Impact of Urban Pollution from the Hanoi Area on Benthic Diatom Communities Collected from the Red, Nhue and Tolich Rivers (Vietnam)

The effects of urban pollution from Hanoi city on the benthic diatom communities of the Nhue–Tolich river system were studied during the 2003 dry season. Benthic diatoms were allowed to grow on glass slides suspended in the water flow for 4 weeks. To reveal the relationship between water quality and diatom communities, Canonical correspondence analysis (CCA) was used on data concerning relative abundances of diatom species and environmental variables. Two diatom indices, IPS and DAIpo, were applied to evaluate water quality in the three rivers. A total of 291 diatom taxa were found in the Red, Nhue and Tolich Rivers. These were mainly cosmopolitan taxa, with some tropical, subtropical and endemic taxa. The most abundant taxa at the Red site were Aulacoseira granulata, Achnanthidium minutissimum, Encyonema minutum, Navicula recens and other halophilous taxa such as Nitzschia kurzii, Seminavis strigosa, Entomoneis paludosa, Bacillaria paradoxa. Diatom assemblages at the Tolich site consisted mainly of Nitzschia umbonata, Nitzschia palea and Eolimna minima. Diatom density ranged from 660 to 30,000 cells/cm². Environmental variables and diatom assemblage composition at all sites were significantly correlated. Two diatom indices gave similar results and indicate the Tolich River with the lowest values as a highly polluted site.     

Comparative analysis of two slc11 (Nramp) loci in Takifugu rubripes

To study the evolution of the solute carrier family 11 (slc11; formerly Nramp) protein, we isolated and characterized two paralogs from the pufferfish Takifugu rubripes (Fugu). These teleost genes, designated Fugu slc11a-a and Fugu slc11a-b, comprise open reading frames of 1743 nucleotides (581 amino acids) and 1662 nt (554 aa), respectively. The proteins are 81% similar, and both exhibit signature features of the slc11 family of proteins including 12 transmembrane domains, a conserved transport motif and a glycosylated loop. Both Fugu paralogs are more Slc11a2-like based on sequence homology and phylogenetic studies. Analysis of gene environment placed both in the proximity of multiple loci syntenic to human chromosome 12q13, that is, within a SLC11A2 gene environment. However, Fugu slc11a-a also gave one match with chromosome 2q35, where human SLC11A1 resides. Functional diversification was suggested by differences in tissue distribution and subcellular localization. Fugu slc11a-a exhibits a restricted expression profile and a complex subcellular localization, including LAMP1 positive late endosomes/lysosomes in transiently transfected mouse macrophages. Fugu slc11a-b is expressed ubiquitously and localizes solely to late endosomes/lysosomes. This comparative analysis extends our understanding of the evolution and function of this important family of divalent cation transporters. [Sequence data from this article have been deposited with the EMBL/GenBank Data Libraries under accession nos. AJ496547/8/9 and AJ496550.]     

A revision and phylogenetic analysis of Stoiba Spaeth?1909 (Coleoptera,Chrysomelidae)

Stoiba Spaeth, 1909 is revised with a phylogenetic analysis of 38 adult morphological characters for nine Stoiba species and 11 outgroup species (Mesomphaliini, Ischyrosonychini, and Hemisphaerotini). Four Cuban species of Stoiba were not sampled. Parsimony analysis located the four most parsimonious trees. The strict consensus (CI=0.59, RI=0.78, Steps=83) resolved the monophyly of Stoiba. The monophyly of Stoiba is supported by pale yellow antennae, antennomere VII broader than its length, and rounded basal line of pronotum. An illustrated key to ten species of Stoiba is provided along with a distribution map of 11 species. Stoiba rufa Blake is synonymized with Stoiba swartzii (Thunberg) by a morphological comparison which includes female genitalia.     

CCR5 promoter haplotypes differentially influence CCR5 expression on natural killer and T cell subsets in ethnically divergent HIV-1 uninfected South African populations

CCR5 plays a critical and central role in HIV-1 infection and, to date, a number of genetic mutations and haplotypes within the gene have been found to positively or negatively influence an individual’s susceptibility and rate of disease progression. In this study, we have evaluated the influence of CCR5 haplotypes, HHA, HHC, HHD, and HHE, on CCR5 expression in healthy HIV-1 uninfected individuals from two populations, South African Africans (SAA, n?=?22) and South African Caucasians (SAC, n?=?31). CCR5 haplotypes were determined through sequencing and real time polymerase chain reaction. Flow cytometry was used to quantitate CCR5 surface expression, as both CCR5 density and percentage of CCR5-expressing cells, on B, T, natural killer (NK) cells and monocytes. SAA individuals positive for the HHA haplotype had significantly lower percentages of CCR5-expressing CD8+ T cells in comparison to individuals without HHA (P?=?0.001). HHC+ SAC individuals had significantly higher CCR5 molecules per cell (density) on NK (CD56+) and CD16+ CD56+ NK cell subsets (P?=?0.030 and P?=?0.024, respectively) compared to HHC? SAC individuals. Haplotypes HHD and HHE had no impact on CCR5 expression. Overall, our data highlight that the protective effect of the HHC haplotype in Caucasians might be explained by higher density of CCR5 expression on NK cells that is not evident in HHC+ SAA individuals. Findings raise the question as to the role of CCR5-expressing cells other than CD4+ T cells in protection from HIV-1 acquisition and disease progression.     

Development of a Fetal Weight Chart Using Serial Trans-Abdominal Ultrasound in an East African Population: A Longitudinal Observational Study

Objective

To produce a fetal weight chart representative of a Tanzanian population, and compare it to weight charts from Sub-Saharan Africa and the developed world.

Methods

A longitudinal observational study in Northeastern Tanzania. Pregnant women were followed throughout pregnancy with serial trans-abdominal ultrasound. All pregnancies with pathology were excluded and a chart representing the optimal growth potential was developed using fetal weights and birth weights. The weight chart was compared to a chart from Congo, a chart representing a white population, and a chart representing a white population but adapted to the study population. The prevalence of SGA was assessed using all four charts.

Results

A total of 2193 weight measurements from 583 fetuses/newborns were included in the fetal weight chart. Our chart had lower percentiles than all the other charts. Most importantly, in the end of pregnancy, the 10^th percentiles deviated substantially causing an overestimation of the true prevalence of SGA newborns if our chart had not been used.

Conclusions

We developed a weight chart representative for a Tanzanian population and provide evidence for the necessity of developing regional specific weight charts for correct identification of SGA. Our weight chart is an important tool that can be used for clinical risk assessments of newborns and for evaluating the effect of intrauterine exposures on fetal and newborn weight.     

Dimebon attenuates methamphetamine, but not MPTP, striatal dopamine depletion

Dimebon is an anti-histamine with central nervous system activity. In this report the effects of dimebon as a neuroprotectant in animal models of Parkinson's disease were tested as assessed in methamphetamine- and MPTP-induced striatal dopaminergic toxicity. Dimebon (1mg/kg) administered at 30 min prior to methamphetamine (40mg/kg) significantly reduced the amount of striatal dopamine depletion in mice, without altering the initial methamphetamine-induced increase in body temperature. In contrast, dimebon at either 1 or 25mg/kg administered at 30 min prior to MPTP (35 mg/kg) was unable to prevent MPTP-induced striatal dopamine loss as determined at 7 days post-methamphetamine/MPTP. These data suggest that dimebon may be exerting a neurotoxin specific neuroprotective effect upon the striatal dopaminergic system and may serve as an important tool for discriminating the mechanistic basis of these two dopaminergic neurotoxins.     

Are rates of species diversification correlated with rates of morphological evolution?

Some major evolutionary theories predict a relationship between rates of proliferation of new species (species diversification) and rates of morphological divergence between them. However, this relationship has not been rigorously tested using phylogeny-based approaches. Here, we test this relationship with morphological and phylogenetic data from 190 species of plethodontid salamanders. Surprisingly, we find that rates of species diversification and morphological evolution are not significantly correlated, such that rapid diversification can occur with little morphological change, and vice versa. We also find that most clades have undergone remarkably similar patterns of morphological evolution (despite extensive sympatry) and that those relatively novel phenotypes are not associated with rapid diversification. Finally, we find a strong relationship between rates of size and shape evolution, which has not been previously tested.     

The stimulation of glycolysis by hypoxia in activated monocytes is mediated by AMP-activated protein kinase and inducible 6-phosphofructo-2-kinase

The activation of monocytes involves a stimulation of glycolysis, release of potent inflammatory mediators, and alterations in gene expression. All of these processes are known to be further increased under hypoxic conditions. The activated monocytes express inducible 6-phosphofructo-2-kinase (iPFK-2), which synthesizes fructose 2,6-bisphosphate, a stimulator of glycolysis. During ischemia, AMP-activated protein kinase (AMPK) activates the homologous heart 6-phosphofructo-2-kinase isoform by phosphorylating its Ser-466. Here, we studied the involvement of AMPK and iPFK-2 in the stimulation of glycolysis in activated monocytes under hypoxia. iPFK-2 was phosphorylated on the homologous serine (Ser-461) and activated by AMPK in vitro. The activation of human monocytes by lipopolysaccharide induced iPFK-2 expression and increased fructose 2,6-bisphosphate content and glycolysis. The incubation of activated monocytes with oligomycin, an inhibitor of oxidative phosphorylation, or under hypoxic conditions activated AMPK and further increased iPFK-2 activity, fructose 2,6-bisphosphate content, and glycolysis. In cultured human embryonic kidney 293 cells, the expression of a dominant-negative AMPK prevented both the activation and phosphorylation of co-transfected iPFK-2 by oligomycin. It is concluded that the stimulation of glycolysis by hypoxia in activated monocytes requires the phosphorylation and activation of iPFK-2 by AMPK.