Cyanoglycosylation products of 17-O-acetyl-testosterone

17-O-Acetyl testosterone, which has no susceptible hydroxyl or carboxyl group for glycosylation, was glycosylated with 2,3,4,6-tetra-O-acetyl-α- -glucopyranosyl bromide in the presence of a mixed catalyst, Hg(CN)₂ and HgBr₂, in benzene–nitromethane. Reaction occurred on the α,β-unsaturated ketone on the six–membered A-ring to give six 3-O-glycosides, each bearing a cyano group at the 3- or 5-position of the aglycon, and a 3-O-glycoside bearing a CONH₂ group at the 3-position. Structural analyses of these products were carried out by various NMR (¹H, ¹³C NMR, ¹H–¹H and ¹H–¹³C COSY, HMBC, and DEPT), FABMS and X-ray analyses. The mechanisms of the formations of the products are discussed. It was determined that mercuric cyanide was essential as a catalyst for the progress of the cyanoglycosylation.     

Insect growth regulating effects of neem extract and azadirachtin on aphids

Neem,Azadirachta indica (A. Juss.), seed oil (NSO) applied to leaf discs at a concentration of 1.0% resulted in 94% to 100% mortality of second instar nymphs of currant-lettuce aphid,Nasonovia ribis-nigri (Mosley), and green peach aphid,Myzus persicae (Sulzer), after nine days. The equivalent amount of pure azadirachtin (AZA) (≈40 ppm), the principle active ingredient of neem, was as effective as NSO. The survival of adult aphids was unaffected by NSO or AZA, but the survival of offspring from treated adultM. persicae andN. ribis-nigri was reduced significantly. The lethal concentration of AZA resulting in 50% mortality of second instar nymphs of nine species of aphids ranged from 2.4 ppm forM. persicae on pepper to 635.0 ppm for the strawberry aphid,Chaetosiphon fragaefolii (Cockerell), on strawberry. ForM. persicae, the growth regulating effect of AZA was influenced by the host plant and the nymphal instar treated.     

Characterization of Immunological Activity of a Low Toxicity Antitumor Lipopolysaccharide from Bordetella pertussis

Immunological properties of a low toxicity lipopolysaccharide (BP-LPS) extracted from Bordetella pertussis (Tohama strain) which was reported to have high antitumor activity against murine tumors were examined and compared with those of LPS extracted from other enterobacteria. The activation or stimulation of murine macrophages and lymphocytes by these LPS, including TNF induction, was found to be similar. However, BP-LPS was clearly less active in its stimulation of murine and human neutrophils as estimated by neutrophil-adherence assay and by their TNF production than E. coli LPS. Furthermore, BP-LPS also suppressed the activation of human neutrophils by Escherichia coli LPS. A comparative study with 7 LPS preparations indicated that their toxicity in terms of animal body weight loss correlated with their ability to induce human neutrophil adherence. The inability of BP-LPS to activate neutrophils may thus have some bearing on its low toxicity.     

Effects of sewage waste stabilization lagoon effluent on stream invertebrates

The ecological impact of discharge to streams of domestic sewage waste stabilization lagoon effluent was investigated. Benthic invertebrates were compared upstream and downstream of discharges to eight New Zealand streams where effluent dilution ranged from 6- to 484-fold. The percentage of common invertebrate taxa whose density changed significantly (ANOVA, P<0.05) downstream declined in proportion with the log of the effluent dilution (r=-0.87) and increased with downstream increase in benthic respiration (r=0.91) and several intercorrelated indicators of organic enrichment (log biochemical oxygen demand, r=0.91; log suspended solids (SS), r=0.84). However, these changes in invertebrate densities did not always reflect degraded community structure. The nature and direction of changes suggests a subsidy-stress gradient of responses. Increases in SS of > 4 g m^-3 were associated with significant changes in density of > 50 percent of the common taxa and > 50 percent reduction of the densities of the sensitive Ephemeroptera, Plecoptera, and Trichoptera (EPT). However, EPT densities increased by up to 50 percent at lower organic solids loadings. No general relationships were found between relative densities of functional feeding groups and metabolic or water quality variables. These findings confirm that early warning of enrichment stress is more easily seen at the species level than at the functional level.     

Effects of salsolinol on cultivated endothelial cells

In view of neurotoxic properties of tetrahydroisoquinolines (TIQ's) there are open questions also in regard to the disturbance of the blood-brain barrier. Because endothelial cells are an important element of this barrier the present study was designed to assess the influence of salsolinol (a TIQ formed by condensation of dopamine and acetaldehyde) on cultivated endothelial cells by physiological, biochemical and morphological investigations. For the investigations we used aortic endothelial cells because of a variety of similarities in physiology and biochemistry to brain capillary endothelial cells. Cytotoxic effects estimated by cell counting after 72 h treatment with salsolinol (IC₅₀=38 mol/l) were possibly caused by mitochondrial damages. Already after 2 h severe ultrastructural alterations of many mitochondria could be observed. The respiration activity of the cells was always inhibited after treatment with salsolinol for some hours. The damage of the mitochondria by salsolinol was not connected with inhibition of the activity of succinate dehydrogenase and cytochrome c+c₁. Nevertheless the damages of mitochondrial integrity support the hypothesis that the neurotoxic effect of salsolinol is primarily caused by damaging the endothelial cells associated with a disturbance of blood-brain barrier.     

Effects of a pregrowth period in Al-free nutrient solution on macronutrient composition of two upland rice cultivars with various Al sensitivity

Effects of Al on growth and macronutrient distribution (K. P. Ca and Mg) were examined in two rice ( Oryza sativa L.) cultivars (BG35 and IR45) pregrown in a nutrient solution without Al for 21 days followed by 14 days at 0.70. 140 or 280 μ M Al (pH 4.2 ± 0.1). Relative growth rate (RGR) of pregrown plants was significantly less hampered by Al compared to their controls, than RGR of plants that were not pregrown. However, a similar ranking of the cultivars for Al sensitivity was obtained irrespective of pregrowth period. The more Al tolerant BG35 consistently outyielded the Al sensitive IR45 under all Al treatments. A comparatively high Al-retention in roots and low Al transport rate to shoots of pregrown IR45 was the opposite of conditions in non-pregrown IR45. In BG35, uptake and transport of nutrients to the shoots were efficient at all Al levels. In IR45, particularly the uptake and distribution of P and Mg were disturbed by Al. It is suggested that a pregrowth or nursery period without Al reduces Al toxicity in both BG35 and IR45 at least up to 280 μ M Al.     

Decline with age of the respiratory chain activity in human skeletal muscle

Mitochondrial respiratory systems have been screened in 63 othopaedic patients of age ranging between 17 and 91 years. The results show a statistically significant definite decrease with ageing of mitochondrial repiratory activity with pyruvate plus malate, succinate and ascorbate plus TMPD. This pattern is associated with an equally significant decrease with age of the enzymatic activity of complex I, II and IV. No significant decrease with age is, on the contrary, observed in the mitochondrial content of cytochromes a+a₃, and c+c₁. Preliminary Western blot analysis indicates an altered polypeptide pattern in cytochrome c oxidase. This study provides evidence for a decline with age of mitochondrial respiratory activity in human skeletal muscle, affecting complex I, II and IV.     

Consistency and sensitivity of community level endpoints in microcosm tests

We review microcosm toxicity tests with 12 chemical stresses and find that the relative sensitivity of certain endpoints is consistent over toxicant type. Changes in species composition occur at very low levels of chronic stress. Endpoints responding at increasing levels of stress are declines in species numbers relative to expected numbers, followed by decreased oxygen production and decreased total production. Other endpoints are quite sensitive in response to some toxicants but insensitive to others (e.g., autotrophic biomass). In addition, other endpoints respond unpredictably to stress, showing stimulation under some conditions and impairment under others. We compare our observations to the progressions of impact suggested from published whole ecosystem experiments and speculate about a general ecosystem distress syndrome and the implications for choosing endpoints in both toxicity testing and monitoring.     

Effects of natural sediment properties on test results in bioassays with oyster larvae (Crassostrea gigas) on sediment elutriates

Toxicity tests with oyster larvae are becoming increasingly important as sensitive bioassays for assessing water and sediment quality. In 1983 a procedure was presented specifically for the testing of seawater elutriates of sediment samples. Testing sediment elutriates with oyster larvae in a sediment-water system invokes specific problems related to natural sediment characteristics. Experiments were set up to study the effects of these sediment properties on the bioassay results. The effects of sediment grain size, suspended solids, elutriation period, as well as the possible effects of naturally occurring toxic nutrients, like ammonia, were studied. Also the effect of presence or absence of the elutriated sediment and the distribution of larvae in the test vessels were studied.It is concluded that natural sediment properties can have substantial effects on the test results in elutriate tests with sediment present in the test vessel. Recommendations are formulated to minimize these effects or to use other test fractions for predicting bulk sediment toxicity.