Evaluation of three different remineralizing agents on artificially demineralized enamel lesions Using scanning electron microscopy-energy dispersive X-ray and magic-angle spinning nuclear magnetic resonance - An in vitro study

Aim: Demineralization can be arrested or reversed when remineralization agents are applied to incipient carious or noncavitated carious lesions. A large number of therapeutic agents, including nonfluoridated products, have been developed to promote enamel remineralization. This study aims to evaluate the efficacy of different remineralizing agents on artificially demineralized enamel lesions. Materials and Methods: The present in vitro study was conducted on 75 sound premolars divided into three groups of normal, demineralized (n = 15 each), and remineralized teeth (n = 45). The remineralized teeth were further subdivided into three groups (n = 15) as remineralized with 2% sodium fluoride (NaF), 2% NaF, and Psoralea corylifolia (bakuchi) and white mineral trioxide aggregate. Specimens of each group were treated with the above-mentioned remineralizing agents and then subjected to Vickers hardness number (VHN), scanning electron microscopy–energy dispersive X-ray (SEM-EDX), and magic-angle spinning nuclear magnetic resonance (MAS-NMR) for further evaluation. Results: The test results showed significantly the highest VHN and the emission peak of elements under the EDX test, such as calcium, phosphorous, oxygen, and fluorine with remineralized with NaF + bakuchi. MAS-NMR spectra showed fluorine and phosphorous peak in a group with NaF + bakuchi indicative of the increase in remineralization. NaF + bakuchi showed effective results in VHN, SEM-EDX, and MAS-NMR with no antagonist interaction. Conclusion: Thus, P. Corylifolia presents an advantage in enhancing remineralization and inhibiting demineralization for early carious lesions and can be used as a herbal extract for effective reduction in pathogenic bacteria.

Metabolic features of acute necrotizing pancreatitis and chronic pancreatitis / 中华胰腺病杂志

ObjectiveTo study the metabolite features of acute necrotizing pancreatitis (ANP) and chronic pancreatitis (CP) in rats.MethodsA total of 22 Wistar rats were divided into ANP group (n =7 ),CP group (n =6) and the control group (n =9).ANP model was induced peritoneous injection of 20％ Larginine,and the rats were sacrificed 12 hours later.CP model was induced by intravenously injection of DBTC (8 mg/kg body weight),and the rats were sacrificed after 2 months.The rats in the control group received same amount of saline.Serum amylase was determined and pancreatic tissues were pathologically examined.Metabolic changes of pancreatic tissues in vitro were studied by high resolution magic angle spinning nuclear magnetic resonance (MAS NMR ),and analyzed by using principal components analysis (PCA).Characteristic metabolites of ANP and CP were compared. Results Compared with the control group,increased leucine,iso-leucine and valine levels were observed in ANP group,however,the opposite trends were observed in CP group.Phosphocholine,glycerophosphocholine,choline levels were increased and fatty acids,lactate,betaine,glycine levels were decreased in both ANP and CP groups.The lipid content in CP group were significantly higher than that in ANP group and the increased taurine was only observed in CP group. Conclusions There were obvious metabolic features in pancreatic tissue in rats with pancreatitis disorders,and the increased taurine could be used as biomarker to discriminate ANP and CP.

The metabolite features of chronic pancreatitis in rats / 中华胰腺病杂志

Objective To investigate the metabolite features of chronic pancreatitis in rats in vitro by high resolution magic angle spinning nuclear magnetic resonance spectroscopy. Methods A total of 30 Spraque-Dawley rats were randomized into experimental group (n =20) and control group (n = 10). All the animals in experimental group were intravenously injected with 8 mg/kg body weight DBTC, and the animals in the control group received same amount of solvent. Pancreatic tissues were examined by histology and Van Gieson staining. Metabolic changes of chronic pancreatitis in vitro in rats were studied by high resolution magic angle spinning nuclear magnetic resonance spectroscopy. Results 60 days after DBTC application, the pancreatic tissue was characterized by an extended interstitial fibrosis with infiltrating mononuclear cells. Compared with the control group, the signal intensities of phosphocholine (Pc) and glycerophosphocholine (Gpc), taurine (Tau), lactate (Lac) of chronic pancreatitis group increased. Oppositely, the signal intensities of betine (Bet), glutamic acid ( Glu ), alanine (Ala), ileucine (He), leucine ( Leu ) and valine (Val) decreased. The signal intensities of acetic acid (Ace) and choline (Cho) were not changed. Conclusions There were obvious metabolic features of chronic pancreatitis in rats, and it is helpful for the application of magnetic resonance spectroscopy in chronic pancreatitis in human studies.