Relationship between boron content and antioxidant compounds in Citrus leaves taken from fields with different water source

Boron contamination in the agricultural lands is an important problem for Western Turkey, which has rich boron deposits. This study was carried out in Nazilli regions upon orange (Citrus sinensis L. Osbeck) plants irrigated with relatively high boron laden channel waters (LCI) and with well waters (LWI) which contain lower amounts of boron. The leaves of the plants irrigated with channel water were found to contain twice the amount of boron compared with those irrigated with well waters. Boron content of leaves in both groups were approximately ten times the boron content in the soil on which they are grown. In the leaves of the plants irrigated with channel waters there were approximately 50% chlorophyll loss and higher chlorophyll a/b and caretonoid/chlorophyll ratios. In the excessive boron containing leaves was found higher soluble protein and carbohydrate contents, but lower determined free proline value. In plants that irrigated with high boron laden channel water significantly lower -tocopherol content and two fold higher ascorbate concentration were determined. The lower activities of catalase and glutathione reductase enzymes and higher total superoxide dismutase activity were measured in high boron content leaves. The retardation of growth due to boron toxicity can be attributed to the chlorophyll loss and inhibition of the carbohydratemetabolism. Boron at toxic level may cause the cell membrane lipids to be damaged by the free radicals by decreasing the -tocopherol levels. The increase in the ascorbate concentration may have a vital role in the protection of the inner cell structures against the boron toxicity.     

Superoxide dismutase activity and zinc and copper concentrations in growth retardation

The aim of this study was to determine the effects of oral zinc treatment on red cell copper/zinc-superoxide dismutase (Cu/Zn-SOD) activity and zinc and copper concentrations in growth retardation. Thirty-five patients, average age of 11 yr, were selected. The control group consisted of 10 healthy children whose average age was 10 yr. Superoxide dismutase activity was determined by spectrophotometer. Copper and zinc concentrations were measured by an atomic absorption spectrophotometer. The activity of Cu/Zn-SOD before zinc treatment was higher than the controls (p<0.001). There was a decrease in Cu/Zn-SOD activity after zinc treatment (p<0.001) and the values after treatment were still higher than the controls (p<0.001). Plasma zinc concentrations before zinc treatment were lower than controls (p<0.01). After treatment, there was an increase in plasma zinc concentrations compared to controls and the patients' values before zinc treatment, respectively (p<0.001, p<0.001). After zinc treatment, plasma copper concentrations were decreased significantly (p<0.01). An increase in red cell zinc concentration (p<0.01) and a decrease in copper concentration (p<0.001), which were statistically significant, were seen after zinc treatment. The results suggested that there were significant alterations in Cu/Zn-SOD activity and zinc and copper concentrations during growth retardation. With zinc treatment, these parameters appeared to approach normal values.     

Adaptations in Pigment Composition and Photosynthesis by Far Red Radiation in Chlorella pyrenoidosa

Chlorella pyrenoidosa has been cultivated in radiation of wavelengths between 690–975 nm for several months. Absorption spectra and action spectra of photo-synthesis have been determined for far red and “white” light brown cultures, In vivo spectrophotometric analyses and action spectra showed that fur red growth Chlorella adapted to the extreme light conditions by an increase both in absorption and photosynthesis above 700 nm. It is proposed that som of the in vivo normal chlorophyll a forms were converted to a far red absorbing chlorophyll a form, giving the far red exposed suspension an increased photosynthetic activity between 700–740 nm. The analyses of far red grown Chlorella have also shown an increased photosynthesis in the blue part of the spectrum, presumably due to a decrease in photosynthetically inactive carotenoid content. By culturing Chlorella in a “white” light gradient between 0.5 × 10⁴ and 3.7 × 10⁴ erg cm^?2 s^?1, it has been demonstrated that light intensity did not influence pigment ratios between 500–750 nm. In the blue part, however, high light levels caused increased absorption because of increased carotenoid content. Some ecological aspects of this far red effect have also been discussed.     

Quantitative untersuchungen der Landschneckenfauna Norwegens. I

Ohne Zusammenfassung     

Über den Einfluss des Kohlenoxyds auf die Atmung der Hefezelle in verschiedenen Substraten

Zusammenfassung Die Atmung unbefruchteter Seeigeleier wird durch CO beschleunigt, die der befruchteten Eier dagegen gehemmt. Es wurde die Frage gestellt, ob man bei Hefe durch Variation des Substrates ähnliche Verhältnisse erhalten kann. Es stellte sich heraus, daß die Eigenatmung der Hefe und die Veratmung des Formiats durch CO beschleunigt wird, was also den Vorgängen im unbefruchteten Ei gleicht.Die Veratmung von Na-Pyruviat, Na-Laktat, Na-Acetat, Acetaldehyd und Alkohol wird durch CO gehemmt. Mit Ausnahme von Alkohol haben alle diese Substrate Hemmungskurven, die mehr oder weniger der der befruchteten Seeigeleier gleichen. Die Hemmungskurve jedes Substrates ist aber typisch und weicht von der der anderen ab. Wird die Konstante in der Verteilungsgleichung Warburgs ausgerechnet, findet man Werte, die am Anfang der Kurve groß sind, aber später stark sinken. Nur Alkohol zeigt eine gesetzmäßige Hemmung nach der Formel Warburgs.Wird die Konzentration des Substrats variiert, bekommt man für jede Konzentration eine andere Hemmungskurve.Versuche mit KCN haben ähnliche Ergebnisse gegeben wie mit CO.In der Diskussion werden einige Erklärungsmöglichkeiten für die Abweichungen von der Formel Warburgs angedeutet.     

Development of a cost-effective production process for Halomonas levan

Bioprocess and Biosystems Engineering - Levan polysaccharide is an industrially important natural polymer with unique properties and diverse high-value applications. However, current bottlenecks...     

Phase Grating from Ordered Polymer Lattices for Optica Image Preprocessing

The inverted retina of the human eye can beemulated by multilayer gratings from polymer latexparticles located in the image plane of opticalsystems. This so called OPTO-RETINA provides v. Laueinterference patterns in visible light with atrichromatic characteristic containing,simultaneously, local spatiotemporal direction anddistance information, which are relevant to 3Dspatial vision and 4D spatiotemporal Fouriercorrelator-optical preprocessing in shape andmotion analysis.As a first step in the realization of OPTO-RETINAproperties the formation of hexagonally orderedmonolayers of polystyrene latex sphereswith diameters in the~m range is reported and firstresults of diffraction and dispersion of white lightby these layers obtained by conoscopical opticalmicroscopy are presented.     

The susceptibility to stress-induced gastric injury of rats exposed to cadmium

In this experimental study, the effect of cadmium on cold and restraint stress-induced gastric lesions has been studied. Rats received 15 μg/mL cadmium-containing water for 30 d, and at the end of this period, they were subjected to cold and restraint stress. Cadmium accumulation in gastric mucosa was associated with increased mucosal lesions, as well as decreased mucin and PGE₂ levels in rats exposed to cadmium. Stress-induced mucosal injury was more pronounced, and the hemoglobin leakage into gastric lumen owing to breakdown in the barrier was 17.30±3.45 μg/mL in control and 35.71±6.18 μg/mL in treated rats. Our data suggest that high cadmium intake facilitates the occurence of stress-induced mucosal lesions by diminishing the mucin content and PGE₂ generation in gastric mucosa.     

A 50-year perspective of a family with chromosome-14-linked Alzheimer’s disease

A Swedish family with two generations suffering from presenile dementia with an unusually severe Alzheimer encephalopathy was first reported in 1946. The hypothesis that the disease was inherited through a dominant gene is strongly supported by the follow-up 50years later of three additional generations and molecular genetic findings of a novel presenilin-1 gene mutation in the family. The pedigree contains six cases with well-documented dementia in four consecutive generations. The Alzheimer encephalopathy was unusually severe in the three cases studied post-mortem, with a pronounced involvement of the central grey structures, such as the claustrum, the nuclei around the third ventricle, the central thalamic nuclei and the brain stem. There were no vascular lesions and little amyloid angiopathy. All six affected cases showed the typical temporoparietal symptom pattern and other core symptoms of Alzheimer’s disease, such as logoclonia, myoclonic twitchings and major motor seizures. Other predominant features were psychomotor slowness, increased muscular tension, a stiff stooped gait and a rapid loss of weight. The symptom pattern is convincingly explained by the consistent and severe involvement of cortical and central grey structures and is probably linked to the presenilin-1 gene mutation. Received: 25 November 1997 / Accepted 4 December 1997