Effect of nutrient supply on photosynthesis and pigmentation to short-term stress (UV radiation) in Gracilaria conferta (Rhodophyta).

The effects of increased photosynthetic active radiation (PAR), UV radiation (UVR), and nutrient supply on photosynthetic activity, pigment content, C:N ratio and biomass yield were studied in tank cultivated Gracilaria conferta (Rhodophyta). Electron transport rate (ETR) and biliprotein content were higher under high nutrient supply (HNS), obtained from fishpond effluents, compared to low nutrient supply (LNS), in contrast to mycosporine-like amino acids (MAAs) dynamic. The high MAA content in LNS-algae could be explained by higher UVR penetration in the thallus and by the competition for the use of nutrients with other processes. Effective quantum yield decreased after short-term exposure to high irradiance whereas full recovery in shade was produced only under slightly heat shock. UVA radiation provoked an additional decrease in photosynthesis under high water temperature. UVB radiation reversed UVA's negative effect mainly with HNS. Results support that nutrient-sufficiency help G. conferta to resist environmental changes as short-term temperature increase.

Chemical composition of sediments, suspended matter, river water and ground water of the Nile (Aswan-Sohag traverse).

Sediment, suspended matter, river water and ground water samples were collected at twelve sites in the drainage valley of the Nile River, around Sohag (Central Egypt) and close to the Aswan High Dam. Elemental composition of the river water (27 elements), ground water (eight elements), suspended matter (12 elements) and sediments (12 elements) was studied. Aswan High Dam construction, agricultural and industrial human activities have led to dramatic changes in the Nile River chemistry. Nowadays, the Nile River has the highest dissolved salt content among the major African rivers. Dissolved transport is a major process for Ca, K, Sr, Zn, Cu, Ni and V. Manganese, Fe and Cr are mainly carried by suspended matter. The Nile suspended matter is exhausted in almost all elements studied (except for Mn) compared to the world average river suspended matter. Along the course of the river, the distribution of elements in the suspended matter and sediments is generally controlled by natural processes: the relative importance of elemental transport phases; and the oxidation, precipitation and sedimentation of mineral species through the varying physico-chemical conditions of the environment. Pollution input in the Nile particulate load is not major, as compared to the natural inputs. Eight genetic particle types describe the composition of the Nile suspended matter and sediments: (1) biogenous-aeolian (or silica); (2) terrigenous (Fe-aluminosilicate); (3) authigenic (calcium carbonate); (4) biogenous (apatite); (5) authigenous-terrigenous (Fe-oxyhydroxide-montmorillonite); (6) diagenetic (iron-sulfide); (7) terrigenous (titanium oxide); (8) authigenous (Mn-Fe-oxyhydroxide).

Influence of standardized pollen extracts (Cernitin) on the respiratory activity of some tissues of rats subchronically exposed to ammonium fluoride.

The respiratory activity of tissue slices of liver, kidney, lung and trachea of rats subchronically exposed to ammonium fluoride was studied. It was demonstrated that pollen extracts have protective properties evidenced by normal oxygen consumption rates of tissues from rats exposed to NH(4)R.

The effect of the pollen extracts quercitin and cernitin on the liver, lungs, and stomach of rats intoxicated with ammonium fluoride.

Quercitin and Cernitin are not in themselves toxic to rats. When administered at the time of intoxication of the animals with ammonium fluoride, they reduced the noxious effects of the toxic agent in the liver and lungs. It is suggested that Quercitin and Cernitin might play a protective role during prolonged exposure to ammonium fluoride. Neither ammonium fluoride nor Quercitin or Cernitin seem to exert any effect on the stomach.

Clinical efficacy of 'essential' phospholipids in patients chronically exposed to organic solvents.

A total of 45 workers, who had been chronically exposed to a potentially hepatotoxic xylene-toluene-benzene mixture in the atmosphere, were treated for 3 months with 'essential' phospholipids. Routine biochemical tests and radioisotope investigations to assess liver damage were carried out both at baseline and after treatment. The liver:spleen index was increased in 71% of subjects and the mean isotope transit time in the liver was reduced in 90% of the patients after treatment. The biochemical parameters remained within the normal range throughout the treatment period. The results suggest that 'essential' phospholipids may be of value in the treatment of liver damage that has arisen as a result of chronic exposure to organic solvents.

[Micromorphology of dentine in rats with chronic exposure to ammonium fluoride]. / Mikromorfologia zebiny siekaczy szczurów przewlekle narazonych na dzialanie fluorku amonowego.

Wistar rats were exposed chronically to ammonium fluoride in a toxicological chamber where the concentration of fluoride ions was 0.0016 mg/m3 of air. The exposure lasted 6 hours daily five times weekly. The animals were sacrificed after 3.6 and 9 months of the experiment. Histological preparations were made from upper incisors with surrounding tissues. Microscopic examination demonstrated striation of dentine in the teeth, of these animals, which was due to development of decalcification bands. This type of changes was observed also by other authors and it is regarded as a characteristic feature of dentine damage by fluorine compounds.

Studies on the toxicology of fluorine compounds. I. Histological and histochemical investigations on the liver, heart, lungs, and stomach of rats exposed to hydrogen fluoride.

The liver, heart, lungs, and stomach of rats exposed to hydrogen fluoride were studied. Histological examination showed partial liver necrosis and emphysema. Using histochemical methods the effect of fluorine ions was found in: a reduction of the activity of succinic and beta-hydroxybutyric dehydrogenases in the liver, heart muscle, superficial and glandular epithelium cells, and in lamina propria of the gastric mucosa; an increase in the activity of lactate dehydrogenase in liver cells; an increase in the activity of acid phosphatase in the liver, heart muscle, bronchus epithelium, bronchioli, and interalveolar septum cells; an increase in the activity of alkaline phosphatase in the liver, lungs, and heart muscle connective tissue, and in all gastric epithelium cells. The results obtained mainly point to the inhibition of oxidative metabolism by fluoride ions.

[Effect of essential phospholipids (EPL) on the course of chronic poisoning with organic solvents in rats]. / Wplyw niezbednych fosfolipidów (EPL) na przebieg przewleklego zatrucia rozpuszczalnikami organicznymi u szczurów.

Male Wistar rats were exposed in toxicological camera to the mixture of organic solvents. Composition and concentrations of the mixture were similar to the conditions in the production hall. The influence of essential phospholipids (EPL) on changes in the liver caused by the organic solvents were studied. Animals were exposed for 6 months. Histochemical and histological evaluation was performed after 2 and 6 months. In the liver of intoxicated animals marked vacuolar degeneration and diminution of glycogen contents were observed. Simultaneously, the protective effect of EPL was noted. It was expressed by distinctly decreased vacuolar degeneration, probably corresponding to neutral fat in hepatocytes as well as by normalization of glycogen contents.

[Morphologic evaluation of the effect of long-term administration of ammonium fluoride on the seminiferous epithelium and epididymis in the rat]. / Morfologiczna ocena wplywu przewleklego stosowania fluorku amonowego na nablonek plemnikotwórczy i najadrze szczura.

Male rats were subjected to 9-month-long exposure to ammonium fluoride. The performed evaluation covered the seminiferous epithelium and epididymis. The greatest changes in animals used in the experiment were observed in epididymis. A small number of spermatozoa were seen in the lumen of ductus epididymis, while in the epithelial cells there were increased phagocytic processes, providing a proof that injured reproductive cells were eliminated from the genital tract.

[The influence of long-term utilization of some herbicides on oral cavity tissues of white rats]. / Wplyw przewleklego stosowania niektórych srodków chwastobójczych na tkanki jamy ustnej szczurów bialych.

Three mixtures of herbicides have been administered to white rats of Wistar strain by means of stomach tube. After 9 months of studies laboratory examinations were carried out in these animals namely analysis of urine, peripheral blood, bone marrow smears and segments of parotid glands and cheek's mucous membrane were uptaken to histopathological examinations. Morphological changes whose intensification didn't depend on the dose and type of preparation have been found in the glands. These changes were of non-specific character--similar changes were also present in the glands in rats in the course of poisoning by other toxic agents. Vacuolar changes whose intensification was increasing with the exposure time have been observed in the cells of mucous membrane epithelium.

Immunogenicity of liposomes and iscoms containing the major outer membrane protein of Neisseria gonorrhoeae: influence of protein content and liposomal bilayer composition.

The influences of Neisseria gonorrhoeae protein IB content and bilayer composition of liposomes and protein content of iscoms on immunogenicity were investigated. Changes in the protein content of liposomes did not influence the immunoglobulin G response, whereas the response was lowered when the amount of protein in iscoms was increased. Bilayer composition only influenced the primary immunoglobulin G response; immunological memory was not affected.