Assessment and evaluation of online education and virtual simulation technology in dental education: a cross-sectional survey.

BACKGROUND: The global outbreak of coronavirus disease (COVID-19) has led medical universities in China to conduct online teaching. This study aimed to assess the effectiveness of a blended learning approach that combines online teaching and virtual reality technology in dental education and to evaluate the acceptance of the blended learning approach among dental teachers and students. METHODS: The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist was followed in this study. A total of 157 students' perspectives on online and virtual reality technology education and 54 teachers' opinions on online teaching were collected via questionnaires. Additionally, 101 students in the 2015-year group received the traditional teaching method (TT group), while 97 students in the 2017-year group received blended learning combining online teaching and virtual reality technology (BL group). The graduation examination results of students in the two groups were compared. RESULTS: The questionnaire results showed that most students were satisfied with the online course and the virtual simulation platform teaching, while teachers held conservative and neutral attitudes toward online teaching. Although the theoretical score of the BL group on the final exam was greater than that of the TT group, there was no significant difference between the two groups (P = 0.805). The skill operation score of the BL group on the final exam was significantly lower than that of the TT group (P = 0.004). The overall score of the BL group was lower than that of the TT group (P = 0.018), but the difference was not statistically significant (P = 0.112). CONCLUSIONS: The blended learning approach combining online teaching and virtual reality technology plays a positive role in students' learning and is useful and effective in dental education.

Mirror training device improves dental students' performance on virtual simulation dental training system.

INTRODUCTION: Clinical practice of dentistry entails the use of indirect vision using a dental mirror. The Mirrosistant is a device that helps dental students become proficient with use of indirect vision mirror operation. This study aimed to explore the role of the Mirrosistant on students' performance with the virtual simulation dental training system. MATERIALS AND METHODS: A total of 72 dental students were equally assigned to the Control group and the Experimental group. Subsequently, Mirrosistant was used to conduct a series of mirror training exercises in the Experimental group. The training consisted of tracing the edge and filling in the blank of the prescribed shape, as well as preparing the specified figure on raw eggs using indirect vision via Mirrosistant. Next, both groups were examined using the SIMODONT system, a virtual reality dental trainer, for mirror operation. In addition, a five-point Likert scale questionnaire was used to assess student feedback by using Mirrosistant. RESULTS: The mirror operation examination conducted by the SIMODONT system revealed that mirror training using Mirrosistant had statistically improved students' performances (score: 80.42 ± 6.43 vs. 69.89 ± 15.98, P = 0.0005) and shorten their performance time of mirror operation (time of seconds: 243.28 ± 132.83 vs. 328.53 ± 111.89, P = 0.0013). Furthermore, the questionnaire survey indicated that the participants had positive attitudes toward the mirror training using Mirrosistant. Most students believed that the mirror training device could improve their perceptions of direction and distance, as well as their sensations of dental operation and dental fulcrum. CONCLUSION: Mirror training using Mirrosistant can enhance dental students' mirror perceptual and operational skills on virtual simulation dental training system.

Salvianolic acid B ameliorates non-alcoholic fatty liver disease by inhibiting hepatic lipid accumulation and NLRP3 inflammasome in ob/ob mice.

Non-alcoholic fatty liver disease (NAFLD) has high occurrence in the global world, which poses serious threats to human health. Salvianolic acid B (SalB), an extract of the root of Salvia miltiorrhiza, has the protective effect on metabolic homeostasis. However, the mechanism is still unknown. In this study, we used ob/ob mice, a model of NAFLD, to explore the hepatoprotective effects of SalB. The results showed that SalB significantly reduced the body weights and liver weights, and ameliorated plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), hepatic free fatty acid (FFA), total cholesterol (TC) levels, and hepatic TG and TC levels in ob/ob mice. SalB reduced the number of lipid droplets and inhibited hepatic lipogenesis by regulating peroxisome proliferator-activated receptor gamma (PPARγ), fatty acid synthase (FASN), stearoyl-Co A desaturase 1 (SCD1), and cluster of differentiation 36 (CD36). Compared to ob/ob mice, the lower expressions of the pro-inflammatory cytokines, such as interleukin-1ß (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and F4/80, were observed after SalB treatment. Importantly, SalB treatment inhibited the activation of NLRP3 inflammasome and reduced the severity of liver inflammation. Our findings suggested that SalB improved NAFLD pathology in ob/ob mice by reducing hepatic lipid accumulation and NLRP3 inflammasome activation, which might be the potential hepatoprotective mechanism of SalB.

Isoflurane Promotes Cell Proliferation, Invasion, and Migration by Regulating BACH1 and miR-375 in Prostate Cancer Cells In Vitro.

The aim of this study was to investigate the mechanism of isoflurane in proliferation, invasion, and migration in prostate cancer (PC) cells in vitro by regulating BACH1 and miR-375. The effect of different concentrations of isoflurane (0%, 0.5%, 1%, and 2%) on PC cell proliferation (PC3 and 22RV1) was measured. After PC cells and normal human prostate stromal immortalized WPMY-1 cells were treated with isoflurane, BACH1 and miR-375 expression was measured. Subsequently, PC3 and 22RV1 cells underwent gain- and loss-of-function assays with or without 4-h 2% isoflurane pretreatment. The levels of miR-375, BACH1, and PTEN were assessed. The binding of BACH1 to miR-375 promoter was detected by ChIP assay. Dual-luciferase reporter assay detected the targeting relationship of miR-375 with BACH1 and PTEN. Isoflurane promoted PC3 and 22RV1 cell proliferation. In addition, isoflurane elevated the levels of BACH1 and miR-375 in a dosage-dependent manner in PC cells. Transfection with miR-375 inhibitor or sh-BACH1 repressed PC cell proliferation, invasion, and migration, while exposure to 2% isoflurane for 4 h before transfection counteracted the inhibitory effects of sh-BACH1 or miR-375 inhibitor on PC cells. PTEN expression was suppressed after 2% isoflurane treatment, but the transfection with miR-375 inhibitor partly abrogated this suppressive effect in PC cells. Moreover, BACH1 bound to miR-375 and miR-375 negatively targeted PTEN. miR-375 mimic could partially reverse the inhibitory effects of sh-BACH1 on the proliferation, invasion, and migration of isoflurane-treated PC cells. Isoflurane facilitated PC cell proliferation, migration, and invasion by activating BACH1 to upregulate miR-375.

Squamous cell carcinoma of the prostate with lower urinary tract symptoms: A case report.

Primary squamous cell carcinoma of the prostate is a rare tumor. An 80-year-old man was admitted to hospital for half a year because of progressive dysuria and pain. Laboratory examination: TPSA 7.24ng/ml; FPSA 1.610ng/ml,%FreePSA 14.3%. Urine routine was normal. He was treated with thulium laser surgery of the prostate. The pathological result was poorly differentiated squamous cell carcinoma of the prostate. This report is helpful to the clinical manifestation and treatment of the disease.

A case of sarcomatoid renal collecting duct carcinoma with paraneoplastic syndrome and peripheral adhesions.

Renal sarcoma-like collecting duct cancer is a rare tumor. A 68-year-old man was admitted to the hospital due to chest tightness and back swelling. Computed tomography showed solid occupying of the superior cyst of the left kidney. He underwent radical resection of left kidney cancer. The pathological result is collecting duct carcinoma with sarcoma-like changes. This report helps to understand the clinical manifestations and treatment of the disease.

[Alpha-momordicin Regulates Hepatocyte Cytokine Expression].

OBJECTIVE: To investigate the regulation effect of α-momordicin (α-MMC) on the synthesis and secretion of cytokines in hepatocytes cells. METHODS: Hepatocytes L02 were treated with 189 µg/mL α-MMC with culture supernatant and lysate samples were harvested in different timepoint. Expressions of T-helper 17 (TH17) cytokine profile in samples were detected by the Bio-Plex 200 suspension chip assay system. RESULTS: Compared with 0 h, after the α-MMC treatment of L02 hepatocytes for 2 h, 4 h and 8 h, the intracellular synthesis of cytokines interleukin (IL)-1b, IL-6, IL-17A, IL-31, IL-33, soluble CD40 ligand (sCD40L), tumor necrosis factor-α (TNF-α) were all significantly decreased (P<0.05), and IL-6, IL-4, IL-17A, and sCD40L secreted into the extracellular fluid also decreased significantly (P<0.05). CONCLUSION: α-MMC can significantly inhibit the synthesis and secretion of cytokines such as IL-6, IL-17A and TNF-α in hepatocytes, which may become a side effect of its anti-tumor application.

Anti-tumor activity and the mechanism of a green tea (Camellia sinensis) polysaccharide on prostate cancer.

In this study, a homogeneous polysaccharide (GTP), with a molecular weight of 7.0 × 104 Da, was isolated from Green tea, which was only composed of glucose. The antitumor effects of GTP on prostate cancer (PC) cell line along with the possible mechanism was examined. First, we investigate the potential role of microRNA-93 (miR-93) in PC progression. Our results showed that miR-93 was significantly upregulated in human PC tissues and several PC cell lines, and its overexpression was correlated with poor survival in PC patients. Furthermore, functional analysis showed that miR-93 overexpression promoted the migration, invasion and proliferation of PC-3 cells transfected with miR-93 mimics, while its knockdown displayed an opposite result in DU145 cells following miR-93 inhibitor transfection. Additionally, in vivo tumorigenic studies on nude mice confirmed that miR-93 mimic treatment accelerated the growth of PC-3 xenograft tumors. As expected, GTP (25, 50 and 100 µg/ml) inhibited growth of PC-3 cells via inducing apoptosis, which was achieved by elevation of bax/bcl-2 ratio and caspae-3 protein expression, as well as a decrease of miR-93. Thus, miR-93 may be a potential therapeutic target by GTP for PC therapy.

MiR-93 functions as a tumor promoter in prostate cancer by targeting disabled homolog 2 (DAB2) and an antitumor polysaccharide from green tea (Camellia sinensis) on their expression.

Our previous work has demonstrated that the role of miR-93 in prostate cancer (PC) progression. The aim of this study was to determine the downstream gene regulated by miR-93 and the molecular mechanisms underlying its roles in PC. Bioinformatics analysis and luciferase reporter assays predicted disabled homolog 2 (DAB2) as a direct target gene of miR-93. Real time quantitative polymerase chain reaction (qRT-PCR) and Western blot analysis revealed that DAB2 was tumor repressor in PC cells, and its mRNA expression was negatively correlated with miR-93 in PC tissues. Gain and loss of function experiments also indicated DAB2 overexpression significantly suppressed PC cells proliferation, invasion and migration, while knockdown of its expression came to the opposite effect. Furthermore, a rescue experiment indicated miR-93 directly regulated PC cell growth and migration, as well as AKT and ERK activation by targeting DAB2. Additionally, antitumor effect of a Green tea polysaccharide (GTP) on PC-3 cells could be achieved by increasing DAB2 protein expression and inactivating AKT and ERK1/2 signaling. Our study suggests that miR-93 promoted PC progression and metastasis by repressing DAB2 to activate Akt/ERK1/2 pathway, and elevation of DAB2 and inactivation of Akt/ERK1/2 might be a potential therapeutic target for PC by GTP.

Single-molecule detection of dihydroazulene photo-thermal reaction using break junction technique.

Charge transport by tunnelling is one of the most ubiquitous elementary processes in nature. Small structural changes in a molecular junction can lead to significant difference in the single-molecule electronic properties, offering a tremendous opportunity to examine a reaction on the single-molecule scale by monitoring the conductance changes. Here, we explore the potential of the single-molecule break junction technique in the detection of photo-thermal reaction processes of a photochromic dihydroazulene/vinylheptafulvene system. Statistical analysis of the break junction experiments provides a quantitative approach for probing the reaction kinetics and reversibility, including the occurrence of isomerization during the reaction. The product ratios observed when switching the system in the junction does not follow those observed in solution studies (both experiment and theory), suggesting that the junction environment was perturbing the process significantly. This study opens the possibility of using nano-structured environments like molecular junctions to tailor product ratios in chemical reactions.

Gelsolin-like actin-capping protein is associated with patient prognosis, cellular apoptosis and proliferation in prostate cancer.

AIM: To investigate the role of gelsolin-like actin-capping protein (CapG) in prostate cancer (PCa). MATERIALS & METHODS: CapG expression and its correlation with clinicopathological characters and patient prognosis were analyzed in 76 cases of PCa by immunohistochemistry and qRT-PCR. Then, the influence of CapG downregulation on cell apoptosis and proliferation were assessed. RESULTS: CapG expression in PCa was significantly higher compared with those in matched adjacent noncancerous prostate tissues, and significantly correlated with clinicopathological characters. Survival analysis indicated that CapG could be an independent prognostic factor in PCa. Moreover, CapG depletion significantly affected cellular proliferation and apoptosis by regulating Caspase 6/Caspase 9/Bcl-2/p-Akt/Akt signaling pathway. CONCLUSION: CapG, as a potential biomarker in PCa, is associated with patient prognosis, cellular apoptosis and proliferation.

PEGylation alleviates the non-specific toxicities of Alpha-Momorcharin and preserves its antitumor efficacy in vivo.

Alpha-Momorcharin (α-MMC) is a ribosome inactivating protein from Momordica charantia with anti-tumor activity. Previously, we had observed that modification of α-MMC with polyethylene glycol (PEG) could reduce toxicity, but it also reduces its anti-tumor activity in vitro. This study aims to investigate whether the metabolism-extended properties of α-MMC resulting from PEGylation could preserve its anti-tumor efficacy in vivo through pharmacokinetics and antitumor experiments. The pharmacokinetics experiments were conducted in rats using the TCA (Trichloroacetic Acid) method. Antitumor activity in vivo was investigated in murine mammary carcinoma (EMT-6) and human mammary carcinoma (MDA-MB-231) transplanted tumor mouse models. The results showed that PEGylation increased the plasma half-life of α-MMC in rats from 6.2-7.5 h to 52-87 h. When administered at 1 mg/kg, α-MMC-PEG and α-MMC showed similar anti-tumor activities in vivo, with a T/C% of 38.56% for α-MMC versus 35.43% for α-MMC-PEG in the EMT-6 tumor model and 36.30% for α-MMC versus 39.88% for α-MMC-PEG in the MDA-MB-231 tumor model (p > 0.05). Importantly, at the dose of 3 mg/kg, all the animals treated with α-MMC died while the animals treated with α-MMC-PEG exhibited only moderate toxic reactions, and α-MMC-PEG exhibited improved anti-tumor efficacy with a T/C% (relative tumor growth rate) of 25.18% and 21.07% in the EMT-6 and MDA-MB-231 tumor models, respectively. The present study demonstrates that PEGylation extends the half-life of α-MMC and alleviates non-specific toxicity, thereby preserving its antitumor efficacy in vivo, and a higher lever of dosage can be used to achieve better therapeutic efficacy.

[Effect of PEGylation of alpha-Momorcharin against its hepatotoxicity in rats].

OBJECTIVE: To explore the effect of PEGylation of alpha-Momorcharin (alpha-MMC), one of ribosome-inactivating proteins from bitter melon seed, against its hepatotoxicity in rats. METHODS: SD rats were randomized into NS group, alpha-MMC treated groups, and alpha-MMC-PEG treated groups. The doses of alpha-MMC and alpha-MMC-PEG were high, middle, and low dose (6.25, 2.08, 0.70 mg/kg). The rats were given different dose of alpha-MMC, or alpha-MMC-PEG via caudal vein every other day for consecutive 28 days and then left for 14 days recovery. The general condition of animals was observed, blood and liver samples were collected for liver function study and pathological examination on day 28 after initiation of administration and on day 14 after withdrawal. RESULTS: On day 28 after initiation of administration, the liver function damages were found in high-dose and middle-dose of alpha-MMC treated groups, such as the decreasing of ALB, increasing of GLB, A/G ratio decreasing and the dose-dependant increasing of AST, BIL and CHO. The pathological changes of hepatotoxicity were also observed in these two groups, including the massive hepatocyte, swelling degeneration, inflammatory cell infiltration, congestion and diffusive necrosis. However, the liver function and pathological changes in alpha-MMC-PEG treated groups were better than those in alpha-MMC treated groups. CONCLUSION: PEGylation could reduce the hepatotoxicity of alpha-MMC to rats.

Reconstructing a flavodoxin oxidoreductase with early amino acids.

Primitive proteins are proposed to have utilized organic cofactors more frequently than transition metals in redox reactions. Thus, an experimental validation on whether a protein constituted solely by early amino acids and an organic cofactor can perform electron transfer activity is an urgent challenge. In this paper, by substituting "late amino acids (C, F, M, T, W, and Y)" with "early amino acids (A, L, and V)" in a flavodoxin, we constructed a flavodoxin mutant and evaluated its characteristic properties. The major results showed that: (1) The flavodoxin mutant has structural characteristics similar to wild-type protein; (2) Although the semiquinone and hydroquinone flavodoxin mutants possess lower stability than the corresponding form of wild-type flavodoxin, the redox potential of double electron reduction Em,7 (fld) reached -360 mV, indicating that the flavodoxin mutant constituted solely by early amino acids can exert effective electron transfer activity.

PEGylation is effective in reducing immunogenicity, immunotoxicity, and hepatotoxicity of α-momorcharin in vivo.

BACKGROUND AND AIM: α-momorcharin (α-MMC), a type I ribosome-inactivating protein (RIP) from Momordica charantia, is well known for its antitumor and antivirus activities. However, the immunotoxicity and hepatotoxicity hampers its potential therapeutic usage. In order to reduce its toxicity, we had modified the α-MMC with polyethylene glycol (PEG), and detected the toxicity of the PEGylated α-MMC conjugates (α-MMC-PEG) in vivo. MATERIALS AND METHODS: After α-MMC purified from bitter melon seeds, α-MMC-PEG was constructed with a branched 20 kDa (mPEG) 2-Lys-NHS, the tests of immunogenicity, immunotoxicity, and general toxicity of α-MMC-PEG were conducted in guinea pig and rat. RESULTS: The titer of specific IgG in rats, immunized by α-MMC-PEG, were approximately one-third of those that by α-MMC, all the guinea pigs treated with α-MMC died of anaphylaxis shock within 5 min, while no animals treated with α-MMC-PEG died in the active systemic anaphylaxis (ASA) test. The passive cutaneous anaphylaxis (PCA) reaction of α-MMC-PEG challenge in rats was significantly smaller than that of the α-MMC. The liver damage was greatly released, such as the change of globulin (GLB), aspartate aminotransferase (AST), total bilirubin (TBIL) cholesterol (CHOL), albumin (ALB), and the degree of hepatocyte necrosis in repeated toxicity study. CONCLUSIONS: PEGylation is effective in reducing the immunogenicity, immunotoxicity, and hepatotoxicity of α-MMC in vivo.

[Study on the immunotoxicity of ribosome inhibiting protein of Momordica charantia].

OBJECTIVE: To separate and purify ribosome inhibiting protein (RIP) from Momordica charantia (bitter melon) seeds and to evaluate its acute toxicity and immunotoxicity in animal. METHODS: Ion exchange chromatography and gel filtration chromatography were applied in the separating and purifying of RIP from Momordica charantia seeds. Then the acute toxicity testing of RIP in mice was conducted to obtain its half lethal dose (LD50). Active systemic anaphylaxis(ASA)test in guinea pig and passive cutaneous anaphylaxis test (PCA) in rat were performed to evaluate its immunotoxicity. RESULTS: The LD50 (iv) in mice of RIP was 25.2 mg/kg in ASA, guinea pigs of the higher and lower RIP group all appeared stong allergic responses and most of them died quickly. In PCA, obvious blue dye in skin were observed in SD rats of the RIP group. CONCLUSION: RIP getting from Momordica charantia seeds had a relatively strong immunotoxicity in animals.

[Laparoscopic abdominoperineal resection for low rectal cancer].

OBJECTIVE: To assess the advantage and disadvantage of laparoscopic abdomino-perineal resection and open abdominoperineal resection for low rectal cancer. METHODS: Patients with low rectal cancer, collected from July 2003 to April 2006, were randomly divided into laparoscopic abdominoperineal resection group (37 cases) and open abdominoperineal resection group (37 cases). Operation time, number of lymph node removed, intra-operative blood loss, time to pass flatus, time to ambulate, time to discharge, complications, early recurrence, and economical cost were compared between the 2 groups. RESULTS: All patients were performed successfully. For the first 10 patients, operation time of laparoscopic group was significantly longer than that of open group, but there was no significant difference between the 2 groups. Intra-operative blood loss of laparoscopic group was significantly less than that of open group, but it was reverse for the first 10 patients. There was no significant difference in time to pass flatus between the 2 groups. Time to ambulate in laparoscopic group was significantly earlier than that in open group. There was no significant difference in time to discharge between the 2 groups, but it was earlier for perineum closure in laparoscopic group. Relative complications of laparoscopic group, including pulmonary infection, abdominal wound infection or split, were significantly less than those of open group. There was no significant difference in number of lymph nodes removed, early recurrence between the 2 groups. Operation cost of laparoscopic group was significantly higher than that of open group, but there was no significant difference. CONCLUSION: Advantages of laparoscopic abdominoperineal resection were characterized for not only minimal invasion and good cosmetic outcome but also less blood loss, complications, and earlier postoperative recovery. The operation time, total costs and oncological clearance of laparoscopic abdominoperineal resection patients were comparable with those of open procedure patients.