Quantitative Calcium Analysis Research Articles

Impact of Extracellular Matrix Injury on the Calcification of Artificial Bovine Pericardial Leaflets: An Experimental Study.

To investigate the role of extracellular matrix (ECM) injury in bioprosthetic valve calcification, we constructed an ECM damage model by applying a 15 N stress to the bovine pericardium sample in both transverse and longitudinal directions after tissue cross-linking, whereas no stress was applied in the control group. Then we implanted two pieces of bovine pericardium on both sides of the dorsal midline in Wistar rats from both groups and measured the calcium content of the implanted bovine pericardium. The results showed that the calcium content of experimental group was significantly higher than that of control group (p < 0.05). Second, we implanted prosthetic valves made from bovine pericardium in the experimental and control groups into small-tailed Han sheep (Ovis aries). After 180 days, the prosthetic valve was removed for gross and histopathological observation as well as quantitative analysis of calcium. We found a higher average calcium content in bovine pericardium from the experimental group than that from controls. Furthermore, calcium salt deposition was detected on the ventricular surface of valves along with roughened valve leaflets in the experimental group. Our data support the hypothesis that the bovine pericardium with ECM injury is more prone to calcification.

A brief review of various analytical methodologies for quantitative analysis of telmisartan and rosuvastatin calcium in different matrices.

A brief review of various analytical methodologies for quantitative analysis of telmisartan and rosuvastatin calcium in different matrices.

Rapid quantitative analysis of calcium in infant formula powder assisted by long short-term memory with variable importance using laser-induced breakdown spectroscopy.

Calcium is the main mineral responsible for healthy bone growth in infants. Laser-induced breakdown spectroscopy (LIBS) was combined with a variable importance-based long short-term memory (VI-LSTM) for the quantitative analysis of calcium in infant formula powder. First, the full spectra were used to establish PLS (partial least squares) and LSTM models. The R2 and root-mean-square error (RMSE) of the test set (R P2 and R M S E P) were 0.1460 and 0.0093 in the PLS method, respectively, and 0.1454 and 0.0091 in the LSTM model, respectively. To improve the quantitative performance, variable selection based on variable importance was introduced to evaluate the contribution of input variables. The variable importance-based PLS (VI-PLS) model had R P2 and R M S E P of 0.1454 and 0.0091, respectively, whereas the VI-LSTM model had R P2 and R M S E P of 0.9845 and 0.0037, respectively. Compared with the LSTM model, the number of input variables in the VI-LSTM model was reduced to 276, R P2 was improved by 114.63%, and R M S E P was reduced by 46.38%. The mean relative error of the VI-LSTM model was 3.33%. We confirm the predictive ability of the VI-LSTM model for the calcium element in infant formula powder. Thus, combining VI-LSTM modeling and LIBS has great potential for the quantitative elemental analysis of dairy products.

Determination Of Macro Mineral Content In Fresh Noni Fruit (Morinda Citrifolia L.) By Atomic Absorption Spectrophotometry

This study aims to determine the levels of macro minerals such as potassium, calcium, sodium, and magnesium in fresh noni fruit. The sample of noni fruit was destructed, then quantitative analysis of potassium, calcium, sodium, and magnesium were performed using atomic absorption spectrophotometry (AAS) at a wavelength 766.5 nm for potassium; 422.7 nm for calcium; 589.0 nm for sodium; and 285.2 nm for magnesium. The advantages of this method are selective and sensitive. The average % recoveries were obtained in 109.7 % for potassium; 96.4 % for calcium; 99.7 % for sodium; and 92.4 % for magnesium. This method is very suitable for determining mineral content in fruit as shown in the recovery results and in accordance with the validation requirements.

Stability Indicating RP-HPLC-DAD Method For Simultaneous Estimation of Atorvastatin Calcium and Teneligliptin Hydrobromide Hydrate in Synthetic Mixture

RP-HPLC stability indicating specific, precise, accurate, cost-effective and isocratic method was developed and validated for quantitative analysis of Atorvastatin calcium and Teneligliptin hydrobromide hydrate in synthetic mixture with presence of its degradants. Separation was achieved by using Gemini, C18, using mobile phase composition [Methanol: 20 mM Ammonium acetate (70:30 v/v)] using a flow rate of 1.0 ml/min, injection volume 10µl with UV detection at 245 nm. Atorvastatin calcium and Teneligliptin hydrobromide hydrate were eluted with retention time 7.47min and 4.74min respectively. This method was validated as per ICH guideline Q2(R1). The calibration plots were over the concentration range of 10-100 μg/ml and 5-50 μg/ml for Atorvastatin calcium and Teneligliptin hydrobromide hydrate with correlation coefficient 1 and 0.9999 respectively. Percentage recovery was obtained between 98.00-100.51 % and 98.90-100.7 % for Atorvastatin calcium and Teneligliptin hydrobromide hydrate respectively. In case of Precision, Repeatability and Robustness RSD should be found less than 2. LOD were found to be 1.22 μg/ml and 0.54 μg/ml and LOQ were found to be 3.70 μg/ml and 1.64 μg/ml for Atorvastatin calcium and Teneligliptin hydrobromide hydrate respectively. The results showed that the developed method is appropriate for the routine analysis of Atorvastatin calcium and Teneligliptin hydrobromide hydrate in a synthetic mixture in presence of its degradants.

Determination of Iron Content, Potassium, Calcium, and Sodium In Chinese Date Fruit (Ziziphus Jujuba Miller.) Fresh and Boiled In Atomic Adsorption Spectrophotometry

Chinese dates fruit are generally used by the people of Indonesia as a fruit that has a fairly good nutritional value, namely every 100 g of Chinese dates fruit contain 79 kcal of energy, 1.2 g protein, 20.23 g carbohydrates, 250 mg potassium, 21 mg calcium, 23 mg. phosphorus, 0.5 mg iron, 3 mg sodium, 10 mg magnesium, 0.1 vitamin B6 and 69 mg vitamin C. Chinese dates fruit are foods that are rich in fiber, so they can lower blood cholesterol and cure chronic constipation. In addition, Chinese dates fruit are foods with good sources of potassium. Adequate potassium intake can lower blood pressure so that it can reduce the risk of cardiovascular disease. High iron content can also prevent anemia. The purpose of this study was to determine the differences in the content of iron, potassium, calcium, and sodium in fresh and boiled Chinese dates fruit fruit, and to determine the percentage decrease in levels after boiling.&#x0D; The method used in this study included dry digestion, then quantitative analysis of iron, potassium, calcium, and sodium was carried out using the Atomic Absorption Spectrophotometry (AAS) method, namely iron at a wavelength of 248.3 nm, for potassium 766.5 nm, to calcium 422.7 nm, and sodium 589.0 nm.&#x0D; The results showed that the iron content in fresh Chinese dates fruit fruit was (0.6687 ± 0.0084) mg/100 g and boiled (0.3285 ± 0.0127) mg/100 g. Potassium levels in fresh Chinese dates fruit fruit (657.9024 ± 0.4713) mg/100 g and boiled (158.6504 ± 0.2510) mg/100 g. Calcium levels in fresh Chinese dates fruit fruit were (47.3501 ± 1.1630) mg/100 g and boiled (26.3968 ± 0.5922) mg/100 g, and sodium levels in fresh Chinese dates fruit fruit (16.1272 ± 0.1543) mg/100 g and boiled at (13.4048 ± 0.1973) mg/100 g. The percentage decrease in mineral content in Chinese dates fruit fruit after boiling, for iron was 50.87%, potassium 75.88%, calcium 44.25%; and 16.88% sodium.&#x0D; Statistically different test of the average mineral levels of iron, potassium, calcium, and sodium using the T distribution, it can be concluded that fresh Chinese dates fruit fruit contain higher levels of iron, potassium, calcium, and sodium minerals than boiled Chinese dates fruit.&#x0D;

The cannabinoid receptor I (CB1) enhanced the osteogenic differentiation of BMSCs by rescue impaired mitochondrial metabolism function under inflammatory condition

BackgroundPeriodontitis is a chronic infectious disease leading to bone resorption and periodontal tissue disruption under inflammatory stimulation. The osteogenic differentiation ability of mesenchymal stem cells (MSCs) is impaired under the inflammatory environment, which limits the effect of treatment. The cannabinoid receptor I (CB1) is the main effector of the endogenous cannabinoid system (ECS), and our previous study verified that CB1 could enhance the osteo/dentinogenic differentiation of dental MSCs, which might be a target for alveolar bone regeneration. However, the effect of CB1 on the osteogenic differentiation of MSCs derived from bone remains unknown. In present study, we investigated the role and mechanism of CB1 on mitochondrial function and osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) under inflammatory environment.MethodsAlkaline phosphatase (ALP) activity, alizarin red staining, quantitative calcium analysis, and osteogenic markers were used to detect the osteogenic differentiation ability of BMSCs. Real-time RT-PCR and Western blot were used to detect the gene expression. Seahorse Cell Mito Stress Test was used to detect the oxygen consumption rate (OCR). JC-10 assay was used to determine the mitochondrial membrane potential (MMP).ResultsCB1 increased osteogenic differentiation potential and mitochondrial energy metabolism, including the OCR, MMP, and enhanced the expressions of Nrf1 and Nrf2 in hBMSCs without or with TNF-α or INF-γ stimulation. Then, the inhibitor of mitochondrial electron transport chain (ETC), rotenone (ROT), inhibited the osteogenic differentiation in hBMSCs, and CB1 could rescue ROT impaired osteogenic differentiation potentials of hBMSCs without or with TNF-α or INF-γ stimulation. Activation of ETC by Coenzyme Q10 (CoQ10) could restore the impaired osteogenic differentiation of hBMSCs by depletion of CB1 without or with TNF-α or INF-γ stimulation. Mechanismly, CB1 could activate the JNK signaling pathway, p38 MAPK signaling pathway, and inhibit the Erk1/2 signaling pathway.ConclusionsThe activating of CB1 enhanced the osteogenic differentiation by rescuing the mitochondrial metabolism function in hBMSCs under the inflammatory environment, suggesting that CB1 is a potential target for enhancing bone regeneration under the inflammatory environment.

Repopulation of decellularised porcine pulmonary valves in the right ventricular outflow tract of sheep: Role of macrophages

The primary objective was to evaluate performance of low concentration SDS decellularised porcine pulmonary roots in the right ventricular outflow tract of juvenile sheep. Secondary objectives were to explore the cellular population of the roots over time. Animals were monitored by echocardiography and roots explanted at 1, 3, 6 (n = 4) and 12 months (n = 8) for gross analysis. Explanted roots were subject to histological, immunohistochemical and quantitative calcium analysis (n = 4 at 1, 3 and 12 months) and determination of material properties (n = 4; 12 months). Cryopreserved ovine pulmonary root allografts (n = 4) implanted for 12 months, and non-implanted cellular ovine roots were analysed for comparative purposes. Decellularised porcine pulmonary roots functioned well and were in very good condition with soft, thin and pliable leaflets. Morphometric analysis showed cellular population by 1 month. However, by 12 months the total number of cells was less than 50% of the total cells in non-implanted native ovine roots. Repopulation of the decellularised porcine tissues with stromal (α-SMA+; vimentin+) and progenitor cells (CD34+; CD271+) appeared to be orchestrated by macrophages (MAC 387+/ CD163low and CD163+/MAC 387−). The calcium content of the decellularised porcine pulmonary root tissues increased over the 12-month period but remained low (except suture points) at 401 ppm (wet weight) or below. The material properties of the decellularised porcine pulmonary root wall were unchanged compared to pre-implantation. There were some changes in the leaflets but importantly, the porcine tissues did not become stiffer. The decellularised porcine pulmonary roots showed good functional performance in vivo and were repopulated with ovine cells of the appropriate phenotype in a process orchestrated by M2 macrophages, highlighting the importance of these cells in the constructive tissue remodelling of cardiac root tissues.

FDA approved L-type channel blocker Nifedipine reduces cell death in hypoxic A549 cells through modulation of mitochondrial calcium and superoxide generation

As hypoxia is a major driver for the pathophysiology of COVID-19, it is crucial to characterize the hypoxic response at the cellular and molecular levels. In order to augment drug repurposing with the identification of appropriate molecular targets, investigations on therapeutics preventing hypoxic cell damage is required. In this work, we propose a hypoxia model based on alveolar lung epithelial cells line using chemical inducer, CoCl2 that can be used for testing calcium channel blockers (CCBs). Since recent studies suggested that CCBs may reduce the infectivity of SARS-Cov-2, we specifically select FDA approved calcium channel blocker, nifedipine for the study. First, we examined hypoxia-induced cell morphology and found a significant increase in cytosolic calcium levels, mitochondrial calcium overload as well as ROS production in hypoxic A549 cells. Secondly, we demonstrate the protective behaviour of nifedipine for cells that are already subjected to hypoxia through measurement of cell viability as well as 4D imaging of cellular morphology and nuclear condensation. Thirdly, we show that the protective effect of nifedipine is achieved through the reduction of cytosolic calcium, mitochondrial calcium, and ROS generation. Overall, we outline a framework for quantitative analysis of mitochondrial calcium and ROS using 3D imaging in laser scanning confocal microscopy and the open-source image analysis platform ImageJ. The proposed pipeline was used to visualize mitochondrial calcium and ROS level in individual cells that provide an understanding of molecular targets. Our findings suggest that the therapeutic value of nifedipine may potentially be evaluated in the context of COVID-19 therapeutic trials.

Depletion of EREG enhances the osteo/dentinogenic differentiation ability of dental pulp stem cells via the p38 MAPK and Erk pathways in an inflammatory microenvironment

BackgroundEpiregulin (EREG) is an important component of EGF and was demonstrated to promote the osteo/dentinogenic differentiation of stem cells from dental apical papilla (SCAPs). Whether EREG can stimulate the osteo/dentinogenic differentiation of dental pulp stem cells (DPSCs) in inflammatory environment is not clear. The purpose of the present study is to investigate the role of EREG on the osteo/dentinogenic differentiation ability of DPSCs in inflammatory environment.MethodsDPSCs were isolated from human third molars. Short hairpin RNAs (shRNAs) were used to knock down EREG expression in DPSCs. Recombinant human EREG (rhEREG) protein was used in the rescue experiment. TNF-α was employed to mimic the inflammatory environment in vitro. Alkaline phosphatase (ALP) staining, Alizarin red staining, quantitative calcium analysis, and real-time RT-PCR were performed to detect osteo/dentinogenic differentiation markers and related signalling pathways under normal and inflammatory conditions.ResultsEREG depletion promoted the ALP activity and mineralization ability of DPSCs. The expression of BSP, DMP-1, and DSPP was also enhanced. Moreover, 50 ng/mL rhEREG treatment decreased the osteo/dentinogenic differentiation potential of DPSCs, while treatment with 10 ng/mL TNF-α for 4 h increased the expression of EREG in DPSCs. Conversely, EREG knockdown rescued the impaired osteo/dentinogenic differentiation ability caused by TNF-α treatment. Further mechanistic studies showed that EREG depletion activated the p38 MAPK and Erk signalling pathways in DPSCs under normal and inflammatory conditions.ConclusionsOur results demonstrated that EREG could inhibit the osteo/dentinogenic differentiation potential of DPSCs via the p38 MAPK and Erk signalling pathways. Under inflammatory environment, EREG depletion enhanced osteo/dentinogenic differentiation potential of DPSCs by improving the expression of p-p38 MAPK and p-Erk.

Pleiotrophin attenuates the senescence of dental pulp stem cells.

Pleiotrophin (PTN), a secreted extracellular matrix-associated protein, plays an important role in regulating the osteo/dentinogenic differentiation potential of dental pulp stem cells (DPSCs). Our previous study has demonstrated that PTN expression in young DPSCs was is 10-fold higher than that in aged DPSCs. However, the role of PTN on the in maintaining the stemness of senescent DPSCs remains unclear. The present study aimed to investigate the effect of PTN on senescent DPSCs in vitro. Dental pulp stem cells were isolated from human third molars. PTN was knocked down using short hairpin RNAs to study the role of PTN on the senescence of DPSCs. DPSCs with aging performance were obtained by a replicative senescence cell model was obtained by the long-term culture of DPSCs to the 15th passage in vitro (P15). We then investigated the effect of PTN on senescent DPSCs (P15 DPSCs). Real-time RT-PCR, western blotting, alizarin red staining, quantitative calcium analysis, SA-β-Gal staining, CFSE, and cell-counting kit-8 (CCK8) assays were used to study cellular senescence and function. The depletion of PTN increased the ratio of SA-β-gal-positive cells, upregulated the expression of p16, and down-regulated the expression of TERT and p-p38. Furthermore, 50pg/ml of PTN recombinant protein rescued these changes the altered ratio of SA-β-gal-positive cells, decreased the expression of p16, enhanced TERT and p-p38 expression, as well as telomere activity, caused by PTN depletion and long-term culture. The15th passage cells displayed typical aging characteristic, including high ratio of SA-β-gal-positive cells, increased aging-related gene expression, decreased proliferation rate, high level of Cyclin D expression, and impaired osteo/dentinogenic differentiation potential. However, 50pg/ml of PTN recombinant protein could partially reverse these alteration rescue these changes. The present study demonstrated that PTN could protect DPSCs from senescence by improving the proliferation and osteo/dentinogenic differentiation ability, probably through the p38 MAPK pathway.

Determination of Pitavastatin Calcium by Analytical Spectrophotometry

Simple and rapid spectrophotometric method for the quantitative analysis of Pitavastatin calcium (PTV) in raw material and tablets pharmaceutical formulation has been described. The method is based on the formation of yellow ion-pair complex between Pitavastatin calcium and Bromocresol purple (BCP) in chloroform medium. Different parameters affecting the reaction such as: effect of solvents, stability, reagent concentration, correlation ratio, etc. were optimized. The formed complex was quantified spectrophotometrically at absorption maximum 405 nm. Linearity range was 2.20 - 35.23 µg/mL, regression analysis showed a good correlation coefficient R2 = 0.9991. The limit of detection (LOD) and limit of quantification (LOQ) were to be 0.367 µg/mL and 1.112 µg/mL respectively. The average percent recovery was found to be (100.62 – 101.14) % for Pitavastatin Calcium. This study was applied on Syrian pharmaceutical trademark: (PAVACRIUM 4 &amp; Londalop). The method was successfully applied for the determination of Pitavastatin calcium in tablets pharmaceutical formulation. The proposed method is simple, direct, sensitive and do not require any extraction process. Thus, this method could be readily applicable for the quality control and routine analysis.

SFRP2 enhances dental pulp stem cell-mediated dentin regeneration in rabbit jaw.

Dental tissue-derived mesenchymal stem cell (MSC)-mediated tooth regeneration may be a useful therapeutic tool for repairing tooth loss. However, the low success rate of tooth regeneration restricts its clinical application. Identifying key factors for enhancing dentinogenesis in MSCs is crucial for promoting tooth regeneration. Human dental pulp stem cells (DPSCs) were transfected with retrovirus to obtain SFRP2-over-expressing DPSCs. Alkaline phosphatase (ALP) activity assay, Alizarin red staining, quantitative analysis of calcium, and dentinogenesis-related genes were detected. Additionally, transplantation in a rabbit tooth extraction model was used to explore the role of SFRP2 in dentin regeneration. We found SFRP2 over-expression greatly enhanced ALP activity, and mineralization in DPSCs. Real-time RT-PCR revealed SFRP2 over-expression promoted the expressions of OSX, RUNX2, DSPP, DMP1, and BSP. Moreover, Micro CT analysis showed high-density calcification occurred to a much higher extent in SFRP2 over-expressing group compared to control group in vivo. Additionally, HE staining, immmunohistochemistry staining, and scanning electron microscopy results showed much more dentin-like tissue formed in SFRP2 over-expressing group compared to control group. Our findings revealed SFRP2 is an important regulator that enhances the dentinogenesis of DPSCs and dentin regeneration in the jaw, which may have clinical applications.

Specific Stability Indicating RP-HPLC Photodiode Array Based Method for Estimation of Novel combination Atorvastatin Calcium and Vitamin D3 for the treatment of Hyperlipidaemia

A specific, precise, accurate, robust and cost-effective stability indicating RP-HPLC method was developed and validated for quantitative analysis of atorvastatin calcium and vitamin D3 in tablet dosage form in the presence of its degradants produced under various stress conditions. These drugs were separated by enable C8 column (15 cm x 4.6 mm, 5 μm), utilizing a mobile phase (93 volume of Methanol: Acetonitrile (50:50) containing 1 mL of 0.1 % formic acid was mixed with 7 mL of 20 mM ammonium formate buffer. The pH of the above mixture was adjusted to 4 using 0.1 % formic acid at a flow rate of 0.6 mL/min, injection volume 5 μL with UV detection at 265 nm. Atorvastatin calcium and vitamin D3 were eluted with the retention time of 3.493 and 9.602 min respectively. The calibration plots were over the concentration range of 50-500 μg/mL and 5-50 IU for atorvastatin calcium and vitamin D3 with correlation coefficient 0.9999 and 0.9996 respectively. Accuracy was obtained between 99.735-100.449 % and 99.768-100.516 % for atorvastatin calcium and vitamin D3 respectively. LOD was found to be 0.2633 and 0.0018 μg/mL and LOQ were found to be 0.7978 and 0.0055 μg/mL for atorvastatin calcium and vitamin D3 respectively. The results showed that the developed method is suitable for the analysis of atorvastatin calcium and vitamin D3 in a tablet dosage form in the presence of generated degradants.

Quantitative analysis of calcium and fluorine by high‐sensitivity low‐energy ion scattering: Calcium fluoride

Low‐energy ion scattering (LEIS) probes the atomic composition of the outer surface. Well‐defined reference samples are used for the quantitation. For elements like fluorine and calcium, it is not easy to find suitable, clean, and homogeneous references, since fluorine is a gas and calcium is a very reactive metal. In contrast to surface analytic techniques such as XPS, the extreme surface sensitivity of LEIS makes it difficult to use stable compounds like CaF2 as reference, since these compounds are not homogeneous at the atomic scale. With LEIS, CaF2 is not expected to show an atomic ratio F/Ca = 2.0. Thus, before CaF2 can be used as reference, its atomic surface concentrations have to be determined. Here, 3‐keV He+ scattering by a LiF(001) single crystal, an evaporated layer of Ca, and a Cu foil are used as basic references. High‐purity CaF2 is available in two forms: a single crystal and a powder. For a practical reference, powders are preferred, since if bulk impurities segregate to the surface, they will be dispersed over a large surface area. It is found that both CaF2 (111) and powder have similar F/Ca atomic ratios. This confirms the F termination for both samples. For the powder, the F and Ca signals are reduced by 0.77 ± 0.03 in comparison with those for the single crystal. The atomic sensitivity factors and relative sensitivity factors have been determined for F, Ca, and Cu.

IGFBP5 enhances the dentinogenesis potential of dental pulp stem cells via JNK and ErK signalling pathways.

Dental stem cell transplantation has become a new method for tooth tissue regeneration. However, its molecular mechanism of the dentinogenic differentiation is still unclear, limited its application. Our previous studies found that insulin-like growth factor-binding protein 5 (IGFBP5) can promote the osteogenic differentiation of periodontal ligament stem cells and the regeneration of periodontal tissues. This study aims to clarify the effect and mechanism of IGFBP5 on the dentinogenesis of dental pulp stem cells (DPSCs). Lentiviral IGFBP5 shRNA was used to knock-down of IGFBP5. And recombinant human IGFBP5 protein (rhIGFBP5) was used to treat DPSCs. Alkaline phosphatase (ALP) staining, Alizarin red staining, quantitative calcium analysis, real-time RT-PCR and Western Blot were used to detect dentinogenic differentiation markers and related signalling pathways. Transplantation in nude mice was used to detect the dentin regeneration in vivo. Depletion of IGFBP5 inhibited ALP activity and the mineralisation and reduced the expressions of osteo/dentinogenic differentiation markers BSP, DMP-1 and DSPP in DPSCs. 0.05ng/mL rhIGFBP5 promoted ALP activity, the mineralisation and the expressions of BSP, DMP-1 and DSPP in DPSCs. In addition, 0.05ng/mL rhIGFBP5 could promote DPSC-mediated dentin-like tissues formation in vivo. Western blot results showed that IGFBP5 activated JNK and Erk signalling pathways in DPSCs. Furthermore, inhibition of JNK pathway by SP600125, the expression of p-JNK and p-Erk was reduced, while inhibition of Erk pathway by PD98059, only p-Erk expression was decreased. Our results demonstrated that IGFBP5 could promote the dentinogenic differentiation and dentinogenesis potential of DPSCs via JNK and ErK signalling pathways.

Ion exchange and ion exclusion chromatographic characterization of wines using conductivity detection

High performance ion chromatography system employing ion exchange and ion exclusion modes was used for the separation and quantitative analysis of tartarate, malate, citrate, lactate, chloride, nitrate, phosphate, sulfate, lithium, sodium, potassium, magnesium, and calcium in 15 wines originated worldwide. All anions were measured by means of conductivity detection. Analytical figures of merit were assessed and reported for all analyzed ions. In addition, the classic physicochemical properties of wines, i.e. color, acidity and density, were determined. Correlations between measured variables were evaluated and discussed. The proposed procedure is exceptionally simple and requires only regular instrumentation; nevertheless, it provides possibility for fast, straightforward and sensitive quantification of aforementioned ions. Sample preparation required only filtration and dilution where necessary.

Retinoic Acid Signal Negatively Regulates Osteo/Odontogenic Differentiation of Dental Pulp Stem Cells.

Retinoic acid (RA) signal is involved in tooth development and osteogenic differentiation of mesenchymal stem cells (MSCs). Dental pulp stem cells (DPSCs) are one of the useful MSCs in tissue regeneration. However, the function of RA in osteo/odontogenic differentiation of DPSCs remains unclear. Here, we investigated the expression pattern of RA in miniature pig tooth germ and intervened in the RA signal during osteo/odontogenic differentiation of human DPSCs. Deciduous canine (DC) germs of miniature pigs were observed morphologically, and the expression patterns of RA were studied by in situ hybridization (ISH). Human DPSCs were isolated and cultured in osteogenic induction medium with or without RA or BMS 493, an inverse agonist of the pan-retinoic acid receptors (pan-RARs). Alkaline phosphatase (ALP) activity assays, alizarin red staining, quantitative calcium analysis, CCK8 assay, osteogenesis-related gene expression, and in vivo transplantation were conducted to determine the osteo/odontogenic differentiation potential and proliferation potential of DPSCs. We found that the expression of RARβ and CRABP2 decreased during crown calcification of DCs of miniature pigs. Activation of RA signal in vitro inhibited ALP activities and mineralization of human DPSCs and decreased the mRNA expression of ALP, osteocalcin, osteopontin, and a transcription factor, osterix. With BMS 493 treatment, the results were opposite. Interference in RA signal decreased the proliferation of DPSCs. In vivo transplantation experiments suggested that osteo/odontogenic differentiation potential of DPSCs was enhanced by inversing RA signal. Our results demonstrated that downregulation of RA signal promoted osteo/odontogenic differentiation of DPSCs and indicated a potential target pathway to improve tissue regeneration.

Pleiotropin enhances the osteo/dentinogenic differentiation potential of dental pulp stem cells

ABSTRACT Purpose: Pleiotrophin (PTN) is a heparin-binding growth-associated molecule and expressed in ameloblasts and odontoblasts throughout tooth maturation. Our previous study has shown that PTN expressed more than 20-fold higher in dental tissue than dental stem cells. However, the role of PTN on proliferation and osteo/dentinogenesis of dental pulp stem cells (DPSCs) is unclear. The purpose of the present study was to investigate the role of PTN on the DPSCs’ function. Methods: DPSCs were isolated from human third molars. Short hairpin RNAs (shRNAs) was used to knock down the PTN expression in DPSCs. Real-time RT-PCR, alizarin red staining, quantitative calcium analysis, in vivo transplantation and cell counting kit-8 (CCK8) assay were used to study the function of DPSCs. Possible mechanism was studied by RNA sequencing. Results: After PTN depletion, ALP activity and mineralization ability of DPSCs decreased. Expression of DMP-1 and BSP weakened. Proliferation of DPSCs at 48 h and 72 h was inhibited. Furthermore, 50 pg/mL PTN recombinant protein rescued the impaired osteo/dentinogenic differentiation potential and proliferation ability caused by PTN depletion. In addition, RNA sequencing showed 221 genes were downregulated and 233 genes upregulated in PTN depleted DPSCs. Several genes including BMP2 and IGFBP5 might be associated with PTN function on the DPSCs. P53 and the AMPK signaling pathways were involved. LncRNA analysis displayed 47 significantly upregulated lncRNA and 31 downregulated lncRNA comparing PTN depleted DPSCs with the control. Conclusion: Our research demonstrated that PTN has a positive role in maintaining DPSCs proliferation and osteo/dentinogenic differentiation potential.

Comparison of remineralizing effect of organic and inorganic fluoride by evaluation of microhardness and quantitative analysis of calcium and phosphorus ratio on enamel surface: an in-vitrostudy

Background Enamel is a highly mineralized tissue of the body which is composed of 96% inorganic salts and 4% organic matter. Enamel is permeable to water and ions, particularly cations and low molecular weight substances. The enamel continues to mature even after eruption with mineral replacing protein. Recently, the interest on the development of calcium phosphate-based remineralization technology has been increased that led to the development of various remineralizing agents like Fluoride, CPP-ACP (Tooth Mouse plus), Bioglass (Novamin), Ozone, Xylitol, Sensistat etc. Aim Aim of the present in vitro study was to evaluate and compare the remineralizing effect of Organic fluoride (AmF) and inorganic fluoride (NaF) by evaluating Vickers microhardness and quantitative analysis of Calcium and Phosphorus ratio on enamel surface using Scanning Electron Microscope-Energy Dispersive X-ray analysis. Materials and methods Sixteen maxillary central incisors were decoronated at the cementoenamel junction and mounted in cylindrical moulds filled with self-cure acrylic resin. Artificial demineralized lesions were created on the enamel surface by suspending them in 0.1 M Citric acid buffer at pH of 3.2 for 72 hrs. The samples were then randomly divided into two groups and labelled, Group A – remineralized with NaF for 3 minutes twice daily for one week and Group B - remineralized with AmF for 3 minutes twice daily for one week. Microhardness and SEM-EDX analysis were done before demineralization, after demineralization and after remineralization. Results Data were analyzed by comparing the mean values between the groups using independent sample t-test. The intra-group analysis was done using repeated-measures ANOVA with posthoc Bonferroni test, and a p-value of <0.05 was considered statistically significant. Conclusion OrganicFluoride resulted in better remineralization than inorganic Fluoride. After remineralization for one week, enamel samples treated with AmF demonstrated a statistically significant increase in mean microhardness and Ca:P ratio when compared to enamel samples treated with NaF.