Protective effects of polydatin against bone and joint disorders: the in vitro and in vivo evidence so far.

Polydatin is an active polyphenol displaying multifaceted benefits. Recently, growing studies have noticed its potential therapeutic effects on bone and joint disorders (BJDs). Therefore, this article reviews recent in vivo and in vitro progress on the protective role of polydatin against BJDs. An insight into the underlying mechanisms is also presented. It was found that polydatin could promote osteogenesis in vitro, and symptom improvements have been disclosed with animal models of osteoporosis, osteosarcoma, osteoarthritis and rheumatic arthritis. These beneficial effects obtained in laboratory could be mainly attributed to the bone metabolism-regulating, anti-inflammatory, antioxidative, apoptosis-regulating and autophagy-regulating functions of polydatin. However, studies on human subjects with BJDs that can lead to early identification of the clinical efficacy and adverse effects of polydatin have not been reported yet. Accordingly, this review serves as a starting point for pursuing clinical trials. Additionally, future emphasis should also be devoted to the low bioavailability and prompt metabolism nature of polydatin. In summary, well-designed clinical trials of polydatin in patients with BJD are in demand, and its pharmacokinetic nature must be taken into account.

Macrophage responses to selective laser-melted Ti-6Al-4V scaffolds of different pore geometries and the corresponding osteoimmunomodulatory effects toward osteogenesis.

Following recent advances in osteoimmunology, there is growing recognition of the vital role of immune cells in the osteogenesis process. The 3D-printed scaffold, as a substitute for injured and/or diseased bone tissues, has demonstrated satisfactory pro-osteogenetic performance. However, whether immune cells prompt the above pro-osteogenetic performance has not been elucidated in detail. In the present study, highly controllable Ti-6Al-4V scaffolds with different pore geometries were fabricated using a selective laser-melting technique, to reveal their osteoimmunological functions with macrophages. The results showed that macrophages displayed characteristics of M2 phenotype in response to scaffolds. As a result, an anti-inflammatory microenvironment was generated. When the pore geometry was considered, such observations were more apparent with the hexagonal pore scaffold than with the triangular one. In addition, inhibition of the toll-like receptor signaling pathway in macrophages has been proposed to cause the above phenomenon. Upon applying conditioned media derived from macrophages on pre-osteoblasts, the hexagonal pore scaffold group was found to significantly enhance osteoblastic differentiation, via macrophage-to-implant interactions. However, the effect of triangular pore scaffold was not statistically significant compared to that of hexagonal pore scaffolds or nonporous samples. In an attempt to quantify scaffold pore geometries, it was suggested that pores with higher circularity values tended to induce M2 polarization of macrophages, promote an anti-inflammatory milieu, and therefore, achieve better osteogenetic performance via immunomodulation.

Clinical Characteristics of 1378 Inpatients with Spinal Tuberculosis in General Hospitals in South-Central China.

In this retrospective study, charts of inpatients with spinal tuberculosis (STB) treated in large-scale general hospitals in Changsha, Hunan, China, between 2007 and 2016 were reviewed to investigate their clinical characteristics. Demographic, epidemiological and clinical features, imaging findings, treatment methods, and prognosis were summarized and analyzed. There were 1378 patients, 805 males and 573 females, with a mean age of 43.7 years. The mean interval between symptom onset and diagnosis was 16.0 months (range 15 days-240 months). The incidence of back pain, radicular pain and symptoms of systemic toxicity was 92.5%, 40.1%, and 32.1%, respectively. The rate of neurological impairment was 49.9 %. STB was present in two or more vertebrae in 91.1% of patients, with two adjacent vertebrae being involved in 67.9% of them. The lumbar segment (38.2%) was the most frequently affected, followed by the thoracic spine (35.7%). The sacrococcygeal area was the least frequently involved (0.8%). Abscesses were detected in 65.5% of patients. One thousand patients (72.6%) were managed with surgery and 378 (27.4%) with anti-TB drugs only. Cure was achieved in 1215 patients (88.2%), whereas 49 (3.5 %) had relapses. Concomitant pulmonary TB (PTB) was diagnosed in 366 patients (26.6%) and 63 (4.6%) had concomitant diabetes. Compared with the previous five years, the number of older patients, urban patients, and medical staff with STB had increased by 6.1%, 5.2%, and 1.3%, respectively in the five years studied. STB remains a severe public health problem that cannot be ignored. Most of the patients ignored early symptoms and therefore received untimely treatment. Thus, surveillance for and treatment of STB in South-central China requires strengthening. In addition to the current China-wide database of patients with PTB, a China-wide database of patients with STB should also be set up.

Only Acyl Carrier Protein 1 (AcpP1) Functions in Pseudomonas aeruginosa Fatty Acid Synthesis.

The genome of Pseudomonas aeruginosa contains three open reading frames, PA2966, PA1869, and PA3334, which encode putative acyl carrier proteins, AcpP1, AcpP2, and AcpP3, respectively. In this study, we found that, although these apo-ACPs were successfully phosphopantetheinylated by P. aeruginosa phosphopantetheinyl transferase (PcpS) and all holo-forms of these proteins could be acylated by Vibrio harveyi acyl-ACP synthetase (AasS), only AcpP1 could be used as a substrate for the synthesis of fatty acids, catalyzed by P. aeruginosa cell free extracts in vitro, and only acpP1 gene could restore growth in the Escherichia coliacpP mutant strain CY1877. And P. aeruginosaacpP1 could not be deleted, while disruption of acpP2 or acpP3 in the P. aeruginosa genome allowed mutant strains to grow as well as the wild type strain. These findings confirmed that only P. aeruginosa AcpP1 functions in fatty acid biosynthesis, and that acpP2 and acpP3 do not play roles in the fatty acid synthetic pathway. Moreover, disruption of acpP2 and acpP3 did not affect the ability of P. aeruginosa to produce N-acylhomoserine lactones (AHL), but replacement of P. aeruginosaacpP1 with E. coliacpP caused P. aeruginosa to reduce the production of AHL molecules, which indicated that neither P. aeruginosa AcpP2 nor AcpP3 can act as a substrate for synthesis of AHL molecules in vivo. Furthermore, replacement of acpP1 with E. coliacpP reduced the ability of P. aeruginosa to produce some exo-products and abolished swarming motility in P. aeruginosa.

Effect of acidity upon attrition-corrosion of human dental enamel.

Attrition-corrosion is a synthesized human enamel wear process combined mechanical effects (attrition) with corrosion. With the rising consumption of acidic food and beverages, attrition-corrosion is becoming increasingly common. Yet, research is limited and the underlying mechanism remains unclear. In this study, in vitro wear loss of human enamel was investigated and the attrition-corrosion process and wear mechanism were elucidated by the analysis of the wear scar and its subsurface using focused ion beam (FIB) sectioning and scanning electron microscopy (SEM). Human enamel flat-surface samples were prepared with enamel cusps as the wear antagonists. Reciprocating wear testing was undertaken under load of 5N at the speed of 66 cycle/min for 2250 cycles with lubricants including citric acid (at pH 3.2 and 5.5), acetic acid (at pH 3.2 and 5.5) and distilled water. All lubricants were used at 37°C. Similar human enamel flat-surface samples were also exposed to the same solutions as a control group. The substance loss of enamel during wear can be linked to the corrosion potential of a lubricant used. Using a lubricant with very low corrosion potential (such as distilled water), the wear mechanism was dominated by delamination with high wear loss. Conversely, the wear mechanism changed to shaving of the softened layer with less material loss in an environment with medium corrosion potential such as citric acid at pH 3.2 and 5.5 and acetic acid at pH 5.5. However, a highly corrosive environment (e.g., acetic acid at pH 3.2) caused the greatest loss of substance during wear.