Combined Action of Inhibitors of S-Adenosylmethionine Decarboxylase with an Antimalarial Drug, Chloroquine, on Plasmodium falciparum

ABSTRACT. Methylglyoxal bis (guanylhydrazone), (MGBG) a potent competitive inhibitor of S-adenosyl-L-methionine decarboxylase activity, Berenil, a trypanocidal agent and chloroquine, the commonly used antimalarial resulted in a dose dependent inhibition of Plasmodium falciparum in vitro. The IC₅₀ values of MGBG, Berenil and chloroquine were 224 μM, 40 μM and 42 nM respectively. Parasites treated with different concentrations of MGBG or Berenil were arrested at the trophozoite stage of the erythrocytic cycle. The combined action of chloroquine (10 nM) with either Berenil (0.1 mM) or MGBG (0.1 mM) on P. falciparum growth showed an additive inhibitory effect. The effect of these inhibitors alone and in combination on polyamine biosynthesis is also reported.     

Differential proteomics of dehydration and rehydration in bryophytes: evidence towards a common desiccation tolerance mechanism

All bryophytes evolved desiccation tolerance (DT) mechanisms during the invasion of terrestrial habitats by early land plants. Are these DT mechanisms still present in bryophytes that colonize aquatic habitats? The aquatic bryophyte Fontinalis antipyretica Hedw. was subjected to two drying regimes and alterations in protein profiles and sucrose accumulation during dehydration and rehydration were investigated. Results show that during fast dehydration, there is very little variation in protein profiles, and upon rehydration proteins are leaked. On the other hand, slow dehydration induces changes in both dehydration and rehydration protein profiles, being similar to the protein profiles displayed by the terrestrial bryophytes Physcomitrella patens (Hedw.) Bruch and Schimp. and, to what is comparable with Syntrichia ruralis (Hedw.) F. Weber and D. Mohr. During dehydration there was a reduction in proteins associated with photosynthesis and the cytoskeleton, and an associated accumulation of proteins involved in sugar metabolism and plant defence mechanisms. Upon rehydration, protein accumulation patterns return to control values for both photosynthesis and cytoskeleton whereas proteins associated with sugar metabolism and defence proteins remain high. The current results suggest that bryophytes from different ecological adaptations may share common DT mechanisms.     

Detection of cross reactive antigens between Pestalotiopsis theae and tea leaves and their cellular location

Among the 12 varieties of tea tested against three isolates of Pestalotiopsis theae, causal agent of grey blight disease, Teen Ali-17/1/54 and TV-23 were found to be highly susceptible while CP-1 and TV-26 were resistant under identical conditions. Leaf antigens were prepared from all the tea varieties, three isolates of P. theae and a non-pathogen of tea (Bipolaris tetramera). Polyclonal antisera were raised against mycelial suspensions of P. theae (isolate Pt-2) and leaf antigens of Teen Ali-17/1/54 and CP-1. These were compared an immunodiffusion test and enzyme-linked immunosorbent assay to detect cross reactive antigens (CRA) shared the host and the parasite. CRA were found among the susceptible varieties and isolates of P. theae (Pt-1, 2 and 3). Such antigens were not detected between isolates of P. theae and resistant varieties, B. tetramera and tea varieties or isolates of P. theae. Indirect staining of antibodies using fluorescein isothiocyanate (FITC) indicated that in cross sections of tea leaves, the CRA was concentrated in the epidermal cells and mesophyll tissues. CRA was present in the young hyphal tips of the mycelia and on the setulae and appendages of the conidia of P. theae.     

Morphometric analysis and taxonomic revision of the Vriesea paraibica complex (Bromeliaceae)

The species related to Vriesea paraibica (Bromeliaceae, Tillandsioideae) have controversial taxonomic limits. For several decades, this group has been identified in herbarium collections as V. × morreniana, an artificial hybrid that does not grow in natural habitats. The aim of this study was to assess the morphological variation in the V. paraibica complex through morphometric analyses of natural populations. Two sets of analyses were performed: the first involved six natural populations (G1) and the second was carried out on taxa that emerged from the first analysis, but using material from herbarium collections (G2). Univariate ANOVA was used, as well as discriminant analysis of 16 morphometric variables in G1 and 18 in G2. The results of the analyses of the two groups were similar and led to the selection of diagnostic traits of four species. Lengths of the lower and median floral bracts were significant for the separation of red and yellow floral bracts. Vriesea paraibica and V. interrogatoria have red bracts; these two species are differentiated by the widths of the lower and median portions of the inflorescence and by scape length. These structures are larger in the former and smaller in the latter. Of the species with yellow floral bracts, V. eltoniana is distinguished by longer leaf blades and scapes and V. flava is characterized by its shorter sepal lengths. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 163–181.     

Actinomycosis in fine needle aspiration cytology

Four cases of actinomycosis were diagnosed by fine needle aspiration (FNA) cytology and eight more cases were detected during a review of FNA smears reported as inflammatory. the age of these 12 cases ranged from 20 to 61 years with a median of 35 years. the male to female ratio was 3:1. the common regions of involvement were cervicofacial in seven cases (58.3%), thoracic in three (25.0%) and abdominal in two (16.7%). Four of the seven cervicofacial cases presented with intra-oral masses; the thoracic lesions were pulmonary in location, and the abdominal lesions presented as bowel masses. the possibility of actinomycosis was not considered clinically in any case. the main reason for missed cytodiagnosis in two thirds of the cases appeared to be observer error. It is suggested that when the aspiration smear from a mass is found to be an inflammatory exudate rich in neutrophils, special efforts must be made to look for this microorganism.