Specific Expansion of Protein Families in the Radioresistant Bacterium Deinococcus Radiodurans

Computer analysis of the complete genome of Deinococcus radioduransR1 reveals a number of protein families, which are over-represented in this organism, compared to most other bacteria with known genome sequences. These families include both previously characterized and uncharacterized proteins. Most of the families whose functions are known or could be predicted seem to be related to stress-response and elimination of damage products (cell-cleaning). The two most prominent family expansions are the Nudix (MutT) family of pyrophosphohydrolases and a previously unnoticed family of proteins related to Bacillus subtilisDinB that could possess a metal-dependent enzymatic activity whose exact nature remains to be determined. Several proteins of the expanded families, particularly the Nudix family, are fused to other domains and form multidomain proteins that are so far unique for Deinococcus. The domain composition of some of these proteins indicates that they could be involved in novel DNA-repair pathways. Such unique proteins are good targets for knock-out and gene expression studies, which are aimed to shed light on the unusual features of this interesting10.6pt bacterium.     

Diverse effects of sphingosine on calcium mobilization and influx in differentiated HL-60 cells

Sphingosine induces a biphasic increase in cytosolic-free Ca(2+)([Ca(2+)](i)) with an initial peak followed by a sustained increase in HL-60 cells differentiated into neutrophil-like cells. The initial peak is not affected by the presence of ethylene glycol bis (beta-aminoethyl ether) N, N, N', N-tetraacetic acid (EGTA) in the buffer and appears to be dependent on conversion of sphingosine to sphingosine -1-phosphate (S1P) by sphingosine kinase, since it is blocked by the presence of N, N-dimethylsphingosine (DMS), which, like sphingosine, causes a sustained increase itself. The sustained increase that is elicited by sphingosine or DMS is abolished by the presence of EGTA in the buffer. The sustained sphingosine-induced Ca(2+)influx does not appear due to Ca(2+)influx through store-operated Ca(2+)(SOC) channels, since the influx is not inhibited by SKF 96365, nor is it augmented by loperamide. In addition, sphingosine and DMS attenuate the Ca(2+)influx through SOC channels that occurs after depletion of intracellular stores by ATP or thapsigargin. Both the initial peak and the sustained increase in [Ca(2+)](i)elicited by sphingosine can be blocked by phorbol 12-myristate 13-acetate (PMA)-elicited activation of protein kinase C. Thus, in HL-60 cells sphingosine causes a mobilization of Ca(2+)from intracellular Ca(2+)stores, which requires conversion to S1P, while both sphingosine and DMS elicit a Ca(2+)influx through an undefined Ca(2+)channel and cause a blockade of SOC channels.     

OVX1 and CEA in patients with colon carcinoma, colon polyps and benign colon disorders

The OVX1 tumor marker promises to complement CA125 for detection of early stage ovarian carcinoma. OVX1 has also been shown to be elevated in colon cancer patients. This study is designed to assess serum OVX1 levels in patients with specific stages of colon cancer, colon polyps or other GI disorders. Serum OVX1 and CEA were measured by radioimmunoassay or enzyme immunoassay for 206 patients at the time of colonoscopy or staging for colon carcinoma. In patients with stage I, II, III, or IV colon carcinoma, serum OVX1 was positive in 37%, 48%, 74% and 63%, respectively. Fifty-three percent of patients with colon polyps had elevated OVX1 levels, while OVX1 levels were positive in only 7% of healthy controls. If both OVX1 and CEA were considered, at least one of these markers was elevated in 36%, 60%, 79% or 89% of patients with stage I, II, III or IV colon carcinoma, respectively. The majority of patients with inflammatory bowel disease or diverticulosis also had elevated OVX1 levels. Both markers were positive in 27% of patients with colon carcinoma, and not in any patients with a normal colonoscopy or with a diagnosis of diverticulosis or hemorrhoids. In conclusion, serum OVX1 improves the sensitivity of CEA for detecting colon polyps and colon cancer; however, the use of OVX1 in this setting is hindered by its elevation in non-malignant colonic processes.     

The impact of length-variable data and alignment criterion on the phylogeny of Decapodiformes (Mollusca: Cephalopoda)

In molecular phylogenetics, mode of analysis is typically the primary reason cited for obtaining different topologies. However, sequence alignment is as important in determining topology as analytical method or optimality criterion, particularly for length-variable sequences. We investigate the effect of alignment strategy and parameters in an analysis of length-variable 18S rDNA sequences from 41 oceanic squids (Decapodiformes), focusing particularly on the impact of including variable regions on the resulting topology. Decapodiformes are an enigmatic group of molluscs whose evolutionary relationships remain unclear because standard molecular analyses have continued to produce poorly supported or poorly resolved trees, possibly due to elevated levels of molecular evolution. We find that alignment strategy (Clustal X versus POY) has a greater affect on topology than does parameter choice. Some groups were robust to shifts in methodology, including cuttlefishes (Sepiidae), bobtail squids (Sepiolidae) and pygmy squids (Idiosepiidae). No alignment strategy supported the monophyly of Oegopsida, although Myopsida did consistently form a monophyletic group. The variable regions consistently provided more well-supported and well-resolved trees than the conserved regions alone, indicating the phylogenetic importance of including length-variable data. © The Willi Hennig Society 2007.     

Emotion-Motion Interactions in Conversion Disorder: An fMRI Study

Objectives

To evaluate the neural correlates of implicit processing of negative emotions in motor conversion disorder (CD) patients.

Methods

An event related fMRI task was completed by 12 motor CD patients and 14 matched healthy controls using standardised stimuli of faces with fearful and sad emotional expressions in comparison to faces with neutral expressions. Temporal changes in the sensitivity to stimuli were also modelled and tested in the two groups.

Results

We found increased amygdala activation to negative emotions in CD compared to healthy controls in region of interest analyses, which persisted over time consistent with previous findings using emotional paradigms. Furthermore during whole brain analyses we found significantly increased activation in CD patients in areas involved in the ‘freeze response’ to fear (periaqueductal grey matter), and areas involved in self-awareness and motor control (cingulate gyrus and supplementary motor area).

Conclusions

In contrast to healthy controls, CD patients exhibited increased response amplitude to fearful stimuli over time, suggesting abnormal emotional regulation (failure of habituation / sensitization). Patients with CD also activated midbrain and frontal structures that could reflect an abnormal behavioral-motor response to negative including threatening stimuli. This suggests a mechanism linking emotions to motor dysfunction in CD.     

Mapping Atmospheric Moisture Climatologies across the Conterminous United States

Spatial climate datasets of 1981–2010 long-term mean monthly average dew point and minimum and maximum vapor pressure deficit were developed for the conterminous United States at 30-arcsec (~800m) resolution. Interpolation of long-term averages (twelve monthly values per variable) was performed using PRISM (Parameter-elevation Relationships on Independent Slopes Model). Surface stations available for analysis numbered only 4,000 for dew point and 3,500 for vapor pressure deficit, compared to 16,000 for previously-developed grids of 1981–2010 long-term mean monthly minimum and maximum temperature. Therefore, a form of Climatologically-Aided Interpolation (CAI) was used, in which the 1981–2010 temperature grids were used as predictor grids. For each grid cell, PRISM calculated a local regression function between the interpolated climate variable and the predictor grid. Nearby stations entering the regression were assigned weights based on the physiographic similarity of the station to the grid cell that included the effects of distance, elevation, coastal proximity, vertical atmospheric layer, and topographic position. Interpolation uncertainties were estimated using cross-validation exercises. Given that CAI interpolation was used, a new method was developed to allow uncertainties in predictor grids to be accounted for in estimating the total interpolation error. Local land use/land cover properties had noticeable effects on the spatial patterns of atmospheric moisture content and deficit. An example of this was relatively high dew points and low vapor pressure deficits at stations located in or near irrigated fields. The new grids, in combination with existing temperature grids, enable the user to derive a full suite of atmospheric moisture variables, such as minimum and maximum relative humidity, vapor pressure, and dew point depression, with accompanying assumptions. All of these grids are available online at http://prism.oregonstate.edu, and include 800-m and 4-km resolution data, images, metadata, pedigree information, and station inventory files.     

INVESTIGATING PROCESSES OF NEOTROPICAL RAIN FOREST TREE DIVERSIFICATION BY EXAMINING THE EVOLUTION AND HISTORICAL BIOGEOGRAPHY OF THE PROTIEAE (BURSERACEAE)

Andean uplift and the collision of North and South America are thought to have major implications for the diversification of the Neotropical biota. However, few studies have investigated how these geological events may have influenced diversification. We present a multilocus phylogeny of 102 Protieae taxa (73% of published species), sampled pantropically, to test hypotheses about the relative importance of dispersal, vicariance, habitat specialization, and biotic factors in the diversification of this ecologically dominant tribe of Neotropical trees. Bayesian fossil‐calibrated analyses date the Protieae stem at 55 Mya. Biogeographic analyses reconstruct an initial late Oligocene/early Miocene radiation in Amazonia for Neotropical Protieae, with several subsequent late Miocene dispersal events to Central America, the Caribbean, Brazil's Atlantic Forest, and the Chocó. Regional phylogenetic structure results indicate frequent dispersal among regions throughout the Miocene and many instances of more recent regional in situ speciation. Habitat specialization to white sand or flooded soils was common, especially in Amazonia. There was one significant increase in diversification rate coincident with colonization of the Neotropics, followed by a gradual decrease consistent with models of diversity‐dependent cladogenesis. Dispersal, biotic interactions, and habitat specialization are thus hypothesized to be the most important processes underlying the diversification of the Protieae.     

Bursera pereirae,a new species and generic record for the Cerrado complex of Brazil. Studies in neotropical Burseraceae XVIII

Bursera pereirae is described and illustrated, and an updated key to Bursera in South America is provided. This new species, which should be considered threatened, is the first record of Bursera for the Cerrado region and the only species of tribe Bursereae endemic to Brazil.