Value of dynamic ³¹P magnetic resonance spectroscopy technique in in vivo assessment of the skeletal muscle mitochondrial function in type 2 diabetes / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Phosphorous magnetic resonance spectroscopy ((31)P-MRS) has been successfully applied to study intracellular membrane compounds and high-energy phosphate metabolism. This study aimed to evaluate the capability of dynamic (31)P-MRS for assessing energy metabolism and mitochondrial function in skeletal muscle from type 2 diabetic patients.</p><p><b>METHODS</b>Dynamic (31)P-MRS was performed on 22 patients with type 2 diabetes and 26 healthy volunteers. Spectra were acquired from quadriceps muscle while subjects were in a state of rest, at exercise and during recovery. The peak areas of inorganic phosphate (Pi), phosphocreatine (PCr), and adenosine triphosphate (ATP) were measured. The concentration of adenosine diphosphate (ADP) and the intracellular pH value were calculated from the biochemistry reaction equilibrium. The time constant and recovery rates of Pi, PCr, and ADP were analyzed using exponential curve fitting.</p><p><b>RESULTS</b>As compared to healthy controls, type 2 diabetes patients had significantly lower skeletal muscle concentrations of Pi, PCr and β-ATP, and higher levels of ADP and Pi/PCr. During exercise, diabetics experienced a significant Pi peak increase and PCr peak decrease, and once the exercise was completed both Pi and PCr peaks returned to resting levels. Quantitatively, the mean recovery rates of Pi and PCr in diabetes patients were (10.74 ± 1.26) mmol/s and (4.74 ± 2.36) mmol/s, respectively, which was significantly higher than in controls.</p><p><b>CONCLUSIONS</b>Non-invasive quantitative (31)P-MRS is able to detect energy metabolism inefficiency and mitochondrial function impairment in skeletal muscle of type 2 diabetics.</p>

Assessment research on the inter-proximal mesial papilla height of single implant-supported maxillary central incisor / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This prospective study was to observe the correlation between the mesial papilla's height of single implant-supported maxillary central incisor and the distance from the base of the contact point to the alveolar bone crest.</p><p><b>METHODS</b>56 patients involved in single implant-supported maxillary central incisor were included in this study. The distances from the base of the contact point to the alveolar bone crest in the digital periapical film of maxillary central incisor were measured using the software Planmeca Dimaxis Version 3.3.2. The time of measurements were as follows: The pre-surgical and post-surgical periods, before and after the crown installation, the follow-up examination of more than 0.5 year. To analyze the factor of influencing distance, and the correlation between the distance and the height of gingival papilla during the whole restored period. Correlation analysis between the distance and the height of gingival papilla during the whole restoration was done by the statistical software SPSS 12.0.</p><p><b>RESULTS</b>The results demonstrated that the ratio of esthetic papilla can achieve 54.5% at the crown installation and 95.5% at the follow-up examination when the distance was between 3 mm and 5 mm. When the distance was between 5 mm and 6 mm, they dropped to 30.0% and 75.0%, respectively. However, when the distance increased to above 7 mm, the papilla could hardly be in an esthetic outcome. There was a significant change of the distance was found during the periods from the post-surgery to pre-restoration, and the scope of the changes was between -0.13 mm and 0.46 mm. A negative correlation was found between the distance and the index of papilla. The correlation coefficient r was -0.715 (P < 0.01).</p><p><b>CONCLUSION</b>It is proposed that the pre-surgery distance of maxillary central incisor from the base of the contact point to the alveolar bone crest can be used as one of the important reference indexes to assess and predict the height conditions of gingival papilla.</p>