Application in the analysis of the occlusal force of free-end missing tooth implant restoration with T-SCAN III.

Introduction: The occlusal force of the teeth in the dental arch and the remaining adjacent natural teeth will change after implant restoration with a free-end missing tooth. This study intends to use the T-SCAN III scanner to collect dynamic quantitative data before and after the restoration of free-end implants and to explore the application of the T-SCAN III in redistributing the occlusal force of free-end implants. Methods: In this study, 24 patients with free-end implant restoration were selected, and their occlusion was tested before, immediately after, and 3 months after implant restoration. Results: In all 24 cases, the bite force of the first natural tooth adjacent to the implanted tooth after restoration changed from 19.12% ± 9.48%-12.93% ± 11.47% (p < 0.01). For additional data analysis, all cases were further subdivided by single implant and fixed bridge restorations. In 17 cases, there was a successful follow-up after 3 months. The percentage of the total bite force of dental arch with implant increased from 41.92% ± 10.78%-53.06% ± 10.71% (p < 0.01). Discussion: This study shows that the free-end implant restoration protects the remaining natural teeth, and the patient's missing dental arch bite force improves within 3 months of implant restoration.

Efficacy and safety of inhalation of pulmonary surfactant using vibrating mesh nebulizers combined with nasal continuous positive airway pressure in the treatment of neonatal respiratory distress syndrome / 中华危重病急救医学

Objective:To investigate the efficacy and safety of nasal continuous positive airway pressure (NCPAP) combined with inhalation of pulmonary surfactant (PS) using vibrating mesh nebulizers in the treatment of neonatal respiratory distress syndrome (RDS).Methods:A prospective study was performed on premature infants with RDS admitted to the First Affiliated Hospital of Bengbu Medical College between December 2020 and June 2021. They were randomly assigned into vibrating mesh atomization technology group and intubation-surfactant-extubation (INSURE) technology group. The two groups were treated with NCPAP combined with PS. PS in the vibrating mesh atomization technology group was inhaled into the lungs by the new vibrating mesh atomization technology, while PS in the INSURE group was injected into the lungs by endotracheal tube. The pH value, arterial partial pressure of carbon dioxide (PaCO 2), oxygenation index (PaO 2/FiO 2), mechanical ventilation via endotracheal tube (MVET) demand rate, duration of respiratory support, secondary use of PS, complications, and hospital mortality were compared between the two groups. The occurrences of adverse events in the two groups were recorded. Results:A total of 42 preterm infants were finally enrolled, including 20 cases in the vibrating mesh atomization technology group and 22 cases in the INSURE technology group. There were no significant differences in blood gas analysis and PaO 2/FiO 2 before PS administration between the two groups. One hour after PS administration, blood gas analysis and PaO 2/FiO 2 were significantly improved in both groups. Compared with the INSURE technology group, the improvement of PaO 2/FiO 2 was more obvious in the vibrating mesh atomization technology group [mmHg (1 mmHg≈0.133 kPa): 198±34 vs. 173±39, P < 0.05], but no significant difference in pH value or PaCO 2 was found between the two groups. The duration of respiratory support in the vibrating mesh atomization technology group was significantly shorter than that in the INSURE technology group (hours: 96±13 vs. 120±18, P < 0.01), but there was no statistical difference in MVET demand rate [5.0% (1/20) vs. 13.6% (3/22), P > 0.05]. The incidence of periventricular-intraventricular hemorrhage (PVH-IVH) in the vibrating mesh atomization technology group was less than that in the INSURE technology group [0% (0/20) vs. 18.2% (4/22)], but no statistical difference was found ( P > 0.05). No significant differences in the secondary use rate of PS and incidence of bronchopulmonary dysplasia (BPD) or other complications were found between the vibrating mesh atomization technology group and the INSURE technology group [5.0% (1/20) vs. 9.1% (2/22), 5.0% (1/20) vs. 4.5% (1/22), both P > 0.05]. There were no deaths or serious adverse events such as pneumothorax, pulmonary hemorrhage, periventricular leukomalacia (PVL), retinopathy of prematurity (ROP), and necrotizing enterocolitis (NEC) in both groups. Conclusion:Compared with the INSURE technique, NCPAP combined with vibrating mesh atomization technology was also effective and safe in the treatment of RDS, which could significantly improve PaO 2/FiO 2 and shorten the duration of respiratory support. Thus, it was worthy of clinical popularization and application.

[Anticancer effect of triptolide-polyethylenimine-cyclodextrin in vitro].

OBJECTIVE: To develop a drug delivery system triptolide-polyethylenimine-cyclodextrin and to evaluate its anticancer activity in vitro. METHODS: Triptolide was conjugated to polyethylenimine-cyclodextrin by N, N'-carbonyldiimidazole to form triptolide-polyethylenimine-cyclodextrin. (1)H-NMR, FT-IR and XRD were used to confirm its structure. The anticancer effect of the polymer was assessed by MTT assay, erasion trace test and hematoxylin-eosin staining. The potential to condense siRNA and to delivery siRNA into cytoplasm was demonstrated by gel retardation assay, zeta-potential determination and fluorescence staining. RESULTS: Triptolide was successfully conjugated to polyethylenimine-cyclodextrin and the conjugation rate of triptolide was 10% (w/w). siRNA was effectively condensed by the polymer at the N/P ratio of 5, and its particle size was 300 ±15 nm and zeta potential was 8 ±2.5 mV. MTT assay, erasion trace test and hematoxylin-eosin staining revealed that triptolide-polyethylenimine-cyclodextrin had anticancer effect and low cytotoxicity to normal cells. The polymer was able to deliver siRNA to the cytoplasm effectively as demonstrated by fluorescence staining. CONCLUSION: Triptolide-polyethylenimine-cyclodextrin is able to inhibit the growth and migration of cancer cells in vitro and to carry siRNA into cells effectively. It is potential to be used as a novel prodrug for co-delivery of gene and drug in cancer treatment.

[Characteristics of cationic polymers PEI-CyD, PEI-PHPA, PEE-PHPA and PEI25kD in vitro and in vivo].

OBJECTIVE: To study the characteristics of cationic polymers polyethylenimine-ß-cyclodextrin (PEI-CyD), polyethylenimine-poly-(3-hydroxypropyl)-aspartamide (PEI-PHPA), N,N-Dimethyldipropylenetriamine-Bis(3-aminopropyl)amine-aspartamide (PEE-PHPA) in vitro and in vivo. METHODS: PEI-PHPA, PEI-CyD and PEE-PHPA were synthesized and the chemistry structure of PEI-PHPA, PEI-CyD and PEE-PHPA was confirmed by (1)H-NMR. The particle size and zeta potential of these polymers were measured, and capacity of plasmid DNA condensation was tested. The inhibition of COS-7, A549, HEK293 and C6 cells was measured by MTT assay. The transfection efficiency was determined in HEK293 cell lines. The toxicity, tissue distribution and transfection efficiency of cationic polymers were tested in vivo. RESULTS: When the N/P of polymers/DNA at 30, the particle sizes were close 250 nm and the zeta-potential were near 35 mv. They were able to condense DNA at N/P ratio < 5. The MTT assay showed that the IC(50) of PEE-PHPA was 21.5, 20.2, 7.30 and 37.1 µg/ml, and that of PEI25kD was 15.8, 18.3, 11.4 and 36.7 µg/ml in C6, COS-7, A549 and HEK293cell lines, respectively. The cell viability of PEI-CyD and PEI-PHPA in above cell lines was over 60%. They had high transfection efficiency in HEK293 cell lines. The LD(50) of PEI25Kd, PEI-CyD, PEI-PHPA and PEE-PHPA in vivo was 19.50, 100.4, 521.2 and 630.0, respectively by intraperitoneal (ip) injection. The contractions of these polymers were higher in kidney than in other organs and tissues.PEE-PHPA had slight effect on kidney and liver function. CONCLUSION: PEE and PEI25kD have higher transfection efficiency and higher toxicity; while PC and PHPA-PEI have lower toxicity and higher transfection efficiency to be used as non-viral gene vector.

[Modified montmorillonite as multifunction gene and drug delivery system].

OBJECTIVE: To develop polyethylenimine-Doxorubicin-montmorillonite (PEI-Dox-MTT) as a novel multifunction delivery system. METHODS: Dox was intercalated into montmorillonite, PEI covered to the surface of Dox/MMT to make the nano-particle. XRD, FT-IR and TGA were used to confirm chemical property of the nano-particle. SEM was used to observe the morphology. The capability of drug release was investigated by PBS buffer solution (pH 7.4). The DNA binding ability of nano-particle was detected by gel electrophoresis retardation assay. The cell viability in COS-7 and SKOV3 cell lines was tested using MTT assay. The gastric mucosa protection was evaluated in vitro. RESULTS: XRD image showed that Dox was intercalated into montmorillonite, inter space of which increased to 31.3Å; the FT-IR spectra showed the vibration bands of PEI at 1 560 cm(-1) and 2 850 cm(-1), the vibration band of Dox at 1 350 cm(-1). Size analysis and SEM revealed that the size of nano-particle was 600 nm, and the zeta-potential was 30 mV. Drug release experiment explored that the nano-particle stably released drug in range of 6 X10(-4) ≊ 8 X10(-4) mg/ml within 72 h. MTT assay showed that the cell viability was over 80% in experiment condition in COS-7 and SKOV3 cell lines. 0.3 mg PEI-MMT nano-particle was able to protect gastric mucosa from alcohol. CONCLUSION: Multifunction system of PEI/Dox/MMT has been prepared successfully.