Morphologic, karyotypic, and molecular evidence of a new form of Chiropotes (primates, pitheciinae)

Morphologic, karyotypic, and molecular analyses were carried out in 25 specimens of a distinct morph of Chiropotes (henceforth termed Chiropotes sp.) obtained from a number of localities in the Brazilian Amazon. Pelage coloration clearly distinguishes the collected specimens and all other known species of this genus. A distinct karyotype was described for Chiropotes sp. It differs from C. satanas chiropotes by two pericentric inversions, and from C. satanas utahicki by three, which suggests that these taxa are reproductively isolated. Morphometric analyses did not show significant differentiation between these Chiropotes taxa. Molecular analyses confirmed the monophyly of the subfamily Pitheciinae and genera Chiropotes, Cacajao, and Pithecia (the latter appearing as the most basal lineage of the pithecine clade). The genetic distances between C. s. utahicki and Chiropotes sp. from Rio Negro were greater than those between three recognized species of Pithecia, but smaller than those between Cacajao calvus and Cacajao melanocephalus. The most appropriate name for Chiropotes sp. from Rio Negro is C. israelita. This species, C. s. chiropotes, and C. s. utahicki are allopatric. Pelage coloration, karyotype, and molecular analysis strongly indicate that C. chiropotes, C. utahicki, and Chiropotes israelita deserve species status.     

Heterologous expression of a mammalian protein tyrosine phosphatase gene in Leishmania: effect on differentiation

Leishmania is a protozoan pathogen which is transmitted to humans through the bite of an infected sandfly. This infection results in a spectrum of diseases throughout the developing world, collectively known as leishmaniasis. During its life cycle, Leishmania differentiates from the promastigote stage in the sandfly vector into the amastigote stage in the mammalian host where it multiplies exclusively in macrophage phagolysosomes. Although differentiation of Leishmania is essential for its survival and pathogenesis in the mammalian host, this process is poorly understood. In higher eukaryotic cells, protein tyrosine phosphorylation plays a central role in cell proliferation, differentiation and overall function. We have therefore investigated the role of protein tyrosine phosphorylation in Leishmania differentiation by undertaking complementary approaches to mediate protein tyrosine dephosphorylation in vivo. In the present study, L. donovani were engineered to express a mammalian protein tyrosine phosphatase, or were treated with inhibitors of protein tyrosine kinases, and the resulting phenotype was examined. Both approaches resulted in a partial differentiation from promastigotes to amastigotes including the expression of the amastigote specific A2 protein, morphological change and increased virulence. These data provide support for the involvement of tyrosine phosphorylation in the differentiation of Leishmania.     

Composition of volatiles of banana cultivars from Madeira Island

The composition of the volatiles of banana fruit from various cultivars grown on Madeira Island has been determined. Using GC-MS, the volatiles were shown to be complex mixtures of several classes of components, mainly esters, alcohols, aldehydes, ketones and acids. The average contents of the total volatiles from cultivars "Dwarf Cavendish", "Giant Cavendish", "Robusta" and "Williams" were 93.0, 116.5, 157.3 and 157.0 mg/kg, respectively. The ester and alcoholic fractions appear to play a decisive role in the organoleptic characteristics of banana fruit, presenting a substantial content ranging from 57.2 to 89.8 mg/ kg and 19.0 to 47.7 mg/kg, respectively, in all cultivars from Madeira Island studied. 3-Methyl butyl butanoate ester was the major constituent.     

Human milk fractions inhibit the adherence of diffusely adherent Escherichia coli (DAEC) and enteroaggregative E. coli (EAEC) to HeLa cells

Binding to a specific receptor is an essential step for most enteropathogens to initiate an intestinal infection. We analyzed the inhibitory effect of human milk and its protein components on adhesion of two diarrheagenic Escherichia coli strains, diffusely adherent E. coli (DAEC) and enteroaggregative E. coli (EAEC), to HeLa cells. Defatted milk, whey proteins, immunoglobulin and non-immunoglobulin fractions, in concentrations lower than usually found in whole milk, inhibited both DAEC and EAEC adhesion, indicating that human milk components may contribute to the defense of the infants against enteropathogens.     

SELECTIVE PERMEABILITY OF THE EXTRACELLULAR ENVELOPE OF THE MICROALGA SPONDYLOSIUM PANDURIFORME (CHLOROPHYCEAE) AS REVEALED BY ELECTRON PARAMAGNETIC RESONANCE

The aim of this work was to investigate the role of the polysaccharide sheath of the microalga Spondylosium panduriforme (Chlorophyceae, Desmidiaceae) in the selective permeability and transport of molecules into the interior of the cell. We have used the electron paramagnetic resonance (EPR) technique applied to a variety of spin labels of a hydrophobic nature with different substitutents on the ring (−OH, =O, −N=C=S, −NH₃⁺, and others). The spin label EPR signals were destroyed as a consequence of metabolic processes once the spin probes had entered the cells. The decay time of the EPR signal was regulated by the diffusion mechanism across the polysaccharide sheath, cell wall, and membrane. To discriminate the effect of the polysaccharide sheath from that of the cell wall and membrane, the polysaccharide sheath was removed by ultrasonic treatment. The decay times for the cells without capsule were faster than those for intact cells, and a possible mechanism of interaction involving hydrogen bonds between the spin labels and the −OH groups of the polysaccharide sheath is presented. These were expressed by their diffusion and friction coefficients as derived from Ficks' Second Law and the Einstein-Stokes equation and were summarized in terms of diffusion coefficients ( D ₁) for the capsule medium in the order: =O < −OH < −phe < −H < −N=C=S; and for cell wall and membrane ( D ₂): −OH < −H < =O < −NH₃⁺≅−phe < −N=C=S. For the friction coefficients ( f ₁ and f ₂), the order was inverted. These results suggest the capsule plays a role in selectivity as a result of polar interactions with the spin labels.     

Molecular evolution of P transposable elements in the genus Drosophila. III. The melanogaster species group

Phylogenetic relationships were determined for 76 partial P-element sequences from 14 species of the melanogaster species group within the Drosophila subgenus Sophophora. These results are examined in the context of the phylogeny of the species from which the sequences were isolated. Sequences from the P-element family fall into distinct subfamilies, or clades, which are often characteristic for particular species subgroups. When examined locally among closely related species, the evolution of P elements is characterized by vertical transmission, whereby the P-element phylogeny traces the species phylogeny. On a broader scale, however, the P-element phylogeny is not congruent with the species phylogeny. One feature of P-element evolution in the melanogaster group is the presence of more than one P-element subfamily, differing by as much as 36%, in the genomes of some species. Thus, P elements from several individual species are not monophyletic, and a likely explanation for the incongruence between P-element and species phylogenies is provided by the comparison of paralogous sequences. In certain instances, horizontal transfer seems to be a valid alternative explanation for lack of congruence between species and P-element phylogenies. The canonical P-element subfamily, which represents the active, autonomous transposable element, is restricted to D. melanogaster. Thus, its origin clearly lies outside of the melanogaster species group, consistent with the earlier conclusion of recent horizontal transfer.      

Synthesis and biodistribution studies of carbohydrate derivatives radiolabeled with technetium-99m

Three carbohydrate derivatives, MAG₃-Gl, MAG₃-Ga, MAG₃-NG, were synthesized and radiolabeled in high yields. These substances were injected in health Swiss mice and their biodistribution were evaluated. Among them, ^99mTc-MAG₃-Ga displayed higher accumulation in hepatic tissue, due to the presence of specific receptors in the liver for this carbohydrate. Thus, the use of ^99mTc-MAG₃-Ga to assess hepatic function can be considered.     

Molecular characterization of early colonizer bacteria from wastes in a steel plant

Aims: Forty‐nine bacteria isolated from four newly‐produced waste samples of a steel industry, which had a high content of CaO, MgO, Cr and P₂O₅, were characterized molecularly and phenotypically by susceptibility testing against heavy metals. Methods and Results: Phylogenetic analysis using 16S rRNA gene sequences revealed that the isolates belonged to nine genera, Pseudomonas, Micrococcus, Acinetobacter, Bacillus, Dietzia, Kocuria, Diaphorobacter, Staphylococcus and Brevibacillus. Besides, some isolates could be affiliated to species: M. luteus, Ac. junii, Ac. schindleri, B. cereus, K. marina, D. nitroreducens and Staph. warneri. The bacteria that were characterized are taxonomically diverse, and Pseudomonas and Micrococcus predominated. Fingerprinting BOX‐PCR revealed high genomic heterogeneity among the isolates. Among the heavy metal compounds Zn, Ni, Pb and Cu were least toxic to the bacterial isolates, whereas Ag inhibited all isolates at 0·001 mmol l^?1. Conclusions: Heterotrophic bacteria, affiliated with several phylogentic groups, were able to colonize different wastes of a steel industry. Significance and Impact of the Study: This study extends our knowledge of the early colonizers bacteria populating siderurgic environments. Some of these bacteria could have potential for recycling siderurgic waste for steel production.     

GEITLERINEMA SPECIES (OSCILLATORIALES,CYANOBACTERIA) REVEALED BY CELLULAR MORPHOLOGY,ULTRASTRUCTURE, AND DNA SEQUENCING1

Geitlerinema amphibium (C. Agardh ex Gomont) Anagn. and G. unigranulatum (Rama N. Singh) Komárek et M. T. P. Azevedo are morphologically close species with characteristics frequently overlapping. Ten strains of Geitlerinema (six of G. amphibium and four of G. unigranulatum) were analyzed by DNA sequencing and transmission electronic and optical microscopy. Among the investigated strains, the two species were not separated with respect to cellular dimensions, and cellular width was the most varying characteristic. The number and localization of granules, as well as other ultrastructural characteristics, did not provide a means to discriminate between the two species. The two species were not separated either by geography or environment. These results were further corroborated by the analysis of the cpcB‐cpcA intergenic spacer (PC‐IGS) sequences. Given the fact that morphology is very uniform, plus the coexistence of these populations in the same habitat, it would be nearly impossible to distinguish between them in nature. On the other hand, two of the analyzed strains were distinct from all others based on the PC‐IGS sequences, in spite of their morphological similarity. PC‐IGS sequences indicate that these two strains could be a different species of Geitlerinema. Using morphology, cell ultrastructure, and PC‐IGS sequences, it is not possible to distinguish G. amphibium and G. unigranulatum. Therefore, they should be treated as one species, G. unigranulatum as a synonym of G. amphibium.     

Cytokine Profiles at Admission Can Be Related to Outcome in AIDS Patients with Cryptococcal Meningitis

Cryptococcal meningitis (CM) remains as common life-threatening AIDS-defining illness mainly in resource-limited settings. Previous reports suggested that baseline cytokine profiles can be associated to fungal burden and clinical outcome. This study aimed to evaluate the baseline cytokine profiles in AIDS patients with CM and its relation with the outcome at weeks 2 and 10. Thirty AIDS patients with CM diagnosed by cerebrospinal fluid (CSF) Cryptococcus neoformans positive culture, India ink stain and cryptococcal antigen test were prospectively evaluated. As controls, 56 HIV-infected patients without CM and 48 non-HIV individuals were included. Baseline CSF and sera levels of IL-2, IL-4, IL-8, IL-10, IL-12p40, IL-17A, INF-γ and TNF-α were measured by ELISA. Of 30 CM patients, 24 (80%) were male, median age of 38.1. The baseline CSF high fungal burden and positive blood culture were associated with a positive CSF culture at week 2 (p = 0.043 and 0.029). Most CSF and sera cytokines presented higher levels in CM patients than control subjects (p < 0.05). CSF levels of IL-8, IL-12p40, IL-17A, TNF-α, INF-γ and sera TNF-α were significantly higher among survivors at weeks 2 and 10 (p < 0.05). Patients with increased intracranial pression exhibited CSF IL-10 high levels and poor outcome at week 10 (p = 0.032). Otherwise, baseline CSF log10 IFN-γ and IL-17A were negatively correlated with fungal burden (r = -0.47 and -0.50; p = 0.0175 and 0.0094, respectively). The mortality rate was 33% (10/30) at week 2 and 57% (17/30) at week 10. The severity of CM and the advanced immunodeficiency at admission were related to a poor outcome in these patients. Otherwise, the predominant Th1 cytokines profile among survivors confirms its pivotal role to infection control and would be a prognostic marker in cryptococcal meningitis.