Home About us Contact
|
Home About us Contact | ||
|
|
||
Clonal Nature (clonal + nature)
Selected AbstractsClonal nature of odontogenic tumoursJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 4 2009Carolina Cavaliéri Gomes Background:, Although clonal origin is an essential step in the comprehension of neoplasias, there have been no studies to examine whether odontogenic tumours are derived from a single somatic progenitor cell. The purpose of this study was to investigate the clonal origin of odontogenic tumours. Methods:, Fresh samples of seven ameloblastomas, two odontogenic mixomas, two adenomatoid odontogenic tumour, one calcifying odontogenic cyst, one calcifying epithelial odontogenic tumour (CEOT) and six odontogenic keratocyst (OKC) of female patients were included in this study. After DNA extraction, the HUMARA gene polymorphism assay was performed. Results:, Most of the informative odontogenic lesions studied (12 out of 16) showed a monoclonal pattern. Among the polyclonal cases, two were OKC, one CEOT and one odontogenic mixoma. Conclusions:, Our results suggest that most odontogenic tumours are monoclonal. [source] Genetic variability in environmental isolates of Legionella pneumophila from Comunidad Valenciana (Spain)ENVIRONMENTAL MICROBIOLOGY, Issue 6 2006Mireia Coscollá Summary Legionella pneumophila is associated to recurrent outbreaks in several Comunidad Valenciana (Spain) localities, especially in Alcoi, where social and climatic conditions seem to provide an excellent environment for bacterial growth. We have analysed the nucleotide sequences of three loci from 25 environmental isolates from Alcoi and nearby locations sampled over 3 years. The analysis of these isolates has revealed a substantial level of genetic variation, with consistent patterns of variability across loci, and comparable to that found in a large, European-wide sampling of clinical isolates. Among the tree loci studied, fliC showed the highest level of nucleotide diversity. The analysis of isolates sampled in different years revealed a clear differentiation, with samples from 2001 being significantly distinct from those obtained in 2002 and 2003. Furthermore, although linkage disequilibrium measures indicate a clonal nature for population structure in this sample, the presence of some recombination events cannot be ruled out. [source] Distribution of Bacteroides forsythus genotypes in a Japanese periodontitis populationMOLECULAR ORAL MICROBIOLOGY, Issue 4 2003Y. Huang Bacteroides forsythus is an important pathogen in periodontal diseases and has been associated with advanced and refractory periodontitis. The difficulties associated with culturing this species have meant that the distribution and pathogenic mechanisms of B. forsythus remain unclear. In this study, the arbitrarily primed polymerase chain reaction (AP-PCR) method was used to investigate the genotype distribution of B. forsythus in a Japanese periodontitis population, as well as the relationship between AP-PCR genotypes and periodontal status. B. forsythus reference strain, ATCC 43037T and 137 clinical bacterial isolates from 64 subjects were separated into 11 distinct AP-PCR genotypes using a single randomly-sequenced primer, 5,-CCGGCGGCG-3, (A-05). The majority (80.9%) of B. forsythus strains examined belonged to AP-PCR genotypes I, II, III and IV (accounting for 39.7%, 20.6%, 10.3% and 10.3%, respectively). Types I and III primarily consisted of isolates from chronic periodontitis subjects (80.8% and 85.7%, respectively), while Types II and IV consisted mainly of isolates from aggressive periodontitis subjects (85.7% and 100%, respectively). Except for three subjects who harbored two different B. forsythus genotypes in the oral cavity, all subjects only infected with one genotype intraindividually. These results demonstrate that the AP-PCR method is useful for genotypic analysis of B. forsythus. This species showed a genetic diversity among the investigated population. A clonal nature of B. forsythus infection is suggested. Furthermore, different AP-PCR genotypes of B. forsythus appear to be associated with different types of periodontitis. [source] Engraftment of NOD/SCID/,cnull mice with multilineage neoplastic cells from patients with juvenile myelomonocytic leukaemiaBRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2005Yoichi Nakamura Summary Several lines of evidence indicate the clonal nature of juvenile myelomonocytic leukaemia (JMML), involving myeloid, erythroid, megakaryocyte and B-lymphoid lineages. However, it is unclear whether the T-lymphocyte lineage is involved. We demonstrated that cells from six patients with JMML repopulated in non-obese diabetic/severe combined immunodeficient/,cnull mice and differentiated into granulocytes, monocytes, erythrocytes, B lymphocytes, T lymphocytes and natural killer cells. The percentage of human CD45 antigen-positive cells ranged from 41% to 73% in the murine bone marrow 12 weeks after transplantation. To examine the involvement of lymphocyte subpopulations, we purified human CD3+, CD19+ and CD56+ cells from murine bone marrow cells transplanted from a patient with monosomy 7. Fluorescence in situ hybridization (FISH) showed the clonal marker in 96,100% of purified CD3+, CD19+ and CD56+ subpopulations. These findings support the concept that JMML originates in transplantable multilineage haematopoietic stem cells. This novel murine xenotransplant model should be useful for investigating the nature of stem cells and testing new therapies for patients with JMML. [source] | ||||||||||