A Prospective Study Comparing Laparoscopic vs. Conventional Stomach Pull Up in Total Pharyngo-Laryngo-Esophagectomy for Post Cricoid Cancer.

The aim of this study is to compare laparoscopic and conventional techniques following Total Pharyngo-laryngo-esophagectomy (TPLE) with respect to perioperative morbidity and mortality and postoperative recovery in post cricoid cancer patients. This is a prospective study, which was undertaken in Gujrat Cancer Research Institute (GCRI) in the period of July 2007 to March 2010. Fifteen consecutive patients who underwent laparoscopic TPLE were compared to that of 18 consecutive patients who underwent open TPLE. Laparoscopic and open TPLE procedure were compared with respect to patient characteristics, intra operative and complications present. The average duration was observed to be 3.5 h in the MIS (Minimally Invasive Group) group and was 5.3 h in the open group. The average blood loss was 300 mL in the MIS group and 500 mL in the open group. Average duration of the hospital stay in the MIS group was 13 days and 16 days in the open group. In the MIS group, one patient (6.7%) had a pneumonic complication and two patients (13%) had wound complications. In the open group, six patients (33%) had pneumonic consolidation and four patients (22%) had wound infections. In both groups, one patient each suffered mortality. Laparoscopic TPLE has been found to be much safer with less morbidity as compared with open surgery.

Folding of diphtheria toxin T-domain in the presence of amphipols and fluorinated surfactants: Toward thermodynamic measurements of membrane protein folding.

Solubilizing membrane proteins for functional, structural and thermodynamic studies is usually achieved with the help of detergents, which, however, tend to destabilize them. Several classes of non-detergent surfactants have been designed as milder substitutes for detergents, most prominently amphipathic polymers called 'amphipols' and fluorinated surfactants. Here we test the potential usefulness of these compounds for thermodynamic studies by examining their effect on conformational transitions of the diphtheria toxin T-domain. The advantage of the T-domain as a model system is that it exists as a soluble globular protein at neutral pH yet is converted into a membrane-competent form by acidification and inserts into the lipid bilayer as part of its physiological action. We have examined the effects of various surfactants on two conformational transitions of the T-domain, thermal unfolding and pH-induced transition to a membrane-competent form. All tested detergent and non-detergent surfactants lowered the cooperativity of the thermal unfolding of the T-domain. The dependence of enthalpy of unfolding on surfactant concentration was found to be least for fluorinated surfactants, thus making them useful candidates for thermodynamic studies. Circular dichroism measurements demonstrate that non-ionic homopolymeric amphipols (NAhPols), unlike any other surfactants, can actively cause a conformational change of the T-domain. NAhPol-induced structural rearrangements are different from those observed during thermal denaturation and are suggested to be related to the formation of the membrane-competent form of the T-domain. Measurements of leakage of vesicle content indicate that interaction with NAhPols not only does not prevent the T-domain from inserting into the bilayer, but it can make bilayer permeabilization even more efficient, whereas the pH-dependence of membrane permeabilization becomes more cooperative. This article is part of a Special Issue entitled: Protein Folding in Membranes.