BACKGROUND:Although several prosthetic methods, such as artificial denture and dental implants, are clinical therapies to tooth loss, they are thought to have safety and usage time issues. With the development of biological and biomaterial sciences, recently, tooth tissue engineering has attracted more and more attention.
OBJECTIVE:To reflect advances and problems of tissue engineering technologies for promotion of tooth regeneration.
METHODS:Using the keywords of“tissue engineering, tooth regeneration”in English and Chinese, PubMed and CNKI databases from 2007 to 2013 were retrieved. A total of 65 literatures addressing tooth regeneration and tissue engineering were col ected, including 25 Chinese articles and 40 English articles. Published early, repetitive, and similar researches were excluded. Final y, 48 articles were included.
RESULTS AND CONCLUSION:The combination of stem cells and suitable scaffolds is widely used in tooth regeneration today, and growth factors or bone marrow which can produce promote tooth regeneration are added as wel , which has achieved partial or whole tooth regeneration. But there are apparent deficiencies in studies which focus on mechanisms behind tooth regeneration.

Objective To investigate the function characteristics of CD4 T cell converted double negative T cell and provide a basis for further insight into the characteristics of mouse converted double negative T cell.Methods The gene expression profile was analyzed by transcriptome sequencing and protein mass spectrometry.The expression of cell active marker CD44,CD69 and OX40 was investigated by flow cytometry and the cytotoxicity of mouse double negative T cell was verified by CFSE staining.Results Mouse CD4 T cell converted double negative T cell expressed cell phenotype that differed from other mature CI4 T cells.Mouse converted double negative T cell expressed high level of active marker of CD44,CD69 and OX40.Cytotoxicity of PrfO DN T was significantly reduced.Conclusions Mouse CD4 T cell converted double negative T cell has distinguishing cell phenotypes,that are not identical to other mature CD4 T cells.Mouse double negative T cell overexpresses cell activation marker and cytotoxic cytokines.The immune suppressive function of mouse double negative T cell is mainly dependent on perforin pathway.

Objective To observe the effect of surface electromyographic biofeedback (sEMG BFB) combined with routine swallow training in treating dysphagia among those with nasopharyngeal carcinoma after radiation therapy.Methods Fifty dysphagic patients with nasopharyngeal carcinoma after radiation therapy were randomly divided into a biofeedback training group and a routine treatment group,each of 25.Both groups were given routine training including orofacial function training,sensory irritation,behavioral swallowing training,and electrical stimulation.The biofeedback group was additionally given behavioral swallowing training based on sEMG BFB.Before and 4 weeks after the treatment,a videofluoroscopic swallowing study was performed to observe the opening of the upper esophageal sphincter (UES).The penetration aspiration scale (PAS) and the functional oral intake scale (FOIS) were used to evaluate the subjects' swallowing function.Results Before the treatment there were no significant differences between the two groups in terms of UES opening,average PAS score or average FOIS score.Everyone improved significantly after the treatment,but compared with the routine treatment group,UES opening was significantly better after the treatment,the average PAS score was lower and the average FOIS score was higher in the biofeedback training group.Conclusion sEMG BFB combined with routine swallowing training can improve the UES opening and swallowing ability of dysphagic patients with nasopharyngeal carcinoma after radiation therapy.

Objective: To investigate the effect of global end-diastolic volume index (GEDI)-guided fluid resuscitation on the prognosis of patients with chronic heart failure and septic shock. Methods: This study was a prospective randomized controlled study. Consecutive eligible patients were divided into 2 groups according to the random number table method: control group (n=21) and experimental group (n=20). On the basis of routine treatment, patients in the control group received early goal-directed therapy until the central venous pressure (CVP) reaching 8-12 mmHg (1 mmHg=0.133 kPa), mean arterial pressure reaching over 65 mmHg, urine volume reaching over 0.5 ml·kg^-1·h^-1, and central venous oxygen saturation reaching more than 70%. On the basis of routine treatment, patients in the experimental group were monitored continuously on cardiac output with pulse indication and fluid resuscitation guided by volume index GEDI. The GEDI should be maintained on the range of 680-800 ml/m². The remaining resuscitation goals were the same as control group. General clinical data of the two groups were collected at admission. Negative fluid balance onset time, duration of mechanical ventilation, ICU mortality and 28-day mortality were compared between the two groups. The outcomes were recorded as listed: start time of negative fluid balance, duration of mechanical ventilation, mortality in ICU and 28-day mortality. Results: There was no significant difference in age, sex, weight, APACHE Ⅱ score, SOFA score and NYHA functional class score between the two groups (all P>0.05). The negative liquid balance onset time in the control group was 3.5 (2.5, 4.0) days, which was significantly longer than that in the experimental group (2.6 (2.0, 3.0) days,U=115.0, P=0.012). The duration of mechanical ventilation was 355 (118, 552) hours in the control group, which was significantly longer than that in the experimental group (132 (36.75, 233.3) hours, U=130, P=0.038). The ICU mortality was 38.1% (8/21) in the control group, tended to be higher than that in the experimental group (20.0%(4/20), χ²=1.620, P=0.203). The 28-day mortality was 42.9% (9/21) in the control group, similar as in the experimental group (25.0%(5/20), χ²=1.482,P=0.477). Conclusion Fluid resuscitation guided by volume index (GEDI) may improve the prognosis of patients with chronic heart failure complicated with septic shock.

Objective To explore the effect of lymphocytes on the innate immune cells in Rag1 and Rag2/IL2rγ gene knockout mice after hepatic ischemia and reperfusion injury (HIRI).Methods C57BL/6 mice (n =10),Rag1 knockout mice (n =10) and Rag2/IL2rγ knockout mice (n =10) were respectively divided into sham group and hepatic ischemia-reperfusion injury group by simple randomization,5 mice in each group.By using the model of hepatic ischemia-reperfusion injury in mice,changes of intrahepatic immune cells were detected by flow cytometry.Hepatic ischemia and reperfusion injury and changes of intrahepatic cell subsets were observed in immune system-deficient mice,both Rag1 and Rag2/IL2rγ knockout.Measurement data were expressed as ((x) ±s),and analyzed using independent samples t test.Results Flow cytometry results showed that immune cells,including NK cells,NKT cells,CD4+T cells,DNT cells,Kupffer cells,BMMs and neutrophils were increased after HIRI.Compared with sham group,Rag1 knockout mice displayed markedly increased proportion of Kupffer cells,BMMs and neutrophils after HIRI.And decreased serum ALT levels [from (1 776.25 ± 219.37) U/L to (932.33 ±58.77) U/L,P=0.003,t =7.350] and less hepatocellular necrosis were exhibited in Rag1 knockout mice after HIRI,comparing to C57BL/6 HIRI group.In addition,increased neutrophils were still observed in Rag2/IL2rγ knockout mice after HIRI,without increased proportion of Kupffer cells and BMMs.Compared with Rag1 knockout mice,ALT levels were further decreased from (932.33 ± 58.77) U/L to (309.00 ± 163.53) U/L (P=0.002,t =6.182) in Rag2/IL2rγ knockout mice.Conclusion Both Rag1 and Rag2/IL2rγ knockout mice exhibite less liver injury after HIRI comparing with C57BL/6 mice,indicating that T cells and NK cells aggravate the liver injury.Moreover,T cells do not affect the recruitment of Kupffer cells,BMMs and neutrophils,but regulate the recruitment of NK cells,while NK cells contribute to the activation of Kupffer cells and BMMs,but not neutrophil influx.