Comparative incidence of cancer in HIV-AIDS patients and transplant recipients

BackgroundStudies have found a relationship between decreased immunity and increased incidence of cancer.MethodsA systematic review of observational studies evaluating the incidence of cancer in both organ recipients and people with HIV/AIDS compared with the general population. Eligible studies were searched up to March 2011 in the following databases: Pubmed, Embase, Scielo, Cancerlit and Google scholar. In this study, the standardized incidence ratios (SIR) of cancer in people with HIV/AIDS and of organ transplant recipients were compared with those found among the general population.ResultsTwenty-five studies of transplant and HIV-associated cancer risk, involving 866 776 people with HIV/AIDS or organ recipients and 21 260 new cases of cancer, were included. The risk for the development of new cancer cases was higher among people with HIV/AIDS (SIR = 4, IC95% 3.78–4.24) and who received organs (SIR = 3.28, IC95% 3.06–3.52) when compared with the general population.ConclusionSimilar SIR in both immunocompromised populations suggests that the weakened immune system is responsible for the increased risk of new cases of cancer among these groups. Research investments are needed to develop effective cancer prevention strategies in these populations.     

Bone formation rather than inflammation reflects Ankylosing Spondylitis activity on PET-CT: a pilot study

Introduction

Positron Emission Tomography - Computer Tomography (PET-CT) is an interesting imaging technique to visualize Ankylosing Spondylitis (AS) activity using specific PET tracers. Previous studies have shown that the PET tracers [¹⁸F]FDG and [¹¹C](R)PK11195 can target inflammation (synovitis) in rheumatoid arthritis (RA) and may therefore be useful in AS. Another interesting tracer for AS is [¹⁸F]Fluoride, which targets bone formation. In a pilot setting, the potential of PET-CT in imaging AS activity was tested using different tracers, with Magnetic Resonance Imaging (MRI) and conventional radiographs as reference.

Methods

In a stepwise approach different PET tracers were investigated. First, whole body [¹⁸F]FDG and [¹¹C](R)PK11195 PET-CT scans were obtained of ten AS patients fulfilling the modified New York criteria. According to the BASDAI five of these patients had low and five had high disease activity. Secondly, an extra PET-CT scan using [¹⁸F]Fluoride was made of two additional AS patients with high disease activity. MRI scans of the total spine and sacroiliac joints were performed, and conventional radiographs of the total spine and sacroiliac joints were available for all patients. Scans and radiographs were visually scored by two observers blinded for clinical data.

Results

No increased [¹⁸F]FDG and [¹¹C](R)PK11195 uptake was noticed on PET-CT scans of the first 10 patients. In contrast, MRI demonstrated a total of five bone edema lesions in three out of 10 patients. In the two additional AS patients scanned with [¹⁸F]Fluoride PET-CT, [¹⁸F]Fluoride depicted 17 regions with increased uptake in both vertebral column and sacroiliac joints. In contrast, [¹⁸F]FDG depicted only three lesions, with an uptake of five times lower compared to [¹⁸F]Fluoride, and again no [¹¹C](R)PK11195 positive lesions were found. In these two patients, MRI detected nine lesions and six out of nine matched with the anatomical position of [¹⁸F]Fluoride uptake. Conventional radiographs showed structural bony changes in 11 out of 17 [¹⁸F]Fluoride PET positive lesions.

Conclusions

Our PET-CT data suggest that AS activity is reflected by bone activity (formation) rather than inflammation. The results also show the potential value of PET-CT for imaging AS activity using the bone tracer [¹⁸F]Fluoride. In contrast to active RA, inflammation tracers [¹⁸F]FDG and [¹¹C](R)PK11195 appeared to be less useful for AS imaging.     

Testing an emerging paradigm in migration ecology shows surprising differences in efficiency between flight modes

To maximize fitness, flying animals should maximize flight speed while minimizing energetic expenditure. Soaring speeds of large-bodied birds are determined by flight routes and tradeoffs between minimizing time and energetic costs. Large raptors migrating in eastern North America predominantly glide between thermals that provide lift or soar along slopes or ridgelines using orographic lift (slope soaring). It is usually assumed that slope soaring is faster than thermal gliding because forward progress is constant compared to interrupted progress when birds pause to regain altitude in thermals. We tested this slope-soaring hypothesis using high-frequency GPS-GSM telemetry devices to track golden eagles during northbound migration. In contrast to expectations, flight speed was slower when slope soaring and eagles also were diverted from their migratory path, incurring possible energetic costs and reducing speed of progress towards a migratory endpoint. When gliding between thermals, eagles stayed on track and fast gliding speeds compensated for lack of progress during thermal soaring. When thermals were not available, eagles minimized migration time, not energy, by choosing energetically expensive slope soaring instead of waiting for thermals to develop. Sites suited to slope soaring include ridges preferred for wind-energy generation, thus avian risk of collision with wind turbines is associated with evolutionary trade-offs required to maximize fitness of time-minimizing migratory raptors.     

A procedure to recruit members to enlarge protein family databases--the building of UECOG (UniRef-Enriched COG Database) as a model

A procedure to recruit members to enlarge protein family databases is described here. The procedure makes use of UniRef50 clusters produced by UniProt. Current family entries are used to recruit additional members based on the UniRef50 clusters to which they belong. Only those additional UniRef50 members that are not fragments and whose length is within a restricted range relative to the original entry are recruited. The enriched dataset is then limited to contain only genomes from selected clades. We used the COG database - used for genome annotation and for studies of phylogenetics and gene evolution - as a model. To validate the method, a UniRef-Enriched COG0151 (UECOG) was tested with distinct procedures to compare recruited members with the recruiters: PSI-BLAST, secondary structure overlap (SOV), Seed Linkage, COGnitor, shared domain content, and neighbor-joining single-linkage, and observed that the former four agree in their validations. Presently, the UniRef50-based recruitment procedure enriches the COG database for Archaea, Bacteria and its subgroups Actinobacteria, Firmicutes, Proteobacteria, and other bacteria by 2.2-, 8.0-, 7.0-, 8.8-, 8.7-, and 4.2-fold, respectively, in terms of sequences, and also considerably increased the number of species.     

Effects of Angular Leaf Spot and Rust on Leaf Gas Exchange and Yield of Common Bean (Phaseolus Vulgaris)

Isolated and interactive effects of angular leaf spot (caused by Phaeoisariopsis griseola) and rust (caused by Uromyces appendiculatus) on leaf gas exchange and yield was studied in common bean (Phaseolus vulgaris L. cv. Carioca) plants. Gas exchange was measured on 37, 44, 51, and 58 d after planting using a portable photosynthesis system. The inoculation of plants with P. griseola (P), U. appendiculatus (U), and the combination of both pathogens (P+U) caused a significant reduction of net photosynthetic rate (P _N) and yield. The reduction of stomatal conductance (g _s), P _N, and yield was higher under P and combination of P+U than under U treatment. By effect of U, the reduction on yield was higher than the reductions on gas exchange parameters. On the treatment P+U, a reduction of 23 % in P _N and a correspondent reduction of 32 % in yield was observed. The interactive effects of the pathogens on yield could be explained in part by the decreases in g _s and in P _N of diseased bean leaves. The combined effect of both diseases on yield and gas exchange parameters suggests an antagonistic interaction.     

Wiederaufstellung der Gattung Sericopelma Ausserer, 1875 (Araneida,Theraphosidae, Theraphosinae)

After the examination of the types of Mygalarachne brevipes Ausserer, 1871, and Sericopelma rubronitens Ausserer, 1875, we declare M. brevipes, a juvenile female, as a species “incertae sedis” since the specimen doesn't present sufficient characteristics which allow a secure identification of the genera and species.     

Bromelain purification through unconventional aqueous two-phase system (PEG/ammonium sulphate)

This paper focuses on the feasibility of unconventional aqueous two-phase systems for bromelain purification from pineapple processing waste. The main difference in comparison with conventional systems is the integration of the liquid–liquid extraction technique with fractional precipitation, which can decrease the protein content with no loss of biological activity by removing of unwanted molecules. The analysis of the results was based on the response surface methodology and revealed that the use of the desirability optimisation methodology (DOM) was necessary to achieve higher purification factor values and greater bromelain recovery. The use of DOM yielded an 11.80-fold purification factor and 66.38 % biological activity recovery using poly(ethylene glycol) (PEG) with a molar mass of 4,000, 10.86 % PEG concentration (m/m) and 36.21 % saturation of ammonium sulphate.