Assuntos
Cromossomos Humanos Par 16/genética , Cromossomos Humanos Par 6/genética , Telômero/genética , Translocação Genética , Adulto , Bandeamento Cromossômico , Quebra Cromossômica/genética , Saúde da Família , Evolução Fatal , Feminino , Humanos , Hibridização in Situ Fluorescente , Lactente , Cariotipagem , Masculino , LinhagemRESUMO
It has been proposed recently that the type of genetic instability in cancer cells reflects the selection pressures exerted by specific carcinogens. We have tested this hypothesis by treating immortal, genetically stable human cells with representative carcinogens. We found that cells resistant to the bulky-adduct-forming agent 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) exhibited a chromosomal instability (CIN), whereas cells resistant to the methylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) exhibited a microsatellite instability (MIN) associated with mismatch repair defects. Conversely, we found that cells purposely made into CIN cells are resistant to PhIP, whereas MIN cells are resistant to MNNG. These data demonstrate that exposure to specific carcinogens can indeed select for tumor cells with distinct forms of genetic instability and vice versa.
Assuntos
Carcinógenos/toxicidade , Imidazóis/toxicidade , Metilnitronitrosoguanidina/toxicidade , Repetições de Microssatélites/efeitos dos fármacos , Western Blotting , Linhagem Celular , Hibridização in Situ FluorescenteRESUMO
We present a new strategy for the detection of subtelomeric rearrangements. This approach is based on two hybridizations with different probe sets. The first set consists of microdissected subtelomeric probes (each 5-10 megabases in size) labeled combinatorially employing 7 different fluorochromes. With this set, subtelomeric interchromosomal exchanges can be detected in a 24-color experiment. The second set comprises a second generation of subtelomeric PAC-, P1- and BAC-clones. Probes for p- and q-arms are labeled with two different colors. This second set detects small deletions; in addition it provides regional information, so that translocated material identified by the first probe set can be assigned to the p- or q-arm of a chromosome. The test has been evaluated in a blind study on a series of subtle translocations and deletions.
Assuntos
Cromossomos Humanos/genética , Telômero/genética , Translocação Genética , Coloração Cromossômica , Humanos , Metáfase , Deleção de SequênciaAssuntos
Cromossomos Humanos Par 12/genética , Duplicação Gênica , Heterogeneidade Genética , Hipopigmentação/genética , Mosaicismo/genética , Trissomia/genética , Anormalidades Múltiplas/genética , Adulto , Criança , Pré-Escolar , Bandeamento Cromossômico , Quebra Cromossômica/genética , Deleção Cromossômica , Cromossomos Artificiais de Levedura , Cromossomos Humanos Par 7/genética , Feminino , Fibroblastos , Genótipo , Humanos , Hibridização in Situ Fluorescente , Lactente , Recém-Nascido , Deficiência Intelectual/genética , Cariotipagem , Linfócitos , Masculino , FenótipoAssuntos
Aminopterina/farmacologia , Fragilidade Cromossômica , Cromossomos Humanos Par 2/genética , Antagonistas do Ácido Fólico/farmacologia , Comunicação Interventricular/genética , Adulto , Sítios Frágeis do Cromossomo , Cromossomos Humanos Par 2/efeitos dos fármacos , Cromossomos Humanos Par 2/ultraestrutura , Feminino , Humanos , Recém-Nascido , MasculinoRESUMO
A 10-year-old boy with a de novo del(16)(q12.1q13) and many features of the deletion 16q phenotype is described. The deletion occurred in a paternal chromosome as demonstrated by DNA studies with polymorphic (AC)n microsatellite repeat markers. Comparison with published cases suggests that deletion of either of two regions (q13 and q22.1) on the long arm of chromosome 16 is associated with an apparently identical phenotype. No parental imprinting of this region was demonstrated.
Assuntos
Anormalidades Múltiplas/genética , Deleção Cromossômica , Cromossomos Humanos Par 16 , Síndrome de Pierre Robin/genética , Adulto , Doenças do Desenvolvimento Ósseo/genética , Criança , Bandeamento Cromossômico , Surdez/genética , Feminino , Humanos , Deficiência Intelectual/genética , Masculino , Reação em Cadeia da Polimerase , SíndromeRESUMO
Following sporadic reports on persistent Schistosoma mansoni (S.m) infections in Israelis of Yemeni origin, we systematically surveyed a group of 129 individuals who immigrated to Israel 38 years ago. Physical examination was uneventful in all members of the study group. A single stool examination revealed S.m eggs in 15 of 129 subjects (12%). Specific anti-S.m. IgE was detected in the sera of 48 individuals (37%). Among the 15 egg-positives, 14 had specific IgE (sensitivity 93.3%), but only 80 of the 114 egg-negatives were also negative for specific IgE (specificity 70%). This specific IgE positivity among egg-negatives in the study group (34/114) and its complete absence from two control groups, one of them comprising Yemenites born in Israel, suggest either an S.m infection with low egg output stemming from a low worm burden or low fecundity of senescent worms, or occult infections. Since the S.m infections could not have been contracted in Israel, our findings point to inordinately persistent infections in the members of our study group, and incidentally also to the diagnostic usefulness of specific IgE testing in such cases.
