BackgroundAnimal African trypanosomiasis, sleeping sickness in humans and Nagana in cattle, is a resurgent disease in Africa caused by Trypanosoma parasites. Trans-sialidases expressed by trypanosomes play an important role in the infection cycle of insects and mammals. Whereas trans-sialidases of other trypanosomes like the American T. cruzi are well investigated, relatively little research has been done on these enzymes of T. congolense.ResultsBased on a partial sequence and an open reading frame in the WTSI database, DNA sequences encoding for eleven T. congolense trans-sialidase 1 variants with 96.3% overall amino acid identity were amplified. Trans-sialidase 1 variants were expressed as recombinant proteins, isolated and assayed for trans-sialylation activity. The purified proteins produced α2,3-sialyllactose from lactose by desialylating fetuin, clearly demonstrating their trans-sialidase activity. Using an HPLC-based assay, substrate specificities and kinetic parameters of two variants were characterized in detail indicating differences in substrate specificities for lactose, fetuin and synthetic substrates. Both enzymes were able to sialylate asialofetuin to an extent, which was sufficient to reconstitute binding sites for Siglec-4. A mass spectrometric analysis of the sialylation pattern of glycopeptides from fetuin revealed clear but generally similar changes in the sialylation pattern of the N-glycans on fetuin catalyzed by the trans-sialidases investigated.ConclusionsThe identification and characterization of a trans-sialidase gene family of the African parasite T. congolense has opened new perspectives for investigating the biological role of these enzymes in Nagana and sleeping sickness. Based on this study it will be interesting to address the expression pattern of these genes and their activities in the different stages of the parasite in its infection cycle. Furthermore, these trans-sialidases have the biotechnological potential to be used for enzymatic modification of sialylated glycoconjugates.

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ObjectiveTo analyse oncological and functional outcomes of salvage radical prostatectomy (SRP) in patients with recurrent prostate cancer and to compare outcomes of patients within and outside the European Association of Urology (EAU) guideline criteria (organ-confined prostate cancer ≤T2b, Gleason score ≤7 and preoperative PSA level <10 ng/mL) for SRP. Patients and MethodsIn all, 55 patients who underwent SRP from January 2007 to December 2012 were retrospectively analysed. Kaplan-Meier curves assessed time to biochemical recurrence (BCR), metastasis-free survival (MFS) and cancer-specific survival. Cox regressions addressed factors influencing BCR and MFS. BCR was defined as a PSA level of >0.2 ng/mL and rising, continence as the use of 0-1 safety pad/day, and potency as a five-item version of the International Index of Erectile Function score of ≥18. ResultsThe median follow-up was 36 months. After SRP, 42.0% of the patients experienced BCR, 15.9% developed metastasis, and 5.5% died from prostate cancer. Patients fulfilling the EAU guideline criteria were less likely to have positive lymph nodes (LNs) and had significantly better BCR-free survival (5-year BCR-free survival 73.9% vs 11.6%; P = 0.001). In multivariate analysis, low-dose-rate brachytherapy as primary treatment (P = 0.03) and presence of positive LNs at SRP (P = 0.02) were significantly associated with worse BCR-free survival. The presence of positive LNs or Gleason score >7 at SRP were independently associated with metastasis. The urinary continence rate at 1 year after SRP was 74%. Seven patients (12.7%) had complications ≥III (Clavien grade). ConclusionSRP is a safe procedure providing good cancer control and reasonable urinary continence. Oncological outcomes are significantly better in patients who met the EAU guideline recommendations.

Patients with LN-positive PCa who received aRT had a significantly better oncological outcome than patients with NT/sRT, independent of tumour characteristics. Patients with early sRT had higher rates of response and better MFS than patients with pre-RT PSA >0.5 ng/mL.

Purpose: Acoustic Radiation Force Impulse Imaging (ARFI) is a new ultrasound elastography technology (Siemens ACUSON S2000 Virtual Touch TM Tissue Quantification), which is integrated in conventional ultrasound equipment. In preliminary studies, ARFI sheer wave speed (SWS) in liver tissue correlated well with transient elastography (TE) values and liver fibrosis stages.Materials and methods: Sixty-eight healthy male and female volunteers were measured with ARFI with two ultrasound tranducers, three measuring positions and during valsalva manoeuvre. A TE (FibroScan TM , Echosens, France) was performed in 60 volunteers.Results: Volunteers had a mean age of 28 years and a mean BMI of 22.3. There was no significant difference of ARFI SWS between the 4C1 and 4V1 ultrasound probes in either intercostal or abdominal approach to liver segment 8 but a higher variance of ARFI SWS with the 4V1/abdominal compared to the intercostal approach (p = 0.0368). The 4C1/intercostal approach had the highest success rates (97.2%), comparable to those of TE (97.18%). Left liver lobe measurements obtained both significantly higher ARFI SWS and value variance (p = 0.0016 and p = 0.0198) compared to 4C1/intercostal approach. Mean ARFI SWS was 1.19 m/s (range 0.77-1.63). Mean TE was 5.39 kPa (range 3.3-9.0 kPa). Valsalva manoeuvre did not significantly alter ARFI SWS and variance. Skin-liver distance significantly influenced ARFI SWS (p < 0.05), while age and gender did not.Conclusion: These results might constitute a first impression of the chances of ARFI SWS to assess liver stiffness, especially in patients with liver diseases due to increased venous pressure.

Despite the relatively poor prognosis of patients with high risk prostate cancer, radical prostatectomy results in favorable 5 and 8-year metastatic progression-free survival, prostate cancer specific mortality-free survival and overall survival rates. Relative to high risk cases, their very high risk counterparts have significantly worse pathological and oncologic outcomes, and more frequently require additional therapies. These observations validate the stratification between high risk and very high risk in European patients with prostate cancer. Interestingly, very high risk patients treated with radical prostatectomy did not have a worse functional outcome than their high risk counterparts.