甘薯块根组织感染黑斑病时产生的自发荧光现象及其应用

1986、87两年分别采用上一年无病种薯28个品种/系各3块,取中部切决于切面上蘸接近等量和等浓度的黑疤病(Ceratocystis fimbriata)孢子悬液,恒温、恒湿培养,定期取样作侵染区组织徒手切片、乳酚油封片用BHZ型0lympus荧光显微镜(B+G滤镜激发)观察,取得以下资料;

香蕉枯萎病镰刀菌ITS序列的PCR扩增及其分子检测

根据香蕉枯萎病菌(Fusarium oxysporum f.sp.cubense)ITS序列设计合成的三条引物:FusF1(5′AACCC CTGTGAACATACCACTTG3′)、FusR1(5′GAGGAACGCGAATTAACGCGAC3′)和FusR2(5′GACGATTACCAGTAGCGAGGGT3′)构成引物对A(FusF1/R1)和B(Fus F1/R2),对尖廉孢菌古巴专化型病菌进行PCR特异扩增试验,结果表明,两对引物对引起香蕉枯萎病的镰刀菌全基因组DNA分别有338bp和408bp的特异扩增产物;在镰刀菌种以上的阶元有较好的分辨力;对目标菌株的检测下限分别是A(100fg)、B(10pg);而且B对香蕉感染枯萎病的病组织有相应的扩增产物,表明该引物对可用于香蕉枯萎病的早期鉴定和病原菌的检测。

香蕉束顶病毒简易制样技术及分子检测

筛选了5对依据香蕉束顶病毒(BananaBunchyTopVirus,BBTV)外壳蛋白基因(CP)、复制酶基因(RF)保守区段设计的引物。结果显示,以RF为靶序列的引物,香蕉束顶病毒PCR特异性高,可以从感病组织中检测到ng(10-9g)级的病毒。样品提取缓冲液经过Sephadex凝胶介质过柱可有效浓缩病毒、去除PCR反应抑制物质,提高检测灵敏度,降低检测的假阴性。

芋常见病害的发生及防治

1疫病 1．1症状 主要危害叶片，也危害叶柄及球茎。在叶片上，初生褐色或黄褐色圆斑，边缘不明显，扩大后为浓、淡褐色相隔的大型轮纹状病斑。边缘不明显，周围常有暗绿色或黄绿色水浸状晕环。天气潮湿时，斑面长出稀疏的白色霉状物或米粒大小的蜜黄色的溢滴液，叶背更明显。发病后期，病组织干枯、脆裂和穿孔，严重时大部分感病组织脱落，仅残留叶脉，病叶呈破伞状。

Histopathological Study on Chickens Artificially Infected with Infectious Laryngotracheitis

[Objective] This study aimed to investigate the histopathological changes in chickens artificially infected with infectious laryngotracheitis（ILT）. [Method] Through ar- tificial injection of allantoic liquid containing ILTV into chickens to induce infectious laryngotracheitis, the clinical symptoms in infected chickens were observed; tissues of trachea, lungs, heart, liver, kidney and spleen were collected from dead chickens, and prepared into paraffin sections, followed by histopathological observation under a microscope. [Results] This disease occured in the inoculated chickens 3d later, with a morbidity rate of 95%. The main symptoms were dyspnea, asthma and coughing up of bloody exudate; yellowish-white pseudomembrane was observed on dissected larynx trachea; swelling, haemorrhage, and further erosion were observed on the in- fected tracheal mucosa, resulting in death of chickens, with the mortality rate of 25%; histopathological observation showed that parenchymal organs exhibited exuda- tive inflammation; swelling, degeneration, necrosis and shedding of epithelial cells were observed; disturbance of blood circulation occured.[Conclusion] This study pro- vides reference bases for the treatment of ILT.

Helicobacter pylori infection and gastropathy:A comparison between Indonesian and Japanese patients

AIM： To compare the effects of He/icobacter py/ori （Hpylon） infection on gastropathy between Indonesian and Japanese patients. METHODS： Biopsy specimens were obtained during upper gastrointestinal endoscopy from 167 subjects （125 Indonesians and 42 Japanese） with uninvestigated symptoms of dyspepsia. The specimens were analyzed for the presence of H pylori using urease analysis, histopathology, and cell culture. The grade and activity of gastritis was assessed using the updated Sydney system. RESULTS： The percentages of Indonesian and Japanese patients who were H py/ori-positive at the antrum or body of the stomach were similar （68% and 59.5%, respectively; P = 0.316）. Of those who were Hpylori-positive, more Japanese patients than Indonesian patients had high levels of polymorphonuclear cells （P = 0.001）, mononuclear cells （P = 0.013）, glandular atrophy （P = 0.000）, and intestinal metaplasia （P = 0.011） in both the antrum and body of the stomach. CONCLUSION： The grade of gastritis and prevalence of mucosal atrophy and intestinal metaplasia were higher in Japanese patients. The difference between Indonesian and Japanese patients was significant.

Interobserver variation in histopathological assessment of Helicobacter pylori gastritis

AIM:Because the presence or absence of H pylori infection has important implications for therapeutic decisions based on histological assessment,the reproducibility of Sydney system is important.The study was designed to test the reproducibility of features of Helicobacter pylori gastritis, using the updated Sydney classification. METHODS:Gastric biopsies of 40 randomly selected cases of H pylori gastritis were scored semiquantitatively by three pathologists.Variables analysed induded chronic inflammation, inflammatory activity,atrophy,intestinal metaplasia,H pylori, surface epithelial damage.κ values below 0.5 represented poor,those between 0.5 and 0.75 good and values over 0.75 excellent interobserver agreement. RESULTS:The best interobserver agreement(κ=0.62)was present for intestinal metaplasia.The agreement was the poorest for evaluating atrophy(κ=0.31). CONCLUSION:Although the results of this study were in accordance with some previous studies,an excellent agreement could not be reached for any features of H pylori gastritis.This low degree of concordance is assumed to be due to the personal evaluation differences in grading the features,the lack of standardized diagnostic criteria,and the ignorance to reach a consensus about the methods to be used in grading the features of H pylori gastritis before initiating the study.

Chinese NGOs in action against HIV/AIDS

Chinese nongovernmental organizations (NGOs) have played a significant role in the battle against AIDS in the People’s Republic of China. This article provides a brief overview of the structure of these organizations, as well as an analysis of their principle accomplishments. Of great significance in this analysis is the fact that Chinese NGOs have effectively dealt with many sensitive health education areas that government authorities have felt reluctant to handle directly. As such, they have provided an indispensable component in the HIV/AIDS prevention and control calculus on the mainland.

Osteopontin expression is associated with hepatopathologic changes in Schistosoma japonicum infected mice

AIM:To investigate osteopontin expression and its association with hepatopathologic changes in BALB/C mice infected with Schistosoma japonicum.METHODS:The schistosomal hepatopathologic mouse model was established by abdominal infection with schistosomal cercaria.Liver samples were obtained from mice sacrif iced at 6,8,10,14,and 18 wk after in-fection.Liver histopathological changes were observed with hematoxylin-eosin and Masson trichrome staining.The expression of osteopontin was determined with im-munohistochemistry,reverse transcription-polymerase chain reaction,and Western blotting.The expressionof α-smooth muscle actin(α-SMA)and transforming growth factor-β1(TGF-β1)were determined by im-munohistochemistry.Correlations of osteopontin ex-pression with other variables(α-SMA,TGF-β1,hepato-pathologic features including granuloma formation and degree of liver f ibrosis)were analyzed.RESULTS:Typical schistosomal hepatopathologic changes were induced in the animals.Dynamic changes in the expression of osteopontin were observed at week 6.The expression increased,peaked at week 10(P<0.01),and then gradually decreased.Positive correla-tions between osteopontin expression and α-SMA(r=0.720,P<0.01),TGF-β1(r=0.905,P <0.01),granu-loma formation(r=0.875,P<0.01),and degree of liver f ibrosis(r=0.858,P<0.01)were also observed.CONCLUSION:Osteopontin may play an important role in schistosomal hepatopathology and may promote granuloma formation and liver fi brosis through an un-explored mechanism.

Murine brain tissues with human cytomegalovirus infection: a proteomic study

To establish two-dimensional electrophoresis profiles with high resolution and reproducibility from murine brain tissues by human cytomegalovirus（HCMV） infection and paired murine brain tissues and to identify the differential expression proteins. Methods： Forty Kunming mice were randomly divided into infection group （20） injected with HCMVAD169 and control group （20） injected with saline into their brain. After 30 days, the murine brain tissues by HCMV infection and paired murine brain tissues were separated by two-dimensional gel electrophoresis（2-DE）, analyzed by Image Master 2D software, and identified by peptide mass fingerprint（PMF） and database searching, and make Western blotting analyses the differential expression of individual proteins. Results： Well resolved, reproducible 2-D maps of the above tissues were obtained. Some of the different proteins identified by mass spectrometry（MS） were matched in the SWISS-2D PAGE database, Western blotting analyses were further carried out to verify the differential expression of individual proteins. Conclusion： These data will be valuable for studying the diagnosis of disease at an early stage, mechanisms of pathogenic and the key to the development of anti-HCMV medicine.

Localization and Dynamic Expression of a 27.8kDa Receptor Protein for Lymphocystis Disease Virus Infection in Sea Bass(Lateolabrax japonicus) Tissues

Lymphocystis disease virus(LCDV) infects target cells by attaching to a 27.8 k Da receptor(27.8R) protein in flounder Paralichthys olivaceus, and anti-27.8R monoclonal antibodies(MAbs) have been developed. However, the 27.8R existence in tissues of sea bass(Lateolabrax japonicus) and its role in LCDV infection have remained unclear. In this study, the results of western blotting demonstrated that the same 27.8R was shared by flounder and sea bass. LCDV-free sea bass individuals were intramuscularly injected with LCDV, and viral copies were detected in tissues from 3 h post infection and showed a time-dependent increase during 9 days infection. Distribution and synthesis of 27.8R in sea bass tissues were investigated by using anti-27.8R MAbs as probes. It was found that 27.8R was distributed in all the tested tissues. The levels of 27.8R protein were highest in gill and skin, then a bit lowly in stomach, head kidney and heart, followed by spleen, intestine, blood cells, gonad and liver, and least in kidney and brain in healthy sea bass. Upon LCDV infection, 27.8R synthesis was up-regulated in each tissue, and higher in the tissues with higher LCDV copies. The 27.8R and LCDV were detected in some peripheral blood leukocytes but not in red blood cells. These results suggested that 27.8R was widely distributed in sea bass tissues, and it served as a receptor and correlated with tissue tropism of LCDV infection. Furthermore, leukocytes had the potential of being a LCDV carrier and were responsible for a systemic infection of LCDV in sea bass.

Malakoplakia of the esophagus caused by human papillomavirus infection

Malakoplakia is a rare granulomatous disease probably caused by infection and characterized histologically by Michaelis-Gutmann bodies.We report a more rarely seen case esophageal malakoplakia in a 54-year-old woman.She presented with coughing while eating and drinking.Gastroscopy showed yellow nodules in the esophagus,and endoscopic ultrasonography showed a space-occupying lesion in the substratum of the esophageal mucosa.All findings highly resembled esophageal cancer.Histopathological examination finally indentified this space-occupying lesion as malakoplakia and not cancer.Immunohistochemistry showed that she had human papillomavirus(HPV) infection in the esophagus,which indicates that infection was responsible for the malakoplakia.This is believed to be the first case of malakoplakia in the esophagus,and more importantly,we established that HPV infection was the initiator of esophageal malakoplakia.

Expressions and clinical significance of CD147 and CK19 in hepatocellular carcinoma

Objective: The aim of this study was to investigate the expressions of CD147 and CK19 in hepatocellular car- cinoma (HCC) and their clinical significance. Methods: The expressions of CD147 and CK19 were determined by tissue microarray and immunohistochemistry (IHC) in 272 cases of HCC and 81 cases of adjacent tumorous tissue. Results: The positive expression of CD147 in HCC and adjacent tumorous tissue was 73.53% (200/272) and 13.58% (11/81) with signifi- cant difference (P < 0.05). The positive expression of CK19 in HCC and adjacent tumorous tissue was 14.34% (39/272) and 0 (0/81) with significant difference (P < 0.05). The positive expression of CD147 were closely correlated to the histological grade, clinical stage, tumor-free survival, diameter of tumor and embolus of cancer in aqueduct or portal vein; but not to the patients' sex, age, liver cirrhosis, AFP level, infection of HBV, lymph node metastasis, number of tumor, invasion liver involucrum and the micro-satellites (P > 0.05). The expression of CK19 in HCC were closely correlate to the tumor-free survival, histological grade, diameter of tumor, liver cirrhosis, micro-satellites, lymph node metastasis and clinical stage; but not to patients' sex, age, number of tumor, invasion liver involucrum, AFP level, infection of HBV and embolus of cancer in aqueduct or portal vein (P > 0.05). Among the patients of positive expression of CD147, the median replacing time and overall survival were 13 and 24 months, lower than 48 and 60 months in the patients of negative expression (P < 0.05). Among the patients of positive expression of CK19, the median replacing time and overall survival were 7 and 13 months, lower than 31 and 42 months in the patients of negative expression (P < 0.05). The expression of CD147 had no correlation with the expression of CK19 (r = 0.061, P = 0.317). Conclusion: The positive of CD147 and CK19 closely correlate with the clinical prognosis of HCC, it may indicate poor prognosis of HCC.

Differential Pathogenic Response in Strawberry Tissues and Organs by Colletotrichum acutatum

The susceptibility of different tissues and organs from strawberry plants, cv ＂Camarosa＂, to Colletotrichum acutatum was tested using a severity index based on infection response. Symptoms developed on inoculated tissues were characterized along 30 days. Flowers, except sepals, petioles and fruits were the most susceptible organs to the pathogen and they became necrotic tissues at 30 days post inoculation （dpi）. Also, well-developed acervuli, which produced masses of orange-pink spores, were observed on these infected organs. An asymptomatic stage or latency phase was observed in green and white strawberry fruits. In spite of they were inoculated anthracnose symptoms were observed only when they became red fruits. On the other hand, strawberry leaves and sepals were resistant to infection by C. acutatum and only small flecks or light brown spots were observed reaching a size of 1 to 5 mm at 30 dpi. Likewise, the susceptibility of stolons and crowns to C. acutatum was evaluated as intermediate at 30 dpi. Finally, the infection process of the fungus on strawberry leaves and petioles was studied using light and electron microscopy. Pre-penetration events were similar on both, leaves and petioles： However, differences between colonization of strawberry leaves and petioles by C. acutatum were observed.

THE DEVELOPMENT OF MONOCLONAL ANTIBODY AGAINST rhTNF AND ITS CURATIVE EFFECTSON E.Coli INFECTED MICE

Fifteen hybridoma cell lines producing monoclonal antiboclies (McAb) against recombinant human tu-mor necrosis factor a (rhTNFa) have been established by fusing SP 2/0 cells with spleen cells from aBALB/c mouse immunized with rhTNFa. Following J M Davis’s Works, semi-solid medium was usedfor initial cloning. Five of them were studied further. Their main chromosome- numbers range were 96 to105, all of them were IgG1 subclass. The affinities of these McAbs were estimated to be 1. 25 ×108 mol/L, 1. 12×108 mol/L, 2. 34×108 mol/L, 8. 55 × 107 mol/L, 1. 04×108 mol/L, respectively.Two groups of mice challenging with E Coli (107 organisms), one group treated with 2mg/kg anti-TNF monoclonal antibody, the other did not. There was a higher survival rate in treated group, the serumTNF level was significantly lower too, and the untreated mice had severe pathologic changes in vlscera.

SARS-CoV-2 induced intestinal responses with a biomimetic human gut-on-chip

Coronavirus disease 2019(COVID-19), caused by severe acute respiratory syndrome coronavirus 2(SARSCo V-2), has become a global pandemic. Clinical evidence suggests that the intestine is another high-risk organ for SARS-Co V-2 infection besides the lungs. However, a model that can accurately reflect the response of the human intestine to the virus is still lacking. Here, we created an intestinal infection model on a chip that allows the recapitulation of human relevant intestinal pathophysiology induced by SARSCo V-2 at organ level. This microengineered gut-on-chip reconstitutes the key features of the intestinal epithelium-vascular endothelium barrier through the three-dimensional(3 D) co-culture of human intestinal epithelial, mucin-secreting, and vascular endothelial cells under physiological fluid flow. The intestinal epithelium showed permissiveness for viral infection and obvious morphological changes with injury of intestinal villi, dispersed distribution of mucus-secreting cells, and reduced expression of tight junction(E-cadherin), indicating the destruction of the intestinal barrier integrity caused by virus.Moreover, the vascular endothelium exhibited abnormal cell morphology, with disrupted adherent junctions. Transcriptional analysis revealed abnormal RNA and protein metabolism, as well as activated immune responses in both epithelial and endothelial cells after viral infection(e.g., upregulated cytokine genes), which may contribute to the injury of the intestinal barrier associated with gastrointestinal symptoms. This human organ system can partially mirror intestinal barrier injury and the human response to viral infection, which is not possible in existing in vitro culture models. It provides a unique and rapid platform to accelerate COVID-19 research and develop novel therapies.

Qualitative and quantitative analyses of influenza virus receptors in trachea and lung tissues of humans,mice,chickens and ducks

To accurately determine the expression and distribution patterns of two infuenza virus receptors （SAa2,3-gal and SAa2,6-gal） in trachea and lung tissues of humans, mice, chickens and ducks, we analyzed lectin immunofluorescence stainings of various tissue sections qualitatively and quantitatively. Results from the qualitative analysis showed that both influenza virus receptors were expressed in lung tissues of humans, mice, chickens and ducks as well as trachea tissues of mice and ducks. However, SAa2,6-gal receptor was expressed only in the human trachea tissue and SAa2,3-gal receptor was expressed only in the chicken trachea tissue. Results from the quantitative analysis demonstrated that both receptors were expressed in trachea tis- sues of human and mouse, as well as in lung tissues of humans, chickens and ducks. Meanwhile, our results also showed that the expression and distribution of influenza virus receptors in the same tissue were not always uniform, indicating that their distribution and expression in various tissues are not simply the distinction between the presence or absence of receptors, but rather the difference in the amount of expressed receptors.

Global dynamics of an age-structured viral infection model with general incidence function and absorption

In this paper, we propose an age-structured viral infection model with general incidence function that takes account of the loss of viral particles due to their absorption into susceptible cells. The proposed model is described by partial differential and ordinary differential equations. We first show that the model is mathematically and biologically well-posed. Furthermore, the uniform persistence and the global behavior of the model are investigated. Moreover, the age-structured models and results presented in many previous studies are improved and generalized.