骨膜下ｔｉｓｓｕｅ ｅｘｐａｎｓｉｏｎを用いたか粒状ヒドロキシアパタイトによる下顎増骨術に関する実験的研究

Repair was compared in 4.4mm experimental rat mandibular ramus defects implanted with dense or porous HA particles with or without a plaster binder. Animals were sacrificed 6 months postimplantation. Specimens underwent gross, radiographic, histochemical and X-ray microanalytical examination. Gross and radiographic examinations showed good particle containment or retention only in defects filled with implants containing plaster. Only porous HA/plaster filled defects showed bone formation throughout the implant when examined histochemically by the PATS reaction and by X-ray microanalysis. They also showed greater radiographic opacity compared to dense HA/plaster implants. Only porous HA/plaster implants showed macroscopic bone formation. Examination of defects filled with porous HA/plaster or porous HA alone by the PATS reaction showed new cancellous bone around, and through the pores of, retained particles. The dense HA/plaster implants showed some new bone around the rims of the defects with only occasional bony incorporation of an HA particle. Dense particles in other areas showed only soft tissue encapsulation. Defects implanted with dense HA without plaster showed no new bone formation but retained particles were incorporated by fibrovascular tissue.

ABSTRACTSintered ceramic, nonresorbable hydroxylapatite (HA) is a calcium phosphate biomaterial widely employed alone for augmentation or maintenance of the mandibular ridge and for filling alveolar bony defects. The small particles used for ridge augmentation or periodontal defects tend to scatter and the larger blocks used for extraction sockets don't fit well. Our recent studies suggest that these problems can be circumvented by composite plaster of Paris/HA implants. In addition to binding the HA particles, the plaster makes the implants easier to shape. Plaster is not only very biocompatible but may actually help prevent infection. It appears to act as a scaffold for incorporation of the HA particles into osseous tissue. In several days the plaster is resorbed but it is replaced at the same rate by infiltrating fibrovascular tissue; plaster definitely promotes the filling of osseous defects initially by connective tissue. This tissue not only maintains the form and integrity of the implant, but its vascular and collagen components promote healing and contribute to subsequent filling of the defects and approximation of the HA particles by new cancellous bone. These composite implants can be preformed on casts prior to surgery or tailored during the surgical procedure. Their use precludes the difficulties encountered when plaster alone is implanted (resorption) or when HA alone is used (particle scatter or nonpenetration of the material by host vascular and connective tissues). By having a resorbable component which permits penetration by fibrovascular tissue and a nonresorbable component which can act as a nidus for new cancellous bone formation, these composite alloplasts act like artificial bone. Their use to support a denture, or for immobilizing teeth and reducing pocket depths in advanced periodontal disease, gives better results than HA alone.

Infrabony defects of 230 periodontal patients have been treated surgically by implantation. These lesions of alveolar bone, up to nineteen per patient, generally displayed pocket depths of at least 8mm and were associated with teeth showing pronounced mobility. Approximately 50% of these teeth could have ordinarily been condemned to extraction. In this study, scaling, root planing, and polishing were performed and patients were instructed in oral hygiene measures prior to surgical implantation. A 1:1 mixture of dense sintered hydroxylapatite(HA) particles (OrthoMatrix HA-500) with plaster of Paris (USG Medical Grade Calcium Sulfate Hemihydrate B, containing 0.85% K2SO4) was moistened with a minimum amount of saline. The mixture was then implanted into the dried defect. After setting, the operative site was closed with silk sutures. The plaster bound the HA particles in the defects and prevented particle straying which frequently occurs when they are implanted with saline alone or with other vehicles. There was an almost immediate and sustained diminution in tooth mobility at most implantation sites. Good retention of particles was seen on physical and radiographic examination of most defects for the length of the study (5 years). Overall, there was a marked reduction in pocket depth and improvement in tissue tone and texture. Less than 1% of the teeth at the implantation sites have been lost. No significant inflammation has been observed. Increased radiopacity and resistance to probing suggest bone formation in some implanted defects. Implantation of periodontal osseous defects with the biocompatible HA/plaster composite appears to result in the clinical cessation of progressive periodontal disease.

Composite hydroxylapatite (HA)/plaster alloplasts were studied for frontal and parietal cranioplasty. The experimental defects were created in 61 anesthetized cats. They were filled with a moist 2:1 mixture of durapatite/plaster or Interpore/plaster containing 0.85% potassium sulfate. After setting, the implant site was sutured. The filled defects were very firm by physical examination and showed little particle scatter by radiography. At the time this report was prepared only 43 of the cat skulls were available for examination. After sacrifice, postmortem visual examination (VE) of the skulls suggested that new bone had formed over some implants. In most implants, however, VE could not determine whether new bone had formed between the HA particles. Probing examination (PE) of the parietal implants with a periodontal explorer gave a better indication; the presence of new bone rather than soft tissue between the HA particles was confirmed by x-ray microanalysis. The ventral surfaces (VS) of the parietal implants showed greater degrees of bone formation by PE; only 12 of 43 parietal implants showed a high degree of bone formation on the dorsal surfaces (DS) by PE whereas 34 of 43 showed this on the VS. The highly significant difference (^3X) in the amount of bone formation on the VS compared with the DS suggests that this osteogenesis, like that observed in cranial trauma, may be stimulated by the dura which acts as a periosteum by supplying blood vessels to the implant.

Summary Introduction. Hydroxyapatite (HAp) scaffolds have become an alternative to autologous bone grafts in orthopedic surgery, because it is possible to fill larger scale bone defects and of the decreased operation time and complication risks at the graft donor site, a promising method in bone regeneration is to load bone marrow - mesenchymal stromal cells (BM-MSCs) on to a HAp scaffold. Aim of the Study. The aim of our study is to compare subcutaneous tissue reaction of experimental animals to implantation of HAp and HAp that is coated with BM-MSCs. Materials and Methods. Autologous BM-MSCs were cultivated from crista iliaca dextra biopsy, 4 HAp ceramic implants were coated with BM-MSC and implanted in subcutaneous tissue on one side and non-coated HAp implants on the other side of the spine of 4 rabbits. Immunohistochemical staining of BM-MSC and connective tissue included TUNEL assay, NFkBp105, HSP 70k, Wnt1, TNF-α, VEGF, MMP-2 antibodies, microscoped at 400X magnification and analyzed semiquantitatively. Results. Routine staining with haemotoxilin and eosin demonstrated formation of granulation tissue around the HAp implant, which was more distinct on the control side. There was an increased number of NFκB p105 positive cells (fibroblasts, myocytes, endotheliocytes) on the experimental side (+++), in comparison to the control side (++). HSP70 and apoptosis index was decreased on the experimental side (++ and 60%), in comparison to the control side (+++ and 70%). Number of MMP2 positive structures was increased on the control side in the fibrous capsule (++), in comparison to the experimental side, where the result varied (0 - +) Conclusions. Cultured BM-MSC activity is partly limited due to the apoptosis, which is probably induced by environmental factors. BM-MSC coated HAp implant stimulates secretion of proliferation marker NFkBp105 in subcutaneous tissue, decreases cell stress, apoptosis and tissue degradation (decreased HSP 70, apoptotic cell count and MMP 2) to improve the local tissue quality and proving BM-MSC tissue protective effect

Composite grafting of the maxillary sinus for placement of endosteal implants. A preliminary report of 48 patients

The scanning electron microscopy of the thyroid gland was done in 16 naturally dead camels (n=16) of both sexes at Veterinary Clinical Complex, RAJUVAS, Bikaner, Rajasthan. The scanning electron microscopy (SEM) of collected thyroid gland was done at Department of Veterinary Microbiology, College of Veterinary and Animal Science, Bikaner. The thyroid gland was covered by a thick fibrous connective tissue capsule and the parenchyma was made up of numerous follicles. The external forms of the follicles were mostly oval and elliptical. Some irregular follicles were observed. The size of the thyroid follicle ranged between 550-800 |rm in summer and 80-350 pm in the winter season. The interfollicular or interstitial connective tissue separated the follicles. The parafollicular or “C” cells were also seen in between the thyroid follicles. The thyroid follicles were filled with gel-like round substances called colloid substances. The follicular epithelium cells of the thyroid gland were squamous to low cuboidal in shape.

Objective To observe the change of fibrous capsular thickness around the expander,and to explore the effect of chitosan on the capsular thickness,in order to find a useful approach to diminish elastic shrinkage.Methods Two animal models (expander group and control group) were set up,in which expandor was embedded with or without chitosan interfere,15 animals each group.Tissues around the expander were sampled and stained with HE in the experimental and control animals.15 pieces of campus visualis were randomly selected in each group,and then thickness of fibrous capsules measured by use of a microscale,and the variability of data obtained in the two groups.The shrinkage rates of the full flap were also calculated by the computer image analysis system.Results The thickness of the fibrous capsule in the group treated with chitosan was (516.000±128.491)μm,that in the control group was (833.000±227.379)μm,and the difference between two groups had statistic significance (P＜0.05).The shrinkage rate of the experimental group was (43.371±7.312)%,that of the control group was (45.637±6.613)%,and the difference of two groups also had statistic significance(P＜0.05).Conclusion Chitosan interferes with the formation of fibrous capsule around the expander,so that its thickness is thinned and elastic recovery weaken. Key words: Chitosan; Fibrous capsule; Elastic recovery

Osteoconduction at porous hydroxyapatite with various pore configurations

Posterior component separation has become a common approach to complex abdominal wall reconstructions. This technique includes creation of an extraperitoneal retromuscular space for subsequent large synthetic mesh reinforcement. In certain cases, when complete restoration of "posterior" layer is precluded by significant tissue loss/damage, one proposed strategy is to replace the posterior fascia with an absorbable synthetic polyglactin (Vicryl) mesh. However, the safety of this strategy to prevent mesh-related visceral complication is unknown. Herein, we aimed to characterize mesh-viscera adhesion profiles and host tissue response of synthetic mesh either exposed directly to the viscera, or protected with Vicryl mesh. Using adult Yorkshire pigs, 5×5cm pieces of mesh were secured to the intact peritoneum in each of the four quadrants (n=6 pigs, 24 mesh samples). The study groups were Vicryl (V), Marlex (M), Softmesh (S), Marlex+Vicryl construct (MV), Softmesh+Vicryl construct (SV). The self-made composite meshes were then implanted with the Vicryl side facing the exposed viscera. The pigs were survived for 60days. At necropsy, grossly, the extent and tenacity of visceral adhesions were evaluated using established scales. Histologically, all specimens for fibrous encapsulation on the visceral surface of the mesh were reviewed by an experienced pathologist blind to meshes used. At necropsy, all Vicryl meshes were completely resorbed. The mean adhesion and tenacity scores for M and MV were 1.8 and 1.1 (P>0.05), 2.0 and 1.5 (P>0.05), respectively; while the mean adhesion extent scores and tenacity scores for S and SV were 2.0 and 1.2 (P>0.05), 2.0 and 1.7 (P>0.05). No significant difference in adhesion extent and tenacity was observed between Synthetic and Vicryl composite mesh groups. Histologically, Marlex+Vicryl mesh and Softmesh+Vicryl mesh constructs had thicker fibrous capsules than the corresponding unprotected Marlex and Soft mesh implants. Furthermore, visceral adhesions in the composite groups were noted to be to the fibrous capsule and not synthetic mesh itself. Utilization of the absorbable polyglactin (Vicryl) mesh as a separating layer between a synthetic mesh and intestines, did not reduce adhesions across various mesh types and composites. Histologically, however, a thick fibrous capsule replaced the Vicryl mesh and may be an important layer to prevent intestinal erosion into retromuscular synthetic meshes.

Objective: To investigate the tissue response and the biomineralization ability of CER prepared with epoxy resin or water compared to Mineral Trioxide Aggregate (MTA). Material and Methods: Polyethylene tubes containing materials or empty tubes for control were inserted into the subcutaneous tissues of 30 rats. After 7, 15, 30, 60, and 90 days, the rats were killed and the tubes were removed for analysis using hematoxylin-eosin staining, von Kossa staining, and under polarized light. Inflammation was graded through a score system; the thickness of the fibrous capsule was classified as thin or thick; the biomineralization ability was recorded as present or absent. The results were statistically analyzed using the Kruskal-Wallis test (p<0.05). Results: Histologic analysis performed after 7 and 15 days for CER prepared with epoxy resin or water and for MTA showed moderate inflammation and a thick fibrous capsule (p>0.05). After 30, 60, and 90 days, mild inflammation, and a thin fibrous capsule were observed in all groups (p>0.05). Conclusion: All materials had structures positive for von Kossa and birefringent to polarized light. CER epoxy resin showed biocompatibility and biomineralization similar to CER water and MTA.

A 20-year-old woman presented to the endocrinologist with an enlarged thyroid. The patient had no history of thyroid disease. On palpation, a firm right thyroid lobe nodule was detected, measuring 6 × 7 cm. No palpable lymph nodes were evident in the neck. Iodine-131 thyroid scintigraphy revealed a cold nodule in the right thyroid lobe. Thyroid function test results were normal; serum concentration of calcitonin and thyroglobulin were within the reference range. Fine-needle aspiration biopsy did not yield sufficient material for diagnosis.Right thyroidectomy was performed without lymph node dissection. Grossly, the thyroid lobe was almost entirely replaced by a firm nodule that measured 6 × 7 × 3 cm. The cut surface was white and lobulated by the fibrous capsule (Figure 1). Microscopically, the tumor was highly cellular and composed of sheets of spindle cells that formed intersecting or streaming fascicles separated by sparsely cellular stromal septa (Figure 2; hematoxylin-eosin, original magnification ×250) and partially circumscribed by a thick fibrous capsule. Small tubulopapillary epithelial foci were intermingled within the spindle cells (Figure 3; hematoxylin-eosin, original magnification ×400). Tumor cells lacked nuclear atypia and mitoses were rare (<2 mitosis per 10 high-power fields). Immunohistochemically, most of the tumor cells, including spindle type, were strongly positive for pancytokeratin (Figure 4; immunohistochemistry, original magnification ×400). The α-smooth muscle actin and vimentin were positive for a few spindle cells. Reaction to epithelial membrane antigen (EMA), desmin, thyroglobulin, calcitonin, and S100 protein were negative.What is your diagnosis?We report a case of spindle epithelial tumor with thymuslike differentiation (SETTLE) of the thyroid in a 20-year-old woman. The tumor located at the right lobe was well circumscribed by fibrous capsule. Microscopically, the highly cellular spindle cell neoplasm was arranged in intersecting fascicles separated by fibrous bands and was intermingled with small tubulopapillary epithelial foci. Immunohistochemically, most of the tumor cells were strong for pancytokeratin and focally positive for smooth muscle actin and vimentin. The cells were negative for EMA, thyroglobulin, S100 protein, and the diagnosis of thyroid spindle thymuslike differentiation was made.Thyroid SETTLE is a rare tumor seen exclusively in children, adolescents, and young adults.1 It presents as a painless thyroid or neck mass and exceptionally as a diffusely enlarged thyroid gland.The term SETTLE emphasizes the epithelial nature of the tumor and suggests its probable thymus line of differentiation.2 Grossly, SETTLE is partially encapsulated or infiltrative; the cut surface is firm and vaguely whorled.2 Histologically, the tumor is highly cellular, composed of masses of spindle cells separated by sclerotic bands of collagen. Spindle cells are arranged in sheets and short fascicles and blended with a few epithelioid cells arranged in tubules and tubulopapillary areas.3 Nuclear atypia and mitoses are rare. Squamous differentiation and remnants of Hassal corpuscle are rarely detected.4Both spindle and “epithelioid” cells are strongly and diffusely positive for pancytokeratin and focally for vimentin; they are negative for EMA, desmin, thyroglobulin, calcitonin, and S100 protein. The negative reaction for thyroglobulin and calcitonin exclude spindle cell variant of the medullary thyroid carcinoma and poorly differentiated thyroid carcinoma, respectively.2After immunohistochemistry, 2 lesions must be differentiated from SETTLE: ectopic cervical thymoma and synovial sarcoma. Ectopic cervical thymoma is composed of plump epithelial cells, often with a spindle shape, admixed with lymphocytes, which are usually absent in SETTLE.3 Synovial sarcoma, especially the monophasic variant, can also mimic SETTLE. However, in synovial sarcoma, spindle cells are more pleomorphic with more mitoses. Staining reaction with pancytokeratin is low or absent, in contrast to SETTLE. In addition, EMA positivity is regarded as a reliable marker of synovial sarcoma, being negative in SETTLE.3SETTLE must be considered a potentially malignant tumor with a possibility of developing late lymph node or pulmonary metastases,4 thereby justifying a correct diagnosis and strict supervision.

Mandibular reconstruction with a bioactive-coated cementless Ti6Al4V modular endoprosthesis in Macaca fascicularis

Transforming growth factor-beta 1 (TGF-beta 1 and recombinant platelet-derived growth factor-BB (rPDGF-BB) promoted an extensive, dose-dependent development of fibrous connective tissue when continuously delivered for 8 days by mini-osmotic pumps implanted subcutaneously in adult guinea pigs. Biochemical analyses demonstrated that TGF-beta 1 and rPDGF-BB stimulated dose-dependent increases in the dry weight, and protein, DNA, collagen, and glycosaminoglycan (GAG) contents of the fibrous connective tissue capsule that enveloped the pumps. The GAG/DNA mass ratio was markedly elevated by TGF-beta 1, but the collagen/DNA, protein/DNA, and collagen/protein ratios were not significantly increased. In contrast, rPDGF-BB generally decreased these mass ratios. Histological analyses suggested that this was due to the fact that rPDGF-BB induced a very cellular response with a marked influx of neutrophils and fibroblasts. TGF-beta 1 induced significantly less cellular response, which consisted primarily fibroblasts and macrophages. These results indicated that rPDGF-BB and TGF-beta 1 induced connective tissue deposition in vivo in a dose-dependent fashion, although the cellular nature of the responses as well as the structural composition of the extracellular matrices were clearly distinguishable between the two growth factors.

처리하지 않은 타이타늄과 양극 산화 처리한 타이타늄 시편의 생체적합성을 평가하기 위해, 시편을 마우스의 복부 피하 조직에 이식하고 2주 동안 생존시켰다. 그 시편에 대한 복부 피하 결합조직의 반응을 조직학적으로 조사하였다. 시편 주위를 둘러싸는 섬유성 결합조직 막이 관찰되었으며 이 막은 섬유모세포, 섬유세포 및 기타 세포로서 중성호성백혈구, 대식세포, 거대다핵세포 등으로 이루어져 있었다. 시편을 둘러싸는 이 막에 새로이 형성된 혈관이 존재하기도 하였다. 임플란트와 접하는 섬유성 막에 거대다핵세포가 관찰되었다. 섬유성 막에 있는 세포 종류와 막의 두께를 조사하였다. 막에 있는 대부분의 세포는 섬유모세포와 섬유세포이었다. 양극 산화 처리를 하지 않은 타이타늄 시편에 비해 산화 처리를 한 시편을 둘러싸는 섬유성 막의 평균 두께가 더 얇았다. 또한 타이타늄 시편의 생체적합성을 세포 배양법으로 조사하였다. 산화 처리를 한 시편 위에서 배양한 MG-63 세포의 수가 유의하게 증가되었다. 이런 결과들은 in vivo 와 in vitro 실험에서 산화 처리를 한 타이타늄 시편이 생체적합성을 증가시키는데 효과적이라는 것을 말해준다. To evaluate the biocompatibility of untreated and anodized titanium specimens, the specimens were implanted in the subcutaneous tissue of the abdominal region of female mice for two weeks. The reaction of connective tissue to specimens was histologically studied. The implants were encapsulated by fibrous connective. tissue consisting of fibroblast, fibrocyte and other cellss including neutroophil, macrophage and giant multinucleated cell. some newly formed blood vessels were located in the fibrous capsule surrounding the implant. Giant multinucleated cells were observed at the fibrous capsule adjacent to the implant. Kind of cell types and the thickness of fibrous capsules were examined quantitatively. Most of cell types located in the fibrous capsule were fibroblast and fibrocyte. The average thickness of fibrous capsules for the anodized specimens was much thinner than that of the untreated titanium specimen. Biocompatibility of titanium specimens were also studied by using cell culture method. The number of MG-63 cells was significantly increased on the anodized titanium specimens in vitro experiment. Our observations suggest that anodized titanium specimens are more effective for the improvement of biocompatibility in vivo and in vitro.