The effect of aromatic side chains on the dilational rheological properties of N-acyltaurate amphiphiles at water-decane interfaces.

To elucidate the effect of aromatic side chains on dilational rheological properties of N-acyltaurate amphiphiles at the decane-water interface, the interfacial rheological properties of sodium N-2-(2-naphthoxy)-tetradecanoyltaurinate (12+N-T) and sodium N-2-(p-butylphenoxy)-tetradecanoyltaurinate (12+4B-T) were investigated utilizing the drop shape analysis method. The effects of adsorption time, interfacial pressure, oscillating frequency, and bulk concentration on the interfacial dilational modulus and phase angle were explored. The results show that the 12+4B-T molecule with a longer hydrophobic chain shows a higher ability for reducing the interfacial tension (IFT). In addition, the interfacial films of both 12+N-T and 12+4B-T are dominated by diffusion exchange at high concentrations. The rigidity of molecules controls the diffusion exchange at low concentrations, while the molecular hydrodynamic radius determines the diffusion exchange at high concentrations. Thus, at low concentrations, the stronger intermolecular interaction between 12+4B-T molecules results in higher dilational modulus values than 12+N-T. When approaching the CMC (critical micelle concentration) value, the rapid diffusion exchange of 12+4B-T between the sublayer micelles and the interface causes a significant decrease in the dilational modulus, while the relatively rigid structure of 12+N-T enables a higher dilational modulus than 12+4B-T. What's more, the longer hydrophobic chain allows 12+4B-T molecules to escape from the interface more easily, resulting in a higher phase angle at low concentrations. However, the diffusion exchange of 12+4B-T is slower than that of 12+N-T, which results in lower phase angles for 12+4B-T than 12+N-T at high concentrations. In general, the introduction of a rigid naphthalene ring in the molecular structure gives the interfacial film greater strength at high concentration. The research results in this paper provide a new technique for the strength regulation of interfacial surfactant adsorption films.

[Application of serum protein fingerprint in diagnosis of pancreatic cancer].

OBJECTIVE: To establish serum protein fingerprint model for early diagnosis of pancreatic cancer with surface enhanced laser desorption/ionization time of flight-mass spectrometry (SELDI-TOF-MS) and bioinformatics techniques. METHODS: A total of 73 samples were analyzed in this study, including 31 cases of pancreatic cancers, 22 cases of pancreatitis and 20 healthy individuals. Samples were first analyzed by SELDI-TOF-MS and two patterns of differentiation model were constructed with support vector machine arithmetic method. RESULTS: The pattern 1 model differentiating pancreatic cancer patients from healthy individuals had a specificity and a sensitivity of both 100.0%. The pattern 2 model differentiating pancreatic cancer from pancreatitis had a specificity of 95.5% and a sensitivity of 93.5%. CONCLUSION: SELDI-TOF-MS technique combined with bioinformatics can facilitate to identify biomarkers for pancreatic cancer.

[Surgical treatment for primary gastrointestinal stromal tumors: a report of 73 cases].

OBJECTIVE: To investigate the effects and prognosis of surgical treatment in primary gastrointestinal stromal tumors (GIST). METHODS: The clinicopathological data of 73 patients with primary GIST underwent operation from April 1997 to December 2007 was retrospectively analyzed, and the prognosis was evaluated too. RESULTS: Among the 73 cases, 68 cases received complete tumor resection, among which 12 cases underwent laparoscopic operation; while palliative resection and biopsy only were carried out in the other 5 cases. There was significant difference in survival rate between the two groups (P = 0.000). The 1-, 3-, 5-year survival rates of the 66 cases had been followed up was 91.0%, 78.2% and 74.1%, respectively. The malignancy risk grades of GIST was related to the survival rates on statistical analysis (P = 0.002). Significant differences were found in the survival rates between the patients with very low grade, low grade and high grade malignancy tumors (P = 0.012, 0.002). CONCLUSIONS: Complete tumor resection should be emphasized in primary GIST, and more attention should be paid to the initial surgical treatment. Extended surgical resection is required for tumors of higher malignancy risk. The indications of laparoscopic surgery in GIST should be selected with caution for tumor complete resection.

Laparoscopic versus open splenectomy for hypersplenism secondary to liver cirrhosis.

BACKGROUND: Since the first laparoscopic splenectomy (LS) in 1991, LS has become the gold standard for the removal of normal-to-moderately enlarged spleens in benign conditions. Compared with open splenectomy (OS), fewer postsurgical complications and better postoperative recovery were observed, but it is contraindicated for hypersplenism secondary to liver cirrhosis owing to technical difficulties associated with splenomegaly, well-developed collateral circulation, and increased risk of bleeding. With the improvements of laparoscopic technique, the concept is changing. METHODS: OS and LS performed for hypersplenism secondary to liver cirrhosis at our institution were analyzed. Relationships between postoperative increases in platelet counts, white blood cell counts, hemoglobin, and liver function were examined. Perioperative data of LSs were compared with those of OSs, including operative time, blood loss, excised spleen weight, complications, and hospital stays. RESULTS: A total of 216 splenectomies (135 OS and 81 LS) were performed from April 1999 to March 2007. Five laparoscopic cases were converted to open surgery owing to operative bleeding or bleeding of splenic fossa. The other 76 patients were performed LSs successfully. No major operative complications occurred. There was no operative death. Excised spleen weight >400 g was present in 56% of cases in this series. At 7 days postoperatively, the platelet counts, white blood cell counts, and hemoglobin significantly increased after open and laparoscopic surgeries, and increase of alanine aminotransferase, aspartate aminotransferase, total bilirubin, and directed bilirubin of LS were significantly different with open cases. Operation times of LS and OS were 2.9+/-0.7 hours and 2.6+/-0.6 hours, respectively. Blood losses were 150.6+/-135.4 mL and 633.8+/-340.3 mL (P<0.01), excised spleen weights were 585.7+/-184.6 g and 591.1+/-153.4 g (P>0.05), and hospital stay were 8.2+/-2.0 days and 11.9+/-3.8 days (P<0.01). Operative associated complications were noted in both LS and OS. Less blood loss, shorter hospital stay, and less impairment of liver function were observed in LS than OS. CONCLUSIONS: LS is feasible, effective, and safe procedures for hypersplenism secondary to liver cirrhosis and contributes to less impairment of liver function, less blood loss, and shorter hospital stay.