The patterns of tungiasis in Araruama township, state of Rio de Janeiro, Brazil

This paper describes patterns of infestation with Tunga penetrans (L., 1758) within the poor community of Araruama municipality, State of Rio de Janeiro, Brazil, assessed by the number of persons and domestic animals parasitized. The overall prevalence of infestation was 49.2% (211 parasitized hosts) of the 429 examined. Humans (p < 0.01) and dogs (p < 0.01) were the most important hosts with 62.6% and 35.6% respectively. Dogs were considered as the potential infestation source to humans. Considering sex and age groups, both measures showed a significant difference (p < 0.01): female (62.2% infested of 143 examined) and male (43.9% infested of 98 examined). All age classes were found infested with significant difference (G = 42.5; p < 0.01) and most of the infestation occurred in children in the 0-9-year old category (27.3%). In contrast and based on mean of chigoe burden per person, the parasitic intensity was significantly higher on male than on female in all age categories, except for the 50+ (H = 27.1; p < 0.01) and decreasing with the increase of age (chi2 = 69.7, A = -124.6, p < 0.01). Growing urbanization, improved housing and sewage systems, use of appropriate footwear, examination of the feet principally in young children, antitetanus prophylaxis and reduction of stray dogs population are the major prophylactic methods recommended.     

Receptor protein tyrosine phosphatase mu expression as a marker for endothelial cell heterogeneity; analysis of RPTPmu gene expression using LacZ knock-in mice

The receptor-like protein tyrosine phosphatase mu (RPTPmu) belongs to the subfamily of meprin, A5, RPTPmu (MAM) domain-containing RPTPs, which are thought to play an important role in cell-cell adhesion mediated processes. The current study was designed to examine the expression pattern of RPTPmu in mice. We have generated RPTPmu-LacZ knock-in mice that express the beta-galactosidase (LacZ) reporter gene under the control of the RPTPmu promoter. LacZ expression patterns were analysed in embryos and adult mice by whole mount LacZ staining. Analysis of beta-galactosidase activity of heterozygous embryos and adult tissues revealed RPTPmu expression in endothelial cells of arteries and capillaries. In contrast, expression was virtually absent in endothelial cells of veins and in fenestrated endothelial cells in the adult liver and spleen. Moreover, RPTPmu expression was found in endothelial cells from the endocardium and the aorta in embryos, but not in adult mice. In addition to heterogeneous expression in endothelial cells, RPTPmu expression was found in cardiac muscle cells but not in skeletal muscle cells or smooth muscle cells. Expression was also found in Type II pneumonocytes in the lung alveoli and in Purkinje cells and other neurons in the brain. The specific expression of RPTPmu in arterial endothelial cells and in cardiac myocytes suggests that RPTPmu may play a role in the regulation of cardiovascular functions.     

Existence of transdominant and potentiating mutants of UL9, the herpes simplex virus type 1 origin-binding protein,suggests that levels of UL9 protein may be regulated during infection

UL9 is a multifunctional protein required for herpes simplex virus type 1 (HSV-1) replication in vivo. UL9 is a member of the superfamily II helicases and exhibits helicase and origin-binding activities. We have previously shown that mutations in the conserved helicase motifs of UL9 can have either a transdominant or potentiating effect on the plaque-forming ability of infectious DNA from wild-type virus (A. J. Malik and S. K. Weller, J. Virol. 70:7859-7866, 1996). In this paper, the mechanisms of transdominance and potentiation are explored. We show that the motif V mutant protein containing a G to A substitution at residue 354 is unstable when expressed by transfection and is either processed to a 38-kDa N-terminal fragment or degraded completely. The overexpression of the MV mutant protein is able to influence the steady-state protein levels of wild-type UL9 and to override the inhibitory effects of wild-type UL9. Potentiation correlates with the ability of the UL9 variants containing the G354A mutation to be processed or degraded to the 38-kDa form. We propose that the MV mutant protein is able to interact with full-length UL9 and that this interaction results in a decrease in the steady-state levels of UL9, which in turn leads to enhanced viral infection. Furthermore, we demonstrate that inhibition of HSV-1 infection can be obtained by overexpression of full-length UL9, the C-terminal third of the protein containing the origin-binding domain, or the N-terminal two-thirds of UL9 containing the conserved helicase motifs and the putative dimerization domain. Our results suggest that transdominance can be mediated by overexpression, origin-binding activity, and dimerization, whereas potentiation is most likely caused by the ability of the UL9 MV mutant to influence the steady-state levels of wild-type UL9. Taken together, the results presented in this paper suggest that the regulation of steady-state levels of UL9 may play an important role in controlling viral infection.     

Partial characterization ofAspergillus fumigatus polygalacturonases for the degumming of natural fibers

Summary Aspergillus fumigatus strain 4, cultured on citrus pectin as the sole carbon source, produced polygalacturonases whose activity was optimum at 65°C and pH 3.5–4.5. The enzymes presented a bimodal thermostability for 10 min, but not 60 min, of incubation. Polygalacturonases showed pH stability between 3.0 to 9.0. The enzymes were stable when stored at 4–6°C for 90 days, but their activity was reduced by 24% when they were stored at 26–30°C. Orange pulp was the best pectic carbon source tested for the production of pectinases capable of retting ramie fibers. The reutilization of these enzymes was possible, suggesting the viability of industrial use of pectinases for degumming ramie fibers.     

Round-cell mutants of Salmonella typhimurium produced by transposition mutagenesis: Lethality of rodA and mre mutations

Summary Thirty-three insertions of transposon Tn10l6l7 into genes involved in the control of rod cell shape were isolated in Salmonella typhimurium by the characteristic glossy appearance of colonies composed of spherical cells. Genetic tests demonstrated that 25 (76%) were insertions in the rodA gene, 7 (21 %) were mre mutants, and 1 (3%) was a divD mutant. No insertion in the pbpA gene were found. Insertions in cell shape genes only appeared when strains displaying resistance to mecillinam (not caused by -lactamase production) were employed. Neither rodA nor mre insertions could be transduced to wild-type strains but they were normally accepted by mecillinam-resistant derivatives and by cya and crp mutants, which, unlike the corresponding Escherichia coli strains, did not display resistance to mecillinam. On the other hand, the divD insertion could be efficiently transduced to any strain. It is concluded that the rodA, mre, and divD genes are involved in the control of rod cell shape but, in addition, the RodA and Mre products perform some function(s) that is essential for wild-type cells but dispensable for some mecillinam-resistant strains, and for cya and crp mutants.     

Initiation of DNA synthesis in mammary epithelium and mammary tumors by lithium ions

The growth promoting effects of lithium and insulin on cultures of mammary gland epithelium and CZF mouse mammary tumor cells were investigated. Lithium chloride exerts a 450-fold increase in the rate of DNA synthesis in mammary epithelium from mid-pregnant mice in organ culture or monolayer culture. There is an increase in both the percentage of cells initiating DNA synthesis and the net accumulation of DNA. The most effective lithium concentration is 10 mM, and the maximally effective rate of stimulation is reached 48 hours after addition. The magnitude of response to lithium varies with the physiological state of the mammary epithelial cell donor: epithelium from non-pregnant or lactating mice is less responsive than that from mid-pregnant mice. In combination, insulin and lithium produce either a synergistic or an additive effect on the growth of epithelium dependent upon the physiological state of the donor animal. Lithium also promotes the growth of mammary tumor cells in the absence of serum or other mitogens. The action of lithium on DNA synthesis appears to be a direct effect on the epithelial cells.     

Microzooplankton grazing of phytoplankton in a tropical upwelling region

We measured grazing by herbivorous zooplankton (<200 μm fraction) in coastal and slope regions of the South Brazil Bight. Using the dilution technique, we performed nine experiments during the austral summer, when nutrient-rich South Atlantic Central Water is present on the shelf, and five during winter. These experiments provide the first estimates of microzooplankton grazing in the western South Atlantic Ocean. Model II regression showed a strong relationship between phytoplankton intrinsic growth rates and grazing, with a slope of 0.64 (±0.28; 95% confidence interval) indicating that microzooplankton grazing could account for the majority of phytoplankton mortality. Both phytoplankton growth and microzooplankton grazing were higher during the summer upwelling season, compared to winter. For the two experiments that were conducted in oligotrophic slope water, grazing accounted for >80% of phytoplankton production. A comparison of incubations with and without added inorganic nutrients showed no consistent stimulation of phytoplankton growth (slope of enriched versus unenriched treatments not significantly different from 1). Estimates from microscopic counts of heterotrophic organisms >10 μm indicated that copepod nauplii comprised the largest share of the microzooplankton biomass (mean 62.4 ± 5.8% SE). Grazing estimates were not correlated with microzooplankton biomass, whether or not nauplii were included, suggesting that most of the grazing was done by nano-sized zooplankton. Electronic Supplementary Material Electronic supplementary material is available in the online version of this article at and is accessible for authorized users. Handling editor: S. Wellekens     

Human Microtubule-Associated Protein 1a (MAP1A) Gene: Genomic Organization, cDNA Sequence, and Developmental- and Tissue-Specific Expression

Microtubule-associated proteins (MAPs) regulate microtubule stability and play critical roles in neuronal development and the balance between neuronal plasticity and rigidity. MAP1a (HGMW-approved symbol MAP1A) stabilizes microtubules in postnatal axons. We describe human MAP1a's genomic organization and deduced cDNA and amino acid sequences. MAP1a is a single-copy gene spanning 10.5 kb. MAP1a coding sequence is contained in five exons. Translation begins in exon 3. Human MAP1a contains 2805 amino acids (predicted molecular weight 306.5 kDa) and is slightly larger than rat MAP1a (2774 amino acids). Like rat and bovine MAP1a, human MAP1a contains conserved tubulin binding motifs in the amino-terminal region. The carboxy-terminal portion contains a conserved pentadecapeptide that is present in the light chain portion of rat and bovine MAP1a/LC2 polyprotein. We show that human MAP1a gene expression occurs almost exclusively in the brain and that there is approximately 10-fold greater gene expression in adult brain compared to fetal brain. Strong, interspecies conservation between human and rat MAP1a cDNA and amino acid sequences indicates important relationships between MAP1a's function and its primary amino acid sequence.     

Shifts in the abundance and distribution of shallow water fish fauna on the southeastern Brazilian coast: a response to climate change

Myriophyllum aquaticum is a semi-submerged exotic macrophyte that was introduced to China for many years. This species may be found in an emergent form in aquatic environments or in an amphibious form under drained conditions. Nuisance growth of this species has often been attributed to excessive amounts of nutrients. Therefore, we tested the following hypotheses: (1) high nutrient availability facilitates the establishment of M. aquaticum and (2) fragment type interacts with nutrient availability to determine the colonization and regeneration capacities of M. aquaticum. Two types of fragments were grown in water solutions with two levels of phosphorous. After 3 weeks, the survival rates showed no significant difference between the phosphorous treatments. However, emergent fragments showed higher RGR in the low and high phosphorous treatments than amphibious fragments. In addition, emergent fragments also showed higher regeneration capacities, indicating higher invasiveness in emergent fragments compared to amphibious fragments. Moreover, the high phosphorous concentration caused emergent fragments to produce more branches, indicating that nutrient availability may increase M. aquaticum propagule pressure. Our study highlights that nutrient supply increased emergent fragment establishment and shaped the invasion dynamics of macrophytes, which could help predict the spread and potential impact of exotic macrophytes in natural aquatic ecosystems.     

Complete genome sequencing of sixteen Francisella noatunensis subsp. orientalis isolates: A genomic approach for molecular characterization and spread dynamics of this clonal population

Francisella noatunensis subsp. orientalis (FNO) is an important emerging pathogen associated with disease outbreaks in farm-raised Nile tilapia. FNO genetic diversity using PCR-based typing, no intra-species discrimination was achieved among isolates/strains from different countries, thus demonstrating a clonal behaviour pattern. In this study, we aimed to evaluate the population structure of FNO isolates by comparing whole-genome sequencing data. The analysis of recombination showed that Brazilian isolates group formed a clonal population; whereas other lineages are also supported by this analysis for isolates from foreign countries. The whole-genome multilocus sequence typing (wgMLST) analysis showed varying numbers of dissimilar alleles, suggesting that the Brazilian clonal population are in expansion. Each Brazilian isolate could be identified as a single node by high-resolution gene-by-gene approach, presenting slight genetic differences associated to mutational events. The common ancestry node suggests a single entry into the country before 2012, and the rapid dissemination of this infectious agent may be linked to market sales of infected fingerlings.