Clinical application of three-dimensional printing implant template in the restoration of free-end missing teeth / 中国组织工程研究

BACKGROUND:Three-dimensional (3D) printing technology is currently one of the most advanced industrial manufacturing technologies. The surgical template prepared based on the 3D printing technology is mainly made of resin, and a great improvement in its accuracy is required. However, the clinical application of the surgical template made of metal is rarely reported. OBJECTIVE:To evaluate the clinical value of 3D-printing implant template in the restoration of free-end missing teeth.METHODS:A prospective study was conducted in 64 enrolled patients with free end-tooth defects. All the patients were randomly assigned to receive traditional implant template (control group,n=32) or 3D-printing implant template (study group,n=32), and 3-6 months later, the patients were subjected to crown restoration. At 6 months after crown restoration, cone beam computed tomography was performed to compare the deviation of the implant tip and neck (including vertical, buccolingual, mesial-distal). Success rate and chewing rate were compared between the two groups at 6 months after crown restoration; patient satisfaction assessment was done and compared between the two groups at 1 year after crown restoration. RESULTS AND CONCLUSION:There were no significant differences between the two groups in the success rate and chewing rate (98.7％ vs. 95.6％; 97.4％ vs. 97.1％,P>0.05). The vertical, buccolingual, mesial-distal deviations of the implant tip were significantly lower in the study group than the control group (P<0.05), while there was no difference in the vertical and buccolingual deviations of the implant neck between the two groups (P>0.05), and the mesial-distal deviation of the implant neck was significantly lower in the study group than the control group (P<0.05). In addition, there was no difference in the patient satisfaction between the study and control groups (94％vs. 91％, P>0.05). To conclude, the 3D printing implant template can effectively reduce implant excursion based on the assurance of therapeutic efficacy and patient satisfaction, which is of great significance in the restoration of free-end tooth loss.

Clinical observation on cervical spondylosis of neck type treated with acupuncture at original and terminal points of trapezius / 中国针灸

<p><b>OBJECTIVE</b>To compare the differences of therapeutic effect of cervical spondylosis of neck type treated with acupuncture at starting and ending points of trapezius and the Jiaji (EX-B 2) points.</p><p><b>METHODS</b>Sixty cases of cervical spondylosis of neck type were randomly divided into an observation group and a control group, 30 cases in each group. In observation group, the acupoints related with starting and ending points of trapezius, such as Tianzhu (BL 10), Fengchi (GB 20), Quyuan (SI 13), Jugu (LI 16) and Ashi were punctured; in control group, Jiaji (EX-B 2) points of neck were punctured. The treatments were applied 5 times a week and 2 weeks made one course. The international simplified McGill scale was adoped to assess the scores of Pain Rating Index (PRI), Visual Analogue Scale (VAS) and Present Pain Intensity (PPI) before treatment and after one course treatment, and the therapeutic effects were measured.</p><p><b>RESULTS</b>After treatment, all the scores were obviously reduced in both groups: (all P < 0.01), and the PRI-sensory subscore, PRI-affective subscore and total score in observation group reduced more obviously than those in control group, and there were statistically significant differences between groups (all P < 0.01). There were no statistically significant differences between groups in VAS and PPI score (both P > 0.05). The total effective rate of 96.7% (29/30) in observation group was superior to that of 70.0% (21/30) in control group (P < 0.01).</p><p><b>CONCLUSION</b>The therapeutic effect of cervical spondylosis of neck type treated with acupuncture at the starting and ending points of trapezius is positive, which is better than that of acupuncture at the Jiaji (EX-B 2) points.</p>

Development of an in vitro digestion model for assessing the bioaccessibility of aflatoxin B group in foods / 中华预防医学杂志

<p><b>OBJECTIVE</b>To develop and validate an in vitro digestion model for assessing the bioaccessibilities of some important mycotoxins of aflatoxin B group (aflatoxin B(1) and aflatoxin B(2), AFB(1) and AFB(2)).</p><p><b>METHODS</b>Using simulating gastrointestinal physiological digestion process, the effects of digestion time (long, medium and short), the fasting and feeding status (fasting, between fasting and semi-feeding, semi-feeding, between semi-feeding and feeding, feeding states), the volume and pH (high, medium and low) of digestive solution, as well as other food ingredients ingested along with aflatoxin B group from mixed foods on bioaccessiblities of AFB(1) and AFB(2) in the mouth, stomach and small intestine were studied. The optimal technical parameters of the model were identified and the model was validated with mycotoxin adsorbents.</p><p><b>RESULTS</b>The optimal conditions of AFB(1) releasing from the ingested foods at the highest concentration in gastrointestinal tract were as follows: digestion time of 6 min, 1.5 h and 2.5 h in mouth, stomach and duodenum, respectively; the optimal pH values of 1.1 and 7.5 for gastric juice and duodenal fluid; the volume of 7, 13, 12 and 6 ml for saliva, gastric juice, intestinal fluid and bile, respectively; the optimal conditions of AFB(2) releasing from the ingested foods at the highest concentration in gastrointestinal tract were as follows: digestion time of 6 min, 2.5 h and 2.5 h in mouth, stomach and duodenum, respectively; the optimal pH values of 1.1 and 7.8 for gastric juice and duodenal fluid; the volume of 5, 12, 13 and 6 ml for saliva, gastric juice, intestinal fluid and bile, respectively. The bioaccessibilities of both AFB(1) and AFB(2) were highest at the fasting state (83.1% and 89.3% respectively). The bioaccessibilities decreased with the increasing of stomach contents, but the changes in bioaccessibility were not significant when the stomach contents reached the semi-feeding state or more. From semi-feeding to feeding state, the biocessibilities of AFB(1) decreased from 72.8% to 71.5% and AFB(2) decreased from 78.3% to 76.9%. Chlorophyll and activated charcoal were the strongest absorbent in reducing the bioaccessibilities of AFB(1) and AFB(2), and the bioaccessibilities decreased to 0.8% and 1.3% respectively.</p><p><b>CONCLUSION</b>The in vitro digestion model developed in the present study is stable and reproducible, and meets the requirements for assessing the bioaccessibilities of AFB(1) and AFB(2) in foods.</p>

Effects of sodium on rat osteoblast and the role of epithelial sodium channel / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effects of sodium on rat osteoblast function and explore the role of epithelial sodium channel (ENaC) in such effects.</p><p><b>METHODS</b>The proliferation and differentiation of rat osteoblasts were evaluated following treatment with 1×10(-4) mol/L to 1 mol/L Na(+). The mRNA expressions of the osteogenic genes and ENaC-α gene in the treated cells were assessed using RT-PCR.</p><p><b>RESULTS</b>Within the concentration of 1×10(-4) mol/L to 1 mol/L, Na(+) showed a two-way effect on the osteoblasts: low-concentration Na(+) (1×10(-4) mol/L) significantly promoted osteoblast differen- tiation, while at higher concentrations (0.5 and 1 mol/L), Na(+) produced an opposite effect. Sodium did not significantly affect osteoblast proliferation. Low-concentration Na(+) significantly increased the transcription of Cbfa1, OPN and OC, while high concentrations of Na(+) decreased their transcription. Low-concentration Na(+) also enhanced the mRNA expression of ENaC-α, but high-concentration Na(+) treatment lowered ENaC-α mRNA expression.</p><p><b>CONCLUSION</b>Na(+) displays a direct dose-related effect on osteoblasts by affecting its differentiation, osteogenic gene expression profile, and ENaC-α gene expression, suggesting the involvement of ENaC in Na(+)-mediated functional modulation of rat osteoblasts.</p>

A new mutation in the GJB1 gene of a Chinese family with Charcot-Marie-Tooth disease associated with vocal cord paresis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To report an X-linked dominant Charcot-Marie-Tooth disease (CMTX) Chinese family with vocal cord paresis and to identify the mutation of gap junction protein beta 1 gene (GJB1).</p><p><b>METHODS</b>Part of the family members with dysphagia, dysphonia and lethal respiratory failure were studied through flexible laryngoscope, clinical, brain MRI and electrophysiological examinations. After excluding large fragment tandem duplication containing peripheral myelin protein 22 gene (PMP22), direct sequencing was performed to analyze the mutation of the GJB1 gene in 5 patients including the proband, 5 unaffected family members and 50 unrelated healthy individuals.</p><p><b>RESULTS</b>Eight members spanning 3 generations in this family were affected with CMTX characterized by progressive atrophy and weakness of the anterior tibial and peroneal muscles, especially in the proband. Vocal cord paresis was observed through flexible laryngoscope in total of 4 affected members with dysarthria and dysphagia, 2 of them died of severe respiratory failure due to complete bilateral vocal cord involvement. Normal brain MRI was observed in the proband. The electrophysiological data showed predominant demyelization involving the motor and sensory nerves in the proband. DNA sequencing revealed a de novo c.186 C>G missense mutation in exon 2 of the GJB1 gene, the mutation cosegregated with phenotype.</p><p><b>CONCLUSION</b>Respiratory failure associated with vocal cord involvement may be a rare and severe symptom in CMTX. The present report provides further evidence for clinical and genetic heterogeneity in the X-linked Charcot-Marie-Tooth disease.</p>