Mechanical stress can regulate temporomandibular joint cavitation via signalling pathways

The temporomandibular joint (TMJ), composed of temporal fossa, mandibular condyle and a fibrocartilage disc with upper and lower cavities, is the biggest synovial joint and biomechanical hinge of the craniomaxillofacial musculoskeletal system. The initial events that give rise to TMJ cavities across diverse species are not fully understood. Most studies focus on the pivotal role of molecules such as Indian hedgehog (Ihh) and hyaluronic acid (HA) in TMJ cavitation. Although biologists have observed that mechanical stress plays an irreplaceable role in the development of biological tissues and organs, few studies have been concerned with how mechanical stress regulates TMJ cavitation. Based on the evidence from human or other animal embryos today, it is implicated that mechanical stress plays an essential role in TMJ cavitation. In this review, we discuss the relationship between mechanical stress and TMJ cavitation from evo-devo perspectives and review the clinical features and potential pathogenesis of TMJ dysplasia.

Systematic analysis of prophages carried by Porphyromonas gingivalis

To systematically investigate the prophages carrying in Porphyromonas gingivalis (P. gingivalis) strains, analyze potential antibiotic resistance genes (ARGs) and virulence genes in these prophages. We collected 90 whole genome sequences of P. gingivalis from NCBI and utilized the Prophage Hunter online software to predict prophages; Comprehensive antibiotic research database (CARD) and virulence factors database (VFDB) were adopted to analyze the ARGs and virulence factors (VFs) carried by the prophages. Sixty-nine prophages were identified among 24/90 P. gingivalis strains, including 17 active prophages (18.9%) and 52 ambiguous prophages (57.8%). The proportion of prophages carried by each P. gingivalis genome ranged from 0.5% to 6.7%. A total of 188 antibiotic resistance genes belonging to 25 phenotypes and 46 different families with six mechanisms of antibiotic resistance were identified in the 17 active prophages. Three active prophages encoded 4 virulence genes belonging to type III and type VI secretion systems. The potential hosts of these virulence genes included Escherichia coli, Shigella sonnei, Salmonella typhi, and Klebsiella pneumoniae. In conclusion, 26.7% P. gingivalis strains carry prophages, while the proportion of prophage genes in the P. gingivalis genome is relatively low. In addition, approximately 39.7% of the P. gingivalis prophage genes have ARGs identified, mainly against streptogramin, peptides, and aminoglycosides. Only a few prophages carry virulence genes. Prophages may play an important role in the acquisition, dissemination of antibiotic resistance genes, and pathogenicity evolution in P. gingivalis.

Comparison of temporomandibular joint disc, meniscus, and intervertebral disc in fundamental characteristics and tissue engineering

The temporomandibular joint (TMJ) disc, meniscus and intervertebral disc (IVD) are three fibrocartilage discs, which play critical roles in our daily life. Their degeneration contributes to diseases such as TMJ disorders, osteoarthritis and degenerative disc disease, affecting patients' quality of life and causing substantial morbidity and mortality. Interestingly, similar in some aspects of fundamental characteristics, they exhibit differences in other aspects such as biomechanical properties. Highlighting these similarities and differences can not only benefit a comprehensive understanding of them and their pathology but also assist in future research of tissue engineering. Likewise, comparing their tissue engineering in cell sources, scaffold and stimuli can guide imitation and improvement of their engineered discs. However, the anatomical structure, function, and biomechanical characteristics of the IVD, TMJ, and Meniscus have not been compared in any meaningful depth needed to advance current tissue engineering research on these joints, resulting in incomplete understanding of them and their pathology and ultimately limiting future research of tissue engineering. This review, for the first time, comprehensively compares three fibrocartilage discs in those aspects to cast light on their similarities and differences.

Robust reduced-rank regression

In high-dimensional multivariate regression problems, enforcing low rank in the coefficient matrix offers effective dimension reduction, which greatly facilitates parameter estimation and model interpretation. However, commonly used reduced-rank methods are sensitive to data corruption, as the low-rank dependence structure between response variables and predictors is easily distorted by outliers. We propose a robust reduced-rank regression approach for joint modelling and outlier detection. The problem is formulated as a regularized multivariate regression with a sparse mean-shift parameterization, which generalizes and unifies some popular robust multivariate methods. An efficient thresholding-based iterative procedure is developed for optimization. We show that the algorithm is guaranteed to converge and that the coordinatewise minimum point produced is statistically accurate under regularity conditions. Our theoretical investigations focus on non-asymptotic robust analysis, demonstrating that joint rank reduction and outlier detection leads to improved prediction accuracy. In particular, we show that redescending ψ-functions can essentially attain the minimax optimal error rate, and in some less challenging problems convex regularization guarantees the same low error rate. The performance of the proposed method is examined through simulation studies and real-data examples.

Effects of graded levels of microbial phytase on apparent total tract digestibility of calcium and phosphorus and standardized total tract digestibility of phosphorus in four sources of canola meal and in soybean meal fed to growing pigs

One hundred twenty pigs were used to determine effects of graded levels of microbial phytase on the apparent total tract digestibility (ATTD) of P and Ca and the standardized total tract digestibility (STTD) of P in 4 sources of canola meal and in 1 source of soybean meal (SBM) fed to growing pigs. The 4 sources of canola meal were produced from 1 source of high-protein canola seeds and 2 sources of conventional canola seeds with 1 of the conventional canola seeds being divided into 2 separate batches before crushing. Pigs (16.2 ± 5.3 kg initial BW) were individually housed in metabolism crates and were randomly allotted to 1 of 20 diets in a 5 × 4 factorial arrangement of treatments with 5 ingredients and 4 levels of phytase. There were 6 replicate pigs per diet. Five basal diets based on high-protein canola meal (CM-HP), high-temperature processed canola meal (CM-HT), low-temperature processed canola meal (CM-LT), conventional canola meal (CM-CV), or SBM were formulated. The basal diets contained no phytase. Fifteen additional diets were prepared by adding approximately 500, 1,500, or 2,500 phytase units/kg to each of the 5 basal diets. Feces were quantitatively collected for 5 d based on the marker-to-marker approach after a 7-d adaptation period. Results indicated that supplementation of microbial phytase increased (linear, < 0.05) the ATTD of Ca in diets containing CM-HP, CM-HT, CM-CV, and SBM but not in diets containing CM-LT. Microbial phytase also increased (linear and quadratic, < 0.05) the ATTD and STTD of P in all 5 ingredients. Compared with the CM-CV diets, the CM-HP diets had greater ( < 0.05) ATTD of Ca. The ATTD of Ca in the SBM diet was greater ( < 0.05) than in all canola meal diets, but no differences were observed in ATTD of Ca between CM-HT and CM-LT diets. The ATTD and the STTD of P were less ( < 0.05) in CM-HP, CM-HT, CM-LT, or CM-CV than in SBM if no microbial phytase was added, but no differences were observed in the ATTD and STTD of P in SBM, CM-HP, CM-HT, or CM-CV if the highest amount of phytase were added (interaction, < 0.05). Regression equations were developed to calculate the response to microbial phytase on the STTD of P in CM-HP, CM-HT, CM-LT, CM-CV, and SBM. In conclusion, inclusion of graded levels of microbial phytase increased the ATTD and STTD of P in CM-HP, CM-HT, CM-LT, CM-CV, and SBM and the response to microbial phytase added to each ingredient can be predicted by regression equations.

Ghrelin to obestatin ratio in maternal serum in pregnancies complicated by intrauterine growth restriction

Ghrelin, an endogenous for the growth hormone secretagogue receptor, has been shown to participate in fetal growth. Obestatin, encoded by the same gene as ghrelin, is described as a physiological opponent of ghrelin. This study was designed to determine the changes of ghrelin/obestatin ratio in maternal serum in pregnancies with intrauterine growth restriction (IUGR). The authors found that the ghrelin levels in maternal serum were significent lower in IUGR group than in control group (236.34 ± 14.58 pg/ml vs. 321.49 ± 18.19 pg/ml, p = 0.003). However, the difference of obestatin levels in maternal serum in IUGR group than in control group was not significent (276.25, ±20.54 pg/ml vs. 256.34 ± 21.21 pg/ml, p = 0.308). The ratio of ghrelin to obestatin in maternal serum were significent lower in UGR group than in control group (1.05 ± 0.09 vs. 0.82 ± 0.08, p = 0.03). Meanwhile, the maternal serum growth hormone (GH) concentration in IUGR group was lower than that in control group (1.08 ± 0.08 pg/ml vs. 1.41 ± 0.09 pg/ml, p = 0.009), and the maternal serum pla- cental growth hormone (PGH) concentration in IUGR group was lower than that in control group (2.21 ± 1.24 pg/ml vs. 2.92 ± 0.27 pg/ml,p = 0.031). The ratio of ghrelin to obestatin in maternal serum were positively correlation with GH and PGH concentrations in IUGR group (r = 0.876, p = 0.52; r = 0.764, p = 0.64). The findings of this study suggest that the ratio of ghrelin to obestatin in maternal serum were low, and were positively correlated with GH and PGH concentration in IUGR group, which can been considered as evidencees of ghrelin/obestatin balance disorder role in pathogenesis of IUGR.

[Effects of anti-PD-L1 monoclonal antibody and EGFR-TKI on the expression of PD-L1 and function of T lymphocytes in EGFR-mutated lung cancer cells]

Objective: To investigate the effects of anti-PD-L1 monoclonal antibody and EGFR-TKI on expression of soluble PD-L1 and function of T lymphocytes in EGFR-mutated lung cancer cells. Methods: Flow cytometry was used to analyze the expression of membrane PD-LI. ELISA was performed to detect the level of sPD-L1 in the supernatant of cultured EGFR-mutated and wild type lung cancer cells before and after erlotinib treatment.After treated with anti-PD-L1 monoclonal antibody alone and in combination with erlotinib, the proliferation of T lymphocytes in co-culture system was measured using Cell Counting Kit-8 (CCK-8) assay. The expression levels of PD-LI and IFN-γ in tumor cells and T lymphocytes treated with erlotinib in co-culture system were analyzed by flow cytometry and ELISA, respectively. Results: PD-L1 was highly expressed in EGFR-mutated lung cancer PC9 cells (78.7±3.1)% and HCC827 cells (82.7±2.6)%.After treated with erlotinib, the expression rates of membrane PD-L1 in PC9 and HCC827 cells were down-regulated (64.7%±3.1% and 73.0%±2.6%, respectively), significantly lower than that in the two cell lines without erlotinib treatment (P<0.05), and the expression levels of sPD-L1 in the supernatant of PC9 and HCC827 cells were also down-regulated (0.680±0.120)ng/ml and (0.903±0.047)ng/ml, respectively, significantly lower than that in the two cell lines without erlotinib treatment (P<0.01). However, no significant changes of membrane PD-L1 and sPD-L1 expression were found in EGFR wild type lung cancer cells (H1299 and A549) before and after erlotinib treatment. In the co-culture system composed of T cells and EGFR-mutated lung cancer cells, treatment with erlotinib alone promoted the proliferation of T lymphocytes (P<0.05), and combined treatment of anti-PD-L1 monoclonal antibody with erlotinib had a stronger effect (P<0.05). In the co-culture system composed of T cells and EGFR wild type cell lines, the proliferation of T cells was not changed after using erlotinib alone or combination of erlotinib and anti-PD-L1 monoclonal antibody (P>0.05). Before and after treatment with erlotinib, the secretion levels of IFN-γ were (856.0±70.3)pg/ml and (1 697.3±161.0)pg/ml, respectively, showing a significant difference (P<0.001). The expression rates of membrane PD-L1 were (76.2±0.5)% and (50.9±0.9)%, respectively, also showing a significant difference (P<0.001). However, no significant changes in the expression of IFN-γ and membrane PD-L1 were found in the co-culture system composed of T cells and A549 cells. Conclusions: Anti-PD-L1 monoclonal antibody combined with EGFR-TKI can effectively promote the proliferation and secretion function of T lymphocytes in the microenvironment of EGFR-mutated lung cancer cells.

Design of water gas shift catalysts for hydrogen production in fuel processors

Low sulfur hydrocarbon fuels can be converted to fuel cell grade H(2) using a compact fuel processor architecture. The necessary high volumetric activity water gas shift (WGS) Pt on ceria-zirconia catalysts reacts CO-rich reformate with steam to yield H(2) and CO(2). Such highly selective, non-pyrophoric noble metal/Ce([1-(x+y)])Zr(x)Dp(y)O(2) catalysts were developed through coordinated atomic modeling, syntheses, structural characterization, kinetic performance tests, and micro-kinetic analyses. Density functional simulations made with the VASP code suggested that the undoped catalyst WGS activity would be limited by the strong binding of CO intermediates, blocking the reoxidation of the reduced oxide by water. These predictions were confirmed by in situ cylindrical internal reflection-Fourier transform infrared spectroscopy and by micro-kinetic analyses of the micro-reactor results. Atomic simulations were used to evaluate the impact transition metal dopants had on the surface chemistry of cubic ceria-zirconia. VASP predicted that acidic transition metal dopants such as Nb, Mo, Ta, and W would increase the oxide surface affinity for water and thus increase the turnover rate of the catalyst. The efficacy of Mo-doped ceria-zirconia compositions was confirmed at lower temperatures in replicated catalyst synthesis-reactor studies.

[Microbiological investigations of high-temperature horizons of the Kongdian petroleum reservoir in connection with field trial of a biotechnology for enhancement of oil recovery]

The physicochemical conditions and microbiological characteristics of the formation waters of the Kongdian bed of the Dagang oil field (China) were studied. It was demonstrated that this bed is a high-temperature ecosystem with formation waters characterized by low mineralization. The concentrations of nitrogen and phosphorus compounds, as well as of electron acceptors, are low. Oil and oil gas are the main organic matter sources. The bed is exploited with water-flooding. The oil stratum was inhabited mostly by anaerobic thermophilic microorganisms, including fermentative (10(2)-10(5) cells/ml), sulfate-reducing (0-10(2) cells/ml), and methanogenic (0-10(3) cells/ml) microorganisms. Aerobic bacteria were detected mainly in the near-bottom zone of injection wells. The rate of sulfate reduction varied from 0.002 to 18.940 microg S(2-) l(-1) day(-1) and the rate of methanogenesis from 0.012 to 16.235 microg CH4 l(-1) day(-1). Microorganisms with great biotechnological potential inhabited the bed. Aerobic thermophilic bacteria were capable of oxidizing oil with the formation of biomass, the products of partial oxidation of oil (volatile acids), and surfactants. During growth on the culture liquid of oiloxidizing bacteria, methanogenic communities produced methane and carbon dioxide, which also had oil-releasing capabilities. Using various labeled tracers, the primary filtration flows of injected solutions at the testing site were studied. Our comprehensive investigations allowed us to conclude that the tested method for microbial enhancement of oil recovery based on the activation of the stratal microflora can be applied in the Kongdian bed horizons.

[Microbiological and production characteristics of the high-temperature Kongdian bed revealed during field trial of biotechnology for the enhancement of oil recovery]

Microbiological technology for the enhancement of oil recovery based on the activation of the stratal microflora was tested in the high-temperature horizons of the Kongdian bed (60 degrees C) of the Dagang oil field (China). This biotechnology consists in the pumping of a water-air mixture and nitrogen and phosphorus mineral salts into the oil stratum through injection wells in order to stimulate the activity of the stratal microflora which produce oil-releasing metabolites. Monitoring of the physicochemical, microbiological, and production characteristics of the test site has revealed large changes in the ecosystem as a result of the application of biotechnology. The cell numbers of thermophilic hydrocarbon-oxidizing, fermentative, sulfate-reducing, and methanogenic microorganisms increased 10-10 000-fold. The rates of methanogenesis and sulfate reduction increased in the near-bottom zone of the injection wells and of some production wells. The microbial oil transformation was accompanied by the accumulation of bicarbonate ions, volatile fatty acids, and biosurfactants in the formation waters, as well as of CH4 and CO2 both in the gas phase and in the oil. Microbial metabolites promoted the additional recovery of oil. As a result of the application of biotechnology, the water content in the production liquid from the test site decreased, and the oil content increased. This allowed the recovery of more than 14000 tons of additional oil over 3.5 years.

Augmentation of apoptosis and tumor regression by flavopiridol in the presence of CPT-11 in Hct116 colon cancer monolayers and xenografts

CPT-11, a DNA topoisomerase I inhibitor, has demonstrated clinical activity in colorectal cancer. Flavopiridol, a cyclin-dependent kinase inhibitor, is rapidly emerging as a chemotherapy modulator. To enhance the therapeutic index of CPT-11 in colon cancer, we studied the combination of these two drugs in relatively resistant human colon cancer cells, Hct116. Exposure of parental Hct116 cells to clinically achievable concentrations of SN-38 (the active metabolite of CPT-11) induces p21 and a G(2) arrest. However, these conditions fail to induce apoptosis. In contrast, Hct116 cells that are p21 deficient (p21-/- Hct116) readily undergo apoptosis after treatment with SN-38. In this study we show that the parental Hct116 cells can be sensitized to undergo apoptosis by the addition of flavopiridol after SN-38 treatment. The induction of apoptosis was greatest with sequential therapy consisting of SN-38 followed by flavopiridol. Clonogenic assays also showed greatest inhibition with this sequence. Sequential treatment with SN-38 followed by flavopiridol was associated with higher activation of caspase-3 and greater cleavage of both p21 and XIAP, an inhibitor of apoptosis, compared with other treatment schedules. CPT-11 induced some tumor regressions but no complete responses in the p21-intact Hct116 xenografts. CPT-11 with flavopiridol more than doubled tumor regression, compared with CPT-11 alone, and produced a 30% complete response rate. Our studies indicate that CPT-11 induces cell cycle arrest rather than cell death and that flavopiridol, by activating the caspase cascade, cleaves the inhibitors of apoptosis and sensitizes the cells to undergo cell death. Thus, flavopiridol combined with CPT-11 may provide a completely new therapeutic approach in the treatment of colon cancer.

Experimental therapeutics with a new 10-deazaaminopterin in human mesothelioma: further improving efficacy through structural design, pharmacologic modulation at the level of MRP ATPases, and combined therapy with platinums

Studies described here sought to evaluate the therapeutic potential of a new 10-deazaaminopterin analogue, 10-propargyl-10-deazaaminopterin (PDX), alone and in combination with platinum compounds in the treatment of human pleural mesothelioma. In vitro studies documented 25-30-fold and 3-fold, respectively, greater cytotoxic potency of PDX compared with methotrexate and another 10-deazaaminopterin, edatrexate, against VAMT-1 and JMN cell lines derived from human mesothelioma. These tumor cell lines were also inhibited by platinum compounds. Cisplatin (CDDP) was somewhat more inhibitory than oxaloplatin and >1 log order in magnitude more inhibitory than carboplatin (CBCDA). Against the JMN tumor xenografted in nude mice, whereas methotrexate and, more so, edatrexate, were potently growth inhibitory, only PDX brought about substantial regression. By comparison, CDDP and CBCDA, but not oxaloplatin were markedly growth inhibitory to this same tumor in vivo. This high level of therapeutic activity of PDX could be additionally enhanced by coadministration of probenecid, an inhibitor of canicular multispecific organic anion transporter/multidrug resistance-related protein (MRP)-like ATPases, which increased the number of complete regressions by >-3 fold. Canicular multispecific organic anion transporter/MRP genes, primarily 1, 3, 4, 5, and 7, were in fact expressed in these human mesothelioma cell lines as determined by real-time reverse transcription-PCR. These same MRP genes, including, to a lesser extent, MRP-4, were also expressed in pleural mesotheliomas derived from patients as shown by the same methodology. When combined with CDDP or CBCDA, PDX achieved 2-fold greater overall regression of the JMN tumor with a 3-4-fold increase in complete regressions, although some attenuation of dosages of each were required in the combination. These results strongly suggest that PDX has significant potential in the treatment of human pleural mesothelioma, particularly when coadministered with probenecid or combined with platinum compounds.

[A pathological comparison between Hirschsprung's enterocolitis and neonate necrotizing enterocolitis]

Autopsy records of 9 cases of neonate Hirschsprung's enterocolitis (HD) and 16 cases of neonate necrotizing enterocolitis (NEC) were analysed. It was found that the NEC lesions were more extensive than HD lesions, the bleeding and inflammation in NEC were also more serious than in HD. From our 21 animal experiments in which we tried to clarify the pathogenesis of Hirschsprung's enterocolitis and NEC, our preliminary hypothesis fro the development of Hirschsprung's enterocolitis being: the distal segment was first obstructed, causing the proximal segment to expand, the increase of pressure within the bowel resulted in ischemia of the intestines, increased bacterial multiplication in the retained feces and bacterial infiltration of the intestinal mucosa. The above being the major cause of HD. When the neonate is in asphyxia or shock, ischemia of the intestines and immunoallergic reactions occur, due to the lack of IgA in the mucosa, the multiplication and infiltration of pathogenic enterobacteria in the intestinal wall results in NEC.