Calcium phosphate ceramics, such as tricalcium phosphate (TCP) and hydroxyapatite (HA) are commonly used as bone substitutes. These materials have different physical and chemical properties and, therefore, display different interactions with the host tissue. Factors such as porosity,osteoconductivity,and biocompatibility seem to become increasingly important in the development of new artificial bone replacement materials. This article focuses on the relationship between the physical and chemical properties of calcium phosphate ceramics and the host tissue.

BACKGROUND: Drug-controlled release preparation by drugs or other active substances combined with carriers, has been an important development trend in field of pharmacy. However different characteristics of controlled release drug carrier materials leas to different drug release behaviors, so recent researches focus on a new type of drug carrier material to obtain the satisfactory drug release. OBJECTIVE: To introduce some drug carrier materials, and analyze those materials' characteristics and their application on drug controlled-release. RETRIEVAL STRATEGY: A computer-based search was undertaken on China Journal Full-text Database from January 1998 to June 2007, with the Keywords of "polymeric hydrogel, polylactic acid, chitosan, silk fibroin, drug controlled-release, drug carrier" and language was limited to Chinese. Inclusion criteria: ①preparations and characteristics of various drug carrier materials;②drug controlled release of various drug carrier materials. Exclusion criteria: outdated literatures. LITERATURE EVALUATION: Eighty-six related articles were screened out, and 28 of them met the criteria, including 10 were reviews and others were clinical or basic experiments. DATA SYNTHESIS: ① At present, the materials applied for drug carrier include polymeric hydrogel, polylactic acid/poly(lactic-co-glycolic acid), chitosan and their derivates, silk fibroin and so on.②Intellectual polymeric hydrogel can respond swelling and contraction for the stimulation of temperature, acidity, pressure and light, etc. And the specific environment sensitiveness enlarges its application in drug delivery system.③Polylactic acid and poly(lactic-co-glycolic acid), as a kind of biodegradable polymer materials, represent biocompatibility, biodegradability and non-toxic degradation products. As for controlled release drug carrier material, it can influence drug release by modulating degradation of polylactic acid, so as to increase drug efficacy.④Chitosan is satisfactory in adsorbability, film forming ability and permeability. Water-soluble chitosan with low relative molecular mass is prone to degrade and difficult to accumulate, so chitosan nanoparticles or chitosan microspheres as carriers for drug delivery system have been the hot topic of recent researches.⑤Native polymer material silk fibroin is non-toxic and non-stimulative, shows good physical, chemical and biological characteristics, as well as satisfactory histocompatibility. The pH value responsibility and zymohydrolysis are also observed when loading and releasing drugs. Chemical modification and addition of other compounds will increase the characteristics and the drug-controlled release of silk fibroin. CONCLUSION: Various drug carrier materials show good biocompatibility, biodegradability, physicochemical and biological stability, extremely low toxicity, and high drug loading property. But the material's performance should be synthesized and modified in practical application to satisfy various preparations of drug-controlled release by specific performance and structure.

Polypeptide and protein microspheres can elevate drug availability, but drug devitalization and drug fast release can result in side effects during microsphere preparation. Fast release in the body is a burning question facting investigators who studying microsphere controlled release system. Relative molecular mass, concentration, structure and drug content of the polyme can greatly affect drug fast release. Fast release can be controlled by structural modification, using additives, controlling particl diameter of microspheres and decreasing drug content.

Objective: To study the impact of basic medical insurance on household consumption. Methods: According to the panel data of the east, central and west regions from 2002 to 2011, time and entity fixed effect model (Two-way FE) is established to test the relationship between the basic medical insurance and household consumption. Results: The basic medical insurance has significant positive effects on consumption, the consumption increased 10%, 16% and 19% in regions of East, Middle and West, respectively. Conclusion: The construction and improvement of the social medical insurance system improve the growth of the consumption, and the government should enhance the security, and consider the regional differences at the same time.

Multi-drug resistance (MDR) of breast cancer is a key factor of breast cancer treatment failure.MicroRNA (miRNA) is a class of endogenous expressed,small,single-stranded RNA molecules,and regulate the expression of genes at post-transcriptional level by combining with target message RNA.MiRNA participate in the mechanisms of drug resistance of breast cancer,and are feasible therapeutic targets for the treatment of drug resistance in breast cancer.Finding and studying miRNA related with drug resistance of breast cancer as well as their mechanisms have become a current research hotspot.

As a neuroprotective measure,the application and research of mild hypothermia in clinical practice have been very extensive.Using mild hypothermia has achieved a positive efficacy in many diseases,such as brain damage after cardiac arrest and neonatal hypoxic-ischemic encephalopathy,etc.Although mild hypothermia has a large number of animal experiments and clinical studies in the treatment of ischemic stroke,and animal experiments have confirmed that it has the exact neuroprotective effect,the neuroprotective effect of mild hypothermia in the treatment of ischemic stroke has not yet come to a unified conclusion in the clinical studies.Its clinical efficacy does not seem to be as optimistic as expected.Therefore,it is necessary to analyze the transforming problems of mild hypothermia for treatment of ischemic stroke from animal experiments to clinical practice,and to provide ideas for the clinical application of mild hypothermia for treatment of ischemic stroke.

Objective To evaluate the effect of excise training on the pulmonary function in patients with chronic obstructive pulmonary disease(COPD).Methods Totally 55 COPD patients received excise training,the patients’pulmonary function,6-minute walking test(6MWT)and St.George's respiratory questionnaire(SGRQ)were measured before and after the 6 months intervention. Result The pulmonary function,6MWT(exercise tolerance)and the quality of life were significantly improved(all P<0?01). Conclusions Excise training can improve COPD patients’exercise tolerance,relieve the symptoms of dyspnea,and thereby improve patients’quality of life?

Objective To observe the changes of plasma lipoprotein concentrations after an oral glucose tolerance test and research their relation to insulin resistance in Type 2 diabetic patients.Methods The age,duration of diabetes,sex,waist circumference,hip circumference,waist-hip ratio,height,body weight,body mass index ( BMI ),systolic blood pressure,diastolic blood pressure,fasting plasma glucose,HbAl C,fasting insulin,and fasting and 60-,120-,180-minute post-load plasma glucose,plasma insulin,triglycerides ( TG),high-density lipoprotein cholesterol (HDL-C),low-density lipoprotein cholesterol(LDL-C) and total cholesterol(TC) after a 75-g oral glucose tolerance test were measured in 26 Type 2 diabetic patients.Comparison of plasma fasting lipoprotein concentrations and postload lipoprotein concentrations was made,and the relation between fasting and post-load lipoprotein concentrations and Homa-IR was researched.Stepwise multiple regression analysis was applied to investigate the areas under the lipoproteins' curves over 180 minutes.Results The declination of post-load lipoprotein concentrations after the 75-g glucose tolerance test was statistically significant( all P ＜0.01 ).Plasma TG concentration both in fasting and post-load state was positively related to Homa-IR( all P ＜ 0.05 ),and plasma HDL-C concentration in fasting and post-load state was negatively related to Homa-IR( all P ＜ 0.05 ).However,the correlation between both fasting and post-load state LDL-C and TC concentration and Homa-IR had no statistical significance.Moreover,stepwise multiple regression analysis revealed Homa-IR was the independent factor capable of modulating the area of HDL-C curve over 180 minutes after the 75-g glucose tolernce test ( P ＜ 0.05 ).Conclusion There was a significant declination of plasma lipoproteins after a 75-g glucose tolerance test,and plasma fasting and post-load TG and HDL-C concentrations were related to insulin resistance.Insulin resistance should play a significant role in the post-load HDL-C concentration after 75-goral glucose tolerance test.

Objective To investigate the effect of pretreatment with penehychidine hydrochloride(PHCD) on NF-κB activity in the lung tissue following acute lung injury(ALI)induced by hemorrhagic shock in rats.Methods Twenty-four Wistar rats of both sexes weighing 200-250 g were randomly divided into 3 groups (n=8 each):group Ⅰ sham operation (group S);group Ⅱ ALI and group Ⅲ PHCD.The animals were anesthetized with intraperitoneal chloral hydrate 350 mg/kg.Hemorrhagic shock was produced in group Ⅱ and Ⅲ.Right carotid artery was cannulated for BP monitoring.Left femoral artery was cannulated for blood letting.MAP was reduced to 35-45 mm Hg within 10 min and maintained for 1 h in group ALI and PHCD(group Ⅱ andⅢ).The animals were then resuscitated with blood and normal saline.PHCD 2 mg/kg was given iv immediately before blood-letting in group PHCD.Blood samples were obtained from artery at 6 h after hemorrhagic shock wag induced for blood gas analysis and from right auricle for determination of plasma TNF-α concentration by ELISA.The lungs were then harvested for microscopic examination and determination of the expression of NF-κB p65 by immuno-histochemistry and W/D lung weight ratio.Results The plasma TNF-α concentration and expression of NF-κB p65 in the lung tissue were significantly increased in group ALI and PHCD as compared with group S and were significantly lower in group PHCD than in group ALI.There was less damage to the lung tissue in group PHCD than in group ALI.Conclusion PHCD pretreatment can attenuate ALl induced by hemorrhagic shock by inhibiting NF-κB activity.

Guidelines as Topic ; Humans ; Infant, Low Birth Weight ; Infant, Newborn ; Infant, Premature ; Nutritional Physiological Phenomena