Construction and Evaluation for Model of Goat Intervertebral Disc Degeneration Induced by Axial Compressive Stress / 医用生物力学

Objective To establish the model of goat intervertebral disc degeneration （IDD） induced by controllable axial compressive stress and evaluate its imaging and pathological characteristics. Methods Twenty goats were randomly divided into 4 groups (control group, 4-week pressure group, 8-week pressure group, 12-week pressure group, n=5, 40 N pressure). Disc height index (DHI) was used to evaluate the change of intervertebral disc height by X-ray, Pfirrmann classification method was used to observe the degree of intervertebral disc degeneration by magnetic resonance imaging (MRI), and histopathological observation and evaluation for intervertebral disc were conducted by HE staining and immunohistochemistry. Results DHI in control group showed no significant changes with the extension of pressure time, while DHI in the experimental group gradually decreased. There was no significant change in Pfirrmann classification in control group. In experimental group, with the extension of time, the higher the degeneration aggravated with the Pfirrmann classification increasing. In experimental group, HE staining showed that the disc nucleus pulposus decreased in volume and nucleus pulposus cells, which were gradually replaced by fibrous tissues. Immunohistochemical staining showed that type I collagen in the nucleus pulposus gradually increased, type Ⅱ collagen gradually decreased, and intervertebral disc degeneration occurred. Conclusions A certain axial compressive stress can lead to degeneration of goat lumbar intervertebral disc, and the degree of degeneration is gradually increased with the extension of time.

Accidental Blunt Abdominal Injury Causing Multiple Small Bowel Loops’ Avulsion from the Mesentery and Dismembered Colon

A 50-year-old male, truck driver, met with an accident with blunt steering wheel injury to the abdomen with no external marks ofinjury over the abdominal wall. He had severe abdominal pain with tossing up in bed. As the abdomen showed no external marksof injuries, strikingly, abdominal palpatory findings were prominent with severe tenderness in the left side umbilical and pelvicregions. He had consumed heavy food with liquids within an hour before the accident. He collided with another stationary lorry;thus, he received massive blow to his abdomen with the steering wheel. He displayed the signs of hemorrhagic shock on arrivalto the emergency care. Computed tomography scan confirmed moderate hemoperitoneum with multiple bowel perforations. Onexploratory laparotomy, multiple jejunal and ileal loops were found completely avulsed from the base of the mesentery, makingthem completely devascularized along with dismembered descending colon from the sigmoid. Resection of nonviable smallbowels and end-to-end jejunoileal anastomosis was done. Colocolic anastomosis was performed after adequate descendingcolon mobilization with protective loop ileostomy in the right lower quadrant. The patient had developed wound infection; hence,he was put on daily dressing. Gradually, the patient improved and was discharged with functioning ileostomy.

Internal Architecture Of Human Tali

Introduction: The talus is one of the seven tarsal bones. It is responsible for receiving the body weight andtransmitting it to the plantar arch below. The architecture of cancellous bone is based on its mechanical demands.The trabecular patterns of a bone are formed by the stress trajectories that are placed on that bone. The preferreddirectional orientation of the trabeculae thus provides a history of the stresses to which the bone has beensubjected.Aim: To study the internal architecture and pressure lines of human tali.Materials and Methods: 30 tali were dissected out from the formalin fixed lower limbs available at the Departmentof Anatomy of KVG Medical College, Sullia and they were dried and serial longitudinal (parasagittal), transverse(coronal) and horizontal sections of the bone were made in 10 each. The coronal sections were made at 3 levelsi.e at the body, neck and head. A good quality digital photograph of the cut surfaces were taken using a digitalcamera for analysis of the trabeculae of cancellous bone. Radiographs of the slices were also taken to study thepressure and the tension lines.Results: The sections showed an outer thin layer of compact bone, but it was much thicker at the neck of the talus.In the head, the cancellous bone was made of thick, parallel running semi-arched plates which consisted of twolimbs i.e vertical and horizontal which were continuous with each otherConclusion: It can be concluded that the part of compressive force, acting vertically downward on the body of thetalus during standing, was converted to tensile force in the neck, and its direction was made perpendicular, toenable this force to go toward the head of the talus. These findings may help in better understanding of fracturelines in the talus, which could improve internal fixation techniques, and help in designing of talar prosthesis.

The p38 MAPK and NF-κB Pathways are Involved in Cyclic Compressive Force-induced IL-6 Secretion in MLO-Y4 Cells

ABSTRACT We previously revealed the involvement of extracellular regulated protein kinases 1/2 (ERK1/2) in interleukin-6 (IL-6) secretion induced by cyclic compressive force (CCF) in MLO-Y4 cells. In this study, we investigated the contributions of the p38 mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) pathways to IL-6 secretion by stimulating MLO-Y4 cells with CCF. At 80% confluence, different magnitudes (1000μstrain, 2000 μstrain and 4000 μstrain), frequencies (0.5 Hz, 1.0 Hz and 2.0 Hz) and durations (10 min, 30 min, 1 h, 3 h and 6 h) of CCF were loaded onto cells using a four-point bending system. Flow Cytometry (FCM) analysis was used to analyze cell mortality rates after CCF loading. p38 and p65 phosphorylation as well as IκBα degradation in MLO-Y4 cells were detected by Western blotting (WB). Changes in IL-6 secretion after inhibitor treatment were assessed by enzyme-linked immunosorbent assays (ELISAs). Cellular viability was over 90 percent after CCF. p38 and p65 phosphorylation increased under all conditions, whereas IκBα protein levels decreased. However, phosphorylation and degradation were not completely dependent on the loading magnitude, frequency or duration. Furthermore, p38 inhibition using the specific inhibitor SB203580 reduced both p38 phosphorylation and IL-6 secretion. Similarly, NF-κB inhibition using BAY 11-7082 decreased p65 phosphorylation and IL-6 secretion but increased the concentration of IκBα. These findings reveal significant roles for the p38 and NF-κB signaling pathways in IL-6 secretion induced by CCF in MLO-Y4 cells.

The change of expression of interleukin-6 and -8 after the application of the static compressive pressure on the fibroblast originated from the periodontal ligaments

The fibroblast in the periodontal ligaments received various stress. Among them, compression and tension are quite important and they are related to the remodeling of tooth and alveolar bone. We studied the change of expression of interleukin-6 (IL-6) and interleukin-8 (IL-8) in the fibroblasts of the periodontal ligaments by real-time RT-PCR and ELISA. In results, the relative activity of IL-6 mRNA in 2 hours after was 1.54+/-0.08 and 1.00+/-0.05 in control and test, respectively (P<0.05). Its 12 hours after was 1.23+/-0.06 and 2.78+/-0.14 in control and test, respectively (P<0.05). The relative activity of IL-8 mRNA in 2 hours after was 1.00+/-0.05 and 0.24+/-0.01 in control and test, respectively (P<0.05). Its 12 hours after was 1.23+/-0.06 and 0.63+/-0.03 in control and test, respectively (P<0.05). The concentration of IL-6 was 1.02+/-0.16 ng/ml, 0.90+/-0.14 ng/ml, and 1.32+/-0.12 ng/ml (P<0.05) in control, 2, and 12 hours after, respectively. The concentration of IL-8 was 2.26+/-0.17 ng/ml, 1.70+/-0.26 ng/ml (P<0.05), and 0.84+/-0.47 ng/ml (P<0.05) in control, 2, and 12 hours after, respectively. In conclusion, the expression of IL-6 was significantly increased after the application of the static compressive force, but IL-8 was significantly decreased. Considering their known function, their expression is quite important in tooth and bone resorption.

MECHANICAL STRESS IN KNEE JOINT DURING RUNNING AT VARIOUS SPEEDS AND STEP LENGTHS / 体力科学

In order to give more effective instruction for running in sports medicine, the mechanical stresses in the knee joint during running at various speeds and step lengths were investigated.<BR>The subjects were five male sprinters. Running conditions were as follows : 1) running at four speeds (2.5 m/s, 4.5 m/s, 6.5 m/s and maximum running speed) with natural step lengths, 2) run-ning with three different step lengths (1.0 m, 1.5m and preferred step length) at 4.5 m/s running speed, and 3) running at maximum speed using four different step lengths (1.0 m, 1.5m 2.5m and preferred step length) . Running movements were recorded using a high speed video camera. And ground reaction forces were also measured by a force platform. The compressive force and shear force in the tibiofemoral joint were computed from the results of two dimensional motion analysis. That is, the external force caused by ground reaction forces, the internal force produced by the mus-cle to develop joint torque and total force (external+internal force) were computed for both com-pressive and shear forces.<BR>The total compressive force that affects the meniscus and articular cartilage in the tibiofemoral joint depended on the magnitude of internal force. The total compressive force increased with running speed and step length. Therefore, caution should be employed in changing running speed and step length for regulating the magnitude of total compressive force on the tibiofemoral joint. On the other hand, the total shear force that caused traction stress in the posterior cruciate ligament depended on the magnitude of external force. The posterior shear force was generated during the foot contact period, and increased with step length. As for total shear force in the tibiofemoral joint, care must be taken to regulate step length.