Partial resection of the urethra is sometimes necessary in the surgical treatment of locally advanced vulvar cancer. In this study, the frequency of urinary incontinence after partial urethral resection was compared with that of patients who were treated without partial resection of the urethra. Eighteen patients with vulvar cancer encroaching or infiltrating the urethra, treated by a radical vulvectomy and partial urethrectomy, were compared with 17 patients treated by vulvectomy without partial removal of the urethra. Data on urinary incontinence pre- and postoperatively from both groups were retrospectively collected from the patient files. A questionnaire on urinary incontinence was sent to a subset of patients from both groups in order to get information on the current micturation pattern. In four out of 18 patients (22%) with a partial urethrectomy, incontinence was reported, versus two out of 17 patients (12%) in the control group (P= 0.860). Eight patients in the study group and 12 in the control group are currently alive, and all responded to the questionnaire. Two (25%) in the study group and three (25%) in the control group reported to have current symptoms of urinary incontinence. This retrospective study shows that partial resection of 1–1.5 cm of the distal urethra in addition to a radical local excision for vulvar cancer does not result in a significant increase in the frequency of urinary incontinence, compared with vulvar cancer patients without partial urethrectomy.
Molecular dynamics (MD) simulations and far-infrared (far-IR) spectroscopy were combined to study peptide binding by the second PDZ domain (PDZ1) of MAGI1, which has been identified as an important target for the Human Papilloma Virus. PDZ1 recognizes and binds to the C-terminal end of the E6 protein from high-risk Human Papilloma Virus. The far-IR spectra of two forms of the protein, an unbound APO form and a HOLO form (where the PDZ1 is bound to an 11-residue peptide derived from the C terminus of HPV16 E6), were obtained. MD simulations were used to determine the most representative structure of each form and these were used to compute their respective IR spectra by normal mode analysis. Far-UV circular dichroism spectroscopy was used to confirm the secondary structure content and the stability through temperature-dependent studies. Both the experimental and calculated far-IR spectra showed a red shift of the low-frequency peaks upon peptide binding. The calculations show that this is coincident with an increased number of hydrogen bonds formed as the peptide augments the protein β-sheet. We further identified the contribution of surface-bound water molecules to bands in the far-IR and, through the calculations, identified potential pathways for allosteric communication. Together, these results demonstrate the utility of combining far-IR experiments and MD studies to study peptide binding by proteins.