Aminoadamantanes containing monoterpene-derived fragments as potent tyrosyl-DNA phosphodiesterase 1 inhibitors

The ability of a number of nitrogen-containing compounds that simultaneously carry the adamantane and monoterpene moieties to inhibit Tdp1, an important enzyme of the DNA repair system, is studied. Inhibition of this enzyme has the potential to overcome chemotherapeutic resistance of some tumor types. Compound (+)-3c synthesized from 1-aminoadamantane and (+)-myrtenal, and compound 4a produced from 2-aminoadamantane and citronellal were found to be most potent as they inhibited Tdp1 with IC₅₀ values of 6 and 3.5 µM, respectively. These compounds proved to have low cytotoxicity in colon HCT-116 and lung A-549 human tumor cell lines (CC₅₀ > 50 µM). It was demonstrated that compound 4a at 10 µM enhanced cytotoxicity of topotecan, a topoisomerase 1 poison in clinical use, against HCT-116 more than fivefold and to a lesser extent of 1.5 increase in potency for A-549.     

Pyridine alkaloids with activity in the central nervous system

This review discusses all pyridine alkaloids with CNS activity, their therapeutic potential, and the interesting array of sources whence they originate.     

Allogibberic acid: An inhibitor of flowering in Lemna perpusilla

Allogibberic acid (I) has been identified as the compound responsible for the inhibition of flowering, increase in frond multiplication rate and decrease in frond size produced in Lemna perpusilla 6746 by autoclaved, unbuffered aqueous solutions of gibberellic acid (VII). 13-Deoxyallogibberic acid (IV), a product of autoclaving aq. GA₇ (VIII) solutions, also inhibits flowering in L. perpusilla and is about 10 times more active than allogibberic acid.     

Plant-derived smoke solutions stimulate the growth of Lycopersicon esculentum roots in vitro

Aqueous extracts of smoke, derived from Themeda triandra, a fire-climax grass, and Passerina vulgaris, a fynbos plant, stimulated the growth of primary root sections of tomato roots in suspension culture. The optimal dilution for both extracts was 1:2000. Several of the fractions obtained from TLC separation of the Themeda and the Passerina extracts significantly promoted primary root growth. The auxins naphthaleneacetic acid (NAA), indolebutyric acid (IBA) and indoleacetic acid (IAA) were found to stimulate the growth of the primary root axis, with IAA and NAA significantly promoting lateral root number. Similarly, the naturally occurring cytokinins, zeatin and its derivatives (zeatin-O-glucoside; dihydrozeatin and zeatin riboside) stimulated primary root length. Zeatin and dihydrozeatin promoted secondary root growth, but only at very low concentrations.     

Selection of Lactobacillus acidophilus strains for use in “acidophilus products”

Recent studies by DNA-DNA hybridization revealed that strains now designated as L. acidophilus, can be divided into several groups and only one group should be classified as L. acidophilus. We studied several phenotypic characteristics in representative strains from the six DNA-homology groups of L. acidophilus. No group specific pattern was observed among the strains for fermentation of eight carbohydrates, growth at 15 and 45°C, resistance to 0.2% oxgall, lysis by lysozyme or sensitivity to 17 antibiotics. However, some differences among groups were observed in -galactosidase (-gal) activity and surface layer (s-layer) protein. Strains in B1 do not have a s-layer or -gal while B2 strains also lack a s-layer but do possess -gal. All strains in groups A1, A2, A3 and A4, capable of growing in lactose, have -gal activity and also have a s-layer composed of protein subunits of different molecular weights (MW). Strains in A1 homology group have a s-layer with 46 Kd protein subunits while strains in other A groups have s-layer protein subunits that varied in MW within each group. On the basis of these two traits several isolates of unknown homology groups have been tentatively placed in A1, B1 or B2 groups. L. acidophilus from A1 group showed strain variation in -gal specific activity and rate of acid production and growth. For use in dietary adjuncts, L. acidophilus strains should be selected for these three and other desirable traits. They should be maintained and grown in media containing lactose.     

The biennial life strategy in a random environment

In a previous paper (J. Math. Biol. 26, 199–215 (1988)) we calculated the mean and variance of the long-run geometric growth rate of a discrete-time population model with two age classes in a random environment. The formula which was used in that paper as the starting point for the computation of the variance represents only the contribution of the one-period variances. Here we supplement these results by a calculation of the exact variance. All qualitative conclusions reached before are unaffected.     

Survey of the mycoflora and mycotoxins of cotton seeds and cotton seed products in Egypt

Thirty-nine species and 16 fungal genera were isolated from Egyptian cotton seeds, cotton seed meal and cotton seed cake on 1% glucose-Czapek's agar medium incubated at 28 °C. Aspergillus was the most frequent genus and it emerged in 87–100% of the samples contributing 70–98% of total fungi in the three substrates tested. The most common species were A. niger, A. flavus, A. fumigatus, A. terreus and Rhizopus stolonifer; A. niger, A. fumigatus and Penicillium corylophilum; and A. niger, A. flavus, A. terreus, A. nidulans and Rhizopus stolonifer, respectively. Cotton seeds and cotton seed products were naturally contaminated by aflatoxin B₁ and B₂. About 16% of the different substrates tested were positive for aflatoxin contamination. No citrinin, ochratoxin A, patulin, sterigmatocystin, diacetoxyscirpenol, T-2 toxin or zearalenone were detected in the samples assayed.     

A mite survey in the dumpsters for urban solid rubbish

Summary The presence of house dust mites and storage mites in dumpsters was investigated in 3 different areas of Venice hinterland. The aim of this study was to find a relationship between some reported respiratory symptoms among 6 workers who were responsible for moving the dumpsters to the truck and the bio-aerosol released from such operation. These symptoms were closely related to the work and after allergological evaluation we found sensitisation to house dust mites in all 6 employees. The mine exposure in the workplace was assessed by a standardized sampling and analysis of dust obtained after brushing the inside surfaces of dumpsters. In 50% of the specimens (10/20) we found mites belonging to the following families: Pyroglyphidae (Dermatophagoides spp.), Acaridae (Acarus siro) and a lower amount of Cheyletidae (Cheyletus spp.). An indirect test (guanine test) was also performed and gave positivity in 16 dust samples (80%). The insides of dumpsters showed to be an optimal environment for mites survival and reproduction because of cracks and grooves on the walls, the high humidity level and the presence of mould. These mites probably come from dwelling places and other environments (markets, slaughters-houses, farms, etc.). This suggests that mites allergens can be released during rubbish discharging from the dumpsters and represent a possible risk for the employees.     

Review article number 6 : Plant molluscicides

A review on the application of plant molluscicides in the control of schistosomiasis is presented. Laboratory bioassays are discussed, together with criteria for activity. An attempt has been made to provide a comprehensive list of known molluscicidal natural products.     

Metabolic,physiological and kinetic aspects of the alcoholic fermentation of whey permeate by Kluyveromyces fragilis NRRL 665 and Kluyveromyces lactis NCYC 571

Optimum growth conditions for the fermentation of non-concentrated whey permeate by Kluyveromyces fragilis NRRL 665 have been defined. Use of 3.75 g yeast extract l^?1, a growth temperature of 38°C and a pH of 4.0 allowed a maximum productivity of 5.23 g ethanol l^?1 h^?1 in continuous culture with a yield 91% of theoretical. Complete batch fermentation of permeate with 100 g lactose l^?1 was possible with a maximum specific growth rate of 0.276 h^?1 without any change in ethanol yield. Fermentation of concentrated permeate resulted, however, in a general decrease of specific substrate consumption rate, demonstrated by the inability to completely convert an initial 90 or 150 g lactose l^?1 in continuous culture, even at dilution rates as low as 0.05 and 0.08 h^?1, respectively. The decrease could be related to substrate inhibition, to an increase in osmotic pressure caused by lactose and salts, and to ethanol inhibition of both alcohol and biomass yield. The decrease in specific productivity could be counterbalanced by use of high cell density cultures, obtained by cell recycle of K. fragilis. Fermentation of a non-concentrated permeáte at a dilution rate of 1 h^?1 resulted in a productivity of 22 g l^?1 h^?1 at 22 g ethanol l^?1. Cell recycle using flocculating Kluyveromyces lactis NCYC 571 was also tested. With this strain a productivity of 9.3 g l^?1 h^?1 at 45 g product l^?1 was attained at a dilution rate of 0.2 h^?1, with an initial lactose concentration of 95 g l^?1.