Degradation of aniline and monochloroanilines by Rhodococcus sp. An 117 and a pseudomonad: a comparative study

Two newly isolated aniline-degrading bacterial strains were characterized with regard to their enzyme systems responsible for aniline catabolism. One of them identified as a Rhodococcus sp. metabolized aniline exclusively via the beta-ketoadipate pathway by means of inducible enzymes. The aniline-degrading enzyme system of the second isolate, presumably a pseudomonad, was shown to consist of an inducible aniline-converting enzyme and constitutive meta-pathway enzymes. Both isolates failed to metabolize monochlorinated anilines in the absence of additional carbon sources. To explain this the ring-cleaving enzymes of both isolates were examined for their substrate specificities. Furthermore, the effect of 4-chlorocatechol on the enzymes catalyzing aniline conversion and catechol oxygenation was investigated.     

Occurrence of Lepidopterism caused by the moth Hylesia nigricans (Berg) (Lepidoptera: Saturniidae) in Rio Grande do Sul State, Brazil

Lepidopterism by Hylesia nigricans (Berg) moth is recorded for the first time in southern Brazil. Preventive strategies of control are proposed based on information on the biology and ecology of this moth.     

The effect of lysolecithin on prostanoid and platelet-activating factor formation by human gall-bladder mucosal cells

It has been demonstrated that lysolecithin (lysophosphatidyl choline, LPC) produces experimental cholecystitis in cats mediated by arachidonic acid metabolites. LPC is a cytolytic agent that has been postulated as a contributing factor in the development of cholecystitis in humans. The purpose of this research was to evaluate the effect of LPC on human gall-bladder mucosal cell phospholipase A(2) and cyclooxygenase activity. Gall-bladder mucosal cells were isolated from the gall-bladders of patients undergoing routine cholecystectomy. Fresh, isolated cells were maintained in tissue culture and stimulated with varying doses of LPC. Platelet-activating factor concentration was quantitated as an index of phospholipase A(2) activity and prostanoids were measured as an index of cyclooxygenase activity. Also, the effect of LPC on cyclooxygenase 1 and 2 expression in microsomal protein was evaluated. LPC caused dose related increases in 6-keto-PGF(1alpha) and PAF produced by human gall-bladder mucosal cells. Exposure of human gall-bladder mucosal cells to LPC failed to elicit expression of constitutive cyclooxygenase-1, while the expression of inducible cyclooxygenase-2 was increased. The results of this study indicate that LPC induces the formation of prostanoids and PAF by human gall-bladder mucosal cells, suggesting that this substance may promote the development of gall-bladder inflammation.     

High-Specificity Targeted Functional Profiling in Microbial Communities with ShortBRED

Profiling microbial community function from metagenomic sequencing data remains a computationally challenging problem. Mapping millions of DNA reads from such samples to reference protein databases requires long run-times, and short read lengths can result in spurious hits to unrelated proteins (loss of specificity). We developed ShortBRED (Short, Better Representative Extract Dataset) to address these challenges, facilitating fast, accurate functional profiling of metagenomic samples. ShortBRED consists of two components: (i) a method that reduces reference proteins of interest to short, highly representative amino acid sequences (“markers”) and (ii) a search step that maps reads to these markers to quantify the relative abundance of their associated proteins. After evaluating ShortBRED on synthetic data, we applied it to profile antibiotic resistance protein families in the gut microbiomes of individuals from the United States, China, Malawi, and Venezuela. Our results support antibiotic resistance as a core function in the human gut microbiome, with tetracycline-resistant ribosomal protection proteins and Class A beta-lactamases being the most widely distributed resistance mechanisms worldwide. ShortBRED markers are applicable to other homology-based search tasks, which we demonstrate here by identifying phylogenetic signatures of antibiotic resistance across more than 3,000 microbial isolate genomes. ShortBRED can be applied to profile a wide variety of protein families of interest; the software, source code, and documentation are available for download at http://huttenhower.sph.harvard.edu/shortbred     

Ethacrynic acid analogues lacking the α,β-unsaturated carbonyl unit—Potential anti-metastatic drugs

A series of ethacrynic acid analogues, lacking the α,β-unsaturated carbonyl unit, was synthesized and subsequently evaluated for their ability to inhibit the migration of human breast cancer cells, MCF-7/AZ. Several of the analogues were already active in the low micromolar range, whereas ethacrynic acid itself shows no potential to inhibit the migration of these cancer cells. Preliminary studies show that the presence of one or more methoxy groups at the phenyl ring of ethacrynic acid is important in order for the ethacrynic acid analogues to demonstrate an inhibitory effect on the migration.     

Trade-offs underlying polyphagy in a facultative ant-tended florivorous butterfly: the role of host plant quality and enemy-free space

The underlying mechanisms mediating the use of multiple host plants were investigated in Parrhasius polibetes (Lycaenidae), a florivorous and facultative myrmecophilous butterfly. Plant traits such as presence of ant–treehopper associations as a source of enemy-free space, flower bud dimensions, toughness, thickness, trichomes, and the corresponding performance and wear of P. polibetes mandibles were examined for three natural hosts: Schefflera vinosa (Araliaceae), Pyrostegia venusta (Bignoniaceae) and Luehea grandiflora (Malvaceae). Parasitism levels of larvae found on the three hosts were also determined. Almost all Luehea had ant–treehopper associations, and all larvae found on this host were non-parasitized. Parasitism was low in larvae found on Schefflera, half of which hosted ant–treehopper associations. No ant–treehopper association was found on Pyrostegia, where parasitism was significantly higher compared to other hosts. In the laboratory, P. polibetes performed well on Schefflera, followed by Pyrostegia. No larvae survived when fed with Luehea. Flower buds of Luehea were thicker and tougher than those of Schefflera and Pyrostegia. Indeed, mandibles of larvae reared on Luehea showed substantial wear, whereas those reared either on Schefflera or Pyrostegia presented no significant damage. Additionally, we suggest that co-occurrence with ant–treehopper associations on a plant provides parasitoid-free space for P. polibetes larvae. Our results support the hypothesis that ecological trade-offs among host plants (i.e., food quality and enemy-free space) promote polyphagy in natural populations of P. polibetes. Host morphological traits seem to play a relevant role in P. polibetes performance. To our knowledge, this is the first report showing the costs of polyphagy in a myrmecophilous butterfly.     

Rectogerochammina eugubina nov. gen., nov. sp., a new agglutinated foraminifer from the Upper Cretaceous of Gubbio, Italy

We describe the new agglutinated foraminiferal genus and species Rectogerochammina eugubina nov. gen., nov. sp. from the Upper Cretaceous Scaglia Rossa Formation of the Umbria-Marche Basin in Italy. The genus differs from Gerochammina (Neagu, 1990) in the presence of a terminal uniserial part.     

Role of Purα in the cellular response to ultraviolet-C radiation

Purα is a nucleic acid-binding protein with DNA-unwinding activity, which has recently been shown to have a role in the cellular response to DNA damage. We have investigated the function of Purα in Ultraviolet-C (UVC) radiation-induced DNA damage and nucleotide excision repair (NER). Mouse embryo fibroblasts from PURA^-/- knockout mice, which lack Purα, showed enhanced sensitivity to UVC irradiation as assessed by assays for cell viability and clonogenicity compared to Purα positive control cultures. In reporter plasmid reactivation assays to measure the removal of DNA adducts induced in vitro by UVC, the Purα-negative cells were less efficient in DNA damage repair. Purα-negative cells were also more sensitive to UVC-induced DNA damage measured by Comet assay and showed a decreased ability to remove UVC-induced cyclobutane pyrimidine dimers. In wild-type mouse fibroblasts, expression of Purα is induced following S-phase checkpoint activation by UVC in a similar manner to the NER factor TFIIH. Moreover, co-immunoprecipitation experiments showed that Purα physically associates with TFIIH. Thus, Purα has a role in NER and the repair of UVC-induced DNA damage.Key words: purα, ultraviolet radiation, DNA damage, DNA repair, nucleotide excision repair, TFIIH