Application of two-stage ridge splitting technique in atrophic mandibular alveolar ridge / 华西口腔医学杂志

Adequate bone volume is the primary condition for successful dental implants. However, sufficient bone volume is often encountered in the vertical direction, but the bone volume in the buccolingual direction is insufficient, making it less suitable to be implanted. If the traditional spitting technique is used in the mandible, fracture and necrosis can easily occur in the labial (buccal) bone plate due to the absence of elasticity, thick cortical bone, poor blood supply, and anastomotic branch. The two-stage ridge splitting technique can be used in patients with narrow alveolar ridge in the mandible. This study summarizes the principles and conditions of application, operational points, clinical efficacy, and analysis of the causes of buccal bone plate absorption.

Effects of sandblasting on surface character and resin bond of zirconia ceramic / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the effect of Al2O3 particles sandblasting on the surface roughness, element composition and resin bond durability of zirconia ceramic.</p><p><b>METHODS</b>Sixty 2.5 mm thick computer aided design and computer aided manufacture (CAD/CAM) zirconia ceramic (Vita Inceram YZ) plates were fired, polished and cleaned. Half of polished ceramic plates was sandblasted with 50 µm alumina particles at 0.3 MPa for 20 s. The surface roughness of polished and sandblasted ceramic surface were measured by 3D-laser scanning microscope, and the surface element weight and atom ratio of the ceramic surface were measured by energy disperse spectroscopy (EDS). Then polished and sandblasted ceramic plates were randomized into six groups. In Group 1 and 2 the polished and sandblasted ceramic plates were bonded irrespectively with conventional resin cement (DUOLINK). In Group 3 and 4 the ceramic plates were bonded with resin cement containing MDP (Panavia F), In Group 5 and 6 the specimens were pretreated with silane coupler acitivated by MDP (Clearfil Ceramic Primer), then bond with Panavia F. The specimens of each test group were then divided into two subgroups, and to received shear test after 0 and 10 000 time thermal cycle. The data was analyzed by one-way ANOVA and independent t test.</p><p><b>RESULTS</b>Comparing with polishing, sandblasting reduced the oxygen atom and weight ratio of zirconia ceramic surface (P < 0.001), and increased the zirconium atom and weight ratio (P < 0.001), meanwhile increased the surface roughness (P < 0.001). The bond strength between ceramic plates and resin cement in all test groups decreased after thermocycling (P < 0.001). All specimen in test group 1 and 2 lost bond, and the bond strength of test group 3 and 5 [(0.59 ± 0.17), (0.89 ± 0.84) MPa] were significantly lower than that of test group 4 and 6 [(14.63 ± 3.03), (16.64 ± 1.90) MPa], and the bond strength of test group 6 were significanlty higher than that of test group 4.</p><p><b>CONCLUSIONS</b>Sandblasting improves durability of bond between zirconia ceramic and resin cement containing MDP, not only by increasing the roughness and area of ceramic surface, but also by changing its surface element composition to obtain more chemical bond.</p>

Screening of phosphoprotein associated with glycosphingolipid microdomains 1 (PAG1) by cDNA microarray and influence of overexpression of PAG1 on biologic behavior of human metastatic prostatic cancer cell line in vitro / 中华病理学杂志

<p><b>OBJECTIVE</b>To screen for novel gene(s) associated with tumor metastasis, and to investigate the effect of overexpression of phosphoprotein associated with glycosphingolipid microdomains 1 (PAG1) on the biological behaviors of human prostatic cancer cell line PC-3M-1E8 in vitro.</p><p><b>METHODS</b>Four cDNA microarrays were constructed using cDNA library of prostatic cancer cells PC-3M-1E8 (high metastatic potential), PC-3M-2B4 (low metastatic potential), lung cancer cells PG-BE1 (high metastatic potential)and PG-LH7 (low metastatic potential)to screen genes which were differentially expressed according to their different metastatic properties. From a battery of differentially expressed genes, PAG1, which was markedly downregulated in both high metastatic sublines of PC-3M and PG was chosen for further investigation. Real-time PCR and Western blot were used to confirm the gene expression of PAG1 at mRNA and protein levels. Full-length coding sequence of human PAG1 was subcloned into plasmid pcDNA3.0 and the recombinant plasmids were stably transfected into PC-3M-1E8. The cell proliferation ability, anchorage-independent growth, cell cycle distribution, apoptosis rates and invasive ability were detected by MTT, and in addition, soft agar colony formation, flow cytometry analysis and matrigel invasion assay using Boyden chamber were also carried out respectively. All experiments contained pcDNA3.0-PAG1-transfected clones, vector transfected clones and non-transfected parental cells.</p><p><b>RESULTS</b>A total of 327 differentially expressed genes were obtained between the high and low metastatic sublines of PC-3M cells, including 123 upregulated and 204 downregulated genes in PC-3M-1E8. A total of 281 genes, including 167 upregulated and 114 downregulated genes were obtained in PG-BE1 cells. Nine genes were simultaneously downregulated and 8 genes were upregulated in both high metastatic cell lines of PC-3M and PG. The expression of PAG1 at mRNA and protein level were decreased in the high metastatic subline PC-3M-1E8. Western blot revealed that PAG1 protein was downregulated in PC-3M-1E8 cell line which was in agreement with the gene expression at mRNA level. The proliferation ability and clonogenicity of PAG1 overexpression cells by stable transfection were markedly decreased in comparing with that of the control cells (P < 0.05). Colonies formed in stably PAG1-transfected cells, the vector-transfected clones and parental cells were 26.7 ± 5.2, 47.2 ± 3.2 and 52.3 ± 3.4 respectively (P < 0.05). Flow cytometry analysis showed that the stable PAG1-transfected cells at G₀-G₁ phase were significantly more than that of the control cells (P < 0.05). However, no difference of the apoptosis rate was found between PAG1-transfected cells and control cells (P > 0.05). The number of cells passing through the matrigel and multipore membrane was also decreased in the stable PAG1-transfected cells (35.1 ± 4.9) compared with those of the vector-transfected clones (127.6 ± 6.6) and parental cells (135.0 ± 5.0, P < 0.05).</p><p><b>CONCLUSIONS</b>Using cDNA microarray technique and differential gene expression analysis of sublines of the parental cancer cell lines enable of revealing the metastasis-related genes, among which PAG1 represents one of those under-expressed genes in the high metastatic subline PC-3M-1E8. Transfection expression of PAG1 suppresses cell proliferation, anchorage-independent growth and invasive ability of PC-3M-1E8 cells in vitro. Conclusively, PAG1 may play an important role in inhibiting the proliferation, invasion and metastasis of the cancer cells.</p>

Autopsy study of 275 medical dispute cases / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the characteristics of autopsies in medical dispute cases, with respect to class of hospitals, clinical units concerned, age of deceased and cause of death.</p><p><b>METHODS</b>Two hundred and seventy-five autopsies performed on medical dispute cases during the period from January 1, 2002 to September 30, 2008 at the Department of Pathology, Health Science Center, Peking University, China were retrospectively reviewed.</p><p><b>RESULTS</b>During the period of study, the number of autopsies performed on medical dispute cases gradually increased. Medical dispute cases happened more often in surgical, obstetric and gynecology departments of grade II and III hospitals, as well as emergency departments of grade I hospitals. Perinatal death in infants of less than 1 year old more frequently caused medical dispute than death occurring in other age groups. According to the International Classification of Diseases (ICD10), disorders of the circulatory system, perinatal illnesses, external injury or iatrogenic conditions represented the major categories of cause of death. In general, the vast majority was due to natural causes and only 13.5% were related to iatrogenic reasons or medical negligence. Pathologic diagnosis of sudden coronary death, myocardial infarction and viral myocarditis should only be made with strict diagnostic criteria.</p><p><b>CONCLUSIONS</b>Autopsies for medical dispute cases can help to delineate the cause of death and provide evidence for further clarification. Meticulous autopsy techniques, application of strict diagnostic criteria and detailed analysis of cause of death are key steps in achieving a high quality service in this area.</p>

Histopathologic study of avian influenza H5N1 infection in humans / 中华病理学杂志

<p><b>OBJECTIVE</b>To identify histopathologic changes of major organs and to correlate clinical symptoms in patients infected by avian influenza H5N1.</p><p><b>METHODS</b>Autopsy study was performed in two patients died of avian influenza HSN1 infection, following conventional protocols and strict safety procedures. Tissue samples from all major organs of two cases and lung samples of one case were collected and fixed in 4% formaldehyde. Histopathologic changes were evaluated by light microscope.</p><p><b>RESULTS</b>Diffuse alveolar damage (DAD) of the lung was seen in both cases. Lesions at various stages of development were seen involving different areas of the lung. At the early stages, the lungs exhibited exudative changes, including capillary congestion, necrosis of alveolar epithelial cells, and intra-alveolar edema. Hyaline membranes were prominent and diffusely distributed along alveoli. In the middle-late stages of the disease, the lungs exhibited proliferative and fibrotic changes, including proliferation of pneumocytes and bronchial epithelium, fibrosis of the interstitium and alveolar spaces. Lung biopsy tissue of one case showed DAD and interstitial fibrosis in a background of bronchiectasis. Lymph nodes and spleens showed quantity reduction of lymphocytes and active hemophagocytosis. Other changes in major organs included interstitial carditis in one case and acute renal tubular necrosis in one case. In one case, the brain showed edema with cytoplasmic eosinophilia, loss of structure, axon welling and focal necrosis around ventricle. Multiple foci of trophoblastic necrosis with dystrophic calcification were observed in placenta of one pregnant patient. Acute necrotizing deciduitis was found focally. Sections of fetal lung showed edema and scattered interstitial neutrophils were consistent with acute interstitial pneumonitis.</p><p><b>CONCLUSIONS</b>The respiratory tract is the major target of avian influenza A H5N1 virus infection. The changes of DAD in the lungs resulted in hypoxia, leading to multiple organ failure and death.</p>

Immunoregulation effects in vitro of the xenoprotein in combination with recombinant human granulocyte-macrophage colony stimulating factor and bacillus Calmette-Guerin / 中国实验血液学杂志

This study was aimed to investigate the effects of xenogeneic antigen neu-Fc in combination with the recombinant human granulocyte-macrophage colony stimulating factor (GM-CSF) and Bacillus Calmette-Guerin (BCG) on the regulation of Th1 and Th2 immune response in vitro. The rat neu L2-S2 domain was engineered as a chimeric protein with human IgG Fc. The eukaryotic expression vector was constructed. The recombinant protein was stably expressed in CHO cells and purified by rProtein A Sepharose Fast Flow column. The recombinant protein was identified by SDS-PAGE and Western blot. Peripheral blood mononuclear cells (PBMNCs) were obtained by means of standard Ficoll separation from the blood of healthy donors. Neu-Fc-induced PBMNC proliferation was tested by MTT. The production of IL-12 and IL-10 was measured by ELISA. The results showed that the level of IL-12 decreased and IL-10 increased after PBMNCs were incubated with MCF-7 cultural supernatant. 10 nmol/L neu-Fc strongly induced the cell proliferation. Compared with neu-Fc or GM-CSF or BCG treatment alone, neu-Fc in combination with GM-CSF and BCG significantly stimulated IL-12 production and inhibited IL-10 production (p < 0.01). It is concluded that the neu-Fc can stimulate the proliferation activity of PBMNCs. neu-Fc, GM-CSF and BCG costimulation efficiently induces Th1 immune response.

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>

Observation of osteoclasts on the root surface during human deciduous teeth resorption / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To observe osteoclasts on the resorbing surface of human deciduous teeth.</p><p><b>METHODS</b>After fixing the collected deciduous teeth, we prepared the tooth slices without decalcification, treated them with HE and TRAP dyestuff, and observed the osteoclasts under light and scanning electron microscope.</p><p><b>RESULTS</b>There were large quantity of various forms of overlapping and huge osteoclasts with many nuclei and silk-like protuberances on the resorbing surface of deciduous teeth. The multinucleated osteoclasts align on the surface of coarse dentin.</p><p><b>CONCLUSION</b>On the resorbing surface of human deciduous teeth there are large amount of osteoclasts which can be used as a source of studying human osteoclast.</p>

Expression and significance of integrin alpha6beta4 in experimental allergic neuritis / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the expression of the integrin alpha6beta4 in experimental allergic neuritis (EAN) and the relationship of the integrin alpha6beta4 with functional states of Schwann cells (Sc) as well as the injury and repair of the myelin during EAN.</p><p><b>METHODS</b>EAN was induced in Lewis rats and sciatic nerves were resected in 18 EAN and 3 normal rats. The expression of tissue integrin alpha6beta4 was analyzed during the course of EAN induction and in controls by in situ hybridization and semi-quantitative RT-PCR.</p><p><b>RESULTS</b>The detection of integrin alpha6 and beta4 subunit by hybridization in situ demonstrated that expression of alpha6 subunit present no significant changes during the course of EAN, while expression of beta4 declined in the early phase, showing less positive signals than those of the control, and restored its expression in the later or recovery phase. The changes of expression of integrin alpha6 and beta4 in EAN were confirmed by semi-quantitative PT-PCR, using GAPDH as the internal standard.</p><p><b>CONCLUSIONS</b>The degeneration and injury of Sc caused by inflammation affect the expression of integrin, which shows similar changes in Sc during embryogenesis, indicating alpha6beta4 may be a marker of Sc differentiation and at least an important molecule to mark the course of EAN. The expression of alpha6beta4 correlate with the injury and repair of myelin during EAN.</p>