The type III secretion system of Salmonella typhimurium directs the translocation of proteins into host cells. Evolutionarily related to the flagellar assembly machinery, this system is also present in other pathogenic bacteria, but its organization is unknown. Electron microscopy revealed supramolecular structures spanning the inner and outer membranes of flagellated and nonflagellated strains; such structures were not detected in strains carrying null mutations in components of the type III apparatus. Isolated structures were found to contain at least three proteins of this secretion system. Thus, the type III apparatus of S. typhimurium, and presumably other bacteria, exists as a supramolecular structure in the bacterial envelope.

SummaryThe flagellar hook-basal body (HBB) complex of the Gram-positive bacterium Bacillus subtilis was purified and analysed by electron microscopy, gel electrophoresis, and amino acid sequencing of the major component proteins. The purified HBB complex consisted of the inner (M and S) rings, a rod and a hook. There were no outer (P and L) rings that are found in Gram-negative bacteria. The hook was 15 nm in thickness and 70 nm in length, which is thinner and longer than the hook of Salmonella typhimurium. The hook protein had an apparent molecular mass of 29 kDa, and its N-terminal sequence was identical to that of B. subtilis FlgG

AIM:To investigate the prognostic significance of phosphatase regenerating liver 3 (PRL-3) protein expression in gastric cancer. METHODS:PRL-3 expression in paraffin-embedded tumor specimens from 293 patients with gastric cancer was studied retrospectively by immunohistochemistry. Monoclonal antibody specifically against PRL-3, 3B6, was obtained with hybridoma technique. RESULTS:Positive PRL-3 expression was detected in 43.3% (127 of 293) of gastric cancer cases. High expression of PRL-3 was positively correlated with tumor size, depth of invasion, vascular/lymphatic invasion, lymph node metastasis, high TNM stage and tumor recurrence. Patients with positive PRL-3 expression had a significantly lower 5-year survival rate than those with negative expression (28.3% vs 51.9%, P < 0.0001). Patients who received curative surgery, and with positive PRL-3 expression had a significant shorter overall survival and disease-free disadvantage over patients with negative expression (hazard ratio of 16.7 and 16.6, respectively; P < 0.0001 for both).Multivariate analysis revealed that PRL-3 expression was an independent prognostic indicator for overall and disease-free survival of gastric cancer patients, particularly for survival in TNM stage Ⅲ patients.CONCLUSION: PRL-3 expression is a new independent prognostic indicator to predict the potential of recurrence and survival in patients with gastric cancer at the time of tumor resection.

Objective: Osteopontin has been shown to facilitate the progression and metastasis of malignancies and to be of prognostic value in several human cancers. In gastric cancer, the protein expression of osteopontin has been found to be correlated with tumor invasion and metastasis, but data on its prognostic value are lacking. The aim of this study was to classify the prognostic significance of osteopontin in gastric cancer. Method: In this retrospective study, 306 tumor tissue samples resected from patients with gastric cancer were investigated by staining with a commercial polyclonal antibody against osteopontin. Results: Positive osteopontin expression (>5% of the cancer cell cytoplasm positive) was found in 132 (43.1%) of 306 stained tumors. High osteopontin expression correlated with deep invasion, lymph node metastasis, distant metastasis and higher TNM stage. Patients with osteopontin-positive expression had poorer overall and disease-free survivals than those with negative expression (p < 0.001 for both). Multivariate analysis revealed osteopontin expression as an independent prognostic indicator of poor disease-free and overall survival in patients with gastric cancer, particularly for survival in TNM stages II (p < 0.05) and III (p < 0.01) patients. Conclusion: Osteopontin protein expression was confirmed as a new independent predictor of tumor recurrence and poor prognosis in patients with gastric cancer.

The aerial parts of Artemisia frigida Willd. are used to treat joint swelling, renal heat, abnormal menstruation, and sore carbuncle. The anti-inflammatory effects of A. frigida have been well-known in folk medicine, suggesting that components extracted from A. frigida could potentially treat inflammatory disease. With the aim of discovering bioactive compounds, in this study, we extracted total flavonoids from the aerial parts of A. frigida and investigated their anti-inflammatory effects against inflammation induced by carrageenan and egg albumin in rats. At the doses studied, total flavonoids (100 mg/kg, 200 mg/kg, and 400 mg/kg) and some isolated compounds (30 mg/kg) showed significant and dose-dependent anti-inflammatory effects. According to the high-performance liquid chromatography analysis of the total flavonoids from A. frigida, there are five major compounds, namely, 5-hydroxy-3',4'-dimethoxy-7-O-β-d-glucuronide (F1), 5-hydroxy-3',4',5'-trimethoxy-7-O-β-d-glucuronide (F2), 5,7,3'-trihydroxy-6,4'-dimethoxyflavone (F3), 5,3'-dihydroxy-6,7,4'-trimethoxyflavone (F4), and 5,3'-dihydroxy-3,6,7,4'-tetramethoxyflavone (F5), which may explain the anti-inflammatory activity.

Reversibility of protein denaturation is a prerequisite for all applications that depend on reliable enzyme catalysis, particularly, for using steam to sterilize enzyme reactors or enzyme sensor tips, and for developing protein-based devices that perform on-off switching of the protein function such as enzymatic activity, ligand binding and so on. In this study, we have successfully constructed an immobilized protein that retains full enzymatic activity even after thermal treatments as high as 120 degrees C. The key for the complete reversibility was the development of a new reaction that allowed a protein to be covalently attached to a surface through its C-terminus and the protein engineering approach that was used to make the protein compatible with the new attachment chemistry.

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