Objective To analysis the effect of axial loading to ADC value, FA of lumbar intervetebral discs. Methods Forty five patients with low back pain (age range, 25 to 54 years) were evaluated with MR T2WI, MR T1WI and diffusion tensor imaging (DTI) of the lumbar spine. Following axial loading with 40% to 50% body weight for 10 minutes, a repeat DTI was performed. DTI were obtained by using an echo-planar imaging ( EPI ) sequence, TE 89 ms, TR 2500 ms, b value of 400 s/mm2,6 noncollinear diffusion directions. Scan time was approximately 4 min 10 s. An isotropic ADC map, FA map and bo map were calculated from DTI sequence. The mean ADC value, FA prior to and following axialloading were analyzed with t test and Rank Sum test. Results Forty five patients with 225 discs were evaluated and 223 discs were included in the study except for 2 calcified discs. The Pfirrmann grading results were as following: 100 Grade Ⅱ , 48 Grade Ⅲ, 59 Grade Ⅳ, and 16 Grade Ⅴ. No significant difference existed in the mean ADC value before [ ( 1666 ± 252 ) × 10-3 mm2/s ] and after [ ( 1662 ± 253 ) ×10 -3 mm2/s ] axial loading ( Z = - 1.363, P ＞ 0.05 ), but the mean FA [ ( 301 ± 104 ) × 10 -3, ( 316 ±112) × 10-3 ] value increased ( Z = - 2.794, P ＜ 0.05 ). The paired-samples t test show that the mean ADC value [ ( 1685 ± 190) × 10-3 mm2/s, ( 1624 ± 180) × 10-3mm2/s] of Grade Ⅲ discs decreased after axial loading, t=3.513, P＜0. 05, Grade Ⅲ, Ⅳdiscs mean FA value [(300±87) ×10-3, (326±87) ×10-3 for Grade Ⅲ and (348 ±67) × 10-3, (351 ± 71 ) × 10-3 for Grade Ⅳ ] increased, t = - 2. 210,- 2.006, P ＜ 0.05. No significant difference existed in Grade Ⅱ , Ⅳ and Ⅴ discs ADC value, all the P ＞0.05. No significant difference existed in Grade Ⅱ and Ⅴ discs FA value, both the P ＞ 0.05. Conclusions Short time axial loading mainly affect the mildly degenerated discs, the ADC value decreases and the disc diffusion ability decreases. No obvious change in ADC value or disc diffusion ability existed in the normal and severely degenerated discs.

Objective To investigate the impacts of LASP-1 on the behavior and cell proliferation ability of tumor derived osteoblast-like cells and non tumor derived osteoblasts. Methods QRT-PCR and Western blot were performed to detect LASP-1 expressions in mouse bone marrow mesenchymal stem cells(BMMSC),human osteoblasts (hOB) and human osteosarcoma cell (MG-63). With the construction of recombinant vector and the transfection of shLASP-1,the expression changes in both LASP-1 and osteocalcin(OCN),and the cell number of cell-cycle phase distribution were analyzed. Results With up-or down-regulation of LASP-1,osteocalcin(OCN) expression,cell proliferation ability and the cell number of G2/M phase in non tumor cells(BMMSC,hOB)had no obvious changes. However,as for the tumor cells(MG-63),with an increased expression of LASP-1,the expression of OCN,cell proliferation number and the cell number at G2/M phase changed. There was no significant effect on the moving ability of each cell. Conclusions LASP-1 has no significant effect on the osteogenic proper-ties,cell proliferation ability and cell cycle distribution of non tumor derived cells,but has a regulatory effect on tumor derived cells(MG-63).

OBJECTIVETo investigate the property of genipin-crosslinked silk fibroin(SF)/chitosan(CS) microspheres for slow releasing of bovine serum albumin (BSA).

METHODSBSA-loaded genipin-crosslinked SF/CS microspheres were prepared by emulsion cross-linking technique. The micropheres were observed for surface morphology and size distribution under scanning electron microscope (SEM), and X-ray diffractometry (XRD) and fourier transform infrared spectroscopy (FTIR) were used to analyze their structural characteristics. BCA method was used for determining the drug entrapment, loading rate and cumulative drug release in 21 days.

RESULTThe microspheres were spherical and showed a smooth surface with an average diameter of 7.84∓0.97 µm. The drug entrapment efficiency of the microspheres was (50.16∓4.32)% with a drug loading ratio of (1.25∓0.11)% and a cumulative release of the total drug of (75.2∓2.53)% in 21 days.

CONCLUSIONGenipin-crosslinked SF/CS microspheres have a high drug entrapment efficiency and possess good capacity of sustained drug release.

Chitosan ; chemistry ; Delayed-Action Preparations ; Emulsions ; Fibroins ; chemistry ; Iridoids ; chemistry ; Microscopy, Electron, Scanning ; Microspheres ; Particle Size ; Spectroscopy, Fourier Transform Infrared ; X-Ray Diffraction ; X-Rays

The crown-root ratio (C/R) theory of natural teeth has been widely recognized in the field of stomatology,and has important clinical significance in predicting and assessing the prognosis of natural teeth as well as for abutment selection during denture restoration. In the past few decades, scholars have advocated for the implantation of implants as long in length as possible to improve the success rate according to the theory of crown-root ratio of natural teeth. However, with the application of short implants, our philosophy of implantation has changed, and the relationship between the crown-implant (C/I) ratio and complications has become one of the current research hotspots. In this paper, the concept of the crown-implant ratio, the research progress of the C/I ratio, the implant survival rate and clinical complications of implant restoration were reviewed and summarized, and the following suggestions were put forward: although most studies have shown no significant correlation between the C/I ratio and implant survival or marginal bone loss, this relationship may increase the risk of mechanical complications. A C/I < 3 and a crown length < 15 mm are recommended in implant restoration; when ultra-short implants are applied, the implant system can increase the bone-to-implant contact area, and splint prostheses such as crown or bridge are recommended.

Objective To investigate the property of genipin-crosslinked silk fibroin(SF)/chitosan(CS) microspheres for slow releasing of bovine serum albumin (BSA). Methods BSA-loaded genipin-crosslinked SF/CS microspheres were prepared by emulsion cross-linking technique. The micropheres were observed for surface morphology and size distribution under scanning electron microscope (SEM), and X-ray diffractometry (XRD) and fourier transform infrared spectroscopy (FTIR) were used to analyze their structural characteristics. BCA method was used for determining the drug entrapment, loading rate and cumulative drug release in 21 days. Results The microspheres were spherical and showed a smooth surface with an average diameter of 7.84±0.97μm. The drug entrapment efficiency of the microspheres was (50.16±4.32)%with a drug loading ratio of (1.25 ± 0.11)% and a cumulative release of the total drug of (75.2 ± 2.53)% in 21 days. Conclusion Genipin-crosslinked SF/CS microspheres have a high drug entrapment efficiency and possess good capacity of sustained drug release.

Objective To investigate the property of genipin-crosslinked silk fibroin(SF)/chitosan(CS) microspheres for slow releasing of bovine serum albumin (BSA). Methods BSA-loaded genipin-crosslinked SF/CS microspheres were prepared by emulsion cross-linking technique. The micropheres were observed for surface morphology and size distribution under scanning electron microscope (SEM), and X-ray diffractometry (XRD) and fourier transform infrared spectroscopy (FTIR) were used to analyze their structural characteristics. BCA method was used for determining the drug entrapment, loading rate and cumulative drug release in 21 days. Results The microspheres were spherical and showed a smooth surface with an average diameter of 7.84±0.97μm. The drug entrapment efficiency of the microspheres was (50.16±4.32)%with a drug loading ratio of (1.25 ± 0.11)% and a cumulative release of the total drug of (75.2 ± 2.53)% in 21 days. Conclusion Genipin-crosslinked SF/CS microspheres have a high drug entrapment efficiency and possess good capacity of sustained drug release.

Objective:To explore the standardization of totally implantable venous power port of nursing process in CT enhancement and application effect of contrast medium injection, so as to provide a safer and more efficient way for contrast medium injection in CT enhanced examination for patients with malignant tumors.Methods:A non-randomized prospective study was conducted, 358 patients with malignant tumors were selected in Sun Yat-sen Memorial Hospital, Sun Yat-sen University who underwent CT enhanced examination from August 1, 2022 to July 31, 2023, 179 patients who had been implanted totally implantable venous power port were selected as the experimental group, and the standardized nursing procedure was given. The other 179 patients were the control group, using radiology routine high-pressure intravenous indwelling needle as the contrast medium access, with routine peripheral venous nursing process. The incidence of contrast medium extravasation during CT enhanced examination was observed and compared between the two groups.Results:All the patients were included. There were 85 males and 94 females, aged (55.50±11.72) years old in the control group. There were 83 males and 96 females, aged (54.50±12.24) years old in the experimental group. The incidence of contrast medium extravasation was 0 in the experimental group and 3.35%(6/179) in the control group. The difference between the two groups was statistically significant (Fisher exact probability, P<0.05). Conclusions:The application of standardized nursing procedure of totally implantable venous power port to the injection of contrast medium in CT enhanced examination of malignant tumor patients, can significantly reduce the incidence of contrast medium extravasation.

Objective : To explore the clinical effect of the alveolar crest approach in the treatment of odontogenic maxillary sinusitis and the repair of edentulous implants in this area. Methods: This was a retrospective case series of 20 patients with odontogenic sinusitis. The pathogenesis in each case was investigated. After elimination of the dental origin, each patient was treated with flushing, drainage and anti-inflammatories through the alveolar crest approach. Postoperative CBCT reexamination was performed to evaluate the therapeutic effect. Maxillary sinus elevation surgery with simultaneous or delayed implantation was performed after maxillary sinusitis healing was confirmed. The patients were followed postoperatively. Results : Twenty patients with odontogenic sinusitis were treated by the alveolar crest approach, and 17 were cured, for a cure rate of 85%. Among them, 17 of the maxillary sinusitis patients were followed for 1 year, with good results. Conclusion The alveolar crest approach is feasible for the treatment of odontogenic maxillary sinusitis and can serve as a minimally invasive method for the repair of edentulism in this area and implantation.

Objective : To investigate the effect of a laser-etched pure titanium surface on proliferation of the human osteosarcoma cell line MG63 and to provide a basis for study of implant surface modification. Methods: The pure titanium plate was cut into titanium pieces by a numerical control machine tool and divided into smooth surface and laser etching groups. The titanium surface of the laser etching group was etched with an Nd:YAG continuous wave laser using predetermined parameters, and the surfaces were observed by scanning electron microscopy (SEM). The surface micromorphology of each titanium sheet was evaluated. The relative element content of the titanium surface was measured by energy dispersive X-ray spectroscopy (EDS). The Ra value of each surface was determined using the Veeco roughness tester. MG63 cells were inoculated on 2 sets of titanium tablets. At 1, 3, and 6 h postinoculation, cell adhesion to the two groups of titanium sheets was observed under the microscope. At 24 h after inoculation, cellular F-actin was directly stained using immunofluorescence, and the morphology of the cytoskeleton was observed by laser confocal microscopy. Cell proliferation was examined at 1, 3, and 5 d using a MTS kit, and the data were analyzed with SAS 9.4. Results : The surface of the smooth surface group was smooth and flat, the element composition was pure titanium, and the roughness Ra was 179.23 nm. The surface of the laser-etched group formed a regular and uniform pore structure. The composition was mainly Ti, O, C, etc, and the surface roughness Ra was 14.11 μm. A large number of cells were uniformly distributed on the two titanium sheets in the observations at 1, 3, and 6 h. At 24 h postinoculation, MG63 cells were completely stretched on the two sets of titanium sheets and had extended a large number of pseudopods and microfilaments to cross-link with peripheral cells; moreover, the cell division phase was observed. The cell proliferation of the two groups at 1, 3, and 5 d showed a significant increase with time, indicating that no cytotoxicity occurred on the surfaces of the two groups. However, the cell proliferation in the laser-etched group was superior to that in the mechanical smooth surface group. Conclusion The surface morphology of titanium can be controlled by laser etching, which is conductive to increase the microstructure of implants without cytotoxicity and promoting osteoblast proliferation in the early stage.

Objective: To investigate the effect of pure titanium surface of large diameter TiO2 nanotubes modified by RGD peptide on the adhesion and proliferation of MG63 osteoblasts. to provide theoretical proof for developing titanium implants. Methods: Commercially pure titanium discs were divided into four groups and treated with SLA to obtain a microrough surface (SLA group). Then, nanotubes were imposed on this microrough surface by anodization (SLA+80 group). The surface was then modified by dopamine (DOPA) (DOPA Group), after which bioactive RGD peptide layers were generated on the TiO2 nanotube surfaces via electrochemical and molecular self-assembly techniques (RGD group). The titanium surface morphology and elemental composition of each group were characterized by field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS). MG63 cells were cultured in vitro to evaluate biological activities of titanium before and after treatment, including the evaluation of early-stage cell adhesion capacity by fluorescence microscopy, proliferation capacity by MTS assay, and mRNA expression of the cell osteoblast-related genes alkaline phosphatase (ALP) and osteocalcin (OCN) by qRT-PCR. Results: FE-SEM and XPS showed that hierarchical micro/nanosurfaces decorated with TiO2 nanotubes were produced on titanium using sandblasting and large grit etching combined with anodization, dopamine was then self-polymerized to form a polydopamine film on the TiO2 nanotube surfaces, and RGD peptides were then conjugated to the polydopamine film, finally forming RGD peptide-modified bioactive layers. In vitro experiments showed that compared with the other three materials, the RGD-modified material was more conducive to cell adhesion and proliferation (P < 0.05). The expression levels of ALP and OCN mRNA in the RGD group were significantly higher than those in the SLA group and DOPA group (P < 0.05). Conclusion Hierarchical micro/nanosurfaces decorated with TiO2 nanotubes functionally modified with RGD peptides have good biocompatibility and could be used for developing titanium implants and further improving early osseointegration.