Ultrastructural features and platelet-derived growth factor receptor A gene mutations in CD117-negative gastrointestinal stromal tumor / 中华病理学杂志

<p><b>OBJECTIVE</b>To explore the ultrastructural features and mutation status of platelet-derived growth factor receptors A (PDGFRA) and c-kit in gastrointestinal stromal tumors that were immunohistochemically negative for CD117 antigen.</p><p><b>METHODS</b>Six cases of gastrointestinal stromal tumors that were CD117 immunostain negative were studied by electron microscopy. Direct PCR sequencing was used to investigate the mutation status of c-kit gene exons 9, 11, 13, 17 and PDGFRA gene exons 12 and 18.</p><p><b>RESULTS</b>The ultrastructural features of all 6 cases were similar to those of the interstitial cell of Cajal (ICC). None of the 6 cases were found to have c-kit gene mutations. However, three tumors were found to harbor PDGFRA exon 18 activating mutations, including two tumors having an Asp-->Val842 missense mutation and one having an Arg-->Ser841 missense mutation.</p><p><b>CONCLUSIONS</b>PDGFRA mutations may provide an important alternative molecular mechanism for the development of gastrointestinal stromal tumor.</p>

Lung pathology and pathogenesis of severe acute respiratory syndrome: a report of six full autopsies / 中华病理学杂志

<p><b>OBJECTIVE</b>Severe acute respiratory syndrome (SARS) is an emerging infectious disease that first manifested in humans in November 2002. The SARS-associated coronavirus (SARS-CoV) has been identified as the causal agent, but the pathology and pathogenesis are still not quite clear.</p><p><b>METHODS</b>Post-mortem lung samples from six patients who died from SARS from April to July 2003 were studied by light and electron microscopy, Masson trichromal staining and immunohistochemistry. Evidence of infection with the SARS-CoV was determined by reverse-transcription PCR (RT-PCR) , serological examination and electron microscopy.</p><p><b>RESULTS</b>Four of six patients had serological and RT-PCR evidence of recent infection of SARS-CoV. Morphologic changes are summarized as follows: (1) Diffuse and bilateral lung consolidation was seen in all patients (6/6) with increasing lung weight. (2) Diffuse alveolar damage was universal (6/6) with hyaline membrane formation (6/6), intra-alveolar edema/hemorrhage (6/6), fibrin deposition (6/6), pneumocyte desquamation (6/6). A marked disruption in the integrity of the alveolar epithelium was confirmed by immunostaining for the epithelial marker AE1/AE3 (6/6). (3) Type II pneumocytes, with mild hyperplasia, atypia, cytomegaly with granular amphophilic cytoplasm and intracytoplasmic lipid accumulation (5/6). (4) Giant cells in the alveoli were seen in five of 6 patients (5/6) , most of which were positive for the epithelial marker AE1/AE3 (5/6), but some cells were positive for the macrophage marker CD68(2/6). (5) A pronounced increase of macrophages were seen in the alveoli and the interstitium of the lung (6/6), which was confirmed by histological study and immunohistochemistry. (6) Haemophagocytosis was present in five of the 6 patients(5/6). (7) Lung fibrosis was seen in five patients(5/6), with alveolar septa and interstitium thickening(5/6), intraalveolar organizing exudates (6/6) and pleura thickening (4/6). Proliferation of collagen was confirmed by Masson trichromal staining, most of which was type III collagen by immunostaining. The formation of distinctive fibroblast/myofibroblast foci was seen in five patients (5/6) by light microscopy and immunochemistry. (8) Squamous metaplasia of bronchial mucosa was seen in five patients(5/6). (9) Thrombi was seen in all patients(6/6). (10) Accompanying infection was present in two patients, one was bacteria, the other was fungus. In addition, electron microscopy revealed viral particles in the cytoplasm of alveolar epithelial cells and endothelial cells corresponding to coronavirus.</p><p><b>CONCLUSION</b>Direct injury of SARS-CoV on alveolar epithelium, prominent macrophage infiltration and distinctive fibroblast/myofibroblast proliferation may play major roles in the pathogenesis of SARS.</p>

Expression of telomerase and telomerase associated-regulation protein and proliferating cell nuclear antigen in ovarian epithelial tumors / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate expression and significance of hTERT, telomerase associated-regulation protein (TRAP) and proliferating cell nuclear antigen (PCNA) in ovarian epithelial tumors.</p><p><b>METHODS</b>106 specimens of ovarian epithelial tumors and their clinical history were collected, including 54 cases of malignancy, 33 borderline cases and 19 benign tumor cases. Immunohistochemical staining for hTERT, TRAP and PCNA were performed. Follow-up information was obtained for 45 of 87 cases (malignancy in 54 and borderline malignancy in 33).</p><p><b>RESULTS</b>The expression of hTERT was significantly different between benign (4/19) and borderline (90.9%, 30/33) cases, benign and malignant (94.4%, 51/54) cases (P < 0.001), as was the expression of TRAP between benign (4/15) and malignant (77.8%, 28/36) cases (P < 0.001). The expression of hTERT and TRAP was not higher in stage III, IV ovarian cancer patients than in stage I and II (P > 0.05, P > 0.3). The expression of PCNA between benign (6.9 +/- 5.9)% and borderline (26.4 +/- 17.8)% cases, benign and malignant (51.8 +/- 22.1)% cases, and borderline and malignant cases were different, and were statistically significant (P < 0.01, P < 0.001, P < 0.05). 33 cases of borderline malignancy are all survive. In 54 cases of malignancy, 35 of them have metastasis (64.8%), including 5 cases of lymph nodes metastasis. 4 of them died (7.4%).</p><p><b>CONCLUSIONS</b>The expression of hTERT and TRAP is associated with the malignant degree of ovarian cancer, but does not correlate with stage. The expression of TRAP resembles hTERT, which may be a new tumor-associated gene. Telomerase activity is positively associated with PCNA.</p>