The viscoelastic properties of hepatocellular carcinoma (HCC) cells were measured by means of micropipette aspiration technique. Further,the authors studied the changes in viscoelastic coefficients by treating with colchicine and cytochalasin D. The results showed that the elastic coefficients of HCC cells were obviously higher than the corresponding value of hepatocytes. By treating with colchicine, the effects on viscoelastic properties of HCC cells were obviously different in ways and extents from those on viscoelastic properties of hepatocytes.,but the viscoelastic properties of hepatocytes by treated with cytochalasin D had the same trend of decreasing as those of HCC cells. These results represent the change in cytoskeleton structure and function among hepatocytes and HCC cells, this change might affect tumor cells invasion and metastasis.

The viscoelastic properties of hepatocellular carcinoma (HCC) cells were measured by means of micropipette aspiration technique. Further,the authors studied the changes in viscoelastic coefficients by treating with colchicine and cytochalasin D. The results showed that the elastic coefficients of HCC cells were obviously higher than the corresponding value of hepatocytes. By treating with colchicine, the effects on viscoelastic properties of HCC cells were obviously different in ways and extents from those on viscoelastic properties of hepatocytes.,but the viscoelastic properties of hepatocytes by treated with cytochalasin D had the same trend of decreasing as those of HCC cells. These results represent the change in cytoskeleton structure and function among hepatocytes and HCC cells, this change might affect tumor cells invasion and metastasis.

As one of the major branches in biomechanics, cellular and molecular biomechanics have made much progress in mechano-biological and mechano-chemical coupling in the past decades. Cells sense various in vivo mechanical stimuli, which initiate downstream signaling via mechanosensitive proteins to balance external forces. It is required to understand what mechanical features of distinct cells are and how external forces are transduced to biochemical signals. Multi-scale integration from cellular, subcellular, to molecular level in a cell promotes the understanding of mechanosensation, mechanotransmission, mechanotransduction, and mechanoepigenetics. In this review, the progress update in cellular and molecular biomechanics is provided and relevant scientific issues, methodological approaches, and potential applications are discussed.

Selectin/ligand interaction plays an important role in such biological processes as inflammatory reaction, tumor metastasis, etc. External forces affect dissociation of receptor-ligand bonds. A novel approach, upon optical trap technique, was developed in this study to investigate the dissociation of P-selectin/PSGL-1 (P-Selectin Glycoprotein Ligand 1) bindings. Stiffness of optical trap was calibrated with laser power using a viscous drag method. While P-selectin and PSGL-1 molecules were functionally coated on surfaces of glass beads, respectively, the dissociation of interacting molecule bond was studied by measuring the rupture force distribution. It was found that most probable rupture force increased with loading rate at < 25 pN/s. These results complemented and validated the current theory at low loading rates.
Humans ; Membrane Glycoproteins ; chemistry ; Optics and Photonics ; instrumentation ; Protein Binding ; Protein Structure, Tertiary

Objective To observe the effect of fructose(Fru),glucose (Glc)and exogenous nitric oxide donor sodium nitroprusside(SNP)on the germination of Psychotria rubra(Lour.)Poir. seeds under drought stress,and to explore the optimal concentration for clearing the drought stress. Methods We established the drought stress model of Psychotria rubra(Lour.)Poir. seeds with 15％(volume fraction)PEG6000 and 0.4 mol/L D-mannitol, measured the germination rate and germination index of Psychotria rubra (Lour.)Poir. seeds under drought stress combined treatment with different concentrations of Fru (0,300,500 μmol/L),Glc (0,300,500 μmol/L) and SNP(0 , 100 , 200 μmol/L). Results The germination process of Psychotria rubra(Lour .) Poir . seeds was significantly suppressed by drought stress. Fru,Glc and SNP could significantly promote the germination of Psychotria rubra (Lour.) Poir. seeds under drought stress. The optimal condition for clearing drought stress induced by 15％ PEG6000 was Fru 300 μmol/L, Glc 500 μmol/Land SNP 200 μmol/L, and the germination rate was 95％ under the optimal condition . The optimal condition for clearing drought stress induced by D-Mannitol was Fru 500 μmol/L, Glc 500 μmol/L and SNP 100 μmol/L, and the germination rate arrived to100％. Conclusion Fru,Glc and SNP can significantly alleviate the negative impact induced by drought stress for the Psychotria rubra(Lour.)Poir. seed germination,improve the drought-resistant ability of the seeds.

Parathyroid hormone (PTH) is a polypeptide molecule synthesized and secreted by parathyroid principal cells. It is an important hormone to maintain the balance of calcium and phosphorus metabolism in the body. It has the dual function of promoting bone formation and bone resorption. In clinic, it promotes osteogenesis by intermittent low-dose subcutaneous injection. In order to avoid the problems of subcutaneous injection, such as poor patient compliance, low utilization of target organs and pain at the injection site, the local application of PTH has attracted much attention in recent years. However, how to realize the local application of PTH and the effect of the local application need to be confirmed by more experiments. This article reviews the local application of PTH and the promotion of jaw regeneration in recent years, in order to provide reference for the local application and research of PTH.

Adenocarcinoma, Mucinous ; chemistry ; genetics ; Female ; Gastrointestinal Stromal Tumors ; chemistry ; genetics ; Humans ; Middle Aged ; Mutation ; Neoplasms, Multiple Primary ; chemistry ; genetics ; Proto-Oncogene Proteins c-kit ; analysis ; Receptors, Platelet-Derived Growth Factor ; genetics ; Stomach Neoplasms ; chemistry ; genetics

OBJECTIVETo investigate the effects of ulinastatin on gut mucosal apoptosis and bacterium translocation in a rat model of sepsis.

METHODSFifty rats were randomly assigned into 4 groups, namely the control (n=5, no operation or drugs), ulinastatin pretreatment (n=15, treated with 25,000 U/kg ulinastatin 2 h before operation), ulinastatin treatment (n=15, treated with 25,000 U/kg ulinastatin 2 h after operation) and sepsis model (n=15, without drug treatment) groups. The rats in the later 3 groups were subjected to cecal ligation and puncture (CLP). At 3, 6 and 12 h after CLP, the rats were sacrificed and the ileum was removed to examine the pathology and apoptosis of the mucosa. The DNA of Bacillus coli in the whole blood was detected using PCR.

RESULTSSepsis caused of epithelial cell loss in the ileal villi, ulceration and blebbing of the lamina propria. Ulinastatin treatment administered before and after the operation both significantly alleviated these morphological anomalies. The sepsis rats showed significantly increased intestinal mucosal apoptotic index as compared with the other 3 groups (P<0.05). Ulinastatin pretreatment, in comparison ulinastatin treatment 12 h after CLP, significantly increased the intestinal mucosal apoptotic index (P<0.05). Bacillus coli DNA was positive in sepsis and postoperative ulinastatin treatment groups but negative in the control and pretreated groups.

CONCLUSIONIncreased intestinal musocal apoptosis and gut bacterial translocation occur in rats following sepsis, and ulinastatin can effectively decrease intestinal mucosal apoptosis and inhibit bacterial translocation.

Animals ; Apoptosis ; drug effects ; Bacterial Translocation ; drug effects ; Female ; Glycoproteins ; pharmacology ; therapeutic use ; Ileum ; drug effects ; microbiology ; pathology ; Intestinal Mucosa ; drug effects ; microbiology ; pathology ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Sepsis ; drug therapy ; Trypsin Inhibitors ; pharmacology ; therapeutic use

Cells sense various in vivo mechanical stimuli, which initiate downstream signaling to mechanical forces. While a body of evidences is presented on the impact of limited mechanical regulators in past decades, the mechanisms how biomechanical responses globally affect cell function need to be addressed. Complexity and diversity of in vivo mechanical clues present distinct patterns of shear flow, tensile stretch, or mechanical compression with various parametric combination of its magnitude, duration, or frequency. Thus, it is required to understand, from the viewpoint of mechanobiology, what mechanical features of cells are, why mechanical properties are different among distinct cell types, and how forces are transduced to downstream biochemical signals. Meanwhile, those in vitro isolated mechanical stimuli are usually coupled together in vivo, suggesting that the different factors that are in effect individually could be canceled out or orchestrated with each other. Evidently, omics analysis, a powerful tool in the field of system biology, is advantageous to combine with mechanobiology and then to map the full-set of mechanically sensitive proteins and transcripts encoded by its genome. This new emerging field, namely mechanomics, makes it possible to elucidate the global responses under systematically-varied mechanical stimuli. This review discusses the current advances in the related fields of mechanomics and elaborates how cells sense external forces and activate the biological responses.
Biomechanical Phenomena ; Gene Expression Regulation ; Humans ; Mechanotransduction, Cellular ; Models, Biological ; Proteome ; genetics ; metabolism ; Stress, Physiological ; Transcriptome

OBJECTIVE: To contrastive analyze the population characteristics and individual variations of enhancement modes of normal pancreas and aorta at intravenous injection rates of 3 mL/s and 2 mL/s. METHODS: Sixty-seven patients with normal pancreas were selected, and were divided randomly into 2 groups with different intravenous injection rates (3 mL/s for 35 patients in Group A and 2 mL/s for 32 patients in Group B). Single-level serial dynamic CT scan was performed at the level where the pancreas was best demonstrated. The enhancement values of pancreas and aorta for each time point of each patient were calculated, and the time-density curves of enhancement of pancreas and aorta of each patient were obtained. The peak enhancement and the time to reach the peak enhancement of pancreas and aorta of each individual patient were evaluated, and the 2 groups were compared. The individual variations of the enhancement modes of pancreas and aorta in each group were analyzed. RESULTS: The peak enhancement of pancreas was (75.7+/-17.0) Hu at (43.9+/-6.6) s for Group A, and (66.5+/-16.0) Hu at (55.2+/-5.0) s for Group B; the peak enhancement of aorta was (226.2+/-35.2) Hu at (35.4+/-4.5) s for Group A, (182.8+/-32.8) Hu at (48.0+/-3.7) s for Group B. There were significant differences in both the peak enhancement and the time to reach the peak enhancement of pancreas and aorta between the 2 groups. The coefficients of variation of time to reach the peak enhancement for pancreas and aorta were 15.0% and 12.7% in Group A, and 9.2% and 7.7% in Group B, respectively. The temporal windows of the optimal enhancement of pancreas were (9.7+/-4.5)s and (13.7+/-3.6)s in Group A and B, respectively. CONCLUSION Better enhancement of pancreas and aorta is obtained at 3 mL/s than 2 mL/s, the time to reach the peak enhancement of pancreas and aorta is comparatively earlier at 3 mL/s than 2 mL/s, and the temporal windows of optimal enhancement of pancreas and aorta are comparatively shorter at 3 mL/s than 2 mL/s.
Adult ; Aged ; Aorta ; Aortography ; methods ; Contrast Media ; Female ; Humans ; Male ; Middle Aged ; Pancreas ; diagnostic imaging ; Spiral Cone-Beam Computed Tomography ; methods ; Young Adult