Effect of poly(tert-butyl methacrylate) stereoregularity on polymer film interactions with peptides, proteins, and bacteria.

The impact of polymer stereoregularity on its interactions with peptides, proteins and bacteria strains was studied for three stereoregular forms of poly(tert-butyl methacrylate) (PtBMA): isotactic (iso), atactic (at) and syndiotactic (syn) PtBMA. Principal component analysis of the time-of-flight secondary ion mass spectrometry data recorded for thin polymer films indicated a different orientation of ester groups, which in the case of iso-PtBMA are exposed away from the surface whereas for at-PtBMA and syn-PtBMA these are located deeper within the film. This arrangement of chemical groups modified the interactions of iso-PtBMA with biomolecules when compared to at-PtBMA and syn-PtBMA. For peptides, the affected interactions were explained by the preferential hydrogen bonding and electrostatic interaction between the exposed polar ester groups of iso-PtBMA and positively charged peptides. In turn, for protein adsorption no impact on the amount of adsorbed proteins was observed. However, the polymer stereoregularity influenced the orientation of immunoglobulin G and induced conformational changes in bovine serum albumin structure. Moreover, the impact of polymer stereoregularity occurred equally for their interactions with Gram-positive bacteria (S. aureus), which absorbed preferentially onto iso-PtBMA films as compared to two other stereoregularities.

Intraoperative injuries during liver resection: analysis of 1,005 procedures.

PURPOSE: Risk of liver resection has been well investigated in many studies. However, the problem of intraoperative injuries is rarely mentioned. The aim of this study was to assess the incidence, the type, and management of intraoperative injuries during liver resection. METHODS: A total of 1,005 liver resections between 2004 and 2009 were included in this retrospective investigation. We analyzed the incidence of intraoperative injuries, risk factors, and an impact on patients' clinical outcome. RESULTS: The overall incidence of intraoperative injuries was 4.4% (44 of 1,005). Injuries of the diaphragm (1.6%, 16 of 1,005) and hepatocaval junction (1%, 10 of 1,005) were the most frequent. In multivariate analysis, tumor recurrence (p = 0.0199) and tumor size (p = 0.0317) were the only independent risk factors for diaphragm injuries, whereas the extent of resection (p = 0.0007) was the only independent risk factor for caval or hepatic vein injuries. Injuries of the inferior vena cava or hepatic veins significantly increased perioperative mortality (p = 0.0005). CONCLUSIONS: Minor injuries causing no significant complications were the most frequent. However, prevention and proper management of the rare injuries of hepatocaval junction are essential to avoid increased mortality in major liver resections.

Long-term results of liver resection in the treatment of patients with hepatocellular carcinoma.

UNLABELLED: The aim of the study was the analysis of the results of liver resection in the treatment of patients with hepatocellular carcinoma, taking into consideration the selected factors based on the department's material. MATERIAL AND METHODS: Data of 122 patients subject to liver resection due to hepatocellular carcinoma at the Department of General, Transplantation and Liver Surgery, Medical University of Warsaw, were subject to retrospective analysis. The influence of selected factors on the long-term treatment results was determined, and the patient survival depending on the tumor stage as per the TNM scale was compared. The statistical significance threshold was set at p = 0.05. RESULTS: 1- and 3-year overall survival and recurrence-free survival in the whole patient group was 82.1% and 56.3%, and 57.7% and 20.1%, respectively. The perioperative mortality rate was 1.6%. The neoplasm advancement exceeding the first stage on the TNM scale was associated with lower values of overall survival (p = 0.001, HR = 3.7) and recurrence-free survival (p = 0.00008, HR = 3.8). Elevation of AFP was the only independent prognostic factor for overall survival (p = 0.04, HR = 1.04 at alpha-fetoprotein levels > 1000 ng/ml), while the presence of neoplastic emboli in small blood vessels was an independent risk factor for HCC recurrence (p = 0.02, HR = 2.24). CONCLUSIONS: The alpha-fetoprotein levels and presence in the histopathological examination of neoplastic emboli in small blood vessels are independent prognostic factors for outcome of patients operated for hepatocellular carcinoma. The diagnosis of neoplasm at stage 1 as per TNM significantly improves long-term results of resective treatment.