摘要:

Cytogenetic effects of an analgesic antipyretic agent Paracetamol were investigated onin vivobone marrow cells of Swiss albino male mice. The mice were orally administered with 0.625, 1.25 and 2.5 mg of Paracetamol. Chromosomal pictures were prepared 24, 48 and 72 h after the administration of the drug. Chromosomal anomalies such as gaps, breaks, fragments and polyploid nuclei were observed. Structural aberrations were of chromatid type. Frequencies of these anomalies suggest that Paracetamol possess a very weak clastogenic and extremely poor c-mitotic influence in single and cumulative dose series. Cumulative doses appears to be more effective.

ISSN:0008-7114    

DOI:10.1080/00087114.1984.10797691

出版商:Taylor & Francis    

年代:1984

数据来源: Taylor

摘要:

Chloroplasts ofMacrozamia mooreiwere observed in submature and mature leaves. Prolamellar bodies and crystalline bodies are an obligate feature in the course of chloroplast development and appear related to thylakoid membrane formation. Mature chloroplasts show randomly oriented grana constituted by a very high number of thylakoids (up to 180 per granum). The probable existence of a cycad-type chloroplast is proposed.

ISSN:0008-7114    

DOI:10.1080/00087114.1984.10797692

出版商:Taylor & Francis    

年代:1984

数据来源: Taylor

摘要:

Karyotype studies were carried out on two fish species of the family Gymnotidae. In five samples ofGymnotus carapofrom different localities chromosome number varied from 2n= 42 to 2n= 54. Specimens from the Amazon Basin had 2n= 42 (Belém—State of Pará) and 2n= 48 (Humaitá - State of Amazonas); from the Paraná Basin, 2n= 52 (Brotas—State of São Paulo) and 2n= 54 (Botucatu—State of São Paulo); from the East Basins, 2n= 54 (Miracatu—State of São Paulo). These differences in diploid number were accompanied by differences in the number of acrocentric chromosomes present in the complement. Only one sample ofGymnotus sp., from Miracatu, was analyzed. Here the diploid number was 2n= 52 and the complement was similar to that ofG. carapofrom Brotas.

ISSN:0008-7114    

DOI:10.1080/00087114.1984.10797693

出版商:Taylor & Francis    

年代:1984

数据来源: Taylor

摘要:

Chenopodium amaranticolorleaves have been supplied with low and high molarity of NaCl. The ultrastructure of the foliar hair shows a cytoplasmic vesiculation when the leaves have been treated with high molarity of NaCl in the light. A similar feature has been described for halophyte salt gland cells. Cytoplasmatic vesicles cannot be observed in dark conditions. PTAC stain, selective for plasmalemma, demonstrated that, in high molarity conditions in the light, some PTAC-positive vesicles are present in the stalk cell, but that they are much less numerous than those detected with the normal counterstain. This may suggest that plasmalemma is not involved in cytoplasmatic vesiculation. Cytochemical detection for Cl−ions shows that in the stalk cell the precipitates do not particularly occur in the cytoplasm but that they are present on the whole plasmalemma profile, inside some vesicles close to it and in correspondence of plasmodesmata. These observations would indicate that at least a part of ion transport occurs in an apoplastic space. The massive accumulation of reaction products can be observed inside the vacuole of the bladder cell, sometimes associated with an electron dense material. Some vesicles interested by precipitates are merging with the bladder cell peripheral plasmalemma suggesting a partial ion secretion. Cl−ion transport seems to be a light dependent process as in dark conditions the number of precipitates diminishes. Na+transport is likewise dependent on light but it occurs through the cytoplasm of the stalk cell. In fact the cytochemical localisation gives reaction products inside the cytoplasm, the endoplasmatic reticulum and some cytoplasmatic vesicles. Na+ion storage mainly occurs in the stalk cell vacuole.

ISSN:0008-7114    

DOI:10.1080/00087114.1984.10797694

出版商:Taylor & Francis    

年代:1984

数据来源: Taylor

摘要:

42,703 metaphases of peripheral lymphocytes from 20 healthy subjects (10 women and 10 men) were examined in order to establish the frequency of endoreduplicated cells and of tetraploid cells without diplochromosomes. Frequencies were found to be 0.016% and 0.112%, respectively. The two sexes did not differ as to the frequency of tetraploid cells, with and without diplochromosomes (about 0.13% in either sex). In a total of 2,135 well spread metaphases examined, 26 cells (i.e. 1.2%) with chromosomal breaks were found. Again, no significant differences between the two sexes were found as to such chromosome abnormalities.

ISSN:0008-7114    

DOI:10.1080/00087114.1984.10797695

出版商:Taylor & Francis    

年代:1984

数据来源: Taylor