Endoscopic treatment of large symptomatic colon lipomas: A systematic review of efficacy and safety.

BACKGROUND: Various techniques have been described for endoscopic resection of large symptomatic colon lipomas. Lipoma unroofing might provide a safer, more time efficient and easier technique compared to dissection-based techniques, endoscopic mucosal resection (EMR) or loop-assisted resection. The aim of this systematic review was to compare efficacy and safety (endoscopic resolution rates, clinical remission rates and adverse events) of lipoma unroofing with respect to dissection-based techniques, EMR or loop-assisted resection. METHODS: As most outcomes were binary in nature and several outcomes did not occur in some studies, routine calculation of standard errors in outcome probability was not possible. Therefore, original patient data were extracted, after which efficacy and safety were compared. RESULTS: Twenty four studies met the selection criteria, which encompassed 77 lesions (46.8% female, mean age 63 years (interquartile range (IQR) 53-72 years), mean size 45.4 mm (IQR 30.0-60.0 mm). Ten patients underwent unroofing (13.0%), whereas 7 (9.1%), 31 (40.3%) and 29 patients (37.7%) underwent dissection-based techniques, EMR and loop-assisted-snare resection, respectively. Endoscopic resolution rates were 60%, 100% (p = 0.103), 93.6% (p = 0.024) and 93.1% (p = 0.028). Clinical remission rates were identical in all four groups (100%). Amongst patients who underwent EMR and loop-assisted techniques, adverse events were identified in 12.9% (p = 0.556) and 13.8% (p = 0.556), respectively, compared to none in the unroofing and dissection-based resection group. CONCLUSIONS: In patients with large colon lipomas, endoscopic treatment by unroofing, dissection-based resection, EMR and loop-assisted resection provided similar clinical remission rates. Amongst patients undergoing EMR and loop-assisted resection, increased endoscopic resolution rates were seen at the expense of more adverse events, although the latter did not reach statistical significance. Until more reliable comparative data are available, the most optimal resection technique should rely on local expertise and patient profile.

Study of the HIV-2 Env cytoplasmic tail variability and its impact on Tat, Rev and Nef.

BACKGROUND: The HIV-2 env's 3' end encodes the cytoplasmic tail (CT) of the Env protein. This genomic region also encodes the rev, Tat and Nef protein in overlapping reading frames. We studied the variability in the CT coding region in 46 clinical specimens and in 2 reference strains by sequencing and by culturing. The aims were to analyse the variability of Env CT and the evolution of proteins expressed from overlapping coding sequences. RESULTS: A 70% reduction of the length of the CT region affected the HIV-2 ROD and EHO strains in vitro due to a premature stop codon in the env gene. In clinical samples this wasn't observed, but the CT length varied due to insertions and deletions. We noted 3 conserved and 3 variable regions in the CT. The conserved regions were those containing residues involved in Env endocytosis, the potential HIV-2 CT region implicated in the NF-kB activation and the potential end of the lentiviral lytic peptide one. The variable regions were the potential HIV-2 Kennedy region, the potential lentiviral lytic peptide two and the beginning of the potential lentiviral lytic peptide one. A very hydrophobic region was coded downstream of the premature stop codon observed in vitro, suggesting a membrane spanning region. Interestingly, the nucleotides that are responsible for the variability of the CT don't impact rev and Nef. However, in the Kennedy-like coding region variability resulted only from nucleotide changes that impacted Env and Tat together. CONCLUSION: The HIV-2 Env, Tat and Rev C-terminal part are subject to major length variations in both clinical samples and cultured strains. The HIV-2 Env CT contains variable and conserved regions. These regions don't affect the rev and Nef amino acids composition which evolves independently. In contrast, Tat co-evolves with the Env CT.

Specific and quantitative detection of human polyomaviruses BKV and JCV by LightCycler real-time PCR.

BACKGROUND: BK virus (BKV) and JC virus (JCV) are the only two known human polyomavirus that typically establish subclinical persistent infections. In immunocompromised hosts reactivation of the JCV infection is the cause of the central nervous system disease progressive multifocal leucoencephalopathy (PML), while BKV may cause renal nephropathy and haemorrhagic cystitis. OBJECTIVES: The goal of this study was to develop a specific quantification assay for each polyomavirus by LightCycler real-time polymerase chain reaction (PCR) based on SYBR Green I detection. STUDY DESIGN: DNA fragments of 138bp and 233bp from the "large T antigen" region of JCV and BKV, respectively, were amplified. The ability of the designed primer sets to separately quantify BKV DNA or JCV DNA and the PCR efficiency were assessed on reference DNA samples. Known amounts of cloned JCV DNA and BKV DNA from TEBU-BIO nv (Boechout, Belgium) were used to generate standard curves for the quantification assays. Species-specificity of the PCR was evaluated with cloned DNA and with DNA from patient samples. RESULTS: The assay allowed a specific quantification over a 7log dynamic range. Seventeen copies each of the viral genes were reproducibly and accurately detected. The primer sets generated specific DNA fragments for each virus confirmed by agarose gel analysis and by cycle sequencing. The similarities of the amplified gene sequences by BLAST analysis were 99% and 100% for BKV and JCV, respectively. There was no cross-reactivity within the dynamic range of the standard dilutions. CONCLUSIONS: We developed LightCycler real-time PCR assay based on SYBR Green I detection that provided rapid and specific quantification of polyomavirus load.