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1.
JMIR Serious Games ; 12: e46789, 2024 Apr 05.
Article in English | MEDLINE | ID: mdl-38596827

ABSTRACT

Background: Removable partial denture (RPD) design is crucial to long-term success in dental treatment, but shortcomings in RPD design training and competency acquisition among dental students have persisted for decades. Digital production is increasing in prevalence in stomatology, and a digital RPD (D-RPD) module, under the framework of the certified Objective Manipulative Skill Examination of Dental Technicians (OMEDT) system reported in our previous work, may improve on existing RPD training models for students. Objective: We aimed to determine the efficacy of a virtual 3D simulation-based progressive digital training module for RPD design compared to traditional training. Methods: We developed a prospective cohort study including dental technology students at the Stomatology College of Chongqing Medical University. Cohort 1 received traditional RPD design training (7 wk). Cohort 2 received D-RPD module training based on text and 2D sketches (7 wk). Cohort 3 received D-RPD module pilot training based on text and 2D sketches (4 wk) and continued to receive training based on 3D virtual casts of real patients (3 wk). RPD design tests based on virtual casts were conducted at 1 month and 1 year after training. We collected RPD design scores and the time spent to perform each assessment. Results: We collected the RPD design scores and the time spent to perform each assessment at 1 month and 1 year after training. The study recruited 109 students, including 58 (53.2%) female and 51 male (56.8%) students. Cohort 1 scored the lowest and cohort 3 scored the highest in both tests (cohorts 1-3 at 1 mo: mean score 65.8, SD 21.5; mean score 81.9, SD 6.88; and mean score 85.3, SD 8.55, respectively; P<.001; cohorts 1-3 at 1 y: mean score 60.3, SD 16.7; mean score 75.5, SD 3.90; and mean score 90.9, SD 4.3, respectively; P<.001). The difference between cohorts in the time spent was not statistically significant at 1 month (cohorts 1-3: mean 2407.8, SD 1370.3 s; mean 1835.0, SD 1329.2 s; and mean 1790.3, SD 1195.5 s, respectively; P=.06) but was statistically significant at 1 year (cohorts 1-3: mean 2049.16, SD 1099.0 s; mean 1857.33, SD 587.39 s; and mean 2524.3, SD 566.37 s, respectively; P<.001). Intracohort comparisons indicated that the differences in scores at 1 month and 1 year were not statistically significant for cohort 1 (95% CI -2.1 to 13.0; P=.16), while cohort 3 obtained significantly higher scores 1 year later (95% CI 2.5-8.7; P=.001), and cohort 2 obtained significantly lower scores 1 year later (95% CI -8.8 to -3.9; P<.001). Conclusions: Cohort 3 obtained the highest score at both time points with retention of competency at 1 year, indicating that progressive D-RPD training including virtual 3D simulation facilitated improved competency in RPD design. The adoption of D-RPD training may benefit learning outcomes.

2.
Int J Prosthodont ; 0(0): 1-32, 2024 Feb 26.
Article in English | MEDLINE | ID: mdl-38408132

ABSTRACT

PURPOSE: To evaluate the surface characteristics, accuracy (trueness and precision), and dimensional stability of tooth preparation dies fabricated using conventional gypsum and direct light processing (DLP), stereolithography (SLA), and polymer jetting printing (PJP) techniques. MATERIALS AND METHODS: Gypsum preparation dies were replicated according to the reference data and imported into DLP, SLA, and PJP printers, and the test data were obtained by scanning after 0, 1, 3, 7, 14, 28, and 42 days. After analyzing the surface characteristics, a best-fit algorithm between the test and the reference data was used to evaluate the accuracy and dimensional stability of the preparation dies. The data were analyzed by one-way analysis of variance and Tukey test or Kruskal-Wallis H test (α = .05). RESULTS: Compared with the gypsum group (3.61 ± 0.59 µm), the root mean square error (RMSE) values of the SLA group (5.33 ± 0.48 µm) was rougher (P < .05), the PJP group (2.43 ± 0.37 µm) was smoother (P < .05), and the DLP group (2.92 ± 0.91 µm) had no significant difference (P > .05). For trueness, the RMSE was greater in the PJP (34.90 ± 4.91 µm) and SLA (19.01 ± 0.95 µm) groups than in the gypsum (16.47 ± 0.47 µm) group (P < .05), and no significant difference was found between the DLP (17.10 Å} 1.77 µm) and gypsum groups. Regarding precision, the RMSE ranking was gypsum = DLP = SLA < PJP group. The RMSE ranges in the gypsum, DLP, PJP, and SLA groups at different times were 6.79 to 8.86 µm, 5.44 to 10.17 µm, 10.16 to 11.28 µm, and 10.94 to 32.74 µm, respectively. CONCLUSION: Although gypsum and printed preparation dies showed statistically significant differences in surface characteristics, accuracy, and dimensional stability, all tooth preparation dies were clinically tolerated and used to produce fixed restorations.

3.
iScience ; 27(1): 108579, 2024 Jan 19.
Article in English | MEDLINE | ID: mdl-38161420

ABSTRACT

Tissue inhibitors of metalloproteinase (TIMPs) play a pivotal role in regulating extracellular matrix (ECM) dynamics and have been extensively studied in vertebrates. However, understanding their evolution across invertebrate phyla is limited. Utilizing the high-quality Pteria penguin genome, we conducted phylogenomic orthology analyses across metazoans, revealing the emergence and distribution of the TIMP gene family. Our findings show that TIMP repertoires originated during eumetazoan radiation, experiencing independent duplication events in different clades, resulting in varied family sizes. Particularly, Pteriomorphia bivalves within Mollusca exhibited the most significant expansion and displayed the most diverse TIMP repertoires among metazoans. These expansions were attributed to multiple gene duplication events, potentially driven by the demands for functional diversification related to multiple adaptive traits, contributing to the adaptation of Pteriomorphia bivalves as stationary filter feeders. In this context, Pteriomorphia bivalves offer a promising model for studying invertebrate TIMP evolution.

4.
Int J Comput Dent ; 26(4): 319-330, 2023 Nov 28.
Article in English | MEDLINE | ID: mdl-36749283

ABSTRACT

AIM: The aim of the present study was to evaluate the effect of cement gap and drill offset on the marginal and internal fit discrepancies of crowns designed with different tooth preparations. MATERIALS AND METHODS: Five tooth preparations were constructed, and crowns with different cement gaps and drill offsets were obtained. Then, best-fit alignment was performed on the crowns with the corresponding tooth preparations, and the fit discrepancies were expressed by color-coded difference images and root mean square (RMS) values. The RMS values of each group were analyzed by the rank-based Scheirer-Ray-Hare test (α = 0.05). RESULTS: The color segments in the sharp line angles area of the Sharp line angles group changed significantly before and after the drill offset. The cement gap had a significant effect on the marginal, internal, or overall fit discrepancies of the five design groups (P < 0.001), while the drill offset had a significant effect on the marginal fit discrepancies of the Shoulder-lip group and the internal or overall fit discrepancies of the Sharp line angles group (P < 0.001). Additionally, the interaction effect between cement gap and drill offset was significant for the marginal fit discrepancies of the Shoulder-lip group and the internal or overall fit discrepancies of the Sharp line angles group (P < 0.01). CONCLUSIONS: The cement gap and drill offset had a significant adverse effect on the marginal or internal fit discrepancies of the crowns designed with the shoulder-lip and sharp line angles designs. Tooth preparation designs with intense curvature changes such as shoulder-lip and sharp line angles should be avoided clinically.


Subject(s)
Crowns , Dental Cements , Humans , Glass Ionomer Cements , Tooth Preparation , Tooth Preparation, Prosthodontic/methods , Dental Prosthesis Design , Computer-Aided Design , Dental Marginal Adaptation , Dental Porcelain
5.
Commun Biol ; 6(1): 5, 2023 01 03.
Article in English | MEDLINE | ID: mdl-36596992

ABSTRACT

The roles of synonymous mutations for adapting to stressful thermal environments are of fundamental biological and ecological interests but poorly understood. To study whether synonymous mutations influence thermal adaptation at specific microhabitats, a genome-wide genotype-phenotype association analysis is carried out in the black mussels Mytilisepta virgata. A synonymous mutation of Ubiquitin-specific Peptidase 15 (MvUSP15) is significantly associated with the physiological upper thermal limit. The individuals carrying GG genotype (the G-type) at the mutant locus possess significantly lower heat tolerance compared to the individuals carrying GA and AA genotypes (the A-type). When heated to sublethal temperature, the G-type exhibit higher inter-individual variations in MvUSP15 expression, especially for the mussels on the sun-exposed microhabitats. Taken together, a synonymous mutation in MvUSP15 can affect the gene expression profile and interact with microhabitat heterogeneity to influence thermal resistance. This integrative study sheds light on the ecological importance of adaptive synonymous mutations as an underappreciated genetic buffer against heat stress and emphasizes the importance of integrative studies at a microhabitat scale for evaluating and predicting the impacts of climate change.


Subject(s)
Bivalvia , Thermotolerance , Animals , Silent Mutation , Bivalvia/genetics , Acclimatization/genetics , Thermotolerance/genetics , Temperature
6.
Article in English | MEDLINE | ID: mdl-38716481

ABSTRACT

Data streaming has many applications in network monitoring, web services, e-commerce, stock trading, social networks, and distributed sensing. This paper introduces a new problem of real-time burst detection in flow spread, which differs from the traditional problem of burst detection in flow size. It is practically significant with potential applications in cybersecurity, network engineering, and trend identification on the Internet. It is a challenging problem because estimating flow spread requires us to remember all past data items and detecting bursts in real time requires us to minimize spread estimation overhead, which was not the priority in most prior work. This paper provides the first efficient, real-time solution for spread burst detection. It is designed based on a new real-time super spreader identifier, which outperforms the state of the art in terms of both accuracy and processing overhead. The super spreader identifier is in turn based on a new sketch design for real-time spread estimation, which outperforms the best existing sketches.

7.
PLoS One ; 17(12): e0278782, 2022.
Article in English | MEDLINE | ID: mdl-36516167

ABSTRACT

Rockburst physical model test, as one of the important means to study deep tunnel engineering, reflects the main influencing factors of rockburst into the model test through similar theory, so as to reveal the formation mechanism, influencing factors and evolution law of different types of rockburst in deep tunnels. In order to study the mechanical properties of white sandstone in deeply buried tunnels at high ground temperatures, materials suitable for conducting rockburst physical and mechanical tests were developed on the basis of the Daqian Shi Ling tunnel project, and similar material ratios were preferentially selected on the basis of white sandstone. Judged by the rock burst propensity, similar materials with low strength and high brittle characteristics, can better simulate the characteristics of white sandstone, and all show a strong propensity to rock burst, is the ideal rock burst similar materials. Uniaxial compressive tests were conducted on similar materials and the original rock at different temperatures, and comparative analysis was performed. Through the study of stress, displacement and modulus of elasticity, it was concluded that the compressive strength of similar materials gradually increased with temperature in the range of 20-100°C, and the vertical displacement at peak strength decreased with increasing temperature. The damage forms of white sandstone and similar materials at different temperatures were comparatively analyzed, and it was obtained that the damage forms of white sandstone and similar materials were basically the same, with a few specimens showing tensile and shear damage, and most specimens showing the form of combined tensile and shear damage. The study of rock burst similar materials and the development of the failure characteristics of rock burst under the action of thermal coupling are of great significance to the mechanism of rock burst generation and prediction.


Subject(s)
Engineering , Gastropoda , Animals , Temperature , Compressive Strength , Elasticity
8.
Global Spine J ; : 21925682221116824, 2022 Aug 05.
Article in English | MEDLINE | ID: mdl-35929422

ABSTRACT

STUDY DESIGN: Retrospective study. OBJECTIVE: Our purpose was to evaluate spinal rotation measurement by scoliometer or EOS Imagings with reference to that by CT images, and to clarify their applicability in clinical practice. METHODS: Patients with adolescent idiopathic scoliosis (AIS) who were indicated for surgery were enrolled and the informed consents were obtained. The angle of trunk rotation (ATR) was measured by the scoliometer. Apical vertebral rotation (AVR) was measured with EOS Imaging and CT images. Paired T tests were used to compare the measurements between ATR or AVR-EOS and AVR-CT. Pearson correlation analysis was performed to explore the relationship between ATR or AVR-EOS and AVR-CT. Then subgroup analysis was performed. RESULTS: Forty-seven consecutive AIS patients with 62 curves were identified. In the whole group, the ATR, as well as AVR-EOS, was significantly smaller than the AVR-CT. Both ATR and AVR-EOS correlated with AVR-CT, although AVR-EOS correlated better. In thoracic group, there was no significant difference between ATR and AVR-CT (P = .236). A significant correlation was found between ATR and AVR-CT(r = .574, P < .001). In TL/L group, no significant difference was noted between AVR-EOS and AVR-CT (P = .414), and a significant correlation was found between AVR-EOS and AVR-CT(r = .824, P < .001). CONCLUSION: ATR by scoliometer is numerically similar to AVR by CT and may evaluate the spinal rotation more appropriately in thoracic spine. AVR by EOS is numerically similar to AVR by CT and may be more applicable in TL/L spine. Appropriate methods could be selected according to the location of the curve.

9.
Int Conf Contemp Comput ; 2022: 502-508, 2022 Aug.
Article in English | MEDLINE | ID: mdl-37143706

ABSTRACT

Artificial neural networks (ANNs) are changing the paradigm in medical diagnosis. However, it remains an open problem how to outsource the model training operations to the cloud while protecting the privacy of distributed patient data. Homomorphic encryption suffers from high overhead over data independently encrypted from numerous sources, differential privacy introduces a high level of noise which drastically increases the number of patient records needed to train a model, while federated learning requires all participants to perform synchronized local training that counters our goal of outsourcing all training operations to the cloud. This paper proposes to use matrix masking for outsourcing all model training operations to the cloud with privacy protection. After outsourcing their masked data to the cloud, the clients do not need to coordinate and perform any local training operations. The accuracy of the models trained by the cloud from the masked data is comparable to the accuracy of the optimal benchmark models that are trained directly from the original raw data. Our results are confirmed by experimental studies on privacy-preserving cloud training of medical-diagnosis neural network models based on real-world Alzheimer's disease data and Parkinson's disease data.

10.
Front Surg ; 9: 1054351, 2022.
Article in English | MEDLINE | ID: mdl-36700020

ABSTRACT

Background: Residual varus after Oxford unicompartmental knee arthroplasty (UKA) happens frequently. This study aims to evaluate the pre-operative contributing factors of residual varus. Methods: A total of 1,002 knees (880 patients, 201 patients were male, and 679 were female) underwent Oxford UKA in the Orthopedic Surgery Department of the Beijing Jishuitan Hospital from March 2018 to April 2021. The mean age of the patient was 64.7 ± 7.7 years. To assess residual varus, the full-length lower extremity is placed upright for EOS imaging, with the knee fully extended. The angle of post-operative residual varus was measured as described by Noyes et al. Of the knees studied, they were either categorized into an under-corrected group (post-operative Noyes angle >5°) or a corrected group (post-operative Noyes angle ≤5°). Age, gender, body mass index (BMI), range of motion (ROM), Clinical American Knee Society Score (Clinical AKSS), and Function American Knee Society Score (Function AKSS) were compared. The following additional parameters were measured: pre-operative Noyes angle, lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), the posterior slope of the proximal tibia angle (PPTA), joint line converge angle (JLCA), and fixed flexion deformity (FFD). Results: There was no statistically significant difference between the two groups in regards to gender (p = 0.428), surgical leg (p = 0.937), age (p = 0.851), BMI (p = 0.064), pre-operative Clinical AKSS (p = 0.206) and Function AKSS (p = 0.100). However, pre-operative ROM statistically differed between the two groups (p < 0.001). The contributing factors of post-operative residual varus were determined to be the following parameters: pre-operative MPTA (p < 0.001, OR = 4.522, 95% CI: 2.927-6.984), pre-operative Noyes (p < 0.001, OR = 3.262, 95% CI: 1.802-5.907) and pre-operative FFD (p = 0.007, OR = 1.862, 95% CI: 1.182-2.934). The effects of pre-operative LDFA (p = 0.146), JLCA (p = 0.942), and pre-operative PPTA (p = 0.899) on the post-operative mechanical axis did not show statistical significance. Conclusions: Patients with severe pre-operative varus, particularly varus deformity mainly from the tibial side or pre-operative FFD, are more prone to get extremity mechanical axis residual varus after UKA with Oxford.

11.
J Adv Prosthodont ; 13(5): 333-342, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34777722

ABSTRACT

PURPOSE: To evaluate the impact of five different tooth preparation designs on the marginal and internal fit discrepancies of cobalt-chromium (CoCr) crowns produced by computer-aided designing (CAD) and selective laser melting (SLM) processes. MATERIALS AND METHODS: Five preparation data were constructed, after which design crowns were obtained. Actual crowns were fabricated using an SLM process. After the data of actual crowns were obtained with structural light scanning, intaglio surfaces of the design crown and actual crown were virtually superimposed on the preparation. The fit-discrepancies were displayed with colors, while the root means square was calculated and analyzed with one-way analysis of variance (ANOVA), Tukey's test or Kruskal-Wallis test (α =.05). RESULTS: The marginal or internal color-coded images in the five design groups were not identical. The shoulder-lip and sharp line angle groups in the CAD or SLM process had larger marginal or internal fit discrepancies compared to other groups (P < .05). In the CAD process, the mean marginal and internal fit discrepancies were 10.0 to 24.2 µm and 29.6 to 31.4 µm, respectively. After the CAD and SLM processes, the mean marginal and internal fit discrepancies were 18.4 to 40.9 µm and 39.1 to 47.1 µm, respectively. The SLM process itself resulted in a positive increase of the marginal (6.0 - 16.7 µm) and internal (9.0 - 15.7 µm) fit discrepancies. CONCLUSION: The CAD and SLM processes affected the fit of CoCr crowns and varied based on the preparation designs. Typically, the shoulder-lip and sharp line angle designs had a more significant effect on crown fit. However, the differences between the design groups were relatively small, especially when compared to fit discrepancies observed clinically.

12.
Proc Int Conf Tools Artif Intell TAI ; 2021: 381-385, 2021 Nov.
Article in English | MEDLINE | ID: mdl-35095256

ABSTRACT

Machine learning and artificial neural networks (ANNs) have been at the forefront of medical research in the last few years. It is well known that ANNs benefit from big data and the collection of the data is often decentralized, meaning that it is stored in different computer systems. There is a practical need to bring the distributed data together with the purpose of training a more accurate ANN. However, the privacy concern prevents medical institutes from sharing patient data freely. Federated learning and multi-party computation have been proposed to address this concern. However, they require the medical data collectors to participate in the deep-learning computations of the data users, which is inconvenient or even infeasible in practice. In this paper, we propose to use matrix masking for privacy protection of patient data. It allows the data collectors to outsource privacy-sensitive medical data to the cloud in a masked form, and allows the data users to outsource deep learning to the cloud as well, where the ANN models can be trained directly from the masked data. Our experimental results on deep-learning models for diagnosis of Alzheimer's disease and Parkinson's disease show that the diagnosis accuracy of the models trained from the masked data is similar to that of the models from the original patient data.

13.
Zhongguo Zhong Yao Za Zhi ; 36(15): 2011-6, 2011 Aug.
Article in Chinese | MEDLINE | ID: mdl-22066430

ABSTRACT

With the rapid development of Chinese economy, the traditional Chinese medicine has been paid more attention worldwide because of its therapeutic effect and the special health care function. The future contract which was born under the modern economic system, by its price discovery function and the circumvention risk function, occupies the main superiority in the commodity exchange. The traditional Chinese medicine, which has a glorious transaction history commodity, whether future contract could be used to carry on the transaction still to lack the scientific examination. This article reviewed traditional Chinese medicine tradition trading mode forms with in the evolution foundation, summarized the Chinese materia medica tradition trading mode characteristic, discussed necessity and feasibility of the future contract as a supplement sale way for traditional Chinese medicine transaction. It also forecasted possible risk of future contract, proposed the preliminary implementation method for traditional Chinese medicine future contract.


Subject(s)
Contracts , Economics, Pharmaceutical , Medicine, Chinese Traditional/economics , Feasibility Studies , Humans
14.
Front Med ; 5(2): 185-94, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21695624

ABSTRACT

Top-geoherbs used in China are always featured with high qualities, and they grow in specified areas with specific environment. Recently, researches on top-geoherbs have attracted increasing attention in China and other countries. In order to have a thorough knowledge of top-geoherbs, this article reviews the concept, historical evolution, common trait and quality characteristics of top-geoherbs, and explains the forming mechanism including genetic mechanism and environmental mechanism. In addition, it introduces the influence of human factors on the quality of top-geoherbs. Finally, it proposes some problems that should be paid attention to in the researches on top-geoherbs.


Subject(s)
Drugs, Chinese Herbal/pharmacology , Ecosystem , Medicine, Chinese Traditional , Plants, Medicinal/genetics , China , Genetic Variation , Geography , Humans , Phenotype
15.
Phytochem Anal ; 22(2): 112-8, 2011.
Article in English | MEDLINE | ID: mdl-21259373

ABSTRACT

INTRODUCTION: Fructus Aurantii, as a component of several compound formulae, shows many bioactivities. As is well known, the constituents of traditional Chinese medicines are very complex and multiple constituents are responsible for the therapeutic effect. However, the concrete compounds are difficult to confirm. Therefore, studies on the constituents absorbed into serum and their metabolites are necessary. OBJECTIVE: To search for the active constituents in Fructus Aurantii. METHODOLOGY: An ultra-performance liquid chromatography-photodiode array detector-quadrupole time-of-flight mass spectrometry (UPLC-PDA-Q-TOF/MS) method was established to analyse the aqueous extract in Fructus Aurantii and the constituents absorbed into blood. Compound identification was made by matching the empirical molecular formula with those of the reported compounds and UV spectra, and further elucidated by lower energy CID mass spectra. RESULTS: Twelve flavonoid O-glycosides were detected, and nine compounds were tentatively identified as polymethoxylated flavones. Six parent compounds were identified and four metabolites were observed in rat plasma, two of which were identified as naringenin glucuronide and hesperetin glucuronide, respectively. CONCLUSION: The approach developed has proved useful in the study of the active constituents in traditional Chinese medicines.


Subject(s)
Citrus/chemistry , Drugs, Chinese Herbal/chemistry , Plasma/chemistry , Tandem Mass Spectrometry/methods , Animals , Chromatography, High Pressure Liquid/methods , Drugs, Chinese Herbal/isolation & purification , Female , Flavanones/blood , Flavanones/chemistry , Flavones/blood , Flavones/chemistry , Fruit/chemistry , Glucuronides/blood , Glucuronides/chemistry , Glycosides/blood , Glycosides/chemistry , Hesperidin/blood , Hesperidin/chemistry , Male , Medicine, Chinese Traditional , Rats , Rats, Wistar , Spectrometry, Mass, Electrospray Ionization/methods , Water
16.
Steroids ; 74(13-14): 1051-6, 2009.
Article in English | MEDLINE | ID: mdl-19699217

ABSTRACT

Rhizoma Paridis saponins (RPS) have been found to show strong antitumor activity. However, few studies have yet investigated its role on pulmonary metastasis treated with this herb. To investigate the molecular mechanisms related to metastasis, we studied RPS-treated T739 mice using histopathology, immunohistochemistry and reverse transcription polymerase chain reaction. Apoptosis was measured by TUNEL assay. As a result, RPS inhibited tumor growth by inducing apoptosis and upregulated the expression of TIMP-2 and down-regulated the level of MMP-2 and MMP-9. In conclusion, RPS is a potent anticancer agent that elicits programmed cell death and inhibits metastases in murine lung adenocarcinoma in vivo.


Subject(s)
Adenocarcinoma/secondary , Antineoplastic Agents/pharmacology , Araceae/chemistry , Drugs, Chinese Herbal/pharmacology , Lung Neoplasms/pathology , Rhizome/chemistry , Saponins/pharmacology , Adenocarcinoma/metabolism , Animals , Antineoplastic Agents/chemistry , Apoptosis , Cell Line, Tumor , Drugs, Chinese Herbal/chemistry , Female , Lung Neoplasms/metabolism , Male , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/metabolism , Matrix Metalloproteinase Inhibitors , Mice , Saponins/chemistry , Tissue Inhibitor of Metalloproteinase-2/agonists , Tissue Inhibitor of Metalloproteinase-2/metabolism , Xenograft Model Antitumor Assays
17.
Anal Bioanal Chem ; 395(2): 495-505, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19657632

ABSTRACT

Rhizoma Paridis saponins are bioactive steroidal saponins derived from Paris polyphylla. Optimization of the ionization process was performed with electrospray ionization tandem mass spectrometry in both positive and negative-ion modes. Negative-ion ESI was adopted for generation of the precursor deprotonated molecules to achieve the best ionization sensitivity for the analytes. Positive ionization was used to choose the most abundant fragment ion. Furthermore, according to the characteristic fragmentation behavior of known steroidal saponins isolated from this plant (polyphyllin D, formosanin C, gracillin, Paris H, Paris VII, and dioscin), 23 constituents were structurally characterized on the basis of their retention time and ESI analyses, including four pairs of naturally occurring isomers. Five of these 23 constituents were new compounds. The analytical method of LC-MS(n) in positive and negative-ion modes has been developed for the direct structural elucidation of steroid saponins of this kind in plant extracts.


Subject(s)
Chromatography, High Pressure Liquid/methods , Drugs, Chinese Herbal/analysis , Magnoliopsida/chemistry , Saponins/analysis , Spectrometry, Mass, Electrospray Ionization/methods , Molecular Structure , Plant Roots/chemistry , Tandem Mass Spectrometry/methods
18.
Clin Exp Metastasis ; 25(8): 855-64, 2008.
Article in English | MEDLINE | ID: mdl-18766303

ABSTRACT

Cyclophosphamide (CTX), as a common use of chemotherapeutic agent, has some side effects in clinical treatment. In our experiments, we studied CTX-treated T739 mice using histopathology, immunohistochemistry, reverse transcription polymerase chain reaction and Western blot for markers of proliferation, angiogenesis, tumor progression and distant metastasis. As a result, CTX increased the number and area of metastases and tumor embolus in lungs by effecting on the expression of matrix metalloproteinase-2, intercellular adhesion molecule-1 and tissue inhibitor of metalloproteinase-2. Taken together, it indicated that CTX enhanced the process of pulmonary metastasis by the synergistic effect of matrix-degrading proteases and adhesion proteins.


Subject(s)
Adenocarcinoma/etiology , Antineoplastic Agents, Alkylating/adverse effects , Cyclophosphamide/adverse effects , Lung Neoplasms/etiology , Neoplasms, Second Primary/etiology , Adenocarcinoma/metabolism , Animals , Blotting, Western , Female , Immunoenzyme Techniques , Intercellular Adhesion Molecule-1/genetics , Intercellular Adhesion Molecule-1/metabolism , Lung Neoplasms/metabolism , Male , Matrix Metalloproteinase 2/genetics , Matrix Metalloproteinase 2/metabolism , Mice , Neoplasms, Second Primary/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Spleen/cytology , Spleen/drug effects , Spleen/metabolism , Tissue Inhibitor of Metalloproteinase-2/genetics , Tissue Inhibitor of Metalloproteinase-2/metabolism , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/metabolism
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