Facile microwave-assisted synthesis of benzimidazole scaffolds via Ugi-type three-component condensation (3CC) reactions.

Two series of fused benzimidazoles were synthesized via a facile, one-pot procedure under microwave irradiation. This procedure generated the desired products in high yields and could provide a useful synthetic platform with potential applications in medicinal chemistry.

[Pilose antler polypeptide CNT14 promoted proliferation and migration of human oral mucosa fibroblast cells].

PURPOSE: To explore the effect of pilose antler polypeptides CNT14 on proliferation and migration of human oral mucosa fibroblast (hOMF) cells and the related molecular mechanism. METHODS: The biosafety of pilose antler polypeptides CNT14 on hOMF cells was verified by live-dead cell staining kit.CCK-8 assay was used to detect the effect of pilose antler polypeptides CNT14 on hOMF cell proliferation. The effect of pilose antler polypeptides CNT14 on hOMF cell migration was detected by scratch test. Western blot was used to detect the expression of α-SMA, TGF-ß1, Smad2 and p-Smad2 proteins in hOMF cells stimulated by pilose antler polypeptides CNT14. The effect of Smad2 inhibitors on fibroblast activation induced by pilose antler polypeptides CNT14 was evaluated.The model of keratinized gingival defect was established in New Zealand white rabbits, and the regenerated gingival tissue was stained with H-E. The expression levels of α-SMA, TGF-ß1, Smad2 and p-Smad2 proteins in the gingival tissues of regenerated New Zealand white rabbits were detected by immunohistochemistry, and the ability of pilose antler polypeptides CNT14 to promote regeneration of oral gingival tissues was verified. Statistical analysis was performed with SPSS 20.0 software package. RESULTS: The survival rate of hOMF cells was above 95% after treated with pilose antler polypeptides CNT14. After stimulation of hOMF cells with pilose antler polypeptides CNT14, the proliferation and migration rates of hOMF cells were increased compared with the control group (P＜0.05). The expression of α-SMA, TGF-ß1, Smad2 and p-Smad2 proteins in hOMF cells stimulated by pilose antler peptide CNT14 was increased, and the difference was statistically significant(P＜0.05). The expression of α-SMA in fibroblasts induced by Smad2 inhibitor was decreased. In animal experiments, H-E staining showed that the inflammatory response of oral mucosal wounds of New Zealand white rabbits treated with CNT14 was less than that of the control group. Immunohistochemical staining results showed that the expressions of α-SMA, TGF-ß1, Smad2 and p-Smad2 in the regenerated gingival tissues of New Zealand white rabbits treated with CNT14 were significantly increased compared with those in the control group on the 9th and 11th days within the gingival wounds(P＜0.05). CONCLUSIONS: Pilose antler polypeptides CNT14 has good biosafety and can promote the proliferation and migration of human oral mucosa fibroblast cells, and the expression levels of α-SMA, TGF-ß1, Smad2 and p-Smad2 were increased, promoting the regeneration of gingival tissues.

To Save Pangolins: A Nutritional Perspective.

Pangolins are one of the world's most trafficked mammals. Since pangolins are highly adapted to ants and termites, they are important for controlling forest termite infestations. In addition to their ecological value, pangolins have economic and medicinal value. Currently, poaching and habitat destruction have radically reduced the number of pangolins, and Manis pentadactyla, Manis javanica, and Manis culionensis are now considered the most threatened pangolin species. In addition to the control of hunting and illegal trade, ex situ breeding is also a useful conservation method. However, many technical obstacles still limit the success of ex situ pangolin breeding. The special feeding traits of pangolins require a diet that meets nutritional and ethological needs. Based on the existing literature and practical experience, this review aims to compare the natural diet and successful diet in the human care of pangolins, to outline the key factors of successful ex situ maintenance from a dietary perspective, and the strategies to improve their conservation success in animal care centers and in the wild. The type of food used in successful pangolin protection agencies is quite variable in nutritional composition. In the diet of pangolins in the wild, the nutrient profile of different species of termites and ants and even the same species of termites and ants but different types (queens, soldiers, etc.) also displays differences. The crude protein content of some ants is higher than that of other foods, such as eggs, milk, and common cat food. The mineral and vitamin concentrations of ants also exceed many common food items, such as oil, meat, and eggs. However, not much is known about the bioavailability of minerals from ants and termites. Based on comparisons between foods, it is clear that the main difference between diets in the wild and in human care of pangolins is that the latter contains fewer insects and vitamins, such as vitamin E, vitamin A, and vitamin B2, and more carbohydrates and non-protein substances than the former. Although many successful dietary formulae have been developed, the pangolin's nutritional needs are still less well studied. A diet with the nutrient concentrations observed in the wild may add to successful ex situ conservation.

Buccal bone dimensional changes at immediate implant sites in the maxillary esthetic zone within a 4-12-month follow-up period: A systematic review and meta-analysis.

OBJECTIVE: To evaluate the changes in buccal bone dimensions (CBD) following immediate implant placement in the maxillary esthetic zone and to identify the factors influencing the degree of buccal bone resorption for different placement and restoration protocols. MATERIAL AND METHODS: An electronic search was conducted using the EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and MEDLINE (PubMed) databases, combined with a manual and gray literature search, up to January 2021. Selected clinical studies had to report the changes in horizontal buccal bone dimension in maxillary immediate implantation sites (premolar to premolar) at baseline and at follow-up visits within a year of implantation. A meta-analysis was conducted to calculate the mean value of the changes in horizontal and vertical buccal bone dimensions (CHBD and CVBD) around implants. To further investigate the heterogeneity and identify factors associated with buccal bone loss after immediate implant placement, subgroup analysis and univariate meta-regression were performed. RESULTS: From a total of 3498 articles, 4 randomized controlled trials and 12 nonrandomized controlled trials were included for analysis. The mean survival rate of 568 implants was 99.6%. The mean CHBD and CVBD values were 0.71 mm (95% confidence interval: [0.56, 0.86]) and 0.58 mm (95% confidence interval: [0.43, 0.72]), respectively. For possible factors that related to bone resorption, including buccal bone thickness, flap design, bone grafting, horizontal defect dimension, and restoration protocol, bone grafting was the only variable that significantly influenced CHBD. CONCLUSIONS: This study demonstrated that immediate implant placement in the esthetic zone does not prevent buccal bone from resorption. Due to data heterogeneity and the small sample size of the studies included in the analysis, further well-conducted, randomized controlled trials with homogeneous samples are required to investigate the correlation of CBD with different variables.

[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].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

[Application of two-stage ridge splitting technique in atrophic mandibular alveolar ridge].

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.

[High-risk factors and clinical pathological analysis in 21 cases of fatal pulmonary embolism].

OBJECTIVE: To explore the clinical and pathological characteristics of fatal pulmonary thromboembolism, especially the contribution of acquired and genetic risk factors of fatal pulmonary thromboembolism, so as to provide some useful information for its clinical prevention and treatment. METHODS: The medical dispute autopsy cases performed at the Department of Pathology, School of Basic Medical Sciences, Peking University from January 1, 2002 to September 30, 2008 were retrospectively reviewed. FV ( factor V ) Leiden mutation and FII ( factor II) G20210A mutation were analyzed by using methods of PCR and restriction fragment length polymorphism (RFLP) in fatal pulmonary embolism cases and random selected control cases of adult autopsy. RESULTS: There were 21 patients who died from fatal pulmonary thromboembolism, accounting for 12.96% (21/162) of adult autopsy cases. In these cases, there was at least one of the known risk factors in each case and more than two risk factors could be found in most cases. The acquired risk factors, such as surgery, trauma and fractures, cancer, pregnancy and puerperium, the elderly, hypertension, diabetes, infections, could be found in these patients. FV Leiden mutation and FII G20210A mutation were not detected in any of the 21 cases of fatal pulmonary thromboembolism cases and six control cases. Of all the 21 cases, quantitative D-dimer measurement was performed only in six patients and D-dime level in these six samples was all significantly increased. According to the records, there was only 1 patient treated by preventive anticoagulants in the 21 patients. CONCLUSION: Fatal pulmonary thromboembolism is an important reason for medical dispute. Fractures and trauma, surgery and other acquired factors are the main reasons for fatal pulmonary embolism in Chinese. Genetic factors (FV Leiden and FII G20210A mutations) are not the reason for Chinese to suffer from fatal pulmonary thromboembolism. Assessment of risk factors (especially traumatic fractures and surgical intervention) of pulmonary thromboembolism may play an important role in taking appropriate preventive procedures, early diagnosis and reasonable treatment to reduce its mortality.

[Autopsy study of 275 medical dispute cases].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Molecular Mechanism for Selective Cytotoxicity towards Cancer Cells of Diselenide-Containing Paclitaxel Nanoparticles.

Diselenide-containing paclitaxel nanoparticles (SePTX NPs) indicated selectivity of cytotoxicity between cancerous and normal cells in our previous work. Herein, the mechanism is revealed by molecular biology in detail. Cancer cells and normal cells were treated with the SePTX NPs and cell proliferation was measured using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay and cell morphology. Measurement of reactive oxygen species (ROS) levels and biochemical parameters were employed to monitor oxidative stress of the cells. JC-1 assay was used to detect the mitochondrial dysfunction of the cells. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) analysis was used to detect apoptosis of the cells. Immunofluorescence analysis and western blotting were employed to monitor changes in signaling pathway-related proteins. Compared with PTX, SePTX NPs has a good selectivity to cancer cells and can obviously induce the proliferation damage of cancer cells, but has no significant toxicity to normal cells, indicating that SePTX NPs has a specific killing effect on cancer cells. The results of mechanism research show that SePTX NPs can successfully inhibit the depolymerization of microtubules and induce cell cycle arrest, which is related to the upregulation of p53 and CyclinB1. Simultaneously, SePTX NPs can successfully induce oxidative stress, cause mitochondrial dysfunction, resulting in mitochondrial pathway-mediated apoptosis, which is related to the upregulation of autophagy-related protein LC3-II. On the other hand, lewis lung cancer C57BL/6 mice were used to evaluate the anti-tumor effects of SePTX NPs in vivo. Our data show that SePTX NPs exhibited high inhibiting efficiency against the growth of tumors and were able to reduce the side effects. Collectively, these data indicate that the high antitumor effect and selective cytotoxicities of SePTX NPs is promising in future cancer therapy.

[Histopathologic study of avian influenza H5N1 infection in humans].

OBJECTIVE: To identify histopathologic changes of major organs and to correlate clinical symptoms in patients infected by avian influenza H5N1. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Effects of Temperature on the Expression of Two Ovarian Differentiation-Related Genes foxl2 and cyp19a1a.

Exposure to stress induces a series of responses and influences a wide range of biological processes including sex differentiation in fish. The present work investigated the molecular and physiological response to thermal stress throughout the early development stage covering the whole period of sex differentiation of bluegill, Lepomis macrochirus. Larvae were treated using three temperatures, 17, 24, and 32°C from 6 to 90 days posthatching (dph) in 30-L round tanks. There is no significant difference of the sex ratio and survival among the three temperature groups in the geographic population used in this study. Two ovarian differentiation-related genes foxl2 and cyp19a1a were detected at 7 dph suggesting that these genes have already played a role prior to sex differentiation. The expression of foxl2 reached the peak and was thermosensitive just prior to the onset of ovarian differentiation at 27 dph. Histological examination displayed that the proliferation of germ cells and ovarian differentiation were delayed at the low-temperature treatment (17°C) at 97 dph compared with higher temperatures. In conclusion, the water temperature regulates the sex differentiation of bluegill through modulation of the expression of foxl2 and cyp19a1a. A comparative study of the expression profile of sex differentiation-related genes in species will shed light on the evolution of sex-determination mechanisms and the impact of stress on sex differentiation.

[Clinical characteristic analysis of the first human case infected by influenza A (H5N1) in Jiangxi Province].

OBJECTIVE: To describe the clinical, laboratory and radiological presentation of a human case infected by influenza A (H5N1), and to understand its management and prognosis. METHODS: The clinical and autopsy data of the first human case infected by influenza A (H5N1) in Jiangxi Province were collected and analyzed. RESULTS: The first case infected by influenza A (H5N1) in Jiangxi Province was confirmed by laboratory findings with reverse transcription-polymerase chain reaction (RT-PCR) and influenza A (H5N1) isolation. The patient had been healthy in the past and exposed to the environment of bird flu before illness. The initial symptoms included high fever with influenza-like symptoms, and then cough and purulent sputum mixed with blood appeared. The clinical situation deteriorated progressively with occurrence of diarrhea and dyspnea. Laboratory abnormalities included decrease of peripheral white blood cells and lymphocytes, urine protein, dramatic increase of enzymes associated with hepatic injury and myocarditis and decrease of serum albumin. Six days later, penicillin-resistant streptococcus pneumoniae was isolated from multiple sputum cultures. With the deterioration of clinical situation, several other bacteria and fungi were found in sputum culture. Pulmonary infiltrates were evident in right middle and lower lobe at day 5 after illness, and rapidly progressed to involve bilateral lungs as acute respiratory distress syndrome (ARDS)-like changes. The patient was treated with antiviral, antibacterial, and antifungal reagents, and corticosteroids and invasive mechanical ventilation were also administered, but without any improvement. The patient died 27 days after the onset of symptoms and an autopsy was performed. Pathologically, the lungs exhibited diffuse alveolar damage. The lymphocytes in the spleen, the lymph nodes and the tonsils were depleted prominently with histiocytic hyperplasia and hemophagocytic phenomena. Edema and degeneration of myocytes in the heart and extensive acute tubular necrosis in the kidney were observed. CONCLUSION: The prognosis was very poor if influenza A (H5N1) infected human cases was developed as ARDS with multiple organ damage or failure.

[Applications of minimally invasive bone splitting technique in cases with missing maxillary anterior teeth and obvious labial alveolar bone depression for dental implantation].

PURPOSE: The purpose of this study was to introduce a minimally invasive bone splitting technique which is suitable for cases with missing anterior teeth and obvious depression of alveolar bone in labial side, and to evaluate its clinical results. METHODS: Minimally invasive bone splitting technique was used in 8 healthy adults with bone defects in the aesthetic zone. The labial alveolar bone incisions were confined around the bone defects which were smaller than traditional incisions. The other procedures were the same as conventional bone splitting technique. Cone-beam CT (CBCT) for missing anterior teeth was taken before surgery, after the surgery and 6 months after surgery and alveolar bone height and width were recorded with landmark identification designed by ourselves in this study. The data were analyzed with SPSS 21.0 software package for paired t test. RESULTS: Paired t test indicated that after surgery and six months after surgery, the labial bone defect was significant improved (P<0.05), but the height of the alveolar ridge bone didn't increase significantly (P>0.05) while the width of the alveolar ridge bone significant improved (P>0.05). CONCLUSIONS: This minimally invasive technique can achieve good clinical results for not only intact labial alveolar ridge bones but also good bone grafts, which is beneficial to implantation and prosthetic aesthetics. The long-term outcome needs to be observed.

[Clinical observation of assisted occlusion therapy for repositioning temporomandibular joint discs].

PURPOSE: To investigate the occurrence of postoperative malocclusion of patients with temporomandibular joint disc repositioning and the necessity of postoperative orthodontic treatment. METHODS: One hundred and eight patients who received temporomandibular joint disc repositioning from 2010.10 to 2015.10 were selected in this study. The patients' occlusion was recorded preoperatively and postoperatively. All patients received functional appliance or orthodontic treatment after surgery. The occlusion and the relative position of the articular disc and condyle were evaluated at regular follow-up. RESULTS: Postoperative malocclusion occurred in all patients. The use of functional appliance for 3-6 months may decrease the proportion of malocclusion. After orthodontic treatment, all patients had a complete recovery of malocclusion and remained good articular disc and condyle relationship during long term follow-up. CONCLUSIONS: Postoperatively malocclusion may occur after temporomandibular joint disc repositioning, and the use of functional appliance and orthodontic treatment are strongly recommended to retain good articular disc and condyle relationship.

[Lung pathology and pathogenesis of severe acute respiratory syndrome: a report of six full autopsies].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

A neutralizing scFv antibody against infectious bursal disease virus screened by flow cytometry.

Infectious bursal disease (IBD) is considered a vital viral disease that threatens the poultry industry worldwide. In this study, a recombinant single chain variable fragment (scFv) antibody library derived from chickens immunized with VP2 protein of infectious bursal disease virus (IBDV) was constructed. The library was subjected to three rounds of screening by flow cytometry (FCM) against VP2/IBDV through a bacteria display technology, resulting in the enrichment of scFvs. Three scFv clones with different fluorescence intensity were obtained by colony pick up at random. The obtained scFv antibodies were expressed and purified. Relative affinity assay showed the three clones had different sensitivity to VP2, in accordance with fluorescence activity cell sorting analysis (FACS). The potential use of the isolated IBDV-specific scFv antibodies was demonstrated by the successful application of these antibodies in Western blotting and ELISA assay. What's more, in vitro neutralization measurement showed that one of the three isolated antibodies possessed the neutralization function against IBDV. This study provides new strategies for screening of antibody library, and scFv antibodies isolated in this study may be utilized as lead candidates for further development of diagnostic or therapeutic antibodies for detection and treatment of IBDV infection.

High throughput screening of scFv antibodies against viral hemorrhagic septicaemia virus by flow cytometry.

Viral hemorrhagic septicaemia (VHS) is an economically important disease that affects salmon and trout worldwide. In this study, a recombinant single chain variable fragment (scFv) antibody library derived from rainbow trout immunized with purified viral hemorrhagic septicaemia virus (VHSV) was constructed. The library was subjected to three rounds of screening by flow cytometry (FCM) against VHSV through a bacteria display technology, resulting in the enrichment of scFv. Four scFv clones with different fluorescence intensity were obtained by colony pick up at random following three rounds of screening. The isolated scFv antibodies were expressed and purified. Relative affinity assay showed the four clones had different sensitivity to VHSV, in accordance with FCM. The potential use of the selected VHSV-specific scFv antibodies was demonstrated by the successful application in Western blotting assay, ELISA and immunofluorescence antibody test (IFAT), and one of the isolated scFv molecular showed excellent in vitro and in vivo blocking activities against VHSV. scFv isolated in this study can be promising diagnostic and/or therapeutic reagents for VHS. This study provides powerful strategies for screening antibodies against new diseases.

[Expression and Characterization of Single-chain Fv-Fc Fusion Protein against Human P185(erbB2)].

In order to increase therapeutic effects and decrease immunogenicity of mouse McAb, the single-chain Fv (scFv) created by fusing the light and heavy chain variable region genes of anti-human P185(erbB2) McAb was conjugated to the Fc gene of human IgG1 to construct a scFv-Fc fusion gene. The scFv-Fc fusion gene was cloned into the expression vector pCIDN. The scFv-Fc fusion protein was synthesized as secreted two-chain molecule in CHO cells, and purified by affinity chromatography on recombinant protein A. A special 185 kD P185(erbB2) protein was immunoprecipitated by the scFv-Fc fusion protein. The fluorescence-activated cell sorting (FACS) using SK-BR-3 cells as the target indicated that the fusion protein could bind to the extracellular domain of P185(erbB2). The affinity of the scFv-Fc fusion protein, determined by ELISA, was K=7.5x10(-10) (mol/L)(-1). This work laid basis for further studies on the anti-P185(erbB2) scFv-Fc fusion protein.

[Pathologic study of circulating blood leukocytes in severe acute respiratory syndrome].

OBJECTIVE: To study the pathologic characteristics and pathogenesis of circulating blood leucocytes infected by severe acute respiratory syndrome associated coronavirus (SARS CoV or SCV) in SARS patients. METHODS: Blood samples of 22 SARS patients were studied, and 4 healthy blood samples were observed as negative controls. The white blood cells were collected from whole blood. The ultrastructural characteristics were observed by transmission electron microscopy. CD45RO antibody was used for pre-embedding immunoelectron microscopy. The SARS viral sequence was detected with real-time polymerase chain reaction (RT-PCR). RESULTS: Coronavirus-like particles were founded in the leukocytes in 6 of the 22 blood samples. Five of them gave positive results in the real-time PCR. The number of granulocytes was increased (P < 0.05) and that of lymphocytes was decreased (P < 0.05) respectively. Immunoelectron microscopy showed that CD45RO positive T lymphocyte decreased to 6% - 7%. Circulating lymphocytes had the highest percentage of infection. The morphologic characteristics of coronavirus-like particles were spherical or oval in shape, about 80 - 120 nm in diameter, with a dense round core and a clear halo around the core. A distinct membrane and club-shaped surface projections were seen in the periphery. The particles were located in the cytoplasm, the cisternae of endoplasmic reticulum, Golgi apparatus and vesicles. Virus entered cells by endocytosis or membrane fusion and was released through a budding process. CONCLUSION: Our data suggested that lymphocytes, particularly T cells, were probably the target cells of SARS CoV. The viruses may actively infected the immune cells during SARS CoV acute infection phase and the destruction of target cells may be one of the important reasons for the death of the circulating leukocytes in SARS.

[Expression and significance of integrin alpha6beta4 in experimental allergic neuritis].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.