Long-Term Temporospatial Complementary Relationship between Degradation and Bone Regeneration of Mg-Al Alloy.

The utilization of guided tissue regeneration membranes is a significant approach for enhancing bone tissue growth in areas with bone defects. Biodegradable magnesium alloys are increasingly being used as guided tissue regeneration membranes due to their outstanding osteogenic properties. However, the degradation rates of magnesium alloy bone implants documented in the literature tend to be rapid. Moreover, many studies focus only on the initial 3-month period post-implantation, limiting their applicability and impeding clinical adoption. Furthermore, scant attention has been given to the interplay between the degradation of magnesium alloy implants and the adjacent tissues. To address these gaps, this study employs a well-studied magnesium-aluminum (Mg-Al) alloy membrane with a slow degradation rate. This membrane is implanted into rat skull bone defects and monitored over an extended period of up to 48 weeks. Observations are conducted at various intervals (2, 4, 8, 12, 24, and 48 weeks) following the implantation. Assessment of degradation behavior and tissue regeneration response is carried out using histological sections, micro-CT scans, and scanning electron microscopy (SEM). The findings reveal that the magnesium alloy membranes demonstrate remarkable biocompatibility and osteogenic capability over the entire observation duration. Specifically, the Mg-Al alloy membranes sustain their structural integrity for 8 weeks. Notably, their osteogenic ability is further enhanced as a corrosion product layer forms during the later stages of implantation. Additionally, our in vitro experiments employing extracts from the magnesium alloy display a significant osteogenic effect, accompanied by a notable increase in the expression of osteogenic-related genes. Collectively, these results strongly indicate the substantial potential of Mg-Al alloy membranes in the context of guided tissue regeneration.

[Intraoperative autologous based blood conservation strategies in mitral valve replacement].

OBJECTIVE: To evaluate whether intraoperative autologous donation (IAD) can reduce perioperative blood transfusion for patients underwent mitral valve replacement (MVR). METHODS: A total of 318 patients received implementation of IAD from January 2011 to December 2013 were analyzed retrospectively, and compared with 517 patients of the previous 36-month period (from January 2008 to December 2012). The method of small-volume retrograde autologous priming, strict blood transfusion standard along with IAD together constituted a progressive blood-saving strategy. Statistical methods including Students' t-test, Pearson's χ(2) test, Kruskal-Wallis analysis and multivariate Logistic regression model were used for comparisons of the data. RESULTS: There were no significant difference between IAD group and non-IAD group considering preoperative patient demographics, characteristics and preoperative comorbidities. However, IAD group significantly reduced number of patients transfused with intra/post-operative packed red-blood cell (PRBC) (55(17.0%) vs. 215 (42.1%), χ(2)=53.0, P=0.000), and had significantly reduced postoperative chest tube output (150(380) ml vs. 700(660) ml, H=195.648, P=0.000), length of stay ((16±6) d vs. (20±8)d, t=9.60, P=0.000). But hematocrit were lower in IAD group (30%±5% vs.33%±4% at end of operation, t=7.76, P=0.000; 30%±4% vs. 32%±5% at discharge, P=0.000, t=3.86). Multivariate logistic aggression analysis revealed that age, IAD and smoking history were factors influencing the probability of intra or postoperative blood transfusion. CONCLUSION: Implementation of blood conservation strategies based on intraoperative autologous donation in mitral valve replacement surgery can significantly reduce intra/postoperative blood transfusion as well as postoperative complications.

[The "Yin/Yang" Functional Features of Neurotrophic Factors].

Neurotrophic factor is a kind of protein family that plays an important role in the nutrition, support and differentiation to central neurons as well as synaptic plasticity. Growing evidences have revealed that pro-forms of various neurotrophic factors, which are generated in process of protein synthesis and might exert opposite roles involving in inducement of neuronal apoptosis and implication in pathogenesis of neurodegenerative diseases. This paper reviews "Yin/Yang" features of neurotrophic factors in the anabolism, receptor regulation, functional aspects, and their related role in pathogenesis of neurodegenerative diseases. It is hopefully to provide new idea on understanding and investigation of the neurotrophic factors regarding on their functional, pathological and potential therapeutic significance.

[Changes in plasticity of rat hypothalamic neurons and astrocytes in humid and hot environment].

OBJECTIVE: To study the changes in the plasticity of the neurons and astrocytes in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) of the hypothalamus of rats exposed to a humid and hot environment. METHODS: The rats were subjected to stimulation with a humid and hot environment for 120 min in a climate chamber (dry bulb temperature of 40.0-/+0.5 degrees C with relative humidity of 60-/+5%). During the exposure, the behavioral responses of the rats were observed, and the changes in the expressions of Fos and GFAP in the PVN and SON in response to the exposure evaluated using immunohistochemical ABC methods. RESULTS: Exposure to a humid and hot environment caused restlessness and agitation in the rats, which showed increased respiratory frequency and scratching of the face with the forelimbs. Two rats died after the 120-min exposure. Significantly increased expressions of Fos and GFAP were detected in the PVN and SON following the exposure as compared with the control group. CONCLUSION: The neurons and astrocytes in the PVN and SON both participate in the regulation of responses to exposure to a humid and hot environment.

Electro-acupuncture of Tsusanli and Shangchuhsu regulates gastric activity possibly through mediation of the vagus-solotary complex.

BACKGROUND/AIMS: Acupuncture has been reportedly used to treat gastrointestinal diseases, however, its precise mechanism remains unknown. METHODOLOGY: In our study, the effects and mechanism of electro-acupuncture (EA) at Tsusanli (ST 36), Shangchuhsu (ST 37) on regulation of gastric activity were observed. RESULTS: EA at Tsusanli showed that gastric electric change was the most obvious, with significantly higher frequency and wave amplitude compared with that of the Shangchuhsu group and other groups. EA at Shangchuhsu demonstrated that the change of gastric electric level was much higher than that of the non-acupoint group and control group. After bilateral vagotomy, Tsusanlis was electro-acupunctured, the changes of electro-gastric graph (EGG) weren't significant with the control group. The frequency of electro-physiological activity in nucleus of solitary tract (NTS) and dorsal motor nucleus of the vagus nerve (DMV) in the Tsusanli group was markedly increased compared with that in the other group. Fos and GFAP expression in NTS and DMV in the Tsusanli group was significantly higher than that in other groups and control group. The results have indicated that EA at Tsusanli and Shangchuhsu cannot only regulate gastric activity, but also activate neurons and astrocytes in NTS and DMV. The effects on regulation and activation of EA at Tsusanli were very obvious. CONCLUSIONS: Our study suggests that this electroacupuncture regulation of gastric activity may partially depend upon integrated nerve pathway and related central neurons and astrocytes in the vagus-solitary complex.

Chinese herbs and herbal extracts for neuroprotection of dopaminergic neurons and potential therapeutic treatment of Parkinson's disease.

Parkinson's disease (PD) is a common and debilitating degenerative disease resulting from massive degenerative loss of dopamine neurons, particularly in the substantia nigra. The most classic therapy for PD is levodopa administration, but the efficacy of levodopa treatment declines as the disease progresses. The neuroprotective strategies to rescue nigral dopamine neurons from progressive death are currently being explored, and among them, the Chinese herbs and herbal extracts have shown potential clinical benefit in attenuating the progression of PD in human beings. Growing studies have indicated that a range of Chinese herbs or herbal extracts such as green tea polyphenols or catechins, panax ginseng and ginsenoside, ginkgo biloba and EGb 761, polygonum, triptolide from tripterygium wilfordii hook, polysaccharides from the flowers of nerium indicum, oil from ganoderma lucidum spores, huperzine and stepholidine are able to attenuate degeneration of dopamine neurons and sympotoms caused by the neurotoxins 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 6-hydroxydopamine (6-OHDA) in vitro and in vivo conditions. In addition, accumulating data have suggested that Chinese herbs or herbal extracts may promote neuronal survival and neurite growth, and facilitate functional recovery of brain injures by invoking distinct mechanisms that are related to their neuroprotective roles as the antioxidants, dopamine transporter inhibitor, monoamine oxidase inhibitor, free radical scavengers, chelators of harmful metal ions, modulating cell survival genes and signaling, anti-apoptosis activity, and even improving brain blood circulation. New pharmaceutical strategies against PD will hopefully be discovered by understanding the various active entities and valuable combinations that contribute to the biological effects of Chinese herbs and herbal extracts.

Electro-acupuncture of Foot YangMing regulates gastric activity possibly through mediation of the dorsal vagal complex.

Acupuncture at some specific acupoints of Foot Yangming can regulate gastric activity. However, its precise mechanism remains unknown. In our study, the effects and mechanism of electro-acupuncture (EA) at Tsusanli (ST 36), Shangchuhsu (ST 37) on the regulation of gastric activity were observed. EA at Tsusanli showed that gastric electric change had a significantly higher frequency and wave amplitude as compared to that of the Shangchuhsu group and other groups. EA at Shangchuhsu demonstrated the change of gastric electric was greater than that of the non-acupoint group and the control group. After bilateral vagotomy, the change of electro gastric graph (EGG) of EA at Tsusanlis was not significant compared to the control group. In the mean time, we have observed the electric discharge of the neurons in NTS and DMV. The frequency of electro-physiological activity in nucleus of solitary tract (NTS) and dorsal motor nucleus of the vagus nerve (DMV) in Tsusanli group and Shangchuhsu group were markedly increased compared with that in other groups. The results have indicated that EA at Tsusanli and Shangchuhsu not only regulate gastric activity, but also activate neurons in NTS and DMV significantly. Our study suggests that the effect of EA at Tsusanli and Shangchuhsu on the gastric activity may partially depend upon integrated nerve pathway and related central neurons in dorsal vagal complex.

Immunocytochemical localization of substance P receptor in hypothalamic oxytocin-containing neurons of C57 mice.

With the use of double immunofluorescence, we have examined the distribution of oxytocin-containing neurons that express substance P receptor (SPR) in the hypothalamus of C57 mice. The distribution of oxytocin-like immunoreactive neurons overlapped with that of SPR-like immunoreactive neurons in the paraventricular nucleus and supraoptic nucleus of the hypothalamus. Neurons showing both oxytocin- and SPR-like immunoreactivities were predominantly found in both nuclei. A few neurons that were double-labeled with oxytocin- and SPR-like immunoreactivities were also scattered in the hypothalamic periventricular and preoptic regions. Semi-quantitative analysis indicated that about 94% of the oxytocin-like neurons displayed SPR-like immunoreactivity. These double-labeled cells constituted about 91% of the SPR-like neurons in the aforementioned regions. The present study provides morphological evidence for tachykinin-induced modulation of oxytocin-containing neurons as mediated by substance P receptor in the hypothalamus of mammals.