Inactivation of mammalian target of rapamycin (mTOR) by rapamycin in a murine model of lipopolysaccharide-induced acute lung injury / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The mammalian target of rapamycin (mTOR) pathway, a key cellular signaling pathway associated with various cellular functions, has distinct roles in the inflammatory process. In this study, the mTOR inhibitor rapamycin (Rapa) was used to test whether inhibition of mTOR activation attenuates lipopolysaccharide (LPS)-induced acute lung injury (ALI) in a murine model.</p><p><b>METHODS</b>Mice pretreated with Rapa or vehicle were given LPS intratracheally. Local cell numbers and inflammatory cytokines present in the bronchoalveolar lavage fluid (BAL), wet-to-dry weight ratio, histopathology of the lungs, and survival were evaluated.</p><p><b>RESULTS</b>The phosphorylation of S6, a major downstream target of mTOR, had a 3-fold increase in lung tissue after LPS stimulation, but the increase was blocked by Rapa. Rapa reduced the levels of TNF-α (LPS vs. LPS + Rapa, (1672.74 ± 193.73) vs. (539.17 ± 140.48) pg/ml, respectively; P < 0.01) and IL-6 (LPS vs. LPS + Rapa: (7790.88 ± 1170.54) vs. (1968.57 ± 474.62) pg/ml, respectively; P < 0.01) in the BAL fluid. However, Rapa had limited effects on the overall severity of ALI, as determined by the wet-to-dry weight ratio of the lungs, number of neutrophils in the BAL fluid, and changes in histopathology. In addition, Rapa failed to reduce mortality in the LPS-induced ALI model.</p><p><b>CONCLUSIONS</b>We confirmed that mTOR was activated during LPS-induced ALI and strongly inhibited by Rapa. Although Rapa reduced the levels of the mediators of inflammation, the overall severity and survival of the ALI murine model were unchanged.</p>

Infection of human papillomavirus 16/18 DNA in patients with head and neck squamous cell carcinoma and its relationship with expression of Ki-67 and P53 protein / 中国医学科学院学报

<p><b>OBJECTIVE</b>To detect the infection of human papillomavirus (HPV) 16/18 in patients with head and neck squamous cell carcinoma and explore the relationship between HPV infection and expressions of Ki-67 and P53 proteins in tumor tissue.</p><p><b>METHOD</b>The level of HPV 16/18 DNA was measured by real time polymerase chain reaction, and Ki-67 and P53 proteins were measured by immunohistochemistry in tissues from head and neck squamous cell carcinoma.</p><p><b>RESULTS</b>HPV 16/18 DNA was detected in 62.8% of our patients. In each cancer tissue sample, Ki-67 protein was expressed between 2% to 70%. P53 protein was expressed in 46.15% of our patients. No significant relation was found between HPV 16/18 DNA level and sex, smoking, drinking, and tumor clinical stages. However, level of HPV 16/18 DNA was found to have positive relation with tumor pathological grades and negative relation with P53 protein expression. No relation with Ki-67 protein expression was found.</p><p><b>CONCLUSION</b>Head and neck squamous cell carcinoma may be initiated by HPV 16/18 infection and the mechanism in carcinogenesis involves abnormal expression in P53 protein.</p>

Lymph node image with ultrasmall superparamagnetic iron oxide and comparison with pathological result / 中国医学科学院学报

<p><b>OBJECTIVE</b>To assess the characteristics of enhanced magnetic resonance image with ultrasmall superparamagnetic iron oxide (USPIO) in the inflammatory and tumor metastatic rabbit model, and explore its relevance with histologic ultrastructural findings.</p><p><b>METHODS</b>Totally 36 New Zealand white rabbits were randomly divided into lymphadenitis group and metastatic group. Complete Freund's adjuvant was injected into the bilateral dorsal footpads of 18 rabbits to set up ipsilateral lymphadenitis model. The other 18 rabbits received a subcutaneous implantation of VX2 tumor cell suspension (1.5 x 10(7) cells/ml) in both thighs to set up metastatic lymph node model. Magnetic resonance scan were performed 24 hours before and after USPIO (90 micromol Fe/kg) injection. T2 values of each lymph node were measured and lymph node T2 enhancement rate was calculated as well. HE staining, Prussian blue staining, and electronic microscopy were performed to observe the pathological microstructure changes and the distribution of the iron particle in lymph node. Relationship between lymph nodes USPIO enhancement and its microstructures were further analyzed. Results Thirty-six lymph nodes in lymphadenitis group showed different degrees of reactive hyperplasia. Twenty-six lymph nodes in metastatic group were invaded by tumor cell. Non-enhanced scan showed mild difference between T2 signal intensity of the two pathological lymph node types. After USPIO enhancement, inflammatory lymph nodes showed distinct T2 signal reduction at the center, and metastatic lymph nodes showed homogenous and faint T2 signal reduction. Enhancement rate of benign and malignant lymph nodes were 57.39% and 29.45% respectively (P < 0.01). HE staining and Prussian blue staining indicated USPIO particles located mainly in the macrophages at inflammatory lymphatic medulla, while paracortical area and cortical area contained relatively much less USPIO particles due to less macrophages distribution. MRI findings were correlated with the pathological results. Electronic microscopy also verified that the majority of USPIO particles were located in the numerous cytophagic bubbles of macrophages. Lymph nodes metastasis including 4 lymph nodes with completed structure destruction due to entire tumor infiltration, 19 lymph nodes with partially lymph node structure destruction but reduced USPIO-contained macrophage numbers or reduced USPIO particles in macrophages, and 3 lymph nodes with only localized foci tumor metastasis at subcapsular area. Conclusions USPIO enhancement pattern of different lymph nodes is closely related to distribution and functional status of the intra-node macrophages. It may affect the accuracy of the lymph node property diagnosis based on USPIO enhanced image.</p>

Morphological study of severe acute respiratory syndrome (SARS) / 中华病理学杂志

<p><b>OBJECTIVE</b>Seven cases of autopsy from SARS patients are studied to investigate the pathogenesis and the pathologic changes of the major organs.</p><p><b>METHODS</b>Detailed gross and microscopic examination of the autopsy specimen is performed, including lung, heart, liver, kidney, spleen and lymph nodes.</p><p><b>RESULTS</b>All of the lungs are markedly enlarged and consolidated. Microscopically, pulmonary edema is a prominent finding, especially at the early stage of the disease (5 days after the onset). The alveolar spaces are filled with fibrinous exudates and lined with hyaline membrane. In 5 cases that undergo over 3 weeks of the course, the main pattern is organization of intra-alveolar deposit, along with fibroblastic proliferation in the alveolar septa, which leads to obliteration of alveolar space and pulmonary fibrosis. All of the lungs show bronchopneumonia, scattered hemorrhage, and proliferation of alveolar epithelial cells with desquamation. Microthrombi are seen in 6 cases. Fungal infection is noted in 2 cases. One of them is disseminative, involving bilateral lungs, heart, and kidney; the other one is diagnosed in hilar lymph nodes. In immune system, hilar and abdominal lymph nodes are usually congested and hemorrhagic, with depletion of lymphocytes, and accompanied with subcapsular sinus histiocytosis. One of the cases shows enlargement of abdominal lymph nodes, which have reduced number of germinal centers. Spleen exhibits atrophy of white pulps, and even lost of white pulps in some areas. The red pulp is markedly congested and hemorrhagic. In 5 cases, cardiomegale is prominent. Thrombosis (2 cases), focal myocarditis (1 case), and fungal myocarditis (1 case) are observed. In addition, liver shows massive necrosis (1 case) and nodular cirrhosis (1 case).</p><p><b>CONCLUSIONS</b>Lung is the major organ affected by SARS, demonstrated as diffuse alveolar damage. It is postulated that viral infection induces severe damage of alveolar epithelial and capillary endothelial cells, leads to pulmonary edema, intra-alveolar fibrin deposit, and hyaline membrane formation. Consequently, intra-alveolar organization and alveolar septal fibrosis causes loss of alveolar spaces, eventually, pulmonary fibrosis and atelectasis. The immune system is often affected, and presented as depletion of lymphoid tissue in lymph nodes and spleen. Secondary infection is a common complication, which should be paid close attention in the management of SARS patients.</p>

Immunohistochemical investigation of lungs with severe acute respiratory syndrome / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the roles of different cells in the pulmonary lesions in the severe acute respiratory syndrome (SARS) patients.</p><p><b>METHODS</b>The monoclonal antibodies of CD8, CD20, CD34, LCA, CD56, CD68, and AE1/AE3 are used to demonstrate the different cells in the lung specimens of SARS patients in order to study the patterns of cell responses in this new disease. Meanwhile the HE stained slides were also carefully studied to compare with the results of immunohistochemical staining.</p><p><b>RESULTS</b>The number of capillaries increased and the capillaries clearly outlined the contour of alveolar wall from beginning to early stage of organization, the number of lymphocytes decreased sharply while the number of macrophage remarkably increased, together with proliferation of type II pneumocytes. The numbers of blood vessels decreased in the fibrotic and consolidated lung tissue, and the vessel cavities enlarged, losing the normal contour of alveolar septa.</p><p><b>CONCLUSIONS</b>The lesions in the lung from SARS patients are consisted of the tissue reaction to the inflammatory injury, including extensive exudation, capillary proliferation, fibrosis, and obvious infiltration of macrophages which may play a key role in the pathogenesis of pulmonary lesions of SARS.</p>

Lung pathology of severe acute respiratory syndrome / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the morphological features of the lungs obtained from autopsies of severe acute respiratory syndrome (SARS) patients.</p><p><b>METHODS</b>Bilateral lungs from 7 patients died from SARS were carefully studied grossly and microscopically. All tissues from these cases were routinely processed and carefully studied.</p><p><b>RESULTS</b>All lungs from these cases were extremely expanded and became solid. Microscopically, the edema and fibrin exudates in the alveoli was the most common findings, especially in the early phase of the disease. The hyaline membrane was almost always present in the lungs of these cases. The organization of intra-alveolar fibrin exudates along with the interstitial fibrosis led to obliteration of alveoli and consolidation of lungs. The desquamation and hyperplasia of alveolar lining cells was also apparent. Foci of haemorrhage and lobular pneumonia, even diffuse fungal infection were frequently seen in these specimens. Micro-thrombus were easily found in these lungs.</p><p><b>CONCLUSIONS</b>The lung of SARS from autopsy is characterized by edema, intra-alveolar fibrin exudates, hyaline membrane formation, organization of intra-alveolar exudates and fibrosis, which lead to the obliteration of alveoli and consolidation of lungs.</p>

Biological effect of hepatocyte growth factor gene transfection to rat cerebral ischemic model:the experimental study / 中华放射学杂志

Objective To investigate hepatocyte growth factor(HGF)gene expression and biological effect after gene transfection into penumbra tissue in rat cerebral ischemic model.Methods Human HGF cDNA was ligated to pIRES2-EGFP vector.The recombinant plasmid was transfected into the penumbra tissue with liposome.Brains of treated and control animals were analyzed 7 days later.Expression of HGF protein was determined by fluorescence microscopy and immunohistochemistry.Vessel numbers were quantified.Changes of cerebral blood flow(CBF)was detected by CT perfusion.Results Enzymatic digestion and electrophoresis confirmed that HGF fragment had been correctly cloned into BamH I and Sal I sites of pIRES2-EGFP.After HGF gene transfection,expression of HGF in transfected neurocytes was observed with fluorescence microscopy and immunohistochemistry.The number of vessels was significantly increased in penumbra tissue transfected with HGF vector as compared with control vector(46.71?7.11, 20.43?3.21,18.00?3.27,respective,F = 74.447;P