Identification and Subgrouping of Cucumber mosaic virus with Mouse Monoclonal Antibodies

ABSTRACT Using a mixture of isolates of Cucumber mosaic virus (CMV) from subgroups I and II as immunogens, 20 mouse hybridoma cell lines secreting monoclonal antibodies were produced. A reliable method for efficient detection and accurate subgrouping of CMV isolates has been developed. Tests with 12 well-characterized strains of CMV and other cucumoviruses demonstrated the presence of epitopes that were virus and subgroup specific. Analyses of 109 accessions of CMV isolates collected from various parts of the world revealed 70% were subgroup I, with 20% identified as subgroup II. Seven isolates (6%) did not react with group-specific antibodies but did react with antibodies that recognized all CMV isolates. Differential reactions among isolates suggested a total of 10 epi-topes were recognized. The antigenic diversity among subgroup II CMVs was greater than for the subgroup I isolates, even though fewer subgroup II isolates were tested.     

A sensitive method for detecting bamboo mosaic virus (BaMV) and establishment of BaMV-free meristem-tip cultures

A sensitive method was used to detect bamboo mosaic virus (BaMV) and its associated satellite RNA (satBaMV) by ³²P- and digoxigenin (Dig)-labelled probes synthesized from cDNA clones of BaMV genomic (L probe) and satBaMV (S probe) RNA. Both the ³²P- and Dig-labelled L and S probes could detect as little as 490 pg of BaMV viral RNA by slot- and dot-blot hybridization. In infected leaf extracts, ³²P-labelled L and S probes detected virus at 25-fold higher dilutions than Dig-labelled probes, which were also successfully used to detect BaMV infection in plants derived from meristem-tip culture. However, immunoassays failed to detect BaMV in meristem culture. By dot-blot hybridization assays, 25% of the seedlings were shown to be virus-free. These results suggest that a highly sensitive method for the detection of BaMV infection is required for the establishment of BaMV-free cultures. Meristem-tip culture also provides an efficient method for obtaining virus-free bamboo plants.     

Protection of cattle against rinderpest with vaccinia virus recombinants expressing the HA or F gene

Rinderpest is a highly contagious ruminant viral disease manifested by a rapid course and greater than 90% mortality. Infectious vaccinia virus recombinants were constructed that express either the hemagglutinin or the fusion gene of rinderpest virus. All cattle vaccinated with either recombinant or with the combined recombinants produced neutralizing antibodies against rinderpest virus and were protected against the disease when challenged with more than 1000 times the lethal dose of the virus.     

Multiclonal origin of polyps in Gardner syndrome

Electrophoretic analysis of glucose-6-phosphate dehydrogenase was performed on polyp tissue from three black female patients with Gardner syndrome and who are heterozygous for the A and B forms of this enzyme. Polyp tissues from the three patients displayed the AB phenotype. This finding suggests a multiclonal origin of polyps in Gardner syndrome. Studies of tumors originating from such polyps may provide information about the sequence of cellular events leading to malignant transformation.     

Cubic AgPb(m)SbTe(2+m): bulk thermoelectric materials with high figure of merit

The conversion of heat to electricity by thermoelectric devices may play a key role in the future for energy production and utilization. However, in order to meet that role, more efficient thermoelectric materials are needed that are suitable for high-temperature applications. We show that the material system AgPb(m)SbTe(2+m) may be suitable for this purpose. With m = 10 and 18 and doped appropriately, n-type semiconductors can be produced that exhibit a high thermoelectric figure of merit material ZTmax of approximately 2.2 at 800 kelvin. In the temperature range 600 to 900 kelvin, the AgPb(m)SbTe(2+m) material is expected to outperform all reported bulk thermoelectrics, thereby earmarking it as a material system for potential use in efficient thermoelectric power generation from heat sources.     

Germline transmission of exogenous genes in the chicken

Difficulties associated with in vitro manipulation and culture of the early chicken embryo have restricted generation of transgenic chickens to approaches that use replication-competent retroviruses. The need to produce transgenic chickens in the absence of replicating virus prompted development of a new method of gene transfer into the chicken. Microinjection of the replication-defective reticuloendotheliosis virus (REV) vector ME111 beneath unincubated chicken embryo blastoderms results in infection of germline stem cells. This vector contains genetic information exogenous to the chicken genome, including both the herpes simplex virus type 1 thymidine kinase gene and the Tn5 neomycin phosphotransferase gene. About 8 percent of male birds hatched from injected embryos contained vector DNA in their semen. All four positive males tested passed vector sequences onto their progeny. Analysis of G1 offspring showed that gonads of G0 male birds were mosaic with respect to insertion of vector provirus. Thus, primordial germ cells present in the unincubated chicken embryo blastoderm are susceptible to infection by defective REV vectors.     

泸沽湖自然保护区森林植被及木本植物区系

泸沽湖自然保护区位于云南省宁蒗县境内,北纬27°36′～27°47′,东经100°43′～100°54′,海拔2680～3870m,这里至今还居住着保留母系家庭结构的摩梭人。根据生态——外貌学的方法,本区的森林植被可划分为6个植被类型和11个群系。云南松、苍山冷杉、丽江云杉、高山栎类是本区森林的主要建群树种。其木本植物区系特征主要表现在下列几方面。(1) 种系密度较小,每平方公里1.06属1.88种;(2) 温带性质明显,是泛北极区系的一部分,温带成分占67.7％;(3) 区系成分多样,与周围地区联系广泛,本区有12个分布类型8个变型,与热带成分的联系以泛热带和热带亚州成分较为密切;(4) 起源古老;(5) 特有现象明显,中国,西南,云南特有种分别为45、65、15种;(6) 喜钙或钙生性种类较多,占总种数的85％。     

Pancreatic carboxypeptidases: activities in zinc-deficient rats

Zinc deficiency in rats caused decrease in the activity of pancreatic carboxypeptidase A, but it had no effect on pancreatic carboxypepti dase B and liver alcohol dehydrogenase. The observed reduction of enzymic activity may be related to the poor utilization of feed that occurs in zincdeficient rats.     

Fungal immunomodulatory protein from Flammulina velutipes induces interferon-gamma production through p38 mitogen-activated protein kinase signaling pathway

FIP-fve is a fungal immunomodulatory protein purified from Flammulina velutipes, an edible golden needle mushroom thought to possess potent immunomodulatory properties. When examined for its effects on lymphocytes, FIP-fve exhibited potent mitogenic effects on human peripheral blood lymphocytes, inducing G1/G0 to S phase proliferation. T cells activated by FIP-fve show significant production and secretion of interferon-gamma (IFN-gamma) associated with intercellular adhesion molecule 1 expression but low detectable levels of interleukin-4 in vitro or in vivo. However, SB203580, the p38 mitogen-activated protein kinase (p38 MAPK) inhibitor, can fully abolish the production of IFN-gamma induced by FIP-fve. At the same time, SB203580 only partially prevents the lymphocytes from progressing from G1 to S phase of the cell cycle. These findings demonstrate that FIP-fve is a potent T-cell activator, mediating its effects via cytokine regulation of p38 MAPK. The immunoprophylatic effects of FIP-fve in Th2-mediated allergic anaphylaxis are believed to be associated with the ability of FIP-fve to enhance activation of IFN-gamma-releasing Th1 cells.     

Inhibitory activities of semicarbazide-sensitive amine oxidase and angiotensin converting enzyme of pectin hydroxamic acid

Solutions of 100 mL of 1% commercial pectin each with a different degree of esterification (DE), DE94, DE65, and DE25, were reacted with 100 mL of 2 M alkaline hydroxylamine (pH 12.0) at room temperature for 4 or 18 h. These pectin hydroxamic acids (PHAs; DE94T4, DE94T18, DE65T4, and DE25T4) were used to test the inhibitory activities against semicarbazide-sensitive amine oxidase (SSAO) and angiotensin-converting enzyme (ACE). Compared to different DE pectins (DE94, DE65, and DE25), the PHAs of DE94T4, DE94T18, DE65T4, and DE25T4 showed different inhibition activities against SSAO or ACE. Commercial pectins with different DE values showed negligible SSAO or ACE inhibitions. The order of SSAO inhibition was DE65T4 > DE94T18 approximately DE25T4 > DE94T4. However, the order of ACE inhibition was DE94T4 > DE94T18 > DE65T4 > DE25T4. The SSAO activity staining or ACE-hydrolyzed products on TLC chromatogram also confirmed the inhibitory activities of PHAs against SSAO or ACE.