Using a modified Giemsa-banding technique we have observed what appear to be chromosomes during interphase in nuclei from Allium cepa root tips and Chinese hamster cells (CHO line). During telophase through G1 chromosomes progressively uncoil and decondense. During S chromosomes are comparatively decondensed, but some segments have structure similar to chromosomes in G1 and G2. During G2 the ch...

Previous studies have shown that the members of the Enterobacter cloacae complex are difficult to differentiate with biochemical tests and in phylogenetic studies using multilocus sequence analysis, strains of the same species separate into numerous clusters. There are only a few complete E. cloacae genome sequences and very little knowledge about the mechanism of pathogenesis of E. cloacae on ...

Moquiniastrum polymorphum subsp floccosum (Cabrera) G. Sancho is used in traditional Brazilian medicine to treat inflammation and infection, which is supported by scientific data. However, only one study has been conducted on the mutagenic activity of the extract, which has important safety implications. This study evaluated the mutagenic/antimutagenic activity of M. polymorphum ethanolic extra...

The exotic syrphid Eumerus strigatus (Fallén) is reported for the first time in Argentina. Individuals of this species were captured two sites distant more than 1,000 km (Villalonga, province Buenos Aires, and Pocito, San Juan) associated with onion crops (Allium cepa L.). We propose monitoring phytophagous hover fly because its potential risk important horticultural crop

Permeability changes of Allium cepa cells were studied by a plasmometric method. Onion epidermis was floated in phosphate buffer solution with kinetin (2.5 milligrams/liter), or buffer without kinetin as a control, for 10 hours. The treated and control tissues were then transferred to one of the following four permeants: thiourea, urea, maloamide, dimethylurea.Kinetin treatment increased the pe...

In the present study we have utilized the Allium cepa root tip meristem model to evaluate the cytotoxic and anti-mitotic activities of latex of Calotropis procera (DL) and podophyllotoxin. Standard cytotoxic drug cyclophosphamide and non-cytotoxic drugs cyprohcptadine and aspirin served as controls. Like cyclophosphamide, both DL and podophyllotoxin significantly inhibited the growth of roots a...

In vivo cytogenetic assay in Allium cepa root tip cells has been carried out to detect the modifying effect of Ocimum sanctum aqueous leaf extract against chromium (Cr) and mercury (Hg) induced genotoxicity. It was observed that the roots post-treated with the leaf extract showed highly significant (p < 0.001) recovery in mitotic index (MI) and chromosomal aberrations (CA) when compared to pre-...

Toxicity and genotoxicity tests were performed on root cells of Allium cepa in order to evaluate wastewater quality following an ECF cellulose bleaching process. The results revealed a toxic effect of the effluent, with inhibition of meristem growth and generally lower values of metaphase, anaphase and telophase indices at pH 10.5 than pH 7 for all effluent concentrations. The genotoxicity effe...

The present study embodied the mutagenic/genotoxic potential of two most commonly used synthetic food dyes, viz., sky blue and orange red, employing Ames Salmonella histidine reversion point mutation assay and Allium cepa root chromosomal aberration assay. It was observed that sky blue and orange red dyes showed 6-fold increase in TA100 strain from the spontaneous count, whereas they showed non...