Euclein: A new binaphthaquinone from Euclea pseudebenus

7-MethyljugIone, 8,8′-dihydroxy-4,4′-dimethoxy-6,6′-dimethyl-2,2′-binaphthyl-1,1′-quinone, 2-methylnaphthazarin, mamegakinone and euclein have been isolated from Euclea pseudebenus. Euclein is the 3,6′-dimer of 7-methyljuglone.     

Evolutionary relationships among hares from North Africa (Lepus sp. or Lepus spp.), cape hares (L. capensis) from South Africa, and brown hares (L. europaeus), as inferred from mtDNA PCR-RFLP and allozyme data

Systematics and taxonomy of hares of the genus Lepus (Lagomorpha) are under contentious debate, and phylogenetic relationships among many taxa are not well understood. Here we study genetic differentiation and evolutionary relationships among North African hares, currently considered subspecies of Lepus capensis , cape hares ( L. capensis ) from the Cape province in South Africa, and brown hares ( L. europeaus ) from Europe and Anatolia, using maternally (mtDNA) and biparentally (allozymes) inherited markers. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of a c. 1.8 kb long segment of the mitochondrial control region using eight hexanucleotide-recognizing restriction endonucleases yielded 28 haplotypes, and horizontal starch gel electrophoresis of proteins encoded by 25 structural gene loci revealed 52 alleles at 18 polymorphic loci. Diverse phylogenetic analyses (neighbor joining dendrogram, median joining network, multidimensional scaling of pairwise distances, AMOVA, F -statistics, hierarchical F -statistics) of genetic variants revealed marked substructuring of mtDNA into three phylogeographic groups, namely an African, a central European, and an Anatolian, but a somewhat less pronounced overall differentiation of the nuclear genome, despite a relatively high number of population-specific (private) alleles. However, all our results are not incongruent with Petter's (1959: Mammalia 23 , 41; 1961: Z. f. Säugetierkunde 26 , 30; 1972 : Société Des Sciences Naturelles et Physiques du Maroc 52 , 122) hypothesis that North African hares generally belong to L. capensis and that brown hares should be included in this species as well.     

Histoplasma capsulatum peritonitis associated with continuous ambulatory peritoneal dialysis

This paper reports a case of infection byHistoplasma capsulatum apparently restricted to the peritoneum in a woman submitted to continuous ambulatory peritoneal dialysis. Diagnosis was established by culture of dialysis fluid and peritoneal nodule and by histopathologic examination.     

Cutaneous zygomycosis caused byAbsidia corymbifera in a leukemic patient

A case of cutaneous zygomycosis caused byAbsidia coryabifera in a leukemic patient submitted to chemotherapy is reported. The lesion was located on the little finger of the right hand and probably resulted from a latent osteomyelitis. It progressed to form extensive necrotic area. No systemic infection was detected and the lesion did not appear to be associated with any trauma.     

Polymorphism in the promoter region of the mannose-binding lectin gene among human T-cell lymphotropic virus infected subjects

The present study investigated the frequency of the mutations at positions -550 and -221 of the mannose-binding lectin (MBL) gene in a sample of 75 human T-cell lymphotropic virus (HTLV) infected patients and 96 HTLV seronegative controls, in order to evaluate the occurrence of a possible association between the polymorphism and HTLV infection. A sequence specific primer-polymerase chain reaction was used for discrimination of the polymorphism. The analysis of allele frequencies at position -550 did not show any significant differences between HTLV infected group and controls, but there was a significant difference at position -221. The comparative analysis of haplotypes frequencies were not significant, but the genotype frequencies between the two groups, revealed a higher prevalence of genotype LYLX (25.3%), associated with medium and low MBL serum levels among HTLV infected subjects. The odds ratio estimation demonstrated that the presence of genotype LYLX was associated with an increased risk of HTLV infection (p = 0.0096; 1.38 < or = IC95% < or = 7.7605). There was no association between proviral load and the promoter polymorphism, but when promoter and exon 1 mutations were matched, it was possible to identify a significant higher proviral load among HTLV infected individuals carrying haplotypes correlated to low serum levels of MBL. The present study shows that the polymorphism in the promoter region of the MBL gene may be a genetic marker associated with HTLV infection, and emphasizes the need for further studies to determinate if the present polymorphism have any impact on diseases linked to HTLV infection.     

Trypanosoma cruzi: Insights into naphthoquinone effects on growth and proteinase activity

In this study we compared the effects of naphthoquinones (α-lapachone, β-lapachone, nor-β-lapachone and Epoxy-α-lap) on growth of Trypanosoma cruzi epimastigotes forms, and on viability of VERO cells. In addition we also experimentally analyzed the most active compounds inhibitory profile against T. cruzi serine- and cysteine-proteinases activity and theoretically evaluated them against cruzain, the major T. cruzi cysteine proteinase by using a molecular docking approach. Our results confirmed β-lapachone and Epoxy-α-lap with a high trypanocidal activity in contrast to α-lapachone and nor-β-lapachone whereas Epoxy-α-lap presented the safest toxicity profile against VERO cells. Interestingly the evaluation of the active compounds effects against T. cruzi cysteine- and serine-proteinases activities revealed different targets for these molecules. β-Lapachone is able to inhibit the cysteine-proteinase activity of T. cruzi proteic whole extract and of cruzain, similar to E-64, a classical cysteine-proteinase inhibitor. Differently, Epoxy-α-lap inhibited the T. cruzi serine-proteinase activity, similar to PMSF, a classical serine-proteinase inhibitor. In agreement to these biological profiles in the enzymatic assays, our theoretical analysis showed that E-64 and β-lapachone interact with the cruzain specific S2 pocket and active site whereas Epoxy-α-lap showed no important interactions. Overall, our results infer that β-lapachone and Epoxy-α-lap compounds may inhibit T. cruzi epimastigotes growth by affecting T. cruzi different proteinases. Thus the present data shows the potential of these compounds as prototype of protease inhibitors on drug design studies for developing new antichagasic compounds.     

Electrocoagulation as a clarifiation and pre-purification step in plant based bioprocesses

Electrocoagulation is a technique that has been applied to water and wastewater treatment. We propose here extension of this technique to the field of plant downstream processing (DSP), where plants are used as a bioreactors for recombinant protein production. The main problem in plant-based bioreactors is the presence of chlorophyll and phenolic compounds in plant extracts, which tend to precipitate and denature proteins. Their removal from the extracts is essential, since they have a large impact on the DSP performance. In the present work we studied the application of an electrocoagulation based technique to clarify tobacco leaf extracts by removing chlorophyll and phenolic compounds. By manipulating the pH of electrocoagulation, 90% of chlorophyll, 65% of phenolic compounds, and only 23% of total protein were removed from the extract. The process preferentially removes proteins with more acidic pI (below 6.03) and the pH of the process differentially effects removal of acidic and basic proteins.