RESUMEN
Acute and chronic treatment of Chinese hamsters and mice with 5, 25 and 125 mg/kg isoniazid (INH) given by oral intubation did not enhance the chromosomal aberration frequencies in spermatogonia. The structural and numerical aberration rates remained in the range of spontaneous events even after the chronic treatment over 12 weeks with 3 x 125 mg/kg INH per week. This dose is much higher than normally used for prevention and therapy in man (3--16 mg/kg).
Asunto(s)
Isoniazida/farmacología , Espermatogonias/efectos de los fármacos , Espermatozoides/efectos de los fármacos , Animales , Aberraciones Cromosómicas , Cricetinae , Masculino , Ratones , Factores de TiempoRESUMEN
Meiotic chromosomes of spermatocytes from INH-treated male mice and Chinese hamsters were analysed for chromosome aberrations in diakinesis-metaphase I and metaphase II. The experiments were performed in two laboratories while a third laboratory participated in the chromosome evaluation. No enhancement of chromosome aberrations could be observed after acute treatment of early primary spermatocytes or chronic treatment of spermatogonia with INH.
Asunto(s)
Isoniazida/farmacología , Espermatocitos/efectos de los fármacos , Espermatozoides/efectos de los fármacos , Animales , Aberraciones Cromosómicas , Cromosomas/efectos de los fármacos , Cricetinae , Masculino , Meiosis , Metafase , Ratones , Factores de TiempoRESUMEN
Within a period of only three months meningococci, Sero B, C and also Y, were detected among the patients of a hospital. The meningococci were isolated as sole pathogen, or in association with other bronchopathogens in five cases of purulent respiratory tract infection, most of whom were suffering from acute or chronic bronchitis. The pathogens were initially identified falsely as "facultative" Neisseria subflava. It is stressed that meningococci must be considered as possible pathogens in such infections if large numbers of the socalled facultative Neisseria have been detected with corresponding culture findings. Reference is made to the possible epidemiological significance of such findings.
Asunto(s)
Bronquitis/microbiología , Infecciones Meningocócicas/microbiología , Neisseria/aislamiento & purificación , Esputo/microbiología , Anciano , Humanos , Masculino , Infecciones Meningocócicas/diagnóstico , Persona de Mediana Edad , Neisseria/clasificaciónRESUMEN
In one short-term-experiment and one long-term-experiment spermatogonia of mice and Chinese hamsters were compared for their sensitivity of X-ray induced chromosome aberrations. Short-term-experiment: Six hours after varying doses of X-rays the spermatogonia of both species were analysed and the number of induced chromatid breaks determined. At the dose range from 25-125 R the number of induced chromatid breaks per cell per roentgen is 0.01 in mice. In Chinese hamsters this value is 0.0072. The frequencies of chromatid breaks were studied in both species after a single dose of 100 R until 48 h p.i. The frequency in mice decreased more slowly than in hamster spermatogonia. After 12 h p.i. the ratio breaks in mice cells: breaks in hamster cells was 3.5:1, after 24 h this ratio was 5.2:1 after 48 h both frequencies were on the same level. Long-term-experiment: Analysis of spermatogonia and primary spermatocytes has been done 5 weeks after irradiation of the mice and 2, and 4 months after irradiation of the Chinese hamsters. The number of observed reciprocal translocations turned out to be higher in spermatogonial mitoses than in diakinesis-metaphases I in each animal. The conclusion is drawn for mice that a selection against abnormal cells is taking place already during pre-meiosis. In hamster pre-meiosis, the results are only indicative for a similar effect.
Asunto(s)
Aberraciones Cromosómicas , Genética de Radiación , Espermatogonias/efectos de la radiación , Espermatozoides/efectos de la radiación , Animales , Cricetinae , Masculino , Ratones , Selección Genética , Epitelio Seminífero/efectos de la radiación , Espermatocitos/efectos de la radiación , Translocación Genética , Rayos XRESUMEN
NMRI mice were treated with single doses of cyclophosphamide (Cytoxan) and spermatogonia were analysed for chromosome aberrations at various time intervals after treatment. The maxima of aberrations were found 24 hrs p.i. Chromatid type aberrations were observed exclusively. About half of the aberrations consisted of chromatid interchanges, 92% of which exchanging short arm fragments close to the centromeric region. The lack of meiotic multivalents in diakinesis-metaphase I after treatment of spermatogonia stem cells with cyclophosphamide in the study of Leonard and Linden (1972) is discussed.