Serum Hepatocyte Growth Factor Concentration in Obese Women Decreases after Vertical Banded Gastroplasty

Background: Human obesity is associated with increased serum hepatocyte growth factor (HGF) concentration. This study examines whether reduced body fat mass after vertical banded gastroplasty (VBG) is associated with a decrease in serum HGF concentration. Methods: Serum HGF concentration and body weight, BMI, body fat mass, blood pressure, serum leptin, insulin, triacylglycerol, and cholesterol concentrations were studied in 10 obese women before and 1 year after VBG. 10 lean, healthy women were used as controls. Results: Obese women showed significantly higher serum HGF concentration than control (lean, healthy) subjects. The mean serum HGF concentration decreased significantly 1 year after VBG, but did not reach the value observed in lean women. After VBG, BMI, body fat mass and serum HGF had similar patterns of decrease. Moreover, serum HGF concentration was positively correlated with both BMI (r=0.6, P<0.01) and body fat mass (r=0.6, P<0.01). Before surgery in obese women, elevated blood pressure was observed, which decreased after VBG. Linear regression analysis between blood pressure and serum HGF concentration using all subjects, showed no correlation between either systolic blood pressure and serum HGF concentration (r=.15, P=NS) or between diastolic blood pressure and serum HGF concentration (r=0.1, P=NS). Insulin resistance index (HOMA score), serum leptin, insulin and triacylglycerol concentrations decreased 1 year after VBG. However, serum cholesterol concentration did not change significantly. Conclusions: These results indicate that VBG results in a reduction in circulating HGF concentration. The reduced body fat mass may contribute in part to the decrease of serum HGF concentration after VBG. Because elevated serum HGF concentration may contribute to the progression of atherosclerosis, the decrease in serum HGF concentration after VBG may be beneficial for obese subjects.     

碱性成纤维细胞生长因子对庆大霉素所致豚鼠前庭损害的保护作用

目的 观察碱性成纤维细胞生长因子（ｂａｓｉｃ ｆｉｂｒｏｂｌａｓｔ ｆａｃｔｏｒ,ｂＦＧＦ）对庆大霉素所致活体豚鼠前庭损害的保护作用。方法 豚鼠皮下注射庆大霉素连续１０天,造成内耳损伤。实验组同时腹腔注射ｂＦＧＦ,对照组则注射生理盐水,检测两组豚鼠的前庭功能,前庭终器行扫描电镜观察。结果 对照组前庭损伤明显重于实验组。结论 ｂＦＧＦ对庆大霉素所致活体豚鼠前庭损害有保护作用。     

Immunohistochemical Studies on EGF Family Growth Factors in Normal and Ulcerated Human Gastric Mucosa

Expression of members of the epidermal growthfactor family, including epidermal growth factor (EGF),transforming growth factor- (TGF-),amphiregulin (AR), and Cripto, as well as their putative receptor, epidermal growth factor receptor(EGFR), was studied immunohistochemically in humangastric mucosa to evaluate their possible roles in cellproliferation of normal and regenerative gastric mucosa. We also examined the correlation between cellproliferation and EGFR by double immunohistochemicalstaining for proliferating cell nuclear antigen (PCNA)and EGFR. In normal gastric mucosa, TGF-, Cripto, and AR immunoreactivities were observed in thesurface epithelial and parietal cells of gastric fundicglands, respectively. EGF immunoreactivity was notobserved in any of normal mucosa examined. EGFR immunoreactivity was detected on foveolar cellsin proliferative zones and in parietal cells. Doubleimmunostaining revealed that EGFR immunoreactivity wasdistributed much more widely than PCNA immunoreactivity. PCNA positive epithelial cells adjacent togastric ulcer margin expressed relatively intense EGFRbut did not express any of the growth factors examined.On the other hand, relatively intense immunoreactivity of both TGF- and Cripto was detected inPCNA-negative regenerative epithelium located distantfrom gastric ulcer margin. Relative immunoreactivity ofAR in regenerative gastric epithelium associated with ulcer was not different from that innormal gastric mucosa. TGF-, AR, and Cripto areconsidered to play important roles in normal gastricmucosal proliferation, and TGF- and Cripto may be involved in ulcer healing, possibly via aparacrine mechanism.     

Inhibition of Parietal Cell Acid Secretion Is Mediated by the Classical Epidermal Growth Factor Receptor

Epidermal growth factor (EGF) and transforminggrowth factor- (TGF-) inhibit gastric acidsecretion both in vivo and in vitro. Previous studieshave indicated that EGF and TGF- bind to the same EGF/TGF- receptor. Nevertheless, weand others have previously demonstrated that inhibitionof acid secretion by these growth factors requiresconcentrations of the peptides that are 10-fold higher than those necessary for induction ofmitogenesis. Therefore, we have sought to investigatewhether gastric parietal cells may possess a secondEGF/TGF- receptor class. Two systems werestudied: First, [¹²⁵I]TGF- was cross-linkedto the receptor in isolated rabbit parietal cellmembranes, and labeled species were resolved onSDS-PAGE. Second, acid secretion was evaluated inpylorus-ligated waved-2 mutant mice, which carry a disabling pointmutation in their classical EGF/TGF- receptor. Inisolated parietal cells, [¹²⁵I]TGF-was cross-linked into a single species of 170 kDa.Cross-linking was inhibited in the presence of unlabeledTGF- with an IC of 80 nM. In the pylorus-ligatedmice, control littermate mice demonstrated adose-dependent inhibition of acid secretion by EGF withan IC of 20 g/kg. In contrast, EGF had noinhibitory effect on acid secretion in 50 waved-2 miceat concentrations up to 100 g/kg. No alterations inparietal cell or gastrin cell numbers were observed.These results in both isolated rabbit parietal cellsand waved-2 mice support the existence of only a singleclass of EGF/TGF- receptors in parietal cells.Differences in growth factor affinity are likely due to the modification of the receptor or oneof its coordinate regulators.     

Keratinocyte Growth Factor Ameliorates Dextran Sodium Sulfate Colitis in Mice

Keratinocyte growth factor (KGF) is emerging asan important mediator of mucosal defense and repair inthe colon. The aim of the present study was to evaluateand further characterize the effects of exogenous KGF administration utilizing the dextran sodiumsulfate (DSS) model of colitis in mice. Colitis wasinduced via oral administration of DSS (5 g/100 ml) toBalb/c mice for eight days. Intraperitonealadministration of KGF (5 mg/kg, once daily) or vehicle (VEH)was initiated 1 hr prior to the induction of the colitis(N = 10, each group). Mucosal injury of the entire colonwas histologically assessed and graded. An approximately fourfold reduction in the cryptdamage score was noted in the KGF group when compared tocontrols (VEH) (2.8 ± 1.03 and 11.4 ±0.78, respectively). The significant reduction ofmucosal injury in KGF treated mice confirms that KGF isa key mediator maintaining the integrity of the colonicmucosa.     

白虎追风胶囊的抗炎作用机理

为揭示白虎追风胶囊的抗炎作用机理,研究了白虎追风胶囊对佐剂性关节炎（ＡＡ）大鼠滑膜细胞介素－１（ＩＬ－１）,肿瘤坏死因子α（ＴＮＦ－α）和前列腺素Ｅ２（ＰＧＥ２）的影响,以及对ＡＡ大鼠血液中氧自由基和ＮＯ的影响。结果显示;白虎追风胶囊能下调ＡＡ大鼠滑膜过度分泌的ＩＬ－１,ＴＮＦ－α和ＰＧＥ２;能降低ＡＡ大鼠过高的ＬＰＯ和ＮＯ水平,使过低的ＳＯＤ和ＧＳＨ－Ｐｘ增高。     

In Vivo Validation of Biological Responses of bFGF Released from Microspheres Formulated by Blending Poly-Lactide-co-Glycolide and Poly(ethylene glycol)-Grafted-Chitosan in Hamster Cheek Pouch Microcirculatory Models

Microspheres formulated from blending poly(lactide-co-glycolide) (PLGA) and poly(ethylene glycol)-grafted-chitosan (PEG-g-CHN), using a modified in-emulsion-solvent-evaporation method, were investigated for the delivery of protein. A model protein, bovine serum albumin (BSA), was incorporated into the PLGA/PEG-g-CHN microspheres and both initial burst and release kinetics could be modulated by varying the PEG-g-CHN content. Basic fibroblast growth factor (bFGF) was formulated into the microspheres containing 5% PEG-g-CHN and the bFGF contents in the releasates were determined by a receptor-based ELISA with their in vitro bioactivities validated by fibroblast cell culture. The in vivo effect of the bFGF microspheres formulation was evaluated in a hamster cheek pouch model using a 7 day exposure (e.g., before significant vascular remodeling was expected). Using intravital microscopy, the tissue showed no evidence of inflammation with any formulation; deliberate activation of a preconditioning response linked to inflammation was attenuated by BSA microspheres alone. Vasoactive responses (receptor-dependant and independent constriction and dilation) linked to nitric oxide were attenuated, and constriction to endothelin was enhanced in bFGF and not BSA containing microspheres. PLGA/PEG-g-CHN blended microspheres were also demonstrated to be non-inflammatory and non-thrombogenic in vivo by observing the vascular changes in the cheek pouch. In conclusion, the addition of PEG-g-CHN to PLGA microspheres can serve as a sustained delivery vehicle for bFGF and the released protein provides vasoactive changes consistent with chronic bFGF exposure.     

Development of bFGF-Chitosan Matrices and Their Interactions with Human Dermal Fibroblast Cells

Chitosan (CH) is a naturally derived, biodegradable polymer of glucosamine with a variable frequency of N-acetyl-D-glucosamine units, and has been demonstrated to have numerous pharmacological and wound-healing properties. Biodegradable chitosan films were fabricated using a solvent casting technique and investigated for skin tissue-engineering applications. Basic fibroblast growth factor (bFGF) was incorporated into the CH matrices (1 μg/film) by 3 methods: adsorption, entrapment and covalent binding. Release rates and biological activity of the incorporated bFGF were monitored. Human dermal fibroblasts (HDF cells) were used as an in vitro model for cell response to CH and bFGF-CH films. Cell attachment, growth and acid-soluble collagen quantification were employed as an assessment of cell function. The fibroblasts were found to remain viable on the chitosan films and scaffolds. CH films without bFGF were compatible with HDF cells; however, the fibroblasts did not proliferate. The release profile of adsorbed and bound bFGF from CH films were similar (indicating that binding was not efficient) while entrapped bFGF was not released in the time frame studied. The concentration of bFGF released to the cell culture medium was not high enough to stimulate HDF proliferation. However, cell attachment was significantly increased in chitosan films with bFGF adsorbed onto the surface as compared to control surfaces. HDF cells grown on CH films produced significantly more collagen than those on control surfaces.     

Influence of gelatin complexation on cell proliferation activity and proteolytic resistance of basic fibroblast growth factor

The objective of this study is to investigate the influence of gelatin complexation on the biological activity of basic fibroblast growth factor (bFGF) and its resistance to trypsin digestion. When bFGF was mixed at 37°C with acidic gelatin with an isoelectric point(IEP)of 5.0, the activity to promote in vitro proliferation of BHK cells became lower compared with that of free bFGF,in contrast to mixing with the basic gelatin with an IEP of 9.0. A maximum reduction in the bFGF activity was observed for the bFGF-gelatin complex prepared at a mixing molar ratio of 1/1. The bFGF activity of cell proliferation reduced at the initial period after mixing with the acidic gelatin at 37°C, followed by no substantial change. Complexation with the acidic gelatin at 4°C had no influence on the bFGF activity, irrespective of the bFGF/gelatin ratio and complexation time. The biological activity of bFGF was reduced by the trypsin treatment, but the reduced extent was suppressed through gelatin complexation at 37°C. In an electrophoresis study, the protective effect of gelatin complexation on the trypsin digestion was also confirmed in terms of the molecular weight loss. It is possible that the complexing gelatin covers bFGF molecules, resulting in suppression of their interaction with the cell surface receptor as well as protection from their enzymatic attack.