Background Osteoinductive ability of bone morphogenetic protein-2 (BMP-2) has been studied in recent reports. In this study, we evaluated
the efficacy of BMP-2 during distraction osteogenesis.
Methods A group of 24 Japanese white rabbits were divided into four groups randomly and underwent lengthening of the right femur.
Distraction was performed for 2 weeks (1.0 mm/day). Group A began distraction following a 7-day waiting period after surgery.
For all other groups (B–D), distraction was started immediately after surgery. Groups A and B did not undergo any surgical
intervention at the osteotomy site, as a control. The delivery system for rhBMP-2 used a polymer-coated gelatin sponge (PGS).
Buffer/PGS was implanted into the osteotomy site in group C, and group D received rhBMP-2/PGS. Callus was evaluated radiographically
at 1, 2, 4, and 6 weeks after the surgery, and all rabbits were killed at 6 weeks. One rabbit from each group was examined
histologically; the remaining five rabbits underwent biomechanical testing.
Results A significant increase in callus formation was evident in group D compared with that in other groups. In group D, regenerative
changes were evident during the earlier phase. Formation of bone cortex and bone marrow cavity was almost complete in group
D, and the cortex was thicker than that in the other groups. Torsional strength values (10−2 Nm) of each group were as follows: A, 118.7 ± 52.4; B, 160.0 ± 40.7; C, 106.8 ± 8.1; D, 266.1 ± 93.1. Stiffness values (10−3 Nm/degree) were as follows: A, 390.2 ± 137.2; B, 391.8 ± 158.4; C, 183.1 ± 78.5; D, 624.4 ± 214.2. Group D exhibited the
highest values for both torsional strength and stiffness.
Conclusions Acceleration of the regenerative changes during the early phase occurred in the BMP-2-treated group. The efficacy of BMP-2
in distraction osteogenesis was recognized radiographically, histologically, and by biomechanical testing (torsional strength
and stiffness). 相似文献
The aim of this study was to assess the radiologic and clinical outcome when beta-tricalcium phosphate is used as a bone graft substitute to backfill the fibular defect that is created by harvesting the fibula. Fourteen patients who had fibula resections to be used as bone grafts for bone tumor resections were assessed radiographically. Callus formation bridging the beta-tricalcium phosphate was seen in 12 of 14 patients at an average of 1.4 months after surgery. In these 12 patients the beta-tricalcium phosphate mostly was absorbed and replaced by newly formed bone at an average of 9.3 months after surgery. In all children, beta-tricalcium phosphate was replaced by newly formed bone at an average of 3.2 months after surgery. Only one adult patient had complete regeneration of the fibula. Few patients had continuity between the regenerated fibula and the native fibula. In one patient in whom free vascularized fibula was harvested, regeneration of the fibula was not observed. Clinical functional outcome was not correlated with successful fibula regeneration and union with the native fibula, as determined using radiographs. The results of the study suggest that, in children, regeneration of the fibula by implanting beta-tricalcium phosphate into a bone defect can reduce morbidity of the fibula harvest sites. 相似文献
BACKGROUND: Pre-clinical and clinical studies suggest that transplantation of bone marrow-derived stem cells can improve global cardiac function. However, no quantitative assessment of regional systolic contraction and correlation with phenotype has been made. Therefore, we used our model of cryoinfarcted rabbit myocardium for intracardiac transplantation of a mixed population of bone marrow-derived cells and assessed both regional function and myogenic conversion of the cells. METHODS: Nineteen New Zealand white rabbits underwent cryoinjury of the left ventricle. Autologous bone marrow (BM) cells were expanded in vitro. After 2 weeks, either 1 x 10(8) mixed BM-derived progenitor cells (BM group, n = 11) or vehicle (control group, n = 8) were injected into the cryoinjured region. Regional systolic function was measured using micromanometry and sonomicrometry before and 4 weeks after cell injection; cell phenotype was evaluated histologically. RESULTS: All animals in the BM group significantly improved both systolic shortening (0.11 +/- 0.7 vs -0.05 +/- 0.05 mm in the control group, p < 0.05) and regional stroke work when compared with control (9.6 +/- 2.4 vs -1.2 +/- 1.2 mm . mm Hg, p < 0.003). In addition, the BM group had improved global diastolic function, as measured by minimum dP/dt and end-diastolic pressure. On histologic assessment, BM cells differentiated toward a myogenic phenotype. CONCLUSIONS: Transplanting a mixed population of marrow-derived cells that can adopt a myogenic phenotype improves regional contractility and diastolic relaxation after myocardial infarction. 相似文献
Background: Propofol (2,6-diisopropylphenol) possesses vasodilating activity in vivo and in vitro. The propofol-induced relaxation of agonist-induced contractions in small resistance arteries has not been clarified.
Methods: The effect of propofol was examined on the contractions induced by norepinephrine and high K+ in endothelium-denuded rabbit mesenteric resistance artery in vitro. The effects of propofol on the [Ca2+]i mobilization induced by norepinephrine and high K+ were studied by simultaneous measurement of [Ca2+]i using Fura 2 and isometric force in ryanodine-treated strips.
Results: Propofol attenuated the contractions induced by high K+ and norepinephrine, the effect being greater on the high K+-induced contraction than on the norepinephrine-induced contraction. In Ca2-free solution, norepinephrine produced a transient contraction resulting from the release of Ca2+ from storage sites that propofol attenuated. In ryanodine-treated strips, propofol increased the resting [Ca2+]i but attenuated the increases in [Ca2+]i and force induced by both high K+ and norepinephrine. In the presence of nicardipine, propofol had no inhibitory action on the residual norepinephrine-induced [Ca2+]i increase, whereas it still modestly increased resting [Ca2+]i, as in the absence of nicardipine. 相似文献
We report two cases of coronary artery aneurysm including one case of the left main coronary artery aneurysm. The coronary angiogram of one patient, a 68-year-old male, having anterior chest pain on exertion, revealed left anterior descending coronary artery (segment 6) aneurysm of 7 mm in diameter with 90% stenosis distal to the aneurysm and 75% stenosis in the right coronary artery (segment 2). The coronary angiogram of another patient, a 69-year-old female, having chest pain unrelated to exertion, revealed left main coronary artery aneurysm of 25 mm in diameter and delayed filling of contrast medium into the left anterior descending coronary artery. We decided to operate by the reason of not only significant coronary artery stenosis but risks of myocardial infarction due to embolization inot distal coronary arteries and rupture of the aneurysm. We performed coronary artery bypass graftings using the great saphenous veins and closure of the coronary arteries running into and out the aneurysm under cardiopulmonary bypass. It is recomended that ligation of the coronary arteries connecting to the aneurysm or resection of the aneurysm followed by coronary artery bypass grafting is performed before developing myocardial infarction or rupture of aneurysm. 相似文献
BACKGROUND: A human thymoma is a thymic epithelial neoplasm and is characterized by its frequent association with myasthenia gravis. The histological characteristic of thymoma is coexistence of a large number of lymphocytes, including CD4(+)CD8(+) double positive T cells, phenotypes of the cortical thymocytes. To elucidate the role of these T lymphocytes in the pathogenesis of thymoma-associated myasthenia gravis, we examined the usage of alphabeta or gammadelta T cell receptor of the T lymphocytes in thymoma in conjunction with the positive selection event. MATERIALS AND METHODS: Thymomas were obtained from 28 patients. Nine patients were associated with myasthenia gravis. Lymphocytes were freshly isolated from the tumor tissue and were subjected to four-color flow cytometric analysis. RESULTS: The average proportion of TCRalphabeta(+) cells in thymomas associated with myasthenia gravis was 47.0% and was significantly higher (P = 0.0008) than that without myasthenia gravis (23.4%). Positive selection event was then examined in terms of CD69, a positive selection marker. The mean proportion of TCRalphabeta(+)CD69(+)CD4(+)CD8(-) cells in the myasthenic thymomas (8.22%) was significantly greater (P = 0.015) than the nonmyasthenic thymomas (2.99%). On the other hand, there was not a significant difference in the mean proportion of TCRalphabeta(+)CD69(+)CD4(-)CD8(+) cells between the myasthenic and the nonmyasthenic thymomas. CONCLUSIONS: The possible role of development of TCRalphabeta(+) T cells, especially the role of positive selection of TCRalphabeta(+)CD4(+)CD8(-) T cells in thymoma, was suggested in the pathogenesis of thymoma-associated myasthenia gravis. 相似文献
Primary spinal osteosarcoma is quite rare, and the 5-year survival rate is very low. Because of its rarity, successful treatment experience with spinal osteosarcoma is limited. The purpose of this study is to report the effect of therapy of primary osteosarcoma of spine by carbon-ion radiotherapy (CIRT) and long-term follow.
Methods
A 70-year-old with primary spinal osteosarcoma who received CIRT underwent combined anterior artificial vertebral body replacement and posterior lumbar fusion (L1–L5) 3 years later.
Results
According to the surgical resection of tumoral lesion, pathological results showed that the intertrabecular space previously filled with tumor cells on the initial biopsy sample now contained necrotic tissue without tumor cells. This means that primary osteosarcoma of the spine was completely eliminated and achieved local control with CIRT, with a 7-year follow-up after the initial treatment.
Conclusions
Carbon ion beam treatment is an effective local treatment for patients with spinal osteosarcoma for whom surgical resection is not a feasible option, especially for elderly patients. However, more patients need to be evaluated over a longer term to assess the curative effect of CIRT.
Previously, we reported that allogeneic skin grafts were rapidly rejected by CD28 and CD40 ligand double deficient mice mediated by CD8+ T cells. These results indicated that some elements in addition to CD28- and CD40-mediated costimulation provide stimulatory signals for the activation of donor-specific CD8+ T cells. In this report, we investigated the role of inflammation associated with transplantation on costimulation-independent priming of CD8+ T cell during graft rejection. B6 RAG1 KO mice were transplanted with BALB/c-skin and adoptively transferred with syngeneic CD8+ T cells the same day or 50 days after transplantation. When blockade of CD28- and CD40-mediated costimulation failed to prevent acute rejection of freshly transplanted skin grafts, it efficiently delayed rejection of well-healed skin grafts. These results showed that factors associated with transplantation have essential roles in inducing costimulation blockade-resistant allograft rejection. Costimulation blockade failed to prevent acute graft-infiltration of NK cells and increasing expression of intragraft IL-12 and IL-15. These factors may trigger the graft-infiltration and priming of CD8+ T cells to induce costimulation blockade-resistant allograft rejection. 相似文献
The incidence of a tracheal bronchus—that is, a congenitally abnormal bronchus originating from the trachea or main bronchi–is
0.1%–2%. Serious hypoxia and atelectasis can develop in such patients with intubation and one-lung ventilation. We experienced
a remarkable decrease in peripheral oxygen saturation () and a rise in airway pressure during placement of a double-lumen endobronchial tube in a patient with patent ductus arteriosus
and tracheal bronchus. Substitution of the double-lumen tube with a bronchial blocker tube provided secure isolation of the
lung intraoperatively. A type I tracheal bronchus and segmental tracheal stenosis were identified on postoperative three-dimensional
(3D) computed tomographic (CT) images. Preoperative examination of chest X-rays, CT images, and preoperative tracheal 3D images
should preempt such complications and assist in securing safe and optimal one-lung ventilation. 相似文献