Psychological trauma, posttraumatic stress disorder and trauma-related depression: A mini-review.

There are various types of traumatic stimuli, such as catastrophic events like wars, natural calamities like earthquakes, and personal trauma from physical and psychological neglect or abuse and sexual abuse. Traumatic events can be divided into type I and type II trauma, and their impacts on individuals depend not only on the severity and duration of the traumas but also on individuals' self-evaluation of the traumatic events. Individual stress reactions to trauma include posttraumatic stress disorder (PTSD), complex PTSD and trauma-related depression. Trauma-related depression is a reactive depression with unclear pathology, and depression occurring due to trauma in the childhood has gained increasing attention, because it has persisted for a long time and does not respond to conventional antidepressants but shows good or partial response to psychotherapy, which is similar to the pattern observed for PTSD. Because trauma-related depression is associated with high risk of suicide and is chronic with a propensity to relapse, it is necessary to explore its pathogenesis and therapeutic strategy.

[Mechanisms and strategies for targeting drugs to myocardial ischemic regions].

The ischemic heart disease has been endangering human health seriously. Although there are many kinds of anti-ischemic drugs, most of them are lacking in tissue specificity, which together with a remarkably reduced blood circulation in the ischemic zone often lead to a quite low drug distribution in the targets. Myocardial ischemia can cause a lot of pathophysiological changes, such as the enhanced permeability of the endothelial cell membrane, the up-regulated expression of various cell adhesion molecules on endothelium, the exposure of intracellular antigenic components, the decrease of pH within the ischemic zone, and so on. To date, some of these changes have been exploited with limited success to gain the passive, active and physicochemical targeting of diagnostic or therapeutic drugs to myocardial ischemic regions. However, more effective delivery strategies are still eagerly needed. Here, we reviewed and discussed the potential targeting-delivery mechanisms and strategies, used or may be used in the future, for myocardial ischemic regions.

Poly(ethylene glycol)-radix Ophiopogonis polysaccharide conjugates: preparation, characterization, pharmacokinetics and in vitro bioactivity.

Radix Ophiopogonis polysaccharide (ROP), a natural graminan-type fructan with Mw of ∼5kDa, had been found to have an excellent anti-myocardial ischemic activity. However, its rapid renal excretion following administration remarkably limits its efficacy and clinical use, which makes necessary the development of an effective delivery system. In this article, the feasibility of PEGylation to solve this problem was examined. A moderate coupling reaction between the hydroxyl-activated ROP and the amino-terminated mPEG was chosen to PEGylate ROP. Five different mPEG-ROP conjugates (with mPEG of molecular mass 2, 5 or 20kDa) were prepared, purified, characterized and evaluated in pharmacokinetics and in vitro bioactivity. Results showed that only when the apparent molecular weight of the conjugate approached to a certain value, would its plasma elimination reduce abruptly. In general, the conjugation caused the reduction in the bioactivity of ROP; however, well-preserved bioactivity was observed when the grafting degree of the conjugate was lower. Among the five conjugates studied, the one with an average 1.3 mPEG (20kDa) residues per single ROP was found to be satisfactory both in plasma retention and in bioactivity. It had a 47.4-fold increased elimination half-life and preserved approximately 74% of the bioactivity of ROP; moreover, the decrease in bioactivity is not significant. These findings demonstrate that PEGylation would be a promising approach for improving the clinical efficacy of ROP by prolonged retention in plasma.

[Evaluation of gingival inflammation related to different retraction agents].

OBJECTIVE: To choose the best retraction agent for the clinic by evaluating the gingival inflammation related to three kinds of retraction agents. METHODS: 40 maxillary premolars were divided into four groups according to the randomized block design: Ferric sulfate group, aluminum chloride group, epinephrine group, sodium chloride group(control group), each 10 teeth, respectively used 25% AlCl3, 15.5% Fe2(SO4)3, 0.1% HCl-epinephrine, sodium chloride as retraction agents. The quantity of gingival crevicular fluid (GCF) and the active level of aspartate amino-transferase (AST) in gingival crevicular fluid were measured before and 1, 3, 5, 7, 9 days after retracting gingiva by four kinds retraction agents. The changes of GCF were calculated. RESULTS: The change of the GCF from the smallest to the largest was sodium chloride, 0.1% HCl-epinephrine, 25% AlCl,, 15.5% Fe2 (SO)3. Compared with sodium chloride, only 15.5% Fe2 (SO)3 in AST was the significant difference in the first day and the third day (P < 0.05). AST of ferric sulfate group after 1, 3 days greater than 800 IU. CONCLUSION: 0.1% HCl-epinephrine is suggested in patient without cardiovascular disease. For patient with cardiovascular disease, the better substitute is 25% AlCl3. 15.5% Fe2 (SO4)3 will not be used until its concentration is fallen.

[Corrosion behavior of micro-arc oxidation film on titanium in simulated body fluid].

OBJECTIVE: To investigate the variation of the corrosion resistance of micro-arc oxidation film on titanium by electrochemical methods in simulated body fluid. METHODS: Micro-arc oxidation film was formed on the titanium surface using micro-arc oxidation. The morphology was observed with scanning electron microscopy (SEM) and the phase composition was analyzed using X-ray diffraction (XRD). Polarization curves and electrochemical impedance spectroscopy (EIS) in simulated body fluid were examined with electrochemical methods. RESULTS: On the titanium surface with micro-arc oxidation, the film consisted of many volcanic micropores. The film formed was a titanium dioxide (TiO(2)) with peaks for both anatase and rutile phases. In addition, hydroxylapatite was also observed. The self-corrosion potential and self-corrosion current density of titanium with micro-arc oxidation film were -0.255 V and 0.80 microA/cm(2) respectively, while those of untreated titanium were -0.358 V and 0.55 microA/cm(2). Electrochemical impedance spectroscopy confirmed the model of equivalent circuits reasonable. CONCLUSIONS: The results of electrochemical examinations indicate that micro-arc oxidation film increases the corrosion resistance of titanium.

[Corrosion behavior of titanium with micro-arc oxidation in simulated body fluid].

PURPOSE: To examine the corrosion resistance of micro-arc oxidation film on titanium by electrochemical methods in simulated body fluid. METHODS: Micro-arc oxidation film was formed on titanium surface by using micro-arc oxidation. The morphology, phase composition and the surface roughness were observed by scanning electron microscopy (SEM), X-ray diffraction(XRD) and profilemeter, respectively. Polarization curves in simulated body fluid was examined by electrochemical methods. SPSS11.0 software package was used for one-way ANOVA. RESULTS: On titanium surface with micro-arc oxidation, the film was consisted of many volcanic microporous, about 0.1microm -5microm in diameter. The film formed was a titanium oxide (TiO(2)) with peaks for both anatase and rutile phases, in addition, hydroxylapatite was also observed. Roughness increased on titanium surface. The self-corrosion potential and self-corrosion current density of titanium with micro-arc oxidation film were -0.255V and 0.80microA/cm(2) respectively, while those of untreated titanium were -0.358V and 0.55microA/cm(2). CONCLUSIONS: The results of electrochemical examinations indicate that micro-arc oxidation film increases the corrosion resistance of titanium.