Magnesium modification of a calcium phosphate cement alters bone marrow stromal cell behavior via an integrin-mediated mechanism

The chemical composition, structure and surface characteristics of biomaterials/scaffold can affect the adsorption of proteins, and this in turn influences the subsequent cellular response and tissue regeneration. With magnesium/calcium phosphate cements (MCPC) as model, the effects of magnesium (Mg) on the initial adhesion and osteogenic differentiation of bone marrow stromal cells (BMSCs) as well as the underlying mechanism were investigated. A series of MCPCs with different magnesium phosphate cement (MPC) content (0∼20%) in calcium phosphate cement (CPC) were synthesized. MCPCs with moderate proportion of MPC (5% and 10%, referred to as 5MCPC and 10MCPC) were found to effectively modulate the orientation of the adsorbed fibronectin (Fn) to exhibit enhanced receptor binding affinity, and to up-regulate integrin α5β1 expression of BMSCs, especially for 5MCPC. As a result, the attachment, morphology, focal adhesion formation, actin filaments assembly and osteogenic differentiation of BMSCs on 5MCPC were strongly enhanced. Further in vivo experiments confirmed that 5MCPC induced promoted osteogenesis in comparison to ot her CPC/MCPCs. Our results also suggested that the Mg on the underlying substrates but not the dissolved Mg ions was the main contributor to the above positive effects. Based on these results, it can be inferred that the specific interaction of Fn and integrin α5β1 had predominant effect on the MCPC-induced enhanced cellular response of BMSCs. These results provide a new strategy to regulate BMSCs adhesion and osteogenic differentiation by adjusting the Mg/Ca content and distribution in CPC, guiding the development of osteoinductive scaffolds for bone tissue regeneration.     

Contribution to the rheological testing of pharmaceutical semisolids

Rheological behaviour of pharmaceutical semisolid preparations significantly affects manufacturing process, administration, stability, homogeneity of incorporated drug, accuracy of dosing, adhesion in the place of application, drug release, and resulting therapeutic effect of the product. We performed test of consistency by penetrometry, rotational, oscillation and creep tests, and squeeze and tack tests of model samples to introduce methods suitable for characterization and comparison of semisolids in practice. Penetrometry is a simple method allowing sorting the semisolids to low and high stress-resistant materials but deficient for rheological characterization of semisolids. Value of yield stress, generally considered to be appropriate feature of semisolids, is significantly influenced by the method of testing and the way of evaluation. The hysteresis loops of model semisolids revealed incomplete thixotropy, therefore, three-step thixotropy test was employed. Semisolids showed nonlinear response in the creep phase of tests and partial recovery of structure by storing energy in the recovery phase. Squeeze and tack tests seem to be convenient ways for comparison of semisolids. Our study can contribute to a better understanding of different flow behaviour of semisolids given by different physicochemical properties of excipients and can bring useful approaches to evaluation and comparison of semisolids in practice.     

Salvage Focal Cryotherapy Offers Similar Short-term Oncologic Control and Improved Urinary Function Compared With Salvage Whole Gland Cryotherapy for Radiation-resistant or Recurrent Prostate Cancer

BackgroundWe compared the short-term oncologic and functional outcomes of salvage focal cryotherapy (SFC) with those of salvage total cryotherapy (STC) for radiotherapy (RT)-persistent/recurrent prostate cancer.Materials and MethodsWe queried the Cryo On-Line Database registry for men who had undergone SFC and STC of the prostate for RT-persistent or recurrent disease. Propensity score weighting was used to match age at treatment, presalvage therapy prostate-specific antigen level, Gleason sum, and presalvage cryotherapy androgen deprivation therapy status. The primary outcome was progression-free survival.ResultsA total of 385 men with biopsy-proven persistent or recurrent prostate cancer after primary RT were included in the present study. The median follow-up, age, prostate-specific antigen, and Gleason sum before salvage cryotherapy was 24.4 months (first and third quartile, 9.8 and 60.3), 70 years (first and third quartile, 66 and 74 years), 4 ng/dL (first and third quartile, 2.7 and 5.6 ng/dL), and 7 (first and third quartile, 6 and 8), respectively. After propensity score weighting, the difference in progression-free survival was not statistically significant between the patients who had undergone STC and those who had undergone SFC (79.8% vs. 76.98%; P = .11 on weighted log-rank test). SFC was associated with a lower probability of post-treatment transient urinary retention (5.6% vs. 22.4%; P < .001). No significant differences were found in the incidence of rectal fistula (1.4% vs. 3.8; P = .30), new-onset urinary incontinence within 12 months (9.3% vs. 15.1%; P = .19), or new-onset erectile dysfunction within 12 months (52.6% vs. 59.6%; P = .47) between the SFC and STC groups, respectively.ConclusionsSTC resulted in similar 2-year oncologic outcomes compared with SFC in the RT-persistent/recurrent disease population. However, the patients who had undergone SFC had a lower urinary retention rate compared with those who had undergone STC.     

Histomorphologic Characterization of Noncarious and Caries-Affected Dentin/Adhesive Interfaces

PURPOSE: The purpose of this study was to compare the dentin/adhesive interfacial characteristics when bonding to noncarious as well as caries-affected dentin. MATERIALS AND METHODS: Seven extracted, unerupted, third molars were sectioned into halves. Artificial caries was created on one-half of each tooth, leaving the other half as a control. Dentin surfaces were treated with UNO adhesive according to the manufacturer's instructions for the wet-bonding technique and under environmental conditions present in the oral cavity. Dentin/adhesive interface sections of each half-tooth were stained with Goldner's trichrome, a classic bone stain, and examined using light microscopy. The width of exposed collagen was measured directly from photomicrographs, and adhesive penetration was analyzed qualitatively. RESULTS: The degree and extent to which the adhesive encapsulated the demineralized dentin matrix were reflected in the color difference in the stained sections with the noncarious dentin sections showing a degree of collagen encapsulation superior to that of the caries-affected dentin sections. The overall mean widths of exposed collagen were significantly (p < or = .05) greater at the caries-affected dentin/adhesive interface, 8.6 (1.7) microm, as compared with those at the noncarious dentin/adhesive interface, 6.0 (1.5) microm. CONCLUSIONS: The morphologic characteristics of the caries-affected dentin/interface suggest an increase in the exposed collagen zone and a decrease in the quality of the adhesive infiltration when compared with noncarious dentin. The evidence suggests that dentin substrate characteristics have a significant effect on the dentin/adhesive interface structure.     

血管内皮生长因子及炎性因子在油酸性犬急性呼吸窘迫综合征中的变化

目的探讨油酸性急性呼吸窘迫综合征（ARDS）beagle犬血浆及肺泡灌洗液血管内皮生长因子（VEGF）、可溶性细胞间黏附分子-1（ICAM-1）、白细胞介素-8（IL-8）、肿瘤坏死因子-α（TNF—α）水平的改变。方法12只英国纯种beagle犬，静脉注射油酸0．15mL／kg，在注射油酸前、后1h，出现ARDS的典型表现时，抽血测VEGF、sICAM-1、IL-8、TNF—α，并对此时相作肺泡灌洗液VEGF、sICAM—1、IL-8、TNF-α的测定。结果beagle犬静脉注射油酸后1h血浆TNF—α升高（P〈0．05），血浆反肺泡灌洗液IL8、sICAM-1和VEGF在1h较油酸前没有明显变化（P〉0．05），beagle犬油酸型ARDS模型建立后血浆及肺泡灌洗液VECF、sICAM-1、IL-8、TNF—α均显著高于建模前（P〈0．05）。结论VEGF、sICAM-1、IL-8、TNF～α在beagle犬油酸型ARDS发生发展过程中可能均起重要作用，其水平的高低可能与ARDS严重程度及预后有关。     

Effect of UVB 311 nm irradiation on normal human skin

Ultraviolet radiation B (UVB) on the skin induces erythema, inflammation and modifications of the immune system. These changes have been reported after excessive short-term or long-term exposure to broad spectrum UVB. In this study, we examined the effects of local repetitive UVB irradiation of 311 nm wavelength on the skin of seven young volunteers. Skin biopsies were taken before and after UVB irradiation, and we immunohistochemically analyzed the expression of CD1a and HLA-DR antigens of Langerhans cells (LC), the possible infiltration of dermis/epidermis by CD11b macrophages, the modifications or the induction of intercellular adhesion molecule-1 (ICAM-1), E-selectin and vascular cell adhesion molecule-1 (VCAM-1) involved in the binding of leukocytes to the endothelial surface and the development of perivascular infiltrates of LFA-1⁺ mononuclear cells. We also determined the expression of substance P receptors (SPR) using biotinylated substance P (SPB). Exposure of UVB 311 nm induced a drastic reduction of CD1a⁺ cells and a moderate increase of HLA-DR⁺ dendritic cells in the epidermis without infiltration by CD11b macrophages. An increase of the binding of SPB to upper layer epidermal cells was noted in five of seven biopsies. In the dermis, vessel-associated ICAM-1 expression increased and an induction of E-selectin occurred on nearly 20 to 40% of endothelial cells, but VCAM-1 expression remained undetectable. The percentage of LFA-1⁺ cells did not change significantly after irradiation. These observations may be compatible with a selective role of UVB 311 nm on the skin immune response.     

可溶性细胞间黏附分子-1在急性肝内胆汁淤积兔模型中的表达

目的探讨可溶性细胞间黏附分子(sICAM-1)在急性肝内胆汁淤积兔模型中的表达及其意义。方法39只健康的新生大耳白兔随机分成4组:3个实验组(n=9)和1个空白对照组(n=12)。每个实验组分别为3个时间点处理组(24、48、72 h)。实验组采用1次灌服α-荼异硫氰酸盐(ANIT)200 mg/kg方法造成急性肝内胆汁淤积。按时分批取标本,检测其血清和胆汁中sICAM-1水平。结果实验组血清、胆汁中sICAM-1各时间点水平明显高于正常对照组(P均<0.05),其中48 h>72 h>24 h。结论sICAM-1在胆汁淤积中表达升高,与肝脏损伤程度和病程相关。