Ascorbate peroxidase catalyses synthesis of protocatechualdehyde from p-hydroxybenzaldehyde in Lycoris aurea.

Protocatechualdehyde is a plant natural phenolic aldehyde and an active ingredient with important bioactivities in traditional Chinese medicine. Protocatechualdehyde is also a key intermediate in the synthesis of Amaryllidaceae alkaloids for supplying the C6-C1 skeleton. However, the biosynthesis of protocatechualdehyde in plants remains obscure. In this study, we measured the protocatechualdehyde contents in the root, bulb, scape and flower of the Amaryllidaceae plant Lycoris aurea (L'Hér.) Herb., and performed the correlation analysis between the protocatechualdehyde contents and the transcriptional levels of the phenolic oxidization candidate protein encoding genes. We found that a novel ascorbate peroxidase encoded by the contig_24999 in the L. aurea transcriptome database had potential role in the biosynthesis of protocatechualdehyde. The LauAPX_24999 gene was then cloned from the cDNA of the scape of L. aurea. The transient expression of LauAPX_24999 protein in Arabidopsis protoplasts demonstrated that LauAPX_24999 protein was localized in the cytoplasm, thus belonging to Class II L-ascorbate peroxidase. Subsequently, LauAPX_24999 protein was heterogenously expressed in Escherichia coli, and identified that LauAPX_24999 biosynthesized protocatechualdehyde from p-hydroxybenzaldehyde using L-ascorbic acid as the electron donor. The protein structure modelling and molecular docking indicated that p-hydroxybenzaldehyde could access to the active pocket of LauAPX_24999 protein, and reside at the δ-edge of the heme group while L-ascorbic acid binds at the γ-heme edge. To our knowledge, LauAPX_24999 is the first enzyme discovered in plants able to biosynthesize protocatechualdehyde from p-hydroxybenzaldehyde, and offers a competent enzyme resource for the biosynthesis of Amaryllidaceae alkaloids via synthetic biology.

Quantitative assessment of aerosol contamination generated during tooth grinding with a speed-increasing handpiece.

OBJECTIVES: Tooth grinding produces a significant amount of aerosol particles. The aim of this study was to quantitatively assess particle contamination produced from tooth grinding with a speed-increasing handpiece across a real-world clinical setting. METHODS: All molar crowns were pretreated into cylinders with a uniform size. A novel computer-assisted numerical control system was used to parametrically study the bur speed: from 20,000 (20 K) to 200 K rpm at 20 K rpm intervals. 5-minute tooth grinding was performed in triplicate at each speed setting. Three online real-time particle counters (ORPC; TR-8301, TongrenCo.) were placed at 3 positions (0.5, 1, and 1.5 m) to evaluate particle production. All experimental instruments were controlled remotely. The data obtained were statistically analyzed using descriptive statistics and non-parametric tests (Scheirer-Ray-Hare and Kruskal-Wallis/ Dunn-Bonferroni tests, p < 0.05). RESULTS: The concentration level of aerosol particles production during the grinding experiment was elevated above the control group for all conditions, and increased with bur speed at any location (the maximum peak, reaching 5.59 × 107 particles/m3, at 200 K and 1 m), with differences between conditions. The effect of speed on the increment of particles across different channels compared to the control group was statistically significant among locations (p < 0.001). CONCLUSIONS: Statistically significant particle contamination was produced using a speed-increasing handpiece, but the contamination level for each experimental condition was reduced to baseline within 30 min, and most particles with a diameter greater than 1üm produced at low speeds (80 K or lower) tended to settle within 1 m. CLINICAL RELEVANCE: Our study suggested that the use of a speed-increasing handpiece below 80 K and 30 min of fallow time may lead to an adequate reduction in the health effects of particle contamination.

Three functional polymorphisms in CCDC170 were associated with osteoporosis phenotype.

MicroRNAs (miRNAs) play essential roles in regulating bone formation and homeostasis. Genomic variations within miRNA target sites may therefore be important sources of genetic differences in osteoporosis risk. The function of CCDC170 in bone biology is still unclear. To verify the function of CCDC170, we knocked down CCDC170 in cells and mice and searched for miRNA recognition sites within CCDC170 using the TargetScan, miRNASNP, and miRBase databases. In this study, our results demonstrated that CCDC170 plays an important role in the positive regulation of bone formation. MiR-153-3p, miR-374b-3p, miR-4274, miR-572 and miR-2964a-5p inhibited CCDC170 expression in an allele-specific manner by binding GWAS lead SNPs rs6932603, rs3757322 and rs3734806. These findings may improve our understanding of the association between CCDC170, miRNAs, GWAS lead SNPs, and osteoporosis pathogenesis and may provide a potential therapeutic target for osteoporosis therapy.

Platelet-to-lymphocyte ratio as a potential prognostic factor in nasopharyngeal carcinoma: A meta-analysis.

BACKGROUND: The aim of this study was to investigate the use of pretreatment platelet-to-lymphocyte ratio (PLR) as a prognostic marker in patients with nasopharyngeal carcinoma (NPC). METHODS: A literature search was conducted using online databases such as MEDLINE, EMBASE, Cochrane Library, and WangFang. Overall survival (OS), progression-free survival (PFS), and clinicopathological features were generated and compared. RESULTS: Ten studies that included 3388 patients were analyzed in this meta-analysis. Among them, 8 studies with 3033 patients with NPC investigated the prognostic role of PLR for OS and showed that elevated PLR was associated with poor OS (HR: 1.77, 95% CI: 1.46-2.15, P < .001). Five studies that included 1156 patients investigated the role of PLR in predicting PFS, and showed that high PLR was associated with poor PFS (HR: 1.65, 95% CI: 1.26-2.17, P < .001). Moreover, high PLR correlated with the N stage (N2-3 vs N0-1; OR: 1.55, 95% CI: 1.02-2.34, P = .04). CONCLUSION: Our study suggested that high PLR is associated with worse prognosis in patients with NPC. Pretreatment PLR could serve as a simple, promising indicator for prognostic evaluation in patients with NPC.

MiR-449 overexpression inhibits osteogenic differentiation of bone marrow mesenchymal stem cells via suppressing Sirt1/Fra-1 pathway in high glucose and free fatty acids microenvironment.

Diabetic osteoporosis is a chronic complication caused by diabetes mellitus, and However, the exact mechanism of diabetes mellitus-induced osteoporosis is still unknown. In this study, we investigate the effect of miR-449 on osteogenic differentiation and its underlying mechanism in human bone marrow-derived mesenchymal stem cells (hBMSCs) with high glucose (HG) and free fatty acids (FFA) treatment. Results showed that after culturing for 14 days, high glucose (HG) and free fatty acids (FFA) treatment dramatically decreased mineralization of human bone marrow-derived mesenchymal stem cells (hBMSCs) compared with cells treated with osteogenic medium (OM) alone. We also found that miR-449 expression was up-regulated during osteogenic differentiation of hBMSCs with HG and FFA treatment. Moreover, during osteogenic differentiation of hBMSCs with HG and FFA treatment, miR-449 mimics notably decreased the alkaline phosphatase (ALP) activity and the mRNA and protein expression levels of runt-related transcription factor 2 (Runx2), ALP, collagen I, osteocalcin (OCN), and bone sialoprotein (BSP), which was remarkably increased by miR-449 inhibitors. Furthermore, miR-449 directly targets Sirt1 by binding to its 3'-UTR. Sirt1 overexpression reverses the suppressive effect of miR-449 mimics on Fra-1 mRNA and protein expression, which was also alleviated by Fra-1 overexpression. In addition, Fra-1 overexpression alleviates the inhibitory effect of miR-449 mimics on the ALP activity and the mRNA and protein of Runx2, collagen I, OCN and BSP. Taken together, our results indicated that miR-449 overexpression inhibited osteogenic differentiation of HG-FFA-treated hBMSCs through the Sirt1/Fra-1 signal pathway. It is conceivable that modulating miR-449 might provide a new therapy for intervention in diabetic osteoporosis.

[Establishment of a rat model of diabetic erectile dysfunction].

OBJECTIVE: To establish a rat model of diabetic erectile dysfunction (ED) with streptozotocin (STZ) injection. METHODS: Thirty male rats were randomized equally into 5 groups (control group and STZ 40 mg/kg, 60 mg/kg, 80 mg/kg, and 100 mg/kg groups). All the rats were examined at 4 days and 1, 2, and 3 weeks after STZ injection for fasting blood glucose, erectile frequency induced by apomorpHine (APO) and body weight changes. RESULTS: Significant difference occurred in the fasting food glucose among the groups at different time points (P=0.001), and also in APO-induced erectile frequency, fasting blood glucose and body weight between the groups with STZ injection at different doses (P<0.001, P=0.045 and P<0.001, respectively). No significant difference was found in induced erectile frequency and body weight between different time points (P=0.306 and P=0.628). CONCLUSION: The optimal dose of STZ for establishing diabetic ED model is 60 mg/kg, and two weeks after the injection can be the optimal time for evaluating model establishment by means of APO-induced penis erection.

[Sexual physiology and psychology of male college students and their clinical significance].

OBJECTIVE: To understand the sexual physiology and psychology of male college students and to provide schools, families and the society with reference for the sexual physiological and psychological education among college students as well as for the diagnosis and treatment of their sexual psychological disorders in Jiangsu. METHODS: An investigation was conducted by using a questionnaire on sexual physiology and psychology among randomly selected 3786 male college students from 18 universities in Jiangsu. RESULTS: As regards sexual education, 5.49% of the subjects were satisfied with their schools, 78.18% wanted it to be strengthened and 68.36% obtained their sexual knowledge from the internet. Concerning sexual physiology, 68.78% experienced their first spermatorrhea at the age of 12-15. As for sexual psychology, 85.79% loved a certain female inwardly, and 70.99% experienced love affairs. With regard to sexual activity, 25.54% had sexual experience. CONCLUSION: College students nowadays are relatively open in sexual ideology, immature in sexual psychology and lacking in sexual knowledge, while schools are inefficient in sexual education. Their sexual health calls for joint attention from schools, families and the society, particularly schools, which need to establish special offices for research and education on sexual health.

[Effect of elastic fiber alterations in the tunica albuginea of the penis on erectile function of diabetic rats].

OBJECTIVE: To investigate the effect of elastic fiber alterations in the tunica albuginea of the penis on erectile function of diabetic rats. METHODS: Streptozotocin (STZ) injection was adopted to produce rat models of diabetes mellitus and erectile dysfunction. Forty rats were randomized equally into two groups according to the time after streptozotocin (STZ) injection, namely 4 week group and 7 week group. Each group was further divided into 4 subgroups, including a control group (n=5, without STZ injection), diabetic with erectile dysfunction group (DM and ED group), diabetic without erectile dysfunction group (DM group) and group with neither diabetes mellitus or erectile dysfunction after STZ injection (None group). Victoria blue/Ponceau red staining and color image analysis were used to observe the content of the elastic fibers in the tunica albuginea, which was quantified by means of integrated optical density (IOD) readings. RESULT: Significant difference in the IOD was observed between different groups (F=10.433, P<0.001). The content of elastic fibers in the tunica albuginea was the lowest in DM and ED group among the 4 groups (P<0.05), and there was no significant difference between 7-week and 4 week groups (F=0.685, P=0.415), nor was any interaction observed (F=0.905, P=0.452). CONCLUSIONS: Decreased elastic fibers in the tunica albuginea can result from diabetes mellitus. Elastic fibers in the tunica albuginea play an important role in the course of erection, and erectile dysfunction may result from decreased elastic fiber content.

[Phenotype modulation of smooth muscle in corpus cavernosum in penis tunica albuginea in diabetes mellitus with erectile dysfunction: experiment with rats].

OBJECTIVE: To investigate the phenotype modulation of smooth muscle of corpus cavernosum in diabetes mellitus with erectile dysfunction. METHODS: Thirty SD rats were randomly divided into 2 equal groups: 4-week group and 7-week group, injected with streptozocin to cause diabetes mellitus (DM), and then subdivided into DM group [with DM and without erectile dysfunction. (ED)], DM + ED group (with DM and ED), and group of failure to cause DM (Group None) according whether DM was induced. Another 10 rats without STZ injection were divided into 4-week and 7-week control groups. The penis was resected and immunohistochemistry and color image analysis were used to observe the expression of alpha-actin and desmin in the corpus cavernosum. In situ hybridization was used to detect the mRNA expression of osteopontin (OPN), characteristic of noncontractil phenotype. RESULTS: The alpha-actin expression of smooth muscle in corpus cavernosum in the DM + ED group was significantly lower than those of the other groups (all P < 0.05). No significant difference existed between the 7 week group and 4 week group (F = 3.801, P = 0.62), and there was significant interaction (F = 1.549, P = 0.225). There was no significant difference in the desmin expression of smooth muscle in corpus cavernosum among different groups (F = 0.045, P = 0.987) and there was not significant interaction (F = 0.572, P = 0.639). The OPN mRNA expression of smooth muscle in corpus cavernosum of the DM + ED group was significantly higher than those of the other subgroups (F = 156.439, P = 0.000). No significant difference existed between the 7 week group and 4 week group (F = 1.288, P = 0.266), and there was no significant interaction (F = 1.819, P = 0.168). CONCLUSION: Phenotype modulation of smooth muscle in corpus cavernosum can be caused by DM. ED can be caused by phenotype modulation of smooth muscle in corpus cavernosum.