OBJECTIVE:The pathophysiology of myocardial fibrosis during hypertension is complicated.Recently,it has been shown that inflammatory response plays an important role in the pathophysiology of myocardial fibrosis.This review describes the relationships among hemodynamic stress,hormonal factors and inflammatory factors,and emphasizes the important position of inflammation during the progress of myocardial fibrosis.DATA SOURCES:Using the terms of "hypertension,myocardial fibrosis,inflammatory response,angiotensin,cytokines" in English and Chinese respectively,we searched Medline database,Chinese Biological Medicine Database (CBM) and CNKI to identify English and Chinese articles of clinical researches and experiments related to the effects of inflammatory response on myocardial fibrosis during hypertension published from January 1991 to May 2007.STUDY SELECTION:The articles were primarily checked.Only articles that reported inflammatory response and myocardial fibrosis were included.The repeated researches and experiments and Meta analysis were deleted.DATA EXTRACTION:A total of 641 articles have been selected.The titles of all the articles and most of the abstracts have been read,and 162 articles met the inclusive criteria whereas the other 479 articles were deleted.42 articles have been analyzed.DATA SYNTHESIS:During hypertension,the extracellular matrix expands because of reactive and reparative fibrosis,which at last results in myocardial fibrosis.Previous clinical and experimental studies showed that hemodynamic stress and hormonal factors affected the progress of myocardial fibrosis.While recently,there are growing evidences indicating that the immune system.related with hemodynamic stress and hormonal factors is activated during hypertension in the progress of myocardial fibrosis.Then the recruitment of inflammatory cells and factors,including chemoattractant proteins,adhesion molecules and cytokines,informing cytokines cascade response,in turn accelerate the progress of myocardial fibrosis.CONCLUSION:Inflammatory response may play an important role in the pathophysiology of myocardial fibrosis during hypertension and then accelerate the progress of heart failure.

How to choose an appropriate design type to arrange research factors and their levels is an important issue in scientific research. Choosing an appropriate design type is directly related to the accuracy, scientificness and credibility of a research result. When facing a practical issue, how can researchers choose the most appropriate experimental design type to arrange an experiment based on the research objective and the practical situation? This article mainly introduces the related contents of the design of one factor with two levels and the design of one factor with k (k≥3) levels by analyzing some examples.

Two-factor designs are very commonly used in scientific research. If the two factors have interactions, research designs like the factorial design and the orthogonal design can be adopted; however, these designs usually require many experiments. If the two factors have no interaction or the interaction is not statistically significant on result in theory and in specialty, and the measuring error of experimental data under a certain condition (usually one of the experimental conditions that are formed by the complete combination of the levels of the two factors) is allowed in specialty, researchers can use random block design without repeated experiments, balanced incomplete random block design without repeated experiments, single factor design with a repeatedly measured factor, two-factor design without repeated experiments and two-factor nested design. This article introduces the last two design types by examples.

In this paper, alpha-tricalcium phosphate (alpha-TCP) and tetracalcium phosphate (TTCP) respectively were chosen as basic compositions of phosphate bone cements. Other auxiliary materials such as hydroxyapatite (HAP), dicalcium phosphate dihydrate (DCPD), calcium carbonate (CaCO3), calcium oxide (CaO) and amorphous calcium silicate (CaSiO3) were added in the cements. Six kinds of composite bone cements were decided with 1.50 as their Ca/P ratio. Then the primary properties of them were studied. Ringer's simulated body fluid (SBF) tests were carried out for the samples. The changes of pH value in SBF and the compressive strength of the samples with the immersion time were studied. The results showed: the mixing liquid 0.25 M K2HPO4/KH2PO4 and amorphous CaSiO3 were effective for accelerating the setting of the cements; the initial setting time (It) was about 4-5.5 min and the final setting time (Ft) was about 18-19. 5 min. Amorphous calcium silicate can increase the compressive strength of the bone cements remarkably; the compressive strength of the alpha-TCP bone cement with the addition of suitable amount amorphous CaSiO3 reached 45.3 MPa after immersion in SBF for 14 days.
Bone Cements ; chemical synthesis ; chemistry ; Calcium Compounds ; chemistry ; Calcium Phosphates ; chemistry ; Compressive Strength ; Humans ; Silicates ; chemistry