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[Purpose] Telocytes are stromal cells that participate in tissue homeostasis. Osteoarthritis is a common degenerative disorder of multiple joint components that causes inflammation; however, the distribution of telocytes in joint components and the impact of osteoarthritis on telocytes is unclear. Therefore, we aimed to clarify the distribution of the telocyte in the joint components and determine the effect of osteoarthritis on telocytes. [Participants and Methods] We divided 30 male rats into control and osteoarthritis groups and surgically induced osteoarthritis by destabilizing the medial meniscus. At two and eight weeks after surgery, we evaluated the changes in CD34-positive and CD31-negative area sizes in the joint components by immunohistochemistry. [Results] The results showed CD34-positive and CD31-negative areas in the loose connective tissue of the lateral meniscus attachment and the infrapatellar fat pad. However, it was not observed in the cartilage, subchondral bone, cruciate ligament, and meniscus. Moreover, there were no significant differences between the CD34-positive and CD31-negative area sizes in control and osteoarthritis groups at both time points. [Conclusion] CD34-positive and CD31-negative cells are distributed in multiple joint components; however, CD34-positive and CD31-negative areas are not affected by the progression of osteoarthritis. This result provides information on telocytes distribution in the knee joint and the impact of osteoarthritis on these cells.

Objective This study aimed to clarify physiological reloading on disuse atrophy of the articular cartilage and bone in the rat knee using the hindlimb suspension model. Design Thirty male rats were divided into 3 experimental groups: control group, hindlimb suspension group, and reloading after hindlimb suspension group. Histological changes in the articular cartilage and bone of the tibia were evaluated by histomorphometrical and immunohistochemical analyses at 2 and 4 weeks after reloading. Results The thinning and loss of matrix staining in the articular cartilage and the decrease in bone volume induced by hindlimb suspension recovered to the same level as the control group after 2 weeks of reloading. The proportion of the noncalcified and calcified layers of the articular cartilage and the thinning of subchondral bone recovered to the same level as the control group after 4 weeks of reloading. Conclusions Disuse atrophy of the articular cartilage and bone induced by hindlimb suspension in the tibia of rats was improved by physiological reloading.

Objective The study aim was to evaluate the histological relationship between osteoarthritis (OA) and articular cartilage in disuse atrophy induced by hindlimb unloading in a post-traumatic OA rat model. Design Forty male rats were divided into the 4 following experimental groups: control, hindlimb suspension (HS), OA induced by destabilization of the medial meniscus (OA), and OA induction after hindlimb suspension (HS-OA). Histological changes in the articular cartilage of the tibia were evaluated by the Osteoarthritis Research Society International (OARSI) scores and histomorphometrical analyses at 2, 4, and 8 weeks after OA induction. Results We confirmed that disuse atrophy of the articular cartilage was caused by thinning of the articular cartilage and the decrease in matrix staining for the nonloading period of 4 weeks. The OARSI scores and histomorphological analyses revealed that OA progressed significantly wider and deeper in the HS-OA group than in the OA group over time. In the sham group, disuse atrophy of the articular cartilage recovered at 2 weeks after reloading. Conclusions This study revealed that OA progressed faster in cartilage atrophy than in normal articular cartilage. Further studies are required for investigating the mechanisms of disuse atrophy of cartilage and its association with OA using the biochemical and immunohistochemical analysis.

Objective The purpose of this study was to determine the preventive effects of treadmill exercise or physiological loading on disuse atrophy in the rat knee joint cartilage and bone during hindlimb suspension. Design Twenty male rats were divided into 4 experimental groups, including the control, hindlimb suspension, physiological loading, and treadmill walking groups. Histological changes in the articular cartilage and bone of the tibia were histomorphometrically and immunohistochemically evaluated 4 weeks after the intervention. Results Compared with the control group, the hindlimb suspension group showed thinning of cartilage thickness, decreased matrix staining, and decreased proportion of noncalcified layers. Cartilage thinning, decreased matrix staining, and decreased noncalcified layers were suppressed in the treadmill walking group. The physiological loading group exhibited no significant suppression of cartilage thinning or decreased noncalcified layers, but the decreased matrix staining was significantly suppressed. No significant prevention of bone mass loss or changes in subchondral bone thickness were detected after physiological loading or treadmill walking. Conclusion Disuse atrophy of the articular cartilage caused by unloading conditions could be prevented by treadmill walking in rat knee joints.

The aim of the study was to examine how mechanical unloading affects articular cartilage degeneration in the patellofemoral (PF) and tibiofemoral (TF) joints of a monosodium iodoacetate (MIA)-induced rat model of osteoarthritis (OA).The study involved 60 male rats. OA was induced by intra-articular injecting MIA into both knee joints. All animals were equally divided into two groups: sedentary (SE) and hindlimb unloading (HU) groups. Histopathological changes in the articular cartilage of the PF and TF joints were evaluated using the Osteoarthritis Research Society International (OARSI) score and modified Mankin score at 2 and 4 weeks after MIA injection.In the SE and HU groups, representative histopathological changes in OA were detected in the PF and TF joints. The OARSI and modified Mankin scores for the PF and TF joints tended to increase over time after the injection of 0.2 mg or 1.0 mg of MIA in the SE and HU groups. Both the scores for the HU group were significantly lower than those for the SE group [OARSI score: P 0.0001 (1.0-mg injection at 4 weeks); modified Mankin score: P = 0.0116 (0.2-mg injection at 4 weeks); P = 0.0004 and0.0001 (1.0-mg injection at 2 and 4 weeks, respectively)].This study revealed new histological evidence that indicates that unloading condition suppresses articular cartilage degeneration and is beneficial in many areas of basal and clinical research involving OA.

This study aimed to perform range of motion exercises on a rat knee joint contracture model and clarify changes in the joint range of motion and number of myofibroblasts in the joint capsule. Eighteen male Wistar rats were used and randomly divided into the following three groups: control, immobilized, and exercise. The right hindlimb knee joints of rats in the immobilized and exercise groups were immobilized, and the animals in the exercise group started the range of motion exercises the day after the joint immobilization. After the two weeks experimental period, the range of knee joint extension angle was measured, and the knee joint was collected. To observe the posterior joint capsule of the rat knee joint, hematoxylin and eosin staining and immunostaining were performed. Differences in knee extension restriction angles were significant between all groups, and differences in the number of alpha smooth muscle actin-positive cells were significant between the control and immobilization groups. These results indicate that joint immobilization leads to myofibroblast proliferation, whereas gentle exercise that does not maintain sufficient range of motion in the joint may inhibit myofibroblast proliferation.

[Purpose] To mobilize the knee joint during cast fixation and to determine whether infrapatellar fat pad changes can be prevented. [Materials and Methods] We randomly allocated Wistar rats into 3 groups as follows: normal group, raised in normal conditions (n=5); contracture group, immobilized with cast fixation (n=5); and prevention group, treated with joint movement during immobilization (n=5). We immobilized the right hindlimb using cast fixation. Joint movement in the prevention group was accomplished by repeatedly pulling the right hindlimb caudally and then returning the leg to the bent position for 10 minutes every day for 2 weeks. We used a metronome to maintain a constant speed, with one set lasting 2 seconds (1-second traction and 1-second return). [Results] The contracture group had adipose cells of various sizes and fibrosis in the infrapatellar fat pad. These changes were also found in milder forms in the prevention group. We found significant differences in the cross section of adipose cells and in knee extension restriction between the groups. [Conclusion] Promoting joint movement may not only have a therapeutic effect on adipose cells but also a preventative effect.

[Purpose] This study was performed to evaluate the long-term histopathological changes in knee-joint components including synovial membrane and joint capsule in a rat model of osteoarthritis (OA) induced by monosodium iodoacetate (MIA). [Subjects and Methods] Fifty male rats were used. OA was induced through intra-articular injection of MIA, and ten rats were randomly allocated to each of five groups induced with OA for 1, 2, 4, 6, or 8 weeks. At the end of each period, the knee components were examined histopathologically. [Results] After 1 and 2 weeks, chondrocytes were weakly stained. After 4 weeks, fibrillation, fissuring, and eburnation were observed, whereas after 6 weeks, chondrocyte clustering and osteophyte formation were detected. In the synovial membrane, the proliferation of spindle-shaped cells and a multilayered structure of the surface cells were observed at 1 and 2 weeks, but the degree of these changes decreased over time. In the joint capsule, a narrowing of the space between collagen fiber bundles was observed at 4–8 weeks. [Conclusion] The long-term histopathological changes of the joint components observed in a rat model of OA induced by MIA were similar to those detected in OA, but differed at specific times and tissues., 出版者照会後に全文公開

[Purpose] This study was performed to immunohistochemically evaluate changes in the periphery of the sciatic nerve in a rat model of knee immobilization, and to assess the effects of range of motion exercise. [Subjects and Methods] Twenty-one male rats were divided randomly into three groups: control (C), immobilized (I), and exercise (E group). Rats in the I and E groups had the right knee joint immobilized for 2 weeks. In the E group, range of motion exercise was also performed. After the experimental period, the periphery of the sciatic nerve was immunohistochemically observed. [Results] Immunohistochemical staining revealed that the myelin sheath and the perineurium in all groups were laminin positive. In the C and E groups, all rats showed normal staining. In contrast, 4 rats in the I group exhibited weak labeling. [Conclusion] Our results suggest that immobilization alters the perineurium at a molecular level and the range of motion exercise is essential for maintaining the environment of the perineurium.

[Purpose] The purpose of our study was to clarify temporal effects on restrictions to range of motion and the histopathological changes of joint components after joint immobilization in a rat knee-contracture model. [Subjects] Fifty-four male Wistar rats were randomly divided into two groups: a fixation group, and a control group. [Methods] In the fixation group, unilateral knee joints were immobilized at full flexion using a plaster cast for 4 weeks. At four weeks the animals were randomly divided into six subgroups, corresponding to the time of examination after cast removal: 0, 4, 8, 16, 24, and 32 weeks. For comparison, control group animals of corresponding age were also examined. [Results] Although movement restrictions of the knee joint had completely recovered 6 weeks after the cast removal, cartilage and synovial membrane structures did not completely recover. [Conclusion] These findings have not previously been reported, and as they form an addition to the fundamental scientific foundations of physical therapy, further research must examine these findings from a variety of perspectives.

We investigated the histopathological and immunohistochemical effects of loading on cartilage repair in rat full-thickness articular cartilage defects. A total of 40 male 9-week-old Wistar rats were studied. Full-thickness articular cartilage defects were created over the capsule at the loading portion in the medial condyle of the femur. Twenty rats were randomly allocated into each of the 2 groups: a loading group and a unloading group. Twenty rats from these 2 groups were later randomly allocated to each of the 2 groups for evaluation at 1 and 2 weeks after surgery. At the end of each period, knee joints were examined histopathologically and immunohistochemically. In both groups at 1 and 2 weeks, the defects were filled with a mixture of granulation tissue and some remnants of hyaline cartilage. The repair tissue was not stained with toluidine blue in both groups. Strong staining of type I collagen was observed in the repair tissue of both groups. The area stained with type I collagen was smaller in the unloading group than in the loading groups, and the stained area was smaller at 2 weeks than at 1 week. In the staining for type II collagen, apparent staining of type II collagen was observed in the repair tissue of both groups at 1 week. At 2 weeks, there was a tendency toward a higher degree of apparent staining in the loading group than in the unloading group. Accordingly, these results indicated that loading and unloading in the early phase of cartilage repair have both merits and demerits.

Background: Cancer stem cells (CSCs) may be postulated mediators of the chemoresistance. This study aimed to determine an effective signal inhibitor with effects on the proliferation of CSCs in combination with anticancer drugs. Methods: We used three gastric cancer cell lines and three side population (SP)-enriched CSC cell lines. We examined the combined effects of inhibitors against stemness signals, including c-Met inhibitor SU11274, and five anticancer drugs on the CSC proliferation and mRNA expression of chemoresistance-associated genes. Results: The IC50 of irinotecan in SP-enriched CSC was 10.5 times higher than parent OCUM-2M cells, whereas that of oxaliplatin, taxol, gemcitabine, and 5-fluorouracil was 2.0, 2.8, 2.0, and 1.2, respectively. The SP cell lines had higher expression levels of UGT1A1, ABCG2, and ABCB1 than their parent cell lines. There was a synergistic antiproliferative effect with a combination of SU11274 and SN38 in SP cells, but not other inhibitors. The SU11274 significantly decreased the expression of UGT1A1, but not ABCG2 and ABCB1. The SN38 plus SU11274 group more effectively suppressed in vivo tumour growth by OCUM-2M/SP cells than either group alone. Conclusion: Cancer stem cells have chemoresistance to irinotecan. The c-Met inhibitor may be a promising target molecule for irinotecan-based chemotherapy of gastric cancer.

[Purpose] This study was performed to investigate the histological changes that occur in the periphery of the sciatic nerve in rats undergoing knee immobilization. [Subjects and Methods] 29 male 9-week-old Wistar rats were divided randomly into a control group (C group, n = 7) and an immobilized group (I group, n = 22). The animals in the I group had the left knee joint immobilized in maximal flexion with plaster casts for two weeks. After the experimental period, we obtained cross-sections of tissues from the center of the left thigh, and the periphery of the sciatic nerve was observed under an optical microscope after hematoxylin-eosin staining. [Results] In contrast to the rats of C group, the rats in I group showed adherence between the bundle of nerve fibers and perineurium, as well as thickening of the perineurium. These histological changes were statistically significant. [Conclusions] Immobilization of the knee joints of rats resulted in characteristic histological changes in the connective tissue around the sciatic nerve.

[Purpose] The purpose of this study was to examine histopathological changes in tissue surrounding the sciatic nerve after spinal cord injury (SCI) in rats. [Subjects and Methods] Thirty adult, nine-week-old, female Wistar rats were used in this study. Fifteen experimental rats underwent spinal cord transection at the level of Th8-9 and the other fifteen control rats were raised normally. Animals were assessed at 1, 2, 4, 8, and 12 weeks following surgery. After the experimental period, we obtained tissue surrounding the sciatic nerve of the thigh after hematoxylin and eosin staining under a microscope. [Results] Adherence between the nerve bundle and perineural innermost layer was observed in tissue surrounding the sciatic nerve in the SCI group. Adherence among the interperineurium was evident at 2 weeks after SCI. It had declined at 4 weeks after SCI, but was still evident at 8 and 12 weeks after SCI. [Conclusion] Histopathological findings in the SCI model may be related to compression of the nerve bundle and neurogenic contracture of tissue surrounding the nerve bundle., Thesis of Ippei Kitade / 北出 一平 博士論文 金沢大学医薬保健学総合研究科（保健学専攻）

[Purpose] The purpose of this study was to examine the histopathological changes in knee joint components after spinal cord injury (SCI) in rats. [Subjects and Methods] Eighteen adult, nine-week-old female Wistar rats were used in this study. Nine experimental rats underwent a spinal cord transection at the level of Th8-9 and the other nine control rats were raised normally. The animals were assessed at 1, 2 and 4 weeks after surgery. Formalin fixed sections from knee joints were morphologically examined after hematoxylin and eosin staining. Alterations of knee joint components were evaluated at four regions: the synovial membrane within the posterior articular capsule region, the cartilage apposite the femur, the cartilage apposite the tibia, and the fat pad under the patellar ligament region. [Results] Dilatation and congestion of the microvasculature and lymphoid infiltration were observed in the synovial membrane in the SCI group. These findings are similar to those found in early osteoarthritis. The surface layer of the articular cartilage in the SCI group showed fibrous proliferation. [Conclusion] The histopathological changes appear not to be progressive and may be related to spasticity of the hindlimb or a disorder in the autonomic function.

[Purpose] We investigated a rat model of full-thickness articular cartilage defect without joint open surgery and histopathologically analyzed the time course of the tissue repair. [Subjects] A total of 40 male Wistar rats aged 9 weeks were used. [Method] Full-thickness defects of the articular cartilage were created over the capsule at the loading portion in the medial condyle of the femur. Ten rats each were randomly allocated to 4 groups, which were evaluated at 0, 4, 8 and 12 weeks after surgery. At the end of each period, knee joints were examined histopathologically. [Results] Full-thickness articular cartilage defects were created uniformly in our model. The defects were spontaneously resurfaced with hyaline-like tissue at 4 weeks postoperatively, but some articular cartilage remnants with aseptic necrosis and cloning of chondrocytes were found in the repair tissue. From 8 weeks to 12 weeks after surgery, the hyaline tissue was maintained, and the aseptic necrosis and cloning were observed in the partially repair tissue. [Conclusion] We have developed a rat model producing identically sized full-thickness defects of the articular cartilage.

[Purpose] We examined the histopathological changes in the joint capsule that occurred due to long-term immobilization of the joint, and compared them with those seen in aged rats. [Subjects] A total of 26 male Wistar rats were used in this study. [Methods] The right knee joints of the experimental group rats were immobilized for periods of 2, 4, 8, 16, or 32 weeks, and three 13-week-old "adult" rats and three 70-week-old "aged" rats were used as control groups. At the end of each immobilization period, the right knee joints of the rats were used as samples for histological examination. [Results] We observed histopathological changes in the joint capsules occurring due to joint immobilization. Increase in the thickness of the joint capsule had occurred by 4 weeks of immobilization and developed with prolongation of the immobilization period. An increase in the thickness was also observed in the joint capsule of aged rats. Further, the areas of elastic fibers in aged rats and those immobilized for 32 weeks were decreased compared to adult rats. [Conclusion] The joint capsules after immobility and aging showed similar changes, suggesting that some kind of identical mechanism causes the two conditions.

The aim of this study is to clarify the benefit of combination chemotherapy in gastric cancer based on a cell-signal inhibitor and an anticancer drug. Two scirrhous gastric cancer cell lines and two non-scirrhous gastric cancer cell lines were used. Five anticancer drugs (5-fluorouracil [5FU], paclitaxel, oxaliplatin, irinotecan, and gemcitabine) and four cell-signal inhibitors, mammalian target of rapamycin (mTOR) inhibitor, glycogen synthase kinase 3beta, p38alphabetaMAPK, and cyclin-dependent kinase, were used. The proliferation of cancer cells was examined by MTT assay and in vivo study. The apoptosis of cancer cells and the expression of apoptosis-related molecules were examined by flow cytometry, real-time PCR, and immunostaining. mTOR inhibitors with 5FU showed a synergistic antiproliferative effect in scirrhous gastric cancer, whereas the other signal inhibitors showed no synergistic effect with any anticancer drugs. mTOR inhibitor decreased the IC(50) of 5FU and increased the apoptosis rate in scirrhous gastric cancer cells, but not in non-scirrhous gastric cancer cells. The pan-caspase inhibitor, zVAD-fmk, inhibits apoptosis induced in combination with 5FU and mTOR inhibitor. mTOR inhibitor decreased dihydropyrimidine dehydrogenase, thymidylatesynthase, and bcl-2 expression, and increased caspase-3 and p21 expression of scirrhous gastric cancer cells, but did not affect those of non-scirrhous gastric cancer cells. In an in vivo study, mTOR inhibitor significantly enhanced the therapeutic efficacy of S1, an analog of 5FU. These findings suggest that mTOR inhibitor interacts with 5FU in a synergistic manner in scirrhous gastric cancer cells by the activation of the apoptosis signal. Therefore, mTOR inhibitor is a promising therapeutic agent in combination with 5FU in scirrhous gastric cancer.

Background: Vascular endothelial growth factor receptor-3 (VEGFR-3) signalling mediates lymphangiogenesis and lymphatic invasion; however, the effect of VEGFR-3 inhibition on the lymph node (LN) metastasis remains unclear. The aim of this study is to clarify the benefit of a VEGFR-3 inhibitor Ki23057 for LN metastasis. Methods: Ki23057 was administered orally to gastric cancer models created by orthotopic inoculation of diffuse-type gastric cancer cells, OCUM-2MLN. The effects of Ki23057 on lymphatic vessel invasion, lymphatic vessel density, and VEGFR-3 phosphorylation were examined by immunostaining or immunoblotting. Results: Ki23057 inhibited the autophosphorylation of VEGFR-3, with IC50 values of 4.3 nM in the cell-free kinase assay. Murine gastric cancer models created by the orthotopic inoculation of OCUM-2MLN cells showed the diffusely infiltrating growth and frequently developed LN metastasis. The oral administration of Ki23057 significantly (P

〔目的〕拘縮後のストレッチが関節包に及ぼす影響を病理組織学的に検討すること。〔方法〕9週齢のWistar系雄ラット14匹を用い，通常飼育のみを行う正常群，ギプス固定のみを行う拘縮群，固定後4週間の通常飼育を行う非治療群，固定後4週間ストレッチを行う治療群の4群にわけた。各群の膝関節可動域の測定と，組織標本による関節包組織の観察を行った。〔結果〕拘縮群は膠原線維束の肥厚と密性化を認め，関節包は肥厚していた。これに比べ治療群，非治療群ともに改善傾向を示したが，両群間に明らかな違いは認められなかった。一方，膝関節可動域は固定後3週以降の治療群で有意な改善を示した。〔結語〕可動域の改善に伴った関節包組織の明らかな改善は認められなかった。

［目的］ラット膝関節拘縮モデルを用い，拘縮時の坐骨神経周囲にどのような変化が見られるかを観察するため実験を行った。［対象と方法］9週齢のWistar系雄ラット26匹をコントロール群4匹と左後肢の膝関節を最大屈曲位にてギプス固定した固定群22匹とに分け，それぞれ2週間飼育した。飼育期間終了後，大腿骨の中間部の断面標本を作製した。染色はヘマトキシリン・エオジン染色を行い，光学顕微鏡下にて坐骨神経周囲を観察した。得られた結果はFisherの直接確率計算法にて統計処理した。［結果］固定群では坐位骨神経の神経束と神経周膜の密着および神経周膜の肥厚が有意に認められ，コントロール群ではこれらは観察されなかった。［結語］関節の不動は神経周囲組織にも影響を与えうることが明らかになった。

〔目的〕関節拘縮の研究のほとんどは関節および筋の変化を調べたものであり，軟部組織である筋間脂肪織が関節拘縮によりどのように変化するのかを観察する事を目的に実験を行った。〔対象〕Wistar雄性ラット36匹を使用し，うち21匹を実験群として先行研究に倣って拘縮モデルを作製し，残りは対照群とした。〔方法〕実験期間は2週間とした。実験終了後，標本作製し筋間脂肪織の存在が確認された坐骨神経に隣接した部位を観察部位とし，脂肪細胞の萎縮・消失の程度を4群にわけ分類した。〔結果〕脂肪細胞の萎縮・消失を示した例が対照群では20％であったのに対し，実験群では71％を占めた。実験群では線維芽細胞の増生と幼弱なコラーゲン線維と考えられる好塩基性の無構造物ないし繊細な線維状物質が増加している組織像が観察された。〔結語〕ラット後肢膝関節を2週間不動化する事により，筋間脂肪にも著明な変化が観察され，この変化は軟部組織性拘縮の一端を担う可能性が示唆された。

症例は56歳の男性で, 心窩部痛, 左側腹部腫瘤自覚を主訴に受診された. 腹部CTにて小腸壁が肥厚した腫瘤像を認め, 小腸造影X線検査では空腸を中心に多数の腫瘤圧排像がみられ多発性小腸腫瘍が疑われた. 入院経過中にイレウス症状がみられ, ショック状態となった. 消化管穿孔による汎発性腹膜炎と診断し, 緊急手術を施行, 術中所見ではトライツ靭帯より約40cmの空腸から小腸全体に至る, 大小さまざまな十数個の腫瘍を認め, 壊死穿孔を伴った. 病理組織学的には腫瘍は未分化細胞からなり, PAS染色にて粘液を証明しえず, 神経内分泌腫瘍マーカーやhCGも陰性であったため原発性小腸未分化癌と診断した. 術後経過は良好であったが, 腫瘍出血のため状態が悪化し, 術後37日目に死亡した. 小腸未分化癌は極めてまれな疾患である. 今回, 我々は多発性小腸壁内転移を伴った原発性小腸未分化癌の症例を経験したので文献的考察を含めて報告する.

拘縮時に生じる関節構成体の変化を明らかにするため，ラット膝関節の外固定モデルを用いて，その病理組織学的変化を観察した。9週齢のWistar系雄ラット20匹の右後肢を膝関節最大屈曲位にてギプス固定し，4匹ずつ2，4，8，16，32週固定群をそれぞれ作成し，ヘマトキシリン・エオジン染色を行い光学顕微鏡下にて観察した。固定2週群から関節周囲脂肪織の萎縮と線維増生を認め，固定期間の延長と共にそれらの変化は進行した。関節軟骨と周囲組織との癒着が固定4週群から観察された。固定16週群以降では，脛骨，大腿骨が線維性に連結する例が見られた。32週に渡る長期ギプス固定により，関節構成体の萎縮，線維化，関節腔の狭小化が進行し，線維性強直に至った。炎症や軟骨の壊死，消失は観察されなかった。

目的：胸鎖関節には関節円板が存在し，関節円板によって胸鎖関節は球関節の機能を持つとされている。本研究の目的は，胸鎖関節の関節円板を病理組織学的に検討することである。方法：剖検症例において摘出されたヒト胸鎖関節円板を，光学顕微鏡を用いて病理組織学的に観察した。結果：胸鎖関節円板に断裂(tear)，粘液様変性(myxoid degeneration)，軟骨細胞の集簇化（chondrocyte cloning）等の所見を認めた。また関節円板の表面が，表面にほぼ平行して層状に剥離する像をよく認めた。他の関節円板との比較では，解剖学的，発生学的に関節円板と同一と考えられる膝半月板の病理組織像に関する過去の報告と今回の結果が類似していたが，層状剥離の記述は見られず，これが胸鎖関節に特異的なfibrillationの表現である可能性が示唆された。

A 68-year-old man was admitted to our hospital because of an abdominal tumor. Computed tomography(CT)showed a 6 cm tumor in the abdominal cavity. Surgery was performed. Upon laparotomy, a 6 cm tumor was found at the small intestine (210 cm)on the anal side from the Treitz ligament. A partial resection of the small intestine was performed. Immunohistochemistry showed positive staining for c-kit, and the diagnosis of gastrointestinal stromal tumor was confirmed. Multiple liver metastases and a lung metastasis were observed over the next 2 years. We started chemotherapy with imatinib mesylate at a dose of 400mg/day. The size of the tumors was unchanged, and no new lesion was observed. The patient has been alive and well as of 6 years after the initial operation.

Background: Acquired drug resistance to irinotecan is one of the significant obstacles in the treatment of advanced gastric cancer. This study was performed to clarify the effect of epidermal growth factor receptor (EGFR) inhibitors in combination with SN38, an active metabolite of irinotecan, on the proliferation of irinotecan-refractory gastric cancer. Methods: Two irinotecan-resistant gastric cancer cell lines, OCUM-2M/SN38 and OCUM-8/SN38 were, respectively, established by stepwise exposure to SN38 from the parent gastric cancer cell lines OCUM-2M and OCUM-8. The combination effects of two EGFR inhibitors, gefitinib and lapatinib, with SN38 on proliferation, apoptosis, and cell cycle on gastric cancer cells were examined. Results: Gefitinib or lapatinib showed synergistic anti-tumour effects against OCUM-2M/SN38 and OCUM-8/SN38 cells when used in combination with SN38, but not against OCUM-2M or OCUM-8 cells. SN38 increased the expression of EGFR and HER2 in OCUM-2M/SN38 and OCUM-8/SN38 cells. The combination of an EGFR inhibitor and SN38 significantly increased the levels of apoptosis-related molecules, caspase-6, p53, and DAPK-2, and resulted in the induction of apoptosis of irinotecan-resistant cells. The EGFR inhibitors increased the S-phase and decreased the UGT1A1 and ABCG expression in irinotecan-resistant cells. The SN38 plus Lapatinib group more effectively suppressed in vivo tumour growth by OCUM-2M/SN38 cells than either alone group. Conclusion: The combination treatment with an EGFR inhibitor and irinotecan might produce synergistic anti-tumour effects for irinotecan-refractory gastric cancer cells. The regulation of SN38 metabolism-related genes and cell cycle by EGFR inhibitors might be responsible for the synergism.

The aim of this study was to examine the effects of hypoxia on radiosensitivity and to analyze the mechanisms responsible for radiation resistance in gastric and esophageal cancer.A gastric cancer cell line, OCUM-12, and an esophageal cancer cell line, TE-6, were used. The effects of hypoxia with irradiation on the growth-activity, cell cycle distribution, and gene expression were examined.Both acute and chronic hypoxia decreased radiosensitivity of cancer cells. The radiosensitivity of chronic hypoxic cells was significantly enhanced by reoxygenation. Acute and chronic all hypoxia reduced the percentage of cells in the G(2)/M and S phases, respectively. In acute hypoxia, the mRNA expression of BRCA1 and BRCA2 was reduced in cancer cells. Reoxygenation increased the expression of BRCA1 and BRCA2.Hypoxia is associated with radiation resistance. Therefore, reoxygenation may enhance the radiosensitivity of hypoxic cells. BRCA1 and BRCA2 may be associated with factors for radiation resistance by regulation of cell cycle progression.

Background Transforming growth factor β (TGFβ) receptor signaling is closely associated with the invasion ability of gastric cancer cells. Although Smad signal is a critical integrator of TGFβ receptor signaling transduction systems, not much is known about the role of Smad2 expression in gastric carcinoma. The aim of the current study is to clarify the role of phosphorylated Smad2 (p-Smad2) in gastric adenocarcinomas at advanced stages. Methods Immunohistochemical staining with anti-p-Smad2 was performed on paraffin-embedded specimens from 135 patients with advanced gastric adenocarcinomas. We also evaluated the relationship between the expression levels of p-Smad2 and clinicopathologic characteristics of patients with gastric adenocarcinomas. Results The p-Smad2 expression level was high in 63 (47%) of 135 gastric carcinomas. The p-Smad2 expression level was significantly higher in diffuse type carcinoma (p = 0.007), tumours with peritoneal metastasis (p = 0.017), and tumours with lymph node metastasis (p = 0.047). The prognosis for p-Smad2-high patients was significantly (p = 0.035, log-rank) poorer than that of p-Smad2-low patients, while a multivariate analysis revealed that p-Smad2 expression was not an independence prognostic factor. Conclusion The expression of p-Smad2 is associated with malignant phenotype and poor prognosis in patients with advanced gastric carcinoma.

The aim of this study was to establish drug-resistant cell lines and to elucidate mechanisms leading to multi-drug resistance in gastric cancer.Five cancer cell lines resistant to 5-fluorouracil, paclitaxel, oxaliplatin, irinotecan, or gemcitabine, were respectively established from a parent gastric cancer cell line, OCUM-2M, by stepwise exposure to each chemotherapeutical agent.Cell death by apoptosis induced by anti-cancer drugs was low in 5 chemo-resistant cell lines. Percentage of cells in S and G(0)/G(1) phase was low in cell lines resistant to oxaliplatin or irinotecan. Cell lines resistant to paclitaxel, oxaliplatin, and gemcitabine showed multi-drug resistance. Alterations in MRP, DAPK1, or DAPK2 expression were found in multi-drug resistant cell lines.The cell-cycle distribution and alterations of MRP, DAPK1, and DAPK2 genes may be integral part of mechanisms responsible for chemo-resistance. These cell lines might be useful to study molecular mechanisms leading to multi-drug resistance.

Embryonic stem cell expressed Ras (ERas) oncogene is associated with the tumorigenicity of embryonic stem cells. The aim of this study was to clarify the significance of ERas expression in clinical samples of gastric carcinomas.Three hundred and few tissues from gastric cancer patients were analyzed by immunohistochemical techniques using an anti-ERas antibody. ERas mRNA expression in 77 gastric carcinomas was examined by reverse-transcription polymerase chain reaction.ERas expression was positive in 135 (44%) of 304 gastric carcinomas. ERas-positive expression had a significant relationship with invasion depth (p0.01), histological type (p0.01), clinical stage (p=0.013) and curability (p=0.001). Prognosis of ERas-negative patients was significantly (p=0.029) poorer than that of ERas-positive patients, while ERas was not an independent prognostic factor. Expression of ERas mRNA was found in 35 (45%) out of 77 gastric cancer tissues.ERas oncogene is associated with the tumorigenic process of human gastric carcinomas.

Scirrhous gastric carcinoma (SGC) carries the highest mortality because of a frequent metastasis to lymph node (LN). S1, a 5-fluorouracil (5-FU) analog, is clinically available for gastric cancer at an advanced stage. Fibroblast growth factor receptor 2 (FGFR2) is required for the proliferation of SGC. The objective of this study is to clarify the benefit of a combination of S1 and kinase inhibitors including FGFR2 inhibitor Ki23057 in gastric cancer. OCUM-2MLN and KATO-III were derived from SGC. MKN-7 and MKN-74 were derived from non-SGC. MTT assay was used to examine the growth-inhibitory activity of 5 small-synthetic molecules including Ki23057, Sunitinib, Glivec, Lapatinib or SU11274, in cells cultured with 5-FU. Combination effects of 5-FU with Ki23057 on proliferation, apoptosis and mRNA expression were examined. S1 and/or Ki23057 were administered to murine models of SGC created by the orthotopic inoculation of OCUM-2MLN cells. Ki23057 at 100 nM significantly (p < 0.01) inhibited the proliferation and decreased the phosphorylation of FGFR2 in SGC cells, but not in non-SGC. Ki23057 showed synergistic antitumor effects for SGC cells in combination with 5-FU using CalcuSyn analysis, but Sunitinib, Glivec, Lapatinib and SU11274 did not. The combination of Ki23057 and 5-FU decreased DPD expression and increased apoptosis rates and p21 expression level of SGC cells. The combined administration of S1 and Ki23057 significantly (p < 0.05) decreased orthotopic tumors as well as LN metastasis more effectively than S1 alone. These findings suggested that the combined treatment with 5-FU and Ki23057 produced synergistic antitumor effects and is therapeutically promising for SGC treatment.

The National Comprehensive Cancer Network guidelines recommend radiotherapy as a standard treatment for patients with a high risk of recurrence in gastric cancer. Because radiation is harmful to the surrounding organs, a radiation sensitizer might therefore be useful to decrease the side effects of patients with advanced gastric carcinoma. The aim of the current study was to clarify the effect of a DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine (CdR), on radiation sensitivity in gastric cancer cells. Five gastric cancer cell lines, OCUM-2M, OCUM-12, KATO-III, MKN-45, and MKN-74, were used. The effects of 5-aza-CdR with irradiation on the growth activity, cell-cycle distribution, apoptosis, and apoptosis-associated gene expression were examined. 5-aza-CdR sensitized three of five gastric cancer cell lines to radiation. A combination of irradiation and 5-aza-CdR significantly (P

Ki23057 is a new, small synthetic tyrosine kinase inhibitor that blocks autophosphorylation of the VEGF receptor2 (VEGFR2). To determine the effect of Ki23057 as an anti-angiogenic agent, we studied the effect of Ki23057 for colon cancer and vascular endothelial cells in vitro and in vivo. Ki23057 inhibited VEGF-induced proliferation of human umbilical vein endothelial cells (HUVECs), whereas no inhibitory effect of Ki23057 on the proliferation of three colon cancer cells (LM-H3, LoVo and LS174T) was observed by means of the cell count assay. Ki23057 inhibited tube formation of HUVECs. Immunoprecipitation demonstrated that Ki23057 inhibited tyrosine phosphorylation of VEGFR2 in HUVECs. Ki23057 exhibited a significant inhibitory effect on the growth of the xenografted LM-H3 tumours and the spreading of cancer cells to the liver. Anti-CD31 antibody stained significantly fewer microvessels in the xenografted tumours treated with Ki23057 compared with controls. Ki23057 may be a promising new antiangiogenic agent for colon cancer.

Purpose: Gastric cancer remains a major global health threat and most patients with advanced stage disease require chemotherapy. The development of drug resistance is a major obstacle in the treatment of gastric cancer and only few effective therapies for combating chemoresistance are currently available. It has been demonstrated that a small subset of cancer cells with stem cell properties, referred to as “cancer stem cells” (CSCs), survive intensive anticancer therapies better than proliferating progenitor cells or differentiated tumor cells. CSCs have been reported to be postulated mediators of chemoresistance, so it might be important to comprehend the drug resistance mechanisms of CSCs to develop a promising therapy to combat chemoresistance. The stemness signal might be associated with the chemosensitivity of CSCs. In the present study, we analyzed the effect of c-Met inhibitors on the chemosensitivity of stem-like cancer cells in gastric cancer. We demonstrated that a c-Met inhibitor synergistically increased the antitumor activity of SN38 in CSCs. To determine mechanisms underlying this observed synergism, we observed that a c-Met inhibitor combined with SN38 also led to a significant increase in UGT1A1 and its subsequent interaction with apoptosis-related genes, i.e., bcl-2 and caspase-6. Experimental Design: We used three gastric cancer cell lines and three side population (SP)-enriched cell lines. We used three signal inhibitors, c-Met inhibitor SU11274, GSK3β inhibitor AR-A014418, and mTOR inhibitor rapamycin, and five anticancer drugs. We examined the combined effects of signal inhibitors and anticancer drugs on proliferation, mRNA expression, and cell cycle. Results: The IC50 of irinotecan, oxaliplatin, taxol, and gemcitabine in SP cells were 10.5, 2.0, 2.8, and 2.0 times higher than their parent cells, respectively. In contrast, the IC50 of 5-fluorouracil did not differ between the two cell lines. There was a synergistic anti-proliferative effect with a combination of c-Met inhibitor and SN38 in SP cells. In contrast, the GSK3β inhibitor and mTOR inhibitor had no synergistic effects in combination with any anticancer drugs. The SP cell lines had higher expression levels of UGT1A1, ABCG2, and ABCB1 than their parent cell lines, while the c-Met inhibitor significantly decreased the expression of UGT1A1, but not ABCG2 and ABCB1. G0-phase of SP cells was higher than their parent cells. c-Met inhibition induced S-phase arrest in SP cells. Conclusions: CSCs are associated with multiresistance during chemotherapy. c-Met inhibitors could be a novel strategy to overcome chemoresistance. c-Met inhibitor may be a promising target molecule for irinotecan-based chemotherapy of gastric cancer. A UGT1A1 alteration might be involved in the irinotecan refractory process in CSCs. Citation Format: Masakazu Yashiro, Tatsunari Fukuoka, Haruhito Kinoshita, Takafumi Nishii, Tsuyoshi Hasegawa, Taro Matsuzaki, Tamami Morisaki, Kosei Hirakawa. A c-Met inhibitor increases the chemosensitivity of cancer stem cells to the irinotecan active metabolite SN38 in gastric carcinoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 225. doi:10.1158/1538-7445.AM2013-225

Purpose: Diffuse-type gastric carcinoma carries the highest mortality because of a frequent metastasis to lymph node. S1, a 5-fluorouracil (5-FU) analog, is clinically available for gastric cancer at advanced stage. Fibroblast growth factor receptor 2 (FGFR2) is required for the proliferation of diffuse-type gastric carcinoma. The objective of this study is to clarify the benefit of a combination of S1 and kinase inhibitors including FGFR2 inhibitor Ki23057 in gastric cancer. Experimental Design: OCUM-2MLN and KATO-III were derived from diffuse-type gastric carcinoma. MKN-7 and MKN-74 were derived from intestinal-type gastric carcinoma. MTT assay was used to examine the growth-inhibitory activity of 5 small-synthetic molecules including Ki23057, Sunitinib, Glivec, Lapatinib, or SU11274, in cells cultured with 5-FU. Combination effects of 5-FU with Ki23057 on proliferation, apoptosis, and mRNA expression were examined. S1 and/or Ki23057 were administered to murine models of diffuse-type gastric carcinoma created by the orthotopic inoculation of OCUM-2MLN cells. Results: Ki23057 at 100 nM significantly (p Conclusion: The combined treatment with 5-FU and Ki23057 produced synergistic anti-tumor effects, and is a therapeutically promising for diffuse-type gastric carcinoma treatment. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2552. doi:10.1158/1538-7445.AM2011-2552