Evaluation of the mutagenic potential of the hair dye N-methyl-amino-2-nitro-4-N′,N′-bis-(2-hydroxyethyl)-aminobenzene in a battery consisting of Drosophila and mammalian cytogenetic assays

The compound N-methyl-amino-2-nitro-4-N′,N′-bis-(2-hydroxyethyl)-aminobenzene was tested for mutagenic activity in the sex-linked recessive lethal test with Drosophila melanogaster, the induction of chromosomal aberrations and sister-chromatid exchanges (SCEs) with Chinese hamster ovary (CHO) cells in vitro, and the micronucleus test with mouse bone-marrow cells in vivo. Consistently negative results were obtained with the 3 tests. The SCE tests gave positive results with prolonged treatments. It is concluded that reliable decisions about mutagenic activity cannot be based on the induction, in vitro, of SCEs alone.     

A comparison of two methods for assessing critical flicker fusion frequency in hens

This paper compared two general methods for assessing critical fusion frequency in hens (gallus gallus domesticus). The first method was a conditional discrimination procedure with the stimuli presented successively. The second was a two-alternative forced-choice procedure with the stimuli presented simultaneously. It was found that both methods of stimulus presentation gave comparable results suggesting that either method is useful when investigating psychophysics in animals. The results also show that hens’ critical fusion frequency is considerably higher than that of humans which may account for hens’ inability to recognise images presented on standard computer or television monitors.     

A comparison of five methods for assaying bacterial hydrophobicity

Five methods for assaying bacterial surface hydrophobicity, namely, bacterial adherence to hydrocarbons, salt aggregation, hydrophobic interaction chromatography, adhesion to polystyrene and latex particle agglutination were used to compare the hydrophobic surface properties of Escherichia coli, Acinetobacter calcoaceticus, Staphylococcus aureus and Streptococcus mitis. Two strains of A. calcoaceticus, including RAG-1, gave strong positive results by all five methods. S. mitis gave weak or negative results by all methods. The results for the other bacteria varied with the method. We conclude that reliance on one method for such tests is inadequate.     

The feeding biology of Hydrobia ventrosa (Montagu). I. The assimilation of different components of the food

The assimilation efficiencies for 7 species of diatoms, two of blue-green algae, and one bacterium have been measured in the deposit-feeding prosobranch Hydrobia ventrosa (Montagu). Two methods have been used, a chemical and a radiotracer one.The results of the first method were difficult to evaluate due to the fact that the time taken to clear the gut is ill-defined. The second method gave more consistent results.All diatoms are assimilated efficiently (60–71 %) as is the bacterium (about 75 %). The blue-green algae are less efficiently utilized; an Oscillatoria sp. was assimilated with an efficiency of about 50 % whereas a Chroococcus sp. was only assimilated with an efficiency of 8 %. It is concluded that resource partitioning based on differential utilization of micro-organisms cannot play an important rôle in the co-existence of Hydrobia ventrosa with other deposit-feeders.     

Characterization of a non-indexible equatorial x-ray reflection from frog sartorius muscle.

X-ray equatorial reflections from frog sartorius muscle were studied using a position sensitive detector. A weak reflection appeared between the 10 and 11 peaks which did not index on the hexagonal filament lattice. This reflection, first reported by Elliott et al. (1967), was further characterized. The spacing of the reflection varied in direct proportion to that of the 10 peaks for sarcomere lengths between 2·0 μm and 3·0 μm. Its intensity appeared relatively insensitive to length changes. Optical diffraction patterns from electron micrographs of oblique sections through muscle gave ratios for the spacings of the myosin filaments and the Z-disc lattice that correlated very closely with the X-ray results. It is suggested that the Z-disc structure is the major source of this nonindexible reflection.     

Auxin binding activities in monocotyledonous and dicotyledonous tissue

A screening study was carried out in order to investigate the binding of NAA to subcellular fractions from various dark grown monocotyledonous and dicotyledonous tissues known to be physiologically responsive to NAA. Napthalene-1-acetic acid (NAA) binding results revealed differences between the monocots and dicots. Maize coleoptile tissue gave the highest concentration of saturable binding sites with a K_d-value of 1.56 μM and another in maize mesocotyl with a K_d-value of 0.83 M indicating a single class of binding site for NAA for both tissues. However, an inability to demonstrate saturable auxin binding in dicotyledonous tissues and maize root tissues was found. It is concluded that the results of this investigation do not negate the hypothesis that the high affinity saturable binding sites found in maize shoot tissues may function as auxin receptors.     

Reactions of five species of stingless bees to some volatile chemicals and to other species of bees

Trigona pectoralis and T. mexicana attacked when volatile chemicals that have been identified from their heads were presented at the nest entrance; mixtures approximating the composition of the head extracts elicited stronger reactions than did any of the single chemicals. Alarm pheromones of T. pectoralis occur in approximately equal concentrations in the mandibular glands and the remainder of the heads; other alarm pheromones occur in small concentrations in the abdomen. Three other species of stingless bees gave defensive reactions when presented with the mixture of chemicals, with some of the single chemicals, with living or freshly killed T. pectoralis, or with the heads of that species. Living or freshly killed Lestrimelitta limao, which are known to live by robbing other bees, elicited strong defence reactions from all species; citral, the major volatile component of the head extract of L. limao, gave similar results. Variations in the strength of reactions of bees to other species and to a wide variety of volatile chemicals led to the conclusion that bees probably learn to recognize the odour of other species that rob from their nests, and that the pheromones of the robbing species are allomones that recruit the victims to the defence of the nest. It is postulated that the reactions to some of the chemicals developed because the bees had been exposed to enemies that contained the chemicals. It is often impossible to decide whether the reactions of bees to a chemical result from an inability to distinguish the chemical from some other, or from the properties and usual origin of the chemical itself.Some of the problems that arise from the reactions of the bees, and particularly from their reactions to 2-heptanone, geraniol, and benzoic acid, are discussed.     

Sugar orthocarbonates

A simple procedure is described for preparing sugar orthocarbonates. It is based on treating the corresponding thionocarbonate in pyridine with cupric acetate and an alcohol, such as methanol, ethanol, or isopropyl alcohol. Treatment of 1,2:5,6-di-O-isopropylidene-D-mannitol 3,4-thionocarbonate with diols, such as 1,2-ethanediol, 1,2-propanediol, or 1,2:5,6-di-O-isopropylidene-D-mannitol, also gave orthocarbonates. Methyl thionocarbonate, S-methyl xanthate, and dithiobis(thioformate) derivatives of 1,2:3,4-di-O-isopropylidene-α-D-galactopyranose all gave the trimethyl orthocarbonate upon treatment with methanol in the presence of pyridine and cupric acetate. The structure of the orthocarbonates was proved by elemental analysis, n.m.r., and mass spectra, and by treatment with mild acid to form carbonates. Treatment of 1,2:5,6-di-O-isopropylidene-3-thio-D-altritol 3,4-thionocarbonate with methanol or ethanol gave the corresponding orthothiocarbonate, but on treatment with 1,2-ethanediol or with sodium ethoxide the 3,4-episulfide resulted.     

Derivate des D-glucosamins : 12. Mitt. Reaktionen von 2-acylamido-1,3,4,6-tetra-O-benzoyl-2-desoxy-α-D-glucopyranosen mit Bromwasserstoff

Acylation of 2-amino-1,3,4,6-tetra-O-benzoyl-2-deoxy-α-D-glucopyranose yielded various 2-acylamido-1,3,4,6-tetra-O-benzoyl-2-deoxy-α-D-glucopyranoses, which on treatment with hydrogen bromide-acetic acid gave halogenoses, oxazolinium bromides or 2-bromo-oxazolidinium bromides depending on the N-acyl substituent. It was found that acetyl bromide-hydrogen bromide is a particularly suited reagent for such transformations.     

Comparison of Methods for the Isolation of Salmonella from Bone Meal

The efficiency of some methods for the isolation of Salmonella from bone meal was studied. Grinding of the granulated, industrial product was found to increase Salmonella recovery. An improvement in the efficiency of the pre-enrichment method was obtained by adding deoxycholate (1%) to mannitol broth. Selective enrichment in selenite cystine medium gave better results than in Kauffmann-Müller medium, when small inocula were used. Experimental data showed that, in the presence of large numbers of coliforms and very small numbers of Salmonella, the Kauffman-Müller medium offers better results, but, in the presence of smaller numbers of coliforms, selenite cystine is preferable. As solid selective medium, Brilliant Green Agar gave, in our laboratory, better results than S S medium.     

Structural studies on the soluble polysaccharide from Iridaea membranacea

Aqueous extraction of the red alga Iridaea membranacea gave a high-sulfated polysaccharide. The structure of the polysaccharide has been investigated by hydrolysis, methanolysis, and fractionation. It resembles carrageenan in composition, but fractionation with KCl, and methylation analysis of two homogeneous fractions, showed that it is a complex mixture of sulfated d-galactans.     

The synthesis of 3-deoxy-4-O-methyl-D-arabino-2-heptulosonic acid and its behaviour in the Warren reaction

3-Deoxy-4-O-methyl-D-arabino-2-heptulosonic acid was synthesized in six steps starting from 2-deoxy-D-arabino-hexose. Treatment with periodate-thiobarbiturate (Warren reaction) gave a positive reaction with a molar absorption coefficient of 3700 to 5000 depending on the conditions of the periodate oxidation. It is suggested that the Warren reaction, which is eminently suitable for the detection of 3-deoxy-aldulosonic acids, should not be used for the quantitative estimation of 3-deoxy-2-aldulosonic acids of undetermined substitution pattern.     

Effect of the immobilization protocol on the properties of lipase B from Candida antarctica in organic media: Enantiospecifc production of atenolol acetate

In this work, we intend to check the effect of the immobilization protocol on the performance of lipase B from Candida antarctica (CalB) in organic medium. To this purpose, CalB has been immobilized on Eupergit C (EC) under different conditions and on EC partially modified with ethylenediamine (EDA), iminodiacetic acid (IDA) or metal chelate (IDA-Cu²⁺) and used for kinetic resolution of (R/S) 4-[2-hydroxy-3-[(1-methylethyl)amino]propoxy]benzeneacetamide (rac-atenolol). Enantiomeric resolution of atenolol was carried out by a transesterification reaction using vinyl acetate as acylant agent and an organic solvent as reaction medium. After a preliminary optimization of the reaction to obtain satisfactory yields, toluene was selected as the optimal solvent and the performances of the different CalB biocatalysts were compared. The R enantiomer was preferred in all cases but their performances were substantially different, with high differences in reaction rates, reaction yields in this kinetically controlled synthesis (EC-CalB gave a conversion of 76% while EC-IDA-Cu²⁺-CalB gave just a 27%), and enantiospecificities (EC-CalB gave an E value of 65 while EC-IDA-Cu²⁺-CalB gave a value of 13). Replacing toluene with hexane caused a decrease in enzyme activity, reaction yields and enantiospecificity of the reaction. It was remarkable that some preparations were much more sensitive to this solvent change than others. Considering that the activity decreased by less than 10% per reaction cycle, these differences are likely associated with the differences in the enzyme catalytic properties caused by the different immobilization protocols and not by inactivation of immobilized enzyme preparations during the reaction. These results confirmed that use of different immobilization protocols may be a powerful tool for altering enzyme properties when used in organic media.     

Inhibition of chloroplast development by tentoxin

Light-dependent chloroplast development in detached pea shoots was measured in terms of chlorophyll synthesis and the synthesis of Fraction 1 protein. Both synthetic processes were inhibited more than 90% by the fungal metabolite, tentoxin (1 or 10 μg/ml). These results place Pisum sativum in the class of tentoxin-sensitive higher plants. Tentoxin, actinomycin D, lincomycin, D-threo-chloramphenicol and carbonyl cyanide m-chlorophenyl-hydrazone (CCCP) were compared in their ability to inhibit RNA and protein synthesis by isolated pea chloroplasts. Energy for the synthetic reactions was supplied either by light or by added ATP. Only CCCP gave the same pattern of inhibition as tentoxin, i.e. inhibition of both RNA and protein synthesis in the light-driven system but no inhibition in the ATP-driven system. It is concluded that chloroplast developmental processes are inhibited by tentoxin through the inhibition of photophosphorylation.     

Freeze preservation of platelets using hydroxyethyl starch (HES); a preliminary report.

A comparative study has been made of platelets stored by freeze preservation following treatment with dimethyl sulfoxide (DMSO) or hydroxyethyl starch (HES) with fresh platelets and platelets stored at 4 °C for 48 hr. The indices studied were platelet recovery, pH, light microscope morphology, platelet Factor 3 (PF₃) availability and the hypotonic stress response. The DMSO preserved platelets gave a better response to hypotonic stress and incurred lesser degrees of membrane damage as demonstrated by PF₃ availability. There was however a significantly higher recovery of platelets treated with HES; with DMSO the osmotic damage inflicted during removal caused considerable lysis. Platelets frozen by DMSO or HES gave consistently better in vitro results than platelets stored at 4 °C for 48 hr. A preliminary clinical trial of HES preserved platelets has confirmed haemostatic effectiveness in vivo. HES being relatively nontoxic, platelets can be infused immediately after thawing and with minimal post thaw manipulation, thus maintaining a relatively closed system. It is concluded that cryopreservation with HES is a practical and effective means for long term platelet storage.     

Metabolism of camphanediols

1. The metabolism of the camphane-2,3-diols and camphane was investigated in rabbits. All the compounds increased the content of glucuronide in the urine. 2. Both trans- and cis-diols gave rise to ketols; the cis-diols gave rise to trans-diols, but not vice versa; camphorquinone gave cis-diol, ketols and trans-diol; camphane did not give rise to diols. 3. The possibility is discussed that an enediol is the intermediate for ketol interconversions in the present series of compounds and in other series such as hydroxyoestrones and hydroxyindanones.     

A Rapid PCR-Based DNA Test for Enterotoxic Bacillus cereus

The occurrence of DNA sequences encoding the hemolysin HblA complex and Bacillus cereus enterotoxin BceT, which have recently been confirmed as enterotoxins, was studied in Bacillus spp. To amplify these DNA sequences, PCR primer systems for the B component of hblA and for bceT DNA sequences were developed. The results from the amplification of hblA sequences correlated well with results obtained with the B. cereus enterotoxin (diarrheal type) test kit (RPLA kit), but not with the results of the Bacillus diarrheal enterotoxin visual immunoassay (BDE kit). Except for two thermophilic strains, all strains that were positive in PCR amplification assays with the hblA primers were also positive when tested with the RPLA kit. The hblA DNA sequence was found in 33 strains, and these strains were closely related according to 16S rDNA-RFLP analysis, except B. pasteurii. In PCR amplifications with the bceT primers only the model strain gave a positive signal. It is concluded that screening of the hemolysin HblA complex by the PCR method allows faster detection of enterotoxin production than does testing with the RPLA enterotoxin kit.     

Indium-mediated alkynylation of sugars: synthesis of C-glycosyl compounds bearing a protected amino alcohol moiety

The coupling of glycals with an alkynyl iodide bearing a protected amino alcohol moiety was achieved in the presence of metallic indium under Barbier conditions. It gave functionalized C-glycosyl compounds, precursors of C-glycosyl amino acids with α configuration.     

Does a non-invasive method – latrine surveys – reveal habitat preferences of raccoon dogs and badgers?

We aimed to examine whether habitat preferences of raccoon dogs Nyctereutes procyonoides and badgers Meles meles can be revealed by using a non-invasive method, latrine surveys. We searched for latrines of these carnivores with scat detection dogs in SW Finland. We compared the results of latrine surveys with the results of a radio-tracking study conducted simultaneously in the same area. Our results showed that latrine surveys and radio-tracking gave fairly similar results: both methods revealed that raccoon dogs favoured deciduous forests, open woodland and reed beds but avoided fields, and badgers favoured deciduous and pine forests but avoided fields, gardens and reed beds. Latrines of both species were often located in the core areas but also along home range borders. Latrine survey revealed possible competition for space between the native badgers and alien raccoon dogs. Latrine survey is a non-invasive method, which gives accurate location points of animals. It could be developed further by combining it with bait-marking and by training the dogs to show us other signs of animals besides latrines.     

Degradation of the parasporal crystal produced by Bacillus thuringiensis var. kurstaki

Degradation products of the parasporal crystals of Bacillus thuringiensis var. kurstaki obtained by treatment with alkali, gut juice from larvae of Bombyx mori, and various plant and mammalian enzymes were compared for elution pattern, approximate molecular weight (MW), and toxicity. The results indicated that with alkaline treatment the most toxic extract was obtained with 0.05–0.1 M NaOH. Toxicity was found associated mainly with a protein peak of 230,000 MW although other toxic peaks were found in the tailing. Heat-treated midgut juice from larval B. mori gave similar results. After digestion of parasporal crystals with clarified midgut juice, five peaks causing toxicity and having MW of approximately 235,000, 67,000, 30,200, 5000, and 1000, respectively, were identified. Treatment of B. thuringiensis δ-endotoxin with α-chymotrypsin gave peaks causing mortality of approximate MW 235,000, 34,000, 5000, and 1000. Trypsin, pronase, carboxypeptidase, and enterokinase digests of the B. thuringiensis δ-endotoxin gave toxic components ranging from 235,000 to 30,000 MW. The protein protoxin molecules are digested to give small toxic subunits that may be of practical value for structural determinations and for molecular mode of action studies.