Aflatoxicosis in rabbits: Effectiveness of Egyptian raw bentonite in prevention or diminution the detrimental effects of naturally aflatoxin contaminated diets

Thirty five females and 15 males of New Zealand White mature rabbits about 6 months of age, were assigned to 1–5 dietary treatments (7 does+3 bucks for each): uncontaminated control diet, naturally aflatoxin contaminated diet without or with 1,2 and 3% bentonite. Rabbit fed with the aflatoxin-diet had a decreased (P<0.01 or 0.05) physical semen characteristics of bucks and a reproductive performance traits of does. The values of conception rate (%), gestation length (days), litter size (n) and litter weights (g) at birth and viability (%) of litters of doe rabbits, fed with the aflatoxin-diet, recorded, respectively: 64.5; 31.0; 4.4; 275.0 and 57.1 versus 85.6; 30.3; 7.9; 508.0; and 100 for those fed with the uncontaminated diet. Addition of bentonite to the aflatoxin contaminated diet improved in general the physical semen characteristics of buck and reproductive performance traits of doe rabbits. The results of the study demonstrate that adding 1% of Egyptian raw bentonite to the naturally aflatoxin contaminated rabbit diets can provide an effective, cheap and safe practical technique for preventing the aflatoxicosis in mature rabbits.     

The reaction of the neuroblastoma cells in the culture on the influence of tretionine and neurotoxine

Effect of the tretionine (retinoid) and aluminum chloride (neurotoxin) on the growth and differentiation of neuroblastoma cells in culture after their introduction into the medium separately and in combination was studied. The introduction of these substances creates a new information field in the medium, which becomes apparent by the reactions of neuroblastoma found on the populational and cellular levels of its organization. The presence of tretionine stimulates proliferation and induces differentiation of the cells into astrocytes. Aluminum chloride inhibits cell proliferation and enhances the process of their destruction in the monolayer. The variety of the reactions of neuroblastoma cells to the presence of these substances in the medium indicates the existence and functioning of a mechanism that selects from the information introduced only the portion which may contribute to adaptation of neuroblastoma cells to the changed culture conditions.     

Harmful cyanobacteria and their cyanotoxins in Egyptian fresh waters – state of knowledge and research needs

Cyanobacterial blooms have increased in freshwater ecosystems worldwide in the last century, mostly resulting from eutrophication and climate change. These blooms represent serious threats to environmental and human health because of the production of harmful metabolites, called cyanotoxins. Like many countries, Egypt has been plagued with cyanobacterial blooms in most water sources, including the Nile River, irrigation canals, lakes and fishponds. However, the data about cyanotoxins produced in these blooms are limited. Only two types of cyanotoxins, microcystins and cylindrospermopsin, have been identified and characterised, mainly from Microcystis and Cylindrospermopsis blooms. The data revealed the presence of microcystins in raw and treated drinking waters at concentrations (0.05–3.8 µg l^?1), exceeding the WHO limit (1 µg l^?1) in some drinking water treatment plants. In addition, Nile tilapia Oreochromis niloticus caught from ponds containing heavy cyanobacterial blooms have accumulated considerable amounts of cyanotoxins in their edible tissues. The data presented here could be the catalyst for the establishment of a monitoring and management programme for harmful cyanobacteria and their cyanotoxins in Egyptian fresh waters. This review also elucidates the important research gaps and possible avenues for future research on cyanobacterial blooms and cyanotoxins in Egypt.     

Human large intestine adenocarcinoma cells (CaCo-2) in the process of cultivation

Using cytomorphometry and cytophotometry cells of human large intestine adenocarcinoma (CaCo-2) were studied under condition of a 10 day cultivation. A reverse dependence was established between proliferative activity and monolayer density. The increase of the latter inhibits proliferation and promotes the formation of islets of polymorph cells. 2c-cells could be seen only at the beginning of culture growth; a larger part of cells polyploidized by cell blocking in G2-phase. These cells do not divide, which is testified by the absence of 2c-cells, but some part of 4c-cells start the next cycle, accumulates 8c-DNA and then divides, replenishing the 4c-cells population. In the process of cultivation, we observed an increase in the number and total volume of nucleoli in the nuclei, and a rise in DNA amount in the peri-nucleolar chromatin. The formation of numerous 4c-cells with multi-nucleolar nuclei may define an increase of functional activity of CaCo-2 culture as the whole, whereas the formation of separated groups of such cells in the monolayer may denote a possible initiation of their differentiation.     

Behavior of HEp-2 cell line cells, their nuclei and nucleoli during cultivation and under the effect of Na-ds-RNA

The behavior of human larynx cancer cells (HEp-2) and of their nuclei and nucleoli during the cultivation without the influence of Na-ds-RNA and after its introduction into the medium was investigated by methods of cytomorphometry and cytophotometry. The density of monolayer (the number of cells on the area unit), percentage of two-nuclear cells, the number of nucleoli in the nuclei, mitotic coefficient, volume and total surface of nuclei and nucleoli have been measured. In addition, the mass of DNA in the nuclei and that of the total RNA and DNA in the nuclei and in each nucleolus was measured. Cells in the culture, not subjected to the influence of Na-ds-RNA, were weakly differentiated, kept active proliferation, and their population contained a small number of two-nuclear elements and a high share of multi-nuclear cell. During cultivation, these indices became even more pronounced, which is typical for the increase in cell malignancy. Under the influence of Na-ds-RNA, the proliferate activity decreases, the number of double-nuclear cells increases, while that of multi-nucleolar cell decreases; also, the share of cells with one- and two-nucleolar nuclei increases. The authors conclude that Na-ds-RNA may have antineoplastic activities, clearly evidenced from its influence on the culture of transformed HEp-2 cells.