Role of Type IV Pilins in Persistence of Vibrio vulnificus in Crassostrea virginica Oysters

Vibrio vulnificus is part of the natural estuarine microflora and accumulates in shellfish through filter feeding. It is responsible for the majority of seafood-associated fatalities in the United States mainly through consumption of raw oysters. Previously we have shown that a V. vulnificus mutant unable to express PilD, the type IV prepilin peptidase, does not express pili on the surface of the bacterium and is defective in adherence to human epithelial cells (R. N. Paranjpye, J. C. Lara, J. C. Pepe, C. M. Pepe, and M. S. Strom, Infect. Immun. 66:5659-5668, 1998). A mutant unable to express one of the type IV pilins, PilA, is also defective in adherence to epithelial cells as well as biofilm formation on abiotic surfaces (R. N. Paranjpye and M. S. Strom, Infect. Immun. 73:1411-1422, 2005). In this study we report that the loss of PilD or PilA significantly reduces the ability of V. vulnificus to persist in Crassostrea virginica over a 66-h interval, strongly suggesting that pili expressed by this bacterium play a role in colonization or persistence in oysters.     

Topical applications of iron chelators in photosensitization.

Generation of the reactive oxygen species (ROS) in skin by exposure to ultraviolet (UV) radiation induces a number of cutaneous pathologies such as skin cancer, photosensitization, and photoaging among others. Skin iron catalyzes UV generation of ROS. Topical application of iron chelators reduces erythema, epidermal and dermal hypertrophy, wrinkle formation, tumour appearance. It has been proposed that iron chelators can be useful agents against damaging effects of both short- and long-term UV exposure. A better understanding of the action mechanisms of iron chelators, might be useful to developing effective anticancer and antiphotoaging cosmetic products. Iron chelators may lead to accumulation of protoporphyrin IX (PpIX), a strong photosensitizer. The action of iron chelators in skin, related to PpIX increase has not yet been thoroughly studied. Therefore, we have investigated the formation of PpIX in normal mouse skin after topical application of creams containing metal chelators. The amount and distribution of porphyrins formed was determined by means of non-invasive fluorescence spectroscopy. Deferoxamine (DF), ethylenediaminetetraacetic acid (EDTA), 1,2-diethyl-3-hydroxypyridin-4-one (CP94), but not meso-2,3-dimercaptosuccinic acid (DMSA), caused increased accumulation of endogenous porphyrins in the skin. Fluorescence excitation and emission spectroscopy confirmed that PpIX was the main fluorescent species. The amount of PpIX accumulated in skin under the present conditions was not large enough to produce any significant erythema after light exposure. Further studies are needed to evaluate the role of PpIX induced by iron chelators used, against photoaging and cancer prevention.     

In vivo effects of adenosine A(2) receptor agonist and antagonist on neuronal and astrocytic intermediary metabolism studied with ex vivo (13)C MR spectroscopy.

The effect of adenosine A(2) receptor agonist 2-[p-(2-carboxyethyl)phenylethylamino]-5'-ethylcarboxamidoadenosine (CGS 21680) and antagonist 3,7-dimethyl-1-propargylxanthine (DMPX) on [1-(13)C]glucose and [1,2-(13)C]acetate metabolism was studied in rats by (13)C magnetic resonance (MR) spectroscopy and HPLC. In the cortex a significant reduction was observed in the amounts of [2-(13)C]GABA and [3-(13)C]aspartate from [1-(13)C]glucose in CGS 21680. In the subcortex the concentration of labelled [4-(13)C]glutamate was increased in both treatment groups. The amounts of [2 + 3-(13)C]succinate and [3-(13)C]lactate were increased in the CGS 21680 group compared to control, and the DMPX group showed an increase in the total amount of [6-(13)C]N-acetyl aspartate compared to control in the subcortex. Astrocyte metabolism was only affected in the cortex as shown by a decrease in the pyruvate carboxylase/pyruvate dehydrogenase ratio in glutamate and glutamine in the treatment groups. Labelling from [1,2-(13)C]acetate was not much affected by CGS 21680 or DMPX. However, the amount of [1,2-(13)C]acetate in cortex and subcortex was reduced in the DMPX group. In the cortex a reduction in the labelling of [3-(13)C]GABA in the DMPX group compared to control and an increase in the total amount of taurine in both treatment groups was detected. The present study shows that A(2) receptor agonist and antagonist have similar effects; however, in cortex GABAergic neurones and astrocytes were affected in contrast to subcortex, where glutamatergic neurones showed the greatest changes.     

Serum Collagen Type II Cleavage Epitope and Serum Hyaluronic Acid as Biomarkers for Treatment Monitoring of Dogs with Hip Osteoarthritis

The aim of this study was to evaluate the use of serum type II collagen cleavage epitope and serum hyaluronic acid as biomarkers for treatment monitoring in osteoarthritic dogs. For this purpose, a treatment model based on mesenchymal stem cells derived from adipose tissue combined with plasma rich in growth factors was used. This clinical study included 10 dogs with hip osteoarthritis. Both analytes were measured in serum at baseline, just before applying the treatment, and 1, 3, and 6 months after treatment. These results were compared with those obtained from force plate analysis using the same animals during the same study period. Levels of type II collagen cleavage epitope decreased and those of hyaluronic acid increased with clinical improvement objectively verified via force plate analysis, suggesting these two biomarkers could be effective as indicators of clinical development of joint disease in dogs.     

Evaluation of Alternate Isotope-Coded Derivatization Assay (AIDA) in the LC–MS/MS analysis of aldehydes in exhaled breath condensate

We present the application of a novel isotope dilution method, named Alternate Isotope-Coded Derivatization Assay (AIDA), to the quantitative analysis of hydrazone derivatives of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) in exhaled breath condensate (EBC) samples using liquid chromatography–tandem mass spectrometry. AIDA is based on the alternate derivatization of the analyte(s) with reagents that are available in two pure isotopic forms, respectively “light” and “heavy”, by using light-derivatized standards for the quantification of the heavy-derivatized analytes, and vice versa. To this purpose, 2,4-dinitro-3,5,6-trideuterophenylhydrazine (d₃-DNPH) has been synthesized and used as “heavy” reagent in combination with commercial “light” DNPH. Using the AIDA method, any unknown concentration of the analyte in the matrix can be calculated without the need of a calibration curve. An external calibration method has been also investigated for comparative purpose. The stability of DNPH and d₃-DNPH derivatives was verified by excluding any exchange of hydrazones with each other. In the range of concentrations of biological interest, e.g., 2–40 nM for MDA and 0.5–10 nM for 4-HNE, the derivatization reactions of MDA and 4-HNE with DNPH and d₃-DNPH showed overlapping kinetics and comparable yields. The MS response of both DNPH and d₃-DNPH hydrazones was similar. The precision of AIDA, calculated as %RSD, was within 3.2–8% for MDA and 4.5–11% for 4-HNE. Accuracy was tested by analyzing a spiked EBC pool sample and acceptable results (accuracy within 98–108% for MDA and 93–114% for 4-HNE) were obtained by AIDA after subtraction of the blank, which was not negligible. The results of quantitative analysis of MDA and 4-HNE in EBC samples obtained by AIDA assay with four analyses per sample were in good agreement with those obtained by external calibration method on the same samples.     

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 June 2010 - 31 July 2010

This article documents the addition of 205 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Bagassa guianensis, Bulweria bulwerii, Camelus bactrianus, Chaenogobius annularis, Creontiades dilutus, Diachasmimorpha tryoni, Dioscorea alata, Euhrychiopsis lecontei, Gmelina arborea, Haliotis discus hannai, Hirtella physophora, Melanaphis sacchari, Munida isos, Thaumastocoris peregrinus and Tuberolachnus salignus. These loci were cross-tested on the following species: Halobaena caerulea, Procellaria aequinoctialis, Oceanodroma monteiroi, Camelus ferus, Creontiades pacificus, Dioscorea rotundata, Dioscorea praehensilis, Dioscorea abyssinica, Dioscorea nummularia, Dioscorea transversa, Dioscorea esculenta, Dioscorea pentaphylla, Dioscorea trifida, Hirtella bicornis, Hirtella glandulosa, Licania alba, Licania canescens, Licania membranaceae, Couepia guianensis and 7 undescribed Thaumastocoris species.     

Nested cytochrome b polymerase chain reaction diagnostics underestimate mixed infections of avian blood haemosporidian parasites: microscopy is still essential

Numerous polymerase chain reaction (PCR)-based methods have been developed and used increasingly to screen vertebrate blood samples for the diagnosis of haemosporidian blood parasites (Sporozoa, Haemosporida), but a rigorous evaluation of the sensitivity of these methods for detecting mixed infections of different haemosporidian species belonging to the same and different genera and subgenera is lacking. This study links the information obtained by nested cytochrome b PCR and traditional microscopy in determining mixed haemosporidian infections in naturally infected birds. Samples from 83 individual passerine birds with single infections of Haemoproteus or Plasmodium spp., as determined by mitochondrial DNA amplification, also were investigated by microscopic examination of stained blood films. Thirty-six samples (43%) were found to harbor mixed Haemoproteus, or Plasmodium spp. infections, or both. Thus, the PCR assays alone underestimate the occurrence of mixed infections of haemosporidian parasites in naturally infected birds. To determine the true species composition of the haemosporidians in each individual host, PCR diagnostics need to be improved. Specific primers for Haemoproteus spp. and Plasmodium spp. should be developed. Ideally, a combination of the approaches of both microscopy and PCR-based methods is recommended for this purpose.     

Consensus pathways implicated in prognosis of colorectal cancer identified through systematic enrichment analysis of gene expression profiling studies

Background

A large number of gene expression profiling (GEP) studies on prognosis of colorectal cancer (CRC) has been performed, but no reliable gene signature for prediction of CRC prognosis has been found. Bioinformatic enrichment tools are a powerful approach to identify biological processes in high-throughput data analysis.

Principal Findings

We have for the first time collected the results from the 23 so far published independent GEP studies on CRC prognosis. In these 23 studies, 1475 unique, mapped genes were identified, from which 124 (8.4%) were reported in at least two studies, with 54 of them showing consisting direction in expression change between the single studies. Using these data, we attempted to overcome the lack of reproducibility observed in the genes reported in individual GEP studies by carrying out a pathway-based enrichment analysis. We used up to ten tools for overrepresentation analysis of Gene Ontology (GO) categories or Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in each of the three gene lists (1475, 124 and 54 genes). This strategy, based on testing multiple tools, allowed us to identify the oxidative phosphorylation chain and the extracellular matrix receptor interaction categories, as well as a general category related to cell proliferation and apoptosis, as the only significantly and consistently overrepresented pathways in the three gene lists, which were reported by several enrichment tools.

Conclusions

Our pathway-based enrichment analysis of 23 independent gene expression profiling studies on prognosis of CRC identified significantly and consistently overrepresented prognostic categories for CRC. These overrepresented categories have been functionally clearly related with cancer progression, and deserve further investigation.     

Association between tumor characteristics and second primary cancers with cutaneous melanoma survival: A nationwide cohort study

The increased survival in malignant cutaneous melanoma (melanoma) is probably due to early diagnosis combined with improved treatment most recently. National health campaigns and screening programs for melanoma detection were started in Sweden several decades ago. We want to assess the influence of tumor characteristics, based on the TNM classification, and of second primary cancers on overall survival in melanoma. We used the Swedish Cancer Registry to assess all‐cause survival in melanoma from 2003 to 2015. Hazard ratios (HRs) were estimated using multivariable Cox regression models. A total of 19,773 melanoma patients were diagnosed with TNM data. Survival showed a strong improving trend over time (p‐trend <.001). T1a was the most common classification (48.0% of all), while higher T class was associated systematically with worse survival (p‐trend <.001). For distant metastases, the HR was 3.17, accounting for 0.9% of the patients. Any types of second primary cancers, other than melanoma, were associated with an HR of 2.00, accounted for 6.7% of all cases. Even if melanoma survival in Sweden ranks among the best national rates, the large percentage of patients with advanced tumors (T3b, T4a, and T4b, 17%) and 21% of deaths with T1a call for improved preventive and follow‐up strategies.