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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.
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OBJECTIVE: To analyze subregional differences in T1rho (T1ρ) and T2 values and their correlation in asymptomatic knee cartilage, and to evaluate angular dependence with magic angles. MATERIALS AND METHODS: Six asymptomatic volunteers underwent knee MRI with T1ρ and T2 mapping. T1ρ and T2 values were measured by two radiologists independently, at nine subregions in the medial femoral condyle (MFC) cartilage, at angles of ± 0°, 15°, 35°, 55°, 75° respective to a vertical line (B0) bisecting the width of the distal femur, and at two locations in the patella. Subregional values of T1ρ and T2 were analyzed and significant differences in three divided portions of the MFC (anterior, central, and posterior) were statistically evaluated. Correlation between T1ρ and T2 and angular dependence with magic angles were also assessed for statistical significance. RESULTS: T1ρ values were lowest at +15° and highest at -55°. T2 values were lowest at +75° and highest at +35°. Both T1ρ and T2 were higher in superior patella than inferior patella. T1ρ showed significant differences in the three divided portions of the MFC, while T2 showed significant differences only between central and posterior portions. There was a weak correlation between T1ρ and T2 (r = 0.217, p = 0.127). T1ρ showed more angular dependence than T2. CONCLUSION: T1ρ and T2 showed different subregional values and angular dependence in asymptomatic knee cartilage with a weak correlation. Awareness of these differences will aid in assessment of cartilage in a specific subregion of the knee.
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Cartílago , Cartílago Articular , Fémur , Rodilla , Magia , Imagen por Resonancia Magnética , Rótula , VoluntariosRESUMEN
The high resolution magic angle spinning NMR spectroscopy (HRMAS) can be directly used to examine in vitro tissues, needing no extracting and separating procedures. Moreover, it can enhance signal intensity and improve resolution of images. HRMAS can directly obtain the structural and conformational information (molecular level) of in vitro tumor samples of the brain, liver, kidney, and lung, which gives it a bright future in early diagnosis of tumors. The present paper mainly reviews the applications of HRMAS in tumor metabonomics research.
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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.
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Objective To observe the metabolic characteristics of an experimental model of chronic pancreatitis,and to investigate its role in the grading of chronic pancreatitis.Methods Thirty-six Wistar rats were injected with dibutyltin chloride (DBTC) solution (8mg/kg) via the tail vein to establish the experimental model of chronic pancreatitis.The 36 rats were divided into 6 groups with 6 rats in each group.On0,7,14,21,28,35 days after modeling,rats was sacrificed and pancreatic tissue of the rats was harvested,and a small part was used for pathologic study,the majority part was kept at-80℃ under liquid nitrogen freezing.Metabolites of pancreatic tissue were determined by high-resolution magic angle spinning nuclear magnetic resonance spectroscopic (HR-MAS NMRS).On the basis of the abnormal structure,tubular complexes,gland atrophy,fibrosis,edema and inflammatory cell infiltration,chronic pancreatitis was graded.Results Pathologic study showed the severity of chronic pancreatitis gradually increased with time after modeling.The 7th,14th day after modeling,the pancreatic change was mild chronic pancreatitis; the 21st,28th,35th day,the pancreatic change was changed into severe chronic pancreatitis.Principal component analysis of HR-MAS NMRS showed that the betaine (Bet) and choline ( Cho)-contained components were significantly increased in severe chronic pancreatitis; while aspartate (Asp),lactate (Lac),isoleucine/leucine/valine (I/L/V) and fatty acid (FA) were significantly reduced when compared with those in mild chronic pancreatitis and normal pancreatic tissue.There was no significant difference in the amount of metabolic characteristics between mild chronic pancreatitis and normal pancreatic tissue.Conclusions HRMAS NMRS was helpful in distinguishing the severe chronic pancreatitis from mild chronic pancreatitis.
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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.
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Metabolic characteristics of 39 human brain tumor tissues, including 15 astrocytomas, 13 fibroblastic meningiomas and 11 transitional meningiomas from 39 individual patients, have been studied using high resolution magic-angle spinning (HRMAS) 1H NMR spectroscopy in conjunction with principal component analysis (PCA). With rich metabolite information, 1H NMR spectra showed that the tumor-tissuc metabonome was dominated by lipids, lactate, myo-inositol, ereatine, choline metabolites such as choline, phosphocholine and glycerophosphocholine, amino acids such as alanine, glutamate, glutamine, taurine, N-acetyl-aspartate and glutathione. PCA of the tumor NMR spectra clearly showed metabonomic differences between low-grade astrocytomas and meningiomas whereas such differences were more moderate between fibroblastic and transitional meningiomas. Compared with meningiomas, the low-grade astrocytomas had higher levels of glycerophosphocholine, phosphocholine, myo-inositol and creatine but lower levels of alanine, glutamate, glutamine, glutathione and taurine. The N-acetyl-aspartate level was low but detectable in low-grade astrocytomas whereas it was not detectable in meningiomas. It is concluded that tissue metabonomics technology consisting of HRMAS 1H NMR spectroscopy and multivariate data analysis (MVDA) offers a useful tool (1) for distinguishing different types of brain tumors, (2) for providing the metabolic information for human brain tumors, which are potentially useful for understanding biochemistry of tumor progression.
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@#ObjectiveTo study effect of Herba Erigerontis on metabolites in cerebral ischemia rats with high-resolution magic angle spinning 1H nuclear magnetic resonance spectroscopy(HR MAS 1H NMR). Methods18 male Wistar rats, weighing 150～200 g, were randomly divided into 3 groups such as normal (n=6), ischemia (n=6), Herba Erigerontis treatment (n=6). Rat ischemia model was established with middle cerebral artery occlusion (MCAO), reperfusing or dosed with Herba Erigerontis after 3 h ischemia. The metabolites, including N-acetylaspartate (NAA), creatine (Cre), choline (Cho), glutamate (Glu), and aspartate (Asp) etc., of cerebra and cerebella was observed using HR MAS 1H NMR. ResultsExcluding Cho, Glu, Asp, the concentrations of most metabolites of rat brain during ischemia were significantly lower than that of normal rats, and could be increased after drug treatment. ConclusionHerba Erigerontis shows positive effect on metabolites in cerebral ischemia rats.