[Treatment of Pipkin type I and II femoral head fractures through modified Smith-Peterson approach and modified Hardinge approach-a case-control studies].

OBJECTIVE: To compare clinical results of treatment of Pipkin type I and II femoral head fractures through modified Smith-Peterson(S-P) approach and modified Hardinge approach. METHODS: From July 2005 to July 2014, 42 patients with Pipkin type I and II femoral head fractures were treated with operation. A total of 23 patients in anterior group was treated with modified S-P approach including 17 males and 6 females with an average age of (29.3±9.4) years old, 5 cases of type I by excision of the fragement, 3 cases of type I and 15 cases of type II cases by fixation of the fragement. While a total of 19 patients in the lateral group was treated with modified Hardinge approach including 15 males and 4 females with an average age of (31.4±10.0) years old, 3 cases of type I by excision of the fragement, 4 cases of type I and 12 cases of type II by fixation of the fragement. Operative time, blood loss during operation and fracture healing time were observed and compared. The clinical and radiographic outcomes of the patients were measured using Thompson-Epstein scoring scale. The effect of hip reduction time of less than 6 h, 6 to12 h, and more than 12 h, the effect of surgery time within 24 h and more than 24 h after injury were compared. RESULTS: All patients were followed up from 24 to 60 months with an average of(30.29±6.95) months. The operation time (61.96±12.22) min, blood loss (46.09±18.03) ml, and (74.74±10.06) min, blood loss (72.11±19.88) ml in lateral group in the anterior group were better than those of lateral group(P<0.05). In anterior group, fracture healing time was(12.22±1.70) weeks, the results were excellent in 8 cases, good in 10 cases, fair in 4 cases and poor in 1 case, the excellent and good rate was 78.3%, the incidence of avascular necrosis of femoral head was 8.69%(2/23), and the incidence of heterotopic ossification was 13.04%(3/23). While in lateral group, the fracture healing time was(12.42±1.95) weeks, the results were excellent in 6 cases, good in 7 cases, fair in 3 cases and poor in 3 cases, the excellent and good rate was 68.4%, the incidence of avascular necrosis of femoral head was 10.53%(2/19), and the incidence of heterotopic ossification was 5.26%(1/19). There was no significant difference in fracture healing time, postoperative effect and postoperative complications between the anterior group and lateral group(P<0.05). The effect of patients with reduction time of hip dislocation less than 12 h was significantly better than that of more than 12 h, there was no significant difference in the effect between reduction time within 6 h and 6 to 12 h. There was no significant difference in the outcome between surgical patients within 24 h and more than 24 h after injury. CONCLUSIONS: Dislocated hip of Pipkin type I and II femoral head fractures should be closed reduction within 6 h. If conditions are limited, the reduction time can be accepted within 12 h. Both of modified S-P approach and modified Hardinge approach are effective in treating Pipkin type I and II femoral head fractures, and can obtain excellent outcomes. Moreover, modified S-P approach has advantage of less trauma, less blood loss, shorter operative time.

Functional characterization of TRPM7 in nasopharyngeal carcinoma and its knockdown effects on tumorigenesis.

The aim of this study was to evaluate the association of functional expression of TRPM7 with nasopharyngeal carcinoma (NPC) growth. We examined the correlation of TRPM7 expression with cell growth and proliferation, cell cycle, and apoptosis in vitro in NPC cell lines and NPC tumorigenesis in mice by conducting experiments in mice and by further analyzing the tumor volume and growth. We further explored to see whether there is any positive correlation with the TRPM7 knockdown in NPC cells with their sensitivity to radiation. We found that the functional expression of TRPM7 in nasopharyngeal carcinoma is a critical requirement for physiological processes such as cell cycle, resistance to apoptosis, and cell proliferation. TRPM7 knockdown also enhanced sensitivity to radiotherapy of nasopharyngeal carcinoma. Moreover, we identified TRPM7 as a novel potential regulator of cell proliferation in NPC, through signal transducer and activator of transcription 3 (STAT3)-mediated signaling pathway and other anti-apoptotic factors. TRPM7 and STAT3 activation might be critical for the growth of NPC cells and could be an effective target for treatment of nasopharyngeal carcinoma.

Sodium-dependent reorganization of the sugar-binding site of SGLT1.

The sodium-dependent glucose cotransporter SGLT1 undergoes a series of voltage- and ligand-induced conformational changes that underlie the cotransport mechanism. In this study we describe how the binding of external Na changes the conformation of the sugar-binding domain, exposing residues that are involved in sugar recognition to the external environment. We constructed 15 individual Cys mutants in the four transmembrane helices (TMHs) that form the sugar binding and translocation domain. Each mutant was functionally characterized for transport kinetics and substrate specificity. Identification of interactions between mutated residues and hydroxyls on the pyranose ring was assessed by comparing the affinities of deoxy sugars to those of glucose. We determined conformation-dependent accessibility to the mutated residues by both a traditional substituted cysteine accessibility method (SCAM) and a new fluorescence binding assay. These data were integrated to orient the helices and construct a framework of residues that comprise the external sugar binding site. We present evidence that R499, Q457, and T460 play a direct role in sugar recognition and that five other residues are indirectly involved in transport. Arranging the four TMHs to account for Na-dependent accessibility and potential for sugar interaction allows us to propose a testable model for the SGLT1 sugar binding site.

Biosynthesis, purification, and substrate specificity of severe acute respiratory syndrome coronavirus 3C-like proteinase.

The 3C-like proteinase of severe acute respiratory syndrome (SARS) coronavirus has been proposed to be a key target for structural-based drug design against SARS. In order to understand the active form and the substrate specificity of the enzyme, we have cloned, expressed, and purified SARS 3C-like proteinase. Analytic gel filtration shows a mixture of monomer and dimer at a protein concentration of 4 mg/ml and mostly monomer at 0.2 mg/ml, which correspond to the concentration used in the enzyme assays. The linear decrease of the enzymatic-specific activity with the decrease of enzyme concentration revealed that only the dimeric form is active and the dimeric interface could be targeted for structural-based drug design against SARS 3C-like proteinase. By using a high pressure liquid chromatography assay, SARS 3C-like proteinase was shown to cut the 11 peptides covering all of the 11 cleavage sites on the viral polyprotein with different efficiency. The two peptides corresponding to the two self-cleavage sites are the two with highest cleavage efficiency, whereas peptides with non-canonical residues at P2 or P1' positions react slower. The P2 position of the substrates seems to favor large hydrophobic residues. Secondary structure studies for the peptide substrates revealed that substrates with more beta-sheetlike structure tend to react fast. This study provides a basic understanding of the enzyme catalysis and a full substrate specificity spectrum for SARS 3C-like proteinase, which are helpful for structural-based inhibitor design against SARS and other coronavirus.

[Inhibition of triclosan to fatty acid synthase from goose uropygial glands and human breast cancer cells in vitro].

BACKGROUND & OBJECTIVE: It has been indicated that fatty acid synthase (FAS) is abnormally overexpressed in human breast cancer compared with normal human tissue. Inhibition of FAS induces apoptosis of human breast cancer cells. The aim of this study was to observe the inhibition of triclosan on FAS from goose uropygial glands for establishing the method and to study the inhibition of triclosan on FAS from human breast cancer SKBr3 cells in vitro. METHODS: The goose uropygial glands FAS was purified by ultra-centrifugation and Superdex PG 200 chromatography; the human breast cancer SKBr3 cell FAS was partially purified by ultra-centrifugation. The FAS was interacted with different concentrations of Triclosan with different times before catalyzing. Then the substrates of FAS were added to the reaction system. The inhibitory activities of triclosan against the FAS were investigated using spectrophotometric assays. RESULTS: In the goose uropygial gland group, FAS was purified as a single band at 250kDa with SDS-PAGE. The inhibitory activities of triclosan(12.5 micromol/L) at 0, 5, and 10 minute on FAS were 26.40%, 28.30%, and 43.93%, respectively. The inhibitory activities of triclosan (25.00 micromol/L) at 0, 5, and 10 minute on FAS were 46.22%, 50.28%, and 97.05%, respectively. The inhibitory activities of triclosan (100.00 micromol/L) at 0, 5, and 10 minute on FAS were 98.11%, 97.75%, and 97.37%, respectively. In human SKBr3 breast cancer cell group, the inhibitory activities of triclosan (25, 50, 100, and 200 micromol/L) at 5 minute on FAS were 20.00%, 26.67%, 60.00%, and 100%, respectively. CONCLUSION: Triclosan inhibits the FAS from goose uropygial glands and human breast cancer SKBr3 cells. The inhibitory activities depended on the concentrations of triclosan and the interaction times between triclosan and FAS before catalyzing.

[Antioxidation activity and protective effection of ginger oil on DNA damage in vitro].

OBJECTIVE: To study the antioxidation activity and protective effect of ginger oil on DNA damage. METHOD: Chemical light assay was used to detect the oxygen radicals scavenging capacity of ginger oil. The erythrocyte oxidation damage was induced by H2O2. The effect of ginger oil on oxidative erythrocyte was observed by the colorimetric analysis assay, and the content of malondialdehyde (MDA) in rabit hepatocyte was measured. The anaylsis of DNA damage was made with single cell gel electrophoresis(SCGE) technique. RESULT: Ginger oil might decrease light value compared with control group and inhibited erythrocyte oxidation damage. Compared with that in control group, the degress of DNA damage reduced significantly in the protected groups. Ginger oil might decrease the content of MDA remarkably and inhitibition rate was 48.16%. CONCLUSION: Ginger oil has dominantive protective effect on DNA damage induced by H2O2. Ginger oil might act as a scavenger of oxygen radical and might be used as an antioxidant.