Dynamic Changes in the Renal Function of Acute Myocardial Infarction Patients with Reduced eGFR After Emergency Percutaneous Coronary Intervention.

Renal dysfunction greatly influences decision-making for emergency percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). This observational study investigated renal function changes and risk factors for renal injury in patients with AMI with reduced estimated glomerular filtration rate (eGFR) who underwent emergency PCI. The study included 85 patients with AMI with decreased eGFR who underwent emergency PCI, categorized into stage 2, 3, and 4 chronic kidney disease groups. Baseline data, laboratory indicators, coronary characteristics, and serum creatinine concentration were monitored at multiple time points. Renal injury was defined using two criteria: an increase in serum creatinine level by 0.3 mg/dL or a 50% increase from baseline. During the 1-year follow-up, renal injury incidence varied from 1.18% to 15.29%. The pattern showed an increasing trend in the 1st week after PCI, peaking at 1 week, followed by a decrease at 3 months, and another increase at one year. Low basal eGFR, high contrast agent dosage, and diabetes were associated with renal injury according to logistic regression analysis. The eGFR cutoff value of 35.475 mL/minute·1.73 m2 had a sensitivity of 83.05% and specificity of 57.69% for predicting renal injury based on receiver operating characteristic curve analysis. In summary, patients with AMI with basal eGFR lower than 35.475 mL/minute·1.73 m2 have a higher risk of renal injury after PCI. These findings emphasize the importance of assessing renal function and considering associated risk factors when deciding on emergency PCI for AMI with reduced eGFR.

A Novel Anterior Transpedicular Screw Artificial Vertebral Body System for Lower Cervical Spine Fixation: A Finite Element Study.

A finite element model was used to compare the biomechanical properties of a novel anterior transpedicular screw artificial vertebral body system (AVBS) with a conventional anterior screw plate system (ASPS) for fixation in the lower cervical spine. A model of the intact cervical spine (C3-C7) was established. AVBS or ASPS constructs were implanted between C4 and C6. The models were loaded in three-dimensional (3D) motion. The Von Mises stress distribution in the internal fixators was evaluated, as well as the range of motion (ROM) and facet joint force. The models were generated and analyzed by mimics, geomagic studio, and ansys software. The intact model of the lower cervical spine consisted of 286,382 elements. The model was validated against previously reported cadaveric experimental data. In the ASPS model, stress was concentrated at the connection between the screw and plate and the connection between the titanium mesh and adjacent vertebral body. In the AVBS model, stress was evenly distributed. Compared to the intact cervical spine model, the ROM of the whole specimen after fixation with both constructs is decreased by approximately 3 deg. ROM of adjacent segments is increased by approximately 5 deg. Facet joint force of the ASPS and AVBS models was higher than those of the intact cervical spine model, especially in extension and lateral bending. AVBS fixation represents a novel reconstruction approach for the lower cervical spine. AVBS provides better stability and lower risk for internal fixator failure compared with traditional ASPS fixation.

Real-time monitoring of stresses and displacements in cervical nuclei pulposi during cervical spine manipulation: a finite element model analysis.

OBJECTIVE: The objective of this study was to research the distribution of stresses and displacements in cervical nuclei pulposi during simulated cervical spine manipulation (CSM). METHODS: A 3-dimensional finite element model of C3/4~C6/7 was established. The detailed mechanical parameters of CSM were analyzed and simulated. During the process, the changes in stresses and displacements of cervical nuclei pulposi within the model were displayed simultaneously and dynamically. RESULTS: Cervical spine manipulation with right rotation was targeted at the C4 spinous process of the model. During traction, levels of stresses and displacements of the nuclei pulposi exhibited an initial decrease followed by an increase. The major stresses and displacements affected the C3/4 nucleus pulposus during rotation in CSM, when its morphology gradually changed from circular to elliptical. The highest stress (48.53 kPa) occurred at its right superior edge, on rotating 40° to the right. It protruded toward the right superior, creating a gap in its left inferior aspect. The highest displacement, also at 40° right, occurred at its left superior edge and measured 0.7966 mm. Dimensions of stresses and displacements reduced quickly on rapid return to neutral position. CONCLUSION: The morphology of the C3/4 nucleus pulposus changed during CSM with right rotation, and it created a gap in its left inferior aspect. Biomechanically, it is more safe and rational to rotate toward the healthy side than the prolapsed side of the intervertebral disk during CSM. Upon ensuring due safety, the closer the application force is to the diseased intervertebral disk, the better is the effect of CSM.

Structure-activity relationships of 3-O-ß-chacotriosyl oleanane-type triterpenoids as potential H5N1 entry inhibitors.

A series of 3-O-ß-chacotriosyl oleanolic acid analogs have been designed, synthesized and evaluated as H5N1 entry inhibitors based on a small molecule inhibitor saponin 1 previously discovered by us. Detailed structure-activity relationships (SARs) studies on the aglycone of compound 1 indicated that the subtle modification of oleanolic acid as an aglycon has key influences on the antiviral activity. These results suggested that either the introduction of a disubstituted amide structure at the 17-COOH of OA or alteration of the C-3 configuration of OA from 3ß-to 3α-forms can significantly improve the selective index while maintaining their antiviral activities in vitro. Compound 8 was selected for further mechanistic study because of its distinguished inhibition activity and good selective index. Molecular simulation study and surface plasmon resonance analysis confirmed that compound 8 stabilized HA2 subunit of hemagglutinin (HA) by binding with amino acid residues LYS-26, ASN-53, ASN-27 and ASN-50, therefore may prevent HA from conformational rearranging, which is a critical step for viral entry.

Biomechanical analysis of differential pull-out strengths of bone screws using cervical anterior transpedicular technique in normal and osteoporotic cervical cadaveric spines.

STUDY DESIGN: Biomechanical in vitro study. OBJECTIVE: To determine whether the peak pull-out force (PPF) of cervical anterior transpedicular screw (ATPS) fixed in osteoporotic vertebrae positively influence screw stability or not before and after fatigue. SUMMARY OF BACKGROUND DATA: Multilevel cervical spine procedures with osteoporosis can challenge the stability of current screw-and-plate systems. A second surgical posterior approach is coupled with potential risks of increased morbidity and complications. Hence, anterior cervical instrumentation that increases primary construct stability, while avoiding the need for posterior augmentation, would be valuable. METHODS: Sixty formalin-fixed vertebrae at different levels were randomly selected. The vertebrae were divided into healthy controls (groups A1, A2), osteoporotic controls (B1, B2), healthy ATPS groups (C1, C2), osteoporotic ATPS groups (D1, D2), and osteoporotic restoration controls (E1, E2). The procedure of ATPS insertion was simulated with 2 pilot holes being drilled on each side of 20 vertebral bodies that were implanted with either vertebral screw or polymethylmethacrylate. Each side randomly received either instant PPF or PPF beyond fatigue (2.5 Hz; 20,000 times). RESULTS: The prefatigue PPFs were significantly higher than the postfatigue PPFs in all groups (group A: 366.06 ± 58.78 vs. 248.93 ± 57.21 N; group B: 275.58 ± 23.18 vs. 142.79 ± 44.78 N; group C: 635.99 ± 185.28 vs. 542.57 ± 136.58 N; group D: 519.22 ± 122.12 vs. 393.16 ± 192.07 N, and group E: 431.78 ± 75.77 vs. 325.74 ± 95.10 N). The postfatigue PPFs were reduced by 32.00% (group A), 48.19% (group B), 14.69% (group C), 24.28% (group D), and 24.72% (group E). The acute and postfatigue PPFs of both control groups were significantly lower than that of ATPS groups (P < 0.05). The cyclic osteoporosis ATPS group achieved the same PPF compared with the vertebral restoration screw group. CONCLUSION: The findings of this study suggest that instant PPF and fatigue resistance capability of an ATPS fixation were significantly better than other control groups, especially in the osteoporotic vertebrae.

Structure-activity relationships of 3-O-ß-chacotriosyl ursolic acid derivatives as novel H5N1 entry inhibitors.

A series of methyl ursolate 3-O-ß-chacotrioside analogs have been designed, synthesized and evaluated as H5N1 entry inhibitors based on a small molecule inhibitor saponin 3 previously discovered by us. Detailed structure-activity relationships (SARs) studies on the aglycone of compound 3 indicated that both the type of pentacyclic triterpene and the subtle modification of ursolic acid as an aglycon had key influences on the antiviral activity. These results suggested that either the introduction of a disubstituted amide structure at the 17-COOH of ursolic acid or alteration of the C-3 configuration of ursolic acid from 3ß-to 3α-forms was helpful to significantly improve the selective index while keeping their antiviral activities.

[The effect of bending and rotation on the lumbar facet joints under load-bearing conditions].

OBJECTIVE: To evaluate the effect of bending and rotation on the lumbar facet joints under load-bearing conditions. METHODS: Eight lumbar-sacral spines (L1-S1) taken from fresh young adult cadavers were placed on the MTS system. The forces of the two facet joints of the L4-5 motion segments were measured using pressure sensitive films. The specimens were measured in erection, bending and rotation postures. RESULTS: In erection posture the L4-5 facet joints could support 31.16+/-7.15 N of 400 N which was axial compressing load. In bending 15 degree posture the forces of each side of the L4-5 facet joints were equal, and were found to have no marked effect on the force in erection. Yeat only opposite facet joints could endure force in rotation, but the force was 7 times that in erection. CONCLUSION: Both sides of lumbar facet joints could support load in bending position but only the opposite could endure load in rotation.

Palmar tilt changes due to distal radius fractures and radiocarpal instability: a biomechanical study.

OBJECTIVE: To investigate the impact of dorsally angulated malunited distal radius fractures on the stability of the radiocarpal joint. METHODS: Eight fresh upper limb specimens from 4 human cadavers were obtained, in which radial osteotomy was performed to prepare models of Frykman I distal radius fracture. Pressure-sensitive film was applied to study the changes in the contact area distribution and the pressure load across the radiocarpal joint in response to palmar tilt variation, and the lateral radiograph of the wrist was taken at the end of pressure loading. RESULTS: When the dorsal tilt exceeded 10 degrees, the radioscaphoid and radiolunate articular contact areas were markedly decreased (P<0.01) and shifted to the dorsal aspect of the radiocarpal joint, where the pressure load was significantly increased (P<0.01). A dorsal radiocarpal subluxation was liable to occur on the sagittal plane when the dorsal tilt exceeded 40 degrees. CONCLUSION: A dorsal tilt over 10 degrees is the most primary cause of radiocarpal instability after a dorsal deformity due to distal radius fractures.

A new internal fixation system using vertebral pedicle screw for unstable lumbar spine: an in vitro biomechanical stability evaluation.

OBJECTIVE: To evaluate the effect of a new internal fixation system utilizing vertebral pedicle screw in fixing unstable lumbar spine in vitro. METHODS: Twelve lumbar spine specimens (L(2 to 5)) obtained from fresh human cadavers were randomly divided into 2 equal groups, namely groups A and B. All intact specimens were subjected to nondestructive testing in 6 loading modalities on a universal testing machine, before complete L(2 to 5) instability was produced by means of a wedge fracture induced by resection of the posterior ligamentous structures. Specimens in group A were fixed with the new internal fixation system, and group B with SOCON pedicle screw. The same nondestructive testing was repeated to determine the structural stability of the spine after fixation in both groups. RESULTS: The injured spines fixed with implants in both groups were significantly more stable than the intact specimens in all modes of tests (P < 0.05), especially in flexion and extension tests, in which a stability increase by 62.8% for flexion and 63.9% for extension was recorded in group A, and 54.9% for flexion and 51.0% for extension in group B. The two fixation systems exhibited similar effect in stabilizing the injured lumbar in all the 6 loading modalities (P < 0.05). CONCLUSION: This internal fixation system with vertebral pedicle screw is capable of providing biomechanical stability for unstable lumbar spine.

[Registration of the image data of the Virtual Chinese Female No.1].

In this study, the authors attempt to find a solution for the image registration before three-dimensional reconstruction of digitized Virtual Chinese Female No.1 (VCH-F1) image data can be completed. On the basis of a thorough understanding of the features of the image data, the parameters were determined based on the marker outside the specimen and the least-square procedure performed on the outline offset distance between two images, prior to the completion of the image registration by means of rigid body transformation with the parameters. In the trial application of these two methods in image registration for these image data, good results were obtained, which approved of the application of the two methods for accomplishing the image registration with simpler calculation processes and easier computer processing.

[Establishment of Internet-based database of the Virtual Chinese Human dataset].

To establish an Internet-based database for the dataset of Virtual Chinese Human that is accessible to the interested researchers, modifications and compression of the original VCH-format dataset of Virtual Chinese Human were performed before it was uploaded to the server, and RAID0+1 storage technology was adopted with specific download accesses designed for different users. After dataset modification and compression, the data size was considerably reduced to allow convenient data storage and transfer. The RAID0+1 storage technology guarantees the security and high-speed download of data through different means established. Internet-based database provides important accesses for sharing the achievement in virtual human study between world-wide researchers, which has been imperative in the present situation of science development.

[Research report of experimental database establishment of digitized virtual Chinese No.1 female].

OBJECTIVE: To establish digitized virtual Chinese No.1 female (VCH-F1) image database. METHODS: A 19 years old female cadaver was scanned by CT, MRI, and perfused with red filling material through formal artery before freezing and em- bedding. The whole body was cut by JZ1500A vertical milling machine with a 0.2 mm inter-spacing. All the images was produced by Fuji FinePix S2 Pro camera. RESULTS: The body index of VCH-F1 was 94%. We cut 8 556 sections of the whole body, and each image was 17.5 MB in size and the whole database reached 149.7 GB. We have totally 6 versions of the database for different applications. CONCLUSIONS: Compared with other databases, VCH-F1 has good representation of the Chinese body shape, colorful filling material in blood vessels providing enough information for future registration and segmentation. Vertical embedding and cutting helped to retain normal human physiological posture, and the image quality and operation efficiency were improved by using various techniques such as one-time freezing and fixation, double-temperature icehouse, large-diameter milling disc and whole body cutting.

Construction of dataset for Virtual Chinese Male No.1.

OBJECTIVE: To establish digitized Virtual Chinese Human Male No.1 (VCH-M1) image dataset with a 0.2-mm equal interval. METHODS: The body of a 24-year-old male was used for this study. Perfusion with phenol and vermilion of the arteries was performed, followed by body shape adjustment by cold saline and pre-embedding with broken ices in an upside-down position, which was completed in a stepwise procedure to minimize body shape deformation. Section milling was conducted subsequently with the section thickness of 2 mm and the section images were captured by digital camera, which were immediately transferred to a computer for storage and processing. RESULTS: A total of 9 232 sections were obtained for the whole body, and the resolution of each of the image in TIF format was 3 024x2 016 pixels, resulting in the size of approximately 18 M for each image and about 161 G for the whole dataset. CONCLUSIONS: Compared with VCH-F1, the image quality in VCH-M1 dataset is significantly improved, demonstrated by much clearer tissue boundary in the images and minimized body shape deformation during the embedding process.

[Immunization with the fusion protein of GBD of Streptococcus mutans glucan binding protein-A against dental caries in SD rats].

PURPOSE: To observe the effect of immunization with the fusion protein of GBD of Streptococcus mutans glucan binding protein-A against dental caries. METHODS: Purified fusion protein of GBD of Streptococcus mutans glucan binding protein-A was used to immune SD rats by subcutaneous injection route. The rats were fed with Keyes Diet 2000 and infected by S.mutans. The caries level was determined and the result was analyzed by t test. RESULTS: The caries score of SD rats decreased in the group of immunized with GBD fusion protein,P<0.01. CONCLUSION: Immunization with GBD fusion protein resulted in significantly reduced dental caries after infection with S.mutans Ingbritt. Supported by PLA Tenth Five-Year Key Project (01Z089).

[3D image analysis of nasal orbit fossa through a laser scanner: a new method and application of 3D image].

OBJECTIVE: This study was to introduce the method for obtaining accurate 3D data of soft tissues using a 3D scanner under non-contact condition and the standard 3D measurement of the nasal orbit fossa for plastic surgery. METHODS: A 3D laser scanner and the Geomagic software were used to obtain the standard facial contour of 30 Chinese people. The nasal orbit fossa, as the feature of beauty, was measured and the data were analyzed. RESULTS: 3D measurement exhibited the three-dimensional facial shape at every meaningful angle, with the advantages of high precision of 0.01 mm. We determined the lowest point and described the 3D feature of the nasal orbit fossa. CONCLUSIONS: This method can illustrate the relation of the nasal orbit fossa and the surrounding structure. It is a new approach to facilitate preoperative plans, operation simulation and postoperative evaluation.