thus the clone may have a useful diagnostic role for the detection of the pathogen in its natural host and in zoonotic episodes.
Subject(s)
Chlamydophila psittaci/genetics , DNA, Bacterial/analysis , Plasmids , Animals , Base Sequence , Birds , Cloning, Molecular , Guinea Pigs , Nucleic Acid Hybridization , Sequence Homology, Nucleic Acid , SheepABSTRACT
We have applied nucleolar organizer region (NOR) silver staining to the promyelocytic leukemia cell line HL-60, before and after dimethylsulfoxide (DMSO) mediated differentiation. The results demonstrated a gradual suppression of rDNA transcription during terminal maturation of these bone-marrow-derived cells and support our hypothesis that there are characteristic NOR staining profiles for different bone marrow cell types.
Subject(s)
Leukemia, Myeloid, Acute/pathology , Nucleolus Organizer Region/ultrastructure , Cell Cycle/drug effects , Cell Differentiation/drug effects , Cell Line , Dimethyl Sulfoxide/pharmacology , Humans , Silver , Staining and LabelingABSTRACT
Over a five-month period 1239 unselected, routine faecal specimens from 856 patients were examined for Clostridium difficile. One hundred specimens representing 69 patients were culture-positive. Toxin was detected in the stool of ten. During the study period, there were 41 Salmonella, 12 Campylobacter and 9 Shigella infections. C difficile was isolated together with Salmonella from 12 patients. No patient required specific treatment for C difficile infection. The significance of these findings is discussed.
Subject(s)
Clostridium/isolation & purification , Cytotoxins/analysis , Feces/microbiology , Adolescent , Adult , Age Factors , Aged , Child , Child, Preschool , Clostridium/pathogenicity , Feces/analysis , Humans , Infant , Infant, Newborn , Middle AgedABSTRACT
In a study of 14 patients who were not treated with either chemotherapy or irradiation, 13 patients had lower sister-chromatid exchange (SCE) frequencies in their bone-marrow cells than in their lymphocytes. For both bone marrow and lymphocytes, there was significant inter-patient variability in SCE frequencies, but there was no correlation between the bone-marrow and lymphocyte values. The effect of exposing bone-marrow cells to busulphan (BUS) in vitro was investigated using doses up to 5.0 microgram/ml. The dose-response relationships between BUS and SCEs in vitro were found to be similar for bone marrow and lymphocytes.
Subject(s)
Bone Marrow/ultrastructure , Busulfan/pharmacology , Crossing Over, Genetic , Lymphocytes/ultrastructure , Sister Chromatid Exchange , Adult , Aged , Breast Neoplasms/genetics , Carcinoma/genetics , Cells, Cultured , Chromosomes/drug effects , Dose-Response Relationship, Drug , Female , Genetic Variation , Humans , Male , Melanoma/genetics , Middle Aged , Skin Neoplasms/geneticsABSTRACT
Sister-chromatid exchanges (SCE( in the peripheral lymphocytes of 13 women and 1 man were scored immediately before, 6 h after and 7 days after the application of a hair dye by a professional hairdresser under normal conditions. All the hair dyes used in this study gave positive results when tested in the Salmonella/microsome test for mutagenic activity. 6 volunteers showed increases and 8 showed decreases in mean numbers of SCE per cell 6 h after dyeing: 2 of these increases and 3 of the decreases wee statistically significant. when the mean SCE per cell of the who group were compared there were no significant difference between the pre-dyeing sample and the 2 samples taken 6 h or 7 days after dyeing. It was concluded that single applications of proprietary hair dyes cause no consistent increase in the SCE levels in the peripheral lymphocytes of the people taking part in this study.
Subject(s)
Chromatids/drug effects , Crossing Over, Genetic , Hair Dyes/pharmacology , Hair Preparations/pharmacology , Sister Chromatid Exchange , Adult , Cells, Cultured , Female , Humans , Lymphocytes/ultrastructure , Male , Mutagenicity Tests , Mutagens , Salmonella typhimurium/genetics , Time FactorsABSTRACT
A second family in which a balanced translocation between 7p and 22q is segregating is described. The clinical features of 2 children with a resulting partial trisomy for 7p are described and compared with the previously described case.
Subject(s)
Chromosome Aberrations/genetics , Chromosomes, Human, 6-12 and X/ultrastructure , Translocation, Genetic , Trisomy , Abnormalities, Multiple/genetics , Child , Chromosome Disorders , Female , Humans , Infant, Newborn , Karyotyping , MaleSubject(s)
Carrier State , Hepatitis B/transmission , Labor, Obstetric , Pregnancy Complications, Infectious/transmission , Carrier State/prevention & control , Female , Hepatitis B/prevention & control , Hepatitis B Surface Antigens/analysis , Humans , Male , Pregnancy , Pregnancy Complications, Infectious/prevention & controlABSTRACT
In vitro exposure of human lymphocytes to busulphan (BUS) produced an increase in chromosome aberrations and in sister-chromatid exchange (SCE) frequency. The distribution of chromosome breaks throughout the karyotype was non-random and they occurred mainly in the G-negative bands. Certain bands had a marked susceptibility to BUS and comparisons with the human chromosome-break distributions reported for a number of drugs revealed that some of these bands were equally susceptible to other alkylating agents. Both the number of chromosome gaps and breaks and the SCE frequency increased with BUS concentration, but only the SCE dose--response was a clearly defined linear relationship. Therefore a standard SCE dose--response curve was constructed for future comparison with the results of similar investigations of patients on BUS therapy.
