Establishment and pathologic analysis of imatinib-resistant gastrointestinal stromal tumor xenografts / 中华病理学杂志

<p><b>OBJECTIVE</b>To establish and characterize imatinib-resistant gastrointestinal stromal tumor (GIST) xenografts. Further provided an ideal experimental platform through the imatinib-resistant GIST xenografts to investigate the mechanism of resistance to imatinib.</p><p><b>METHODS</b>Imatinib-resistant GIST cells were injected under the skin of athymic nude mice to establish animal models of human imatinib-resistant GIST. The molecular and histopathologic features of GIST xenografts were also analysed and compared with their counterpart of cell lines.</p><p><b>RESULTS</b>The xenograft tumor models had been established by subcutaneously injection of GIST cells into nude mice. Immunohistochemistry results showed CD117 expression was positive in GIST-PR2 xenograft tumor, but negative in GIST-R. In GIST-PR1, tumor areas showing rhabdomyoblastic differentiation were presented next to areas with classic GIST morphology. The rhabdomyoblastic component demonstrated consistently positivity for desmin and myogenin, whereas CD117 was completely negative. The mutation profiles of these xenograft tumors were the same as their counterpart of cell lines.</p><p><b>CONCLUSIONS</b>Human GIST xenografts with mutation in c-kit have been established from imatinib-resistant GIST lines. Those models will enable further studies on mechanisms of resistance, combination therapies and allow testing of novel targeted therapies.</p>

Interdigitating dendritic cell sarcoma/tumor: a study of 3 cases / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the pathologic features, diagnosis and differential diagnosis of interdigitating dendritic cell sarcoma (IDCS).</p><p><b>METHODS</b>The clinical findings, morphologic features and immunophenotype of 3 cases of IDCS were investigated.</p><p><b>RESULTS</b>Gross examination showed that IDCS had a greyish-white to greyish-yellow cut surface. The site of occurrence included lung, spleen (with lymph node metastasis) and lymph node. Histologically, the tumor cells were arranged in nests, fascicles and whorls, with intimate admixture of many lymphocytes and plasma cells. They were oval to spindle in shape and contained pale eosinophilic cytoplasm, oval and sometimes grooved nuclei, small distinct nucleoli and ill-defined cell borders. Immunohistochemical study showed that the tumor cells expressed S-100 protein.</p><p><b>CONCLUSIONS</b>IDCS is a rare type of histiocytic and dendritic cell malignancy with distinctive morphologic findings. It needs to be distinguished from follicular dendritic cell sarcoma, inflammatory pseudotumor, Langerhans' cell histiocytosis, malignant melanoma, undifferentiated carcinoma and anaplastic large cell lymphoma. Immunohistochemical staining for S-100 protein is helpful in confirming the diagnosis.</p>

Adrenal myelolipoma within myxoid cortical adenoma associated with Conn's syndrome / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The coexistence of myelolipoma within adrenal cortical adenoma is extremely rare, for both tumors present usually as separate entities. There are only 16 such cases reported worldwide. To the best of our knowledge, the case we reported here is the first one of myxoid adrenal cortical adenoma associated with myelolipoma reported. A 32-year-old Chinese woman with 4-year history of hypertension was presented in our study. Computed tomography (CT) of the abdomen showed a large heterogeneously-enhancing mass (4.5 cm in diameter) in the left suprarenal region. Clinical history and laboratory results suggest a metabolic disorder as Conn's syndrome. The patient underwent a left adrenalectomy, and a histopathological study confirmed the mass to be a myxoid adrenal cortical adenoma containing myelolipoma. The patient was postoperatively well and discharged uneventfully. In the present case report, we also discuss the etiology of simultaneous myelolipoma and adrenal adenoma associated with Conn's syndrome, and the methods of the diagnosis and differential diagnosis.

Schwann cell apoptosis in Wallerian-degenerated sciatic nerve of the rat / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate systematically Schwann cell apoptosis in Wallerian-degenerated sciatic nerve of the rat, and evaluate its time-related feature.</p><p><b>METHODS</b>Ninety-five SD rats were divided randomly into one normal group (8 rats) and 11 experimental groups (66 rats, 6 in each). Both hind legs of each rat in experimental groups were randomly divided into test leg (sciatic nerve transected) and control one (nerve uninjured). All test legs constituted a test group and all control legs constituted a control one. After operation, all rats were respectively sacrificed at 1 h, 6 h, 12 h, 24 h, 2 d, 3 d, 4 d, 8 d, 14 d, 21 d, and 30 d. We analyzed the specimens of mid-distal sciatic nerve, especially the morphological changes of the nerve, the different expression levels of S-100 protein and apoptosis-related proteins such as Bcl-2, Bax, and Fas in Schwann cells. The TUNEL method was used to detect the apoptotic rate of Schwann cells.</p><p><b>RESULTS</b>(1) The test group showed Wallerian degeneration. The number of Schwann cells began to decrease at 24 h, obviously decreased on day 3 and 4, then began to increase from day 8 and formed Bungner belt after 14 days. (2) Schwann cells generally expressed S-100 at a low level in all groups. The control group was not significantly different from the normal group. The test group had statistical significance at 1 h and day 21. (3) As an inhibitory gene protein of Schwann cell apoptosis, Bcl-2 positive rates in the control and test groups apparently elevated and were statistically different from the normal group. (4) As a promotive gene protein of Schwann cell apoptosis, the control and test groups expressed Bax at a high level and were statistically different from the normal group. (5) As a promotive gene protein of Schwann cell apoptosis, Fas positive rate in control group was slightly elevated, but had no statistical significance compared with the normal group. Fas positive rate in test group continuously elevated in a fluctuant way, with highly statistical significance compared with the normal group. (6) TUNEL detection further proved that Schwann cell apoptosis rarely existed in the normal group, and the left sciatic nerve had no statistical significance compared with the right sciatic nerve. While the test group showed lots of apoptotic nuclei at 6 h, 2 d, 4 d, and 21 d. It had highly statistical significance compared with the normal group.</p><p><b>CONCLUSIONS</b>Schwann cell apoptosis does exist in Wallerian-degenerated sciatic nerve of the rat after transection. Schwann cell apoptosis and its apoptotic genes expression have a time-related feature.</p>