Acute toxicity effects of ibuprofen on behaviour and haematological parameters of African catfish Clarias gariepinus (Burchell, 1822)

Indiscriminate discharge of pharmaceutical waste into the aquatic ecosystem may pose serious health challenges to aquatic biota. The effect of acute exposure to ibuprofen was evaluated using changes in behaviour and haematological parameters under static bio-assay method in Clarias gariepinus. Test specimens were exposed to acute concentrations of ibuprofen (0.28, 0.33, 0.38, 0.43 and 0.48 mg l^?1) for 24, 48, 72 and 96 h durations respectively. Behavioural and phenotypic changes were observed in surviving fish. There were significant (p < 0.05) concentration and duration-dependent increases in erythrocyte (RBC), haemoglobin (Hb), pack cell volume (PCV) and leukocytes (WBC) in treated fish compared to the control. Insignificant decreases (p > 0.05) in mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were observed in treated fish compared to the control. Ibuprofen elicited dose and duration- dependent decrease in neutrophil counts with the decreases being significant (p < 0.05) in the higher doses of 0.43 and 0.48 mg l^?1. Ibuprofen did not elicit any significant changes in monocytes, basophils and eosinophils. Changes observed in this study showed that ibuprofen negatively affected the health of the fish and we recommend that discharge of ibuprofen into the aquatic environment should be monitored and controlled.     

Cycleanine from Synclisia scabrida: conformational information from the 1H NMR spectrum at 300 MHz

Cycleanine, a bisbenzylisoquinoline alkaloid, has been isolated from the roots of Synclisia scabrida. The ¹H NMR spectrum at 300 MHz reveals that, in chloroform solution, cycleanine has a conformation whereby ring B partly shields ring C′ and ring C is similarly influenced by ring B′.     

High pressure liquid chromatograph ic separation of C18 AND C19 steroids

High Pressure liquid chromatographic procedures for the resolution of mixtures of C₁₈ and C₁₉ steroids of biologic importance are described. On-line monitoring of the absorbance and refractive index of the eluate was found to be suitable for the quantitative measurement of the amounts of eluted steroids. Using a high sensitivity absorbance detector, reliable measurements of as little as 5 ng Δ⁴?3 keto steroids were possible.     

Input-output analysis of in vivo photoassimilate translocation using Positron-Emitting Tracer Imaging System (PETIS) data

The Positron-Emitting Tracer Imaging System (PETIS) is introduced for monitoring the distribution of (11)C-labelled photoassimilates in Sorghum. The obtained two-dimensional image data were quantitatively analysed using a transfer function analysis approach. While one half of a Sorghum root in a split root system was treated with either 0, 100, or 500 mM NaCl dissolved in the nutrient solution, tracer images of the root halves and the lower stem section were recorded using PETIS. From the observed tracer levels, parameters were estimated, from which the mean speed of tracer transport and the proportion of tracer moved between specified image positions were deduced. Transport speed varied between 0.7 and 1.8 cm min(-1) with the difference depending on which part of the stem was involved. When data were collected in the lowest 0.5-1 cm of the stem, which included the point where the roots emerge, transport speed was less. Rapid changes in NaCl concentration, from 0 to 100 mM, resulted in short-term increases of assimilate import into the treated root. This response represented a transient osmotic effect, that was compensated for in the medium-term by osmotic adaptation. Higher concentrations of NaCl (500 mM) resulted in distinctly less photoassimilate transport into the treated root half. The present results agree with earlier observations, showing that transport of (11)C-labelled photoassimilates measured with the PETIS detector system can be quantified using the method of input-output analysis. It is worth noting that with the PETIS detector system, areas of interest do not need to be defined until after data collection. This means that unexpected behaviour of a plant organ will be seen, which is not necessarily the case with conventional detector systems looking at predefined areas of interest.     

Rapid N transport to pods and seeds in N-deficient soybean plants

Non-nodulated soybean (Glycine max (L.) Merr.) plants were cultivated hydroponically under N-sufficient (5 mM NaNO(3)) or N-deficient (0.5 mM NaNO(3)) conditions. (13)N- or (15)N- labelled nitrate was fed to the cut end of the stems, and the accumulation of nitrate-derived N in the pods, nodes and stems was compared. Real-time images of (13)N distribution in stems, petioles and pods were obtained using a Positron Emitting Tracer Imaging System for a period of 40 min. The results indicated that the radioactivity in the pods of N-deficient plants was about 10 times higher than that of N-sufficient plants, although radioactivity in the stems and nodes of N-deficient versus N-sufficient plants was not different. A similar result was obtained by supplying (15)NO(3) to cut soybean shoots for 1 h. The fact that the N translocation into the pods from NO(3) fed to the stem base was much faster in N-deficient plants may be due to the strong sink activity of the pods in N-deficient plants. Alternatively, the redistribution of N from the leaves to the pods via the phloem may be accelerated in N-deficient plants. The temporal accumulation of (13)NO(3) in nodes was suggested in both N-sufficient and N-deficient plants. In one (13)NO(3) pulse-chase experiment, radioactivity in the stem declined rapidly after transferring the shoot from the (13)NO(3) solution to non-labelled NO(3); in contrast, the radioactivity in the node declined minimally during the same time period.     

Irreversible inhibition of pancreatic lipase by bis-p-nitrophenyl methylphosphonate

The reaction of porcine pancreatic lipase with an organophosphorus compound bis-p-nitrophenyl methylphosphonate (BNMP) resulted in the complete and irreversible inhibition of lipase activity on tributyrin emulsion (25 degrees C, pH 7.5, 40 mM Na-veronal-HCl buffer) whereas the activity of the enzyme on p-nitrophenyl acetate solution remained unchanged. The BNMP-modified enzyme did not bind on hydrophobic interfaces (siliconized glass beads). Tyr 49 was presumed to be the modification site, and the conclusion has been made that this residue is implicated in the interface recognition site of pancreatic lipase.