Collagen autoimmunity and arthritis

Collagen-induced arthritis in animals is an example of polyarthritis that sufficiently resembles human rheumatoid arthritis to be used as a model. It is caused by immunizing susceptible animals with type II collagen isolated from articular cartilage. Susceptibility is genetically determined and linked to the major histocompatibility locus. It is important because some human arthritis is also associated with major histocompatibility genes and may be caused or aggravated by the presence of autoimmunity to normal cartilage components. Collagen-induced arthritis is also important because it is an example of immunologically mediated joint destruction, which may share some of the mechanisms present in human disease. Although it is caused by autoimmunity to collagen, susceptibility and responsiveness to type II collagen are not completely correlated, and there are examples of animals with high levels of collagen immunity who do not develop arthritis. The initial lesion appears to be the deposition of an antibody on the surface of articular cartilage, which precedes development of overt arthritis by several days. Disease can be readily transferred with specific antibody. Arthritogenic antibodies appear to have restricted epitope specificity, which may partially explain the disparities between responsiveness to immunization with collagen and susceptibility to arthritis, but precise delineation of the epitopes involved has not yet been accomplished. Complement activation also appears to be intimately involved since the disease correlates with the presence of high levels of complement-binding IgG isotypes, and passive transfer is possible only into complement-sufficient recipients. Inflammation progresses rapidly so that cartilage destruction and marginal erosion develop over a period of a few days. Collagen-induced arthritis offers a unique opportunity to study autoimmune-mediated arthritis in which the inducing antigen is well characterized and readily available. Analysis of the disease has permitted the proposal of a schema for its pathogenesis.     

The ontogeny of the vascular cambium inGinkgo biloba roots

Observation was made on early ontogeny of vascular cambium in the developing root ofGinkgo biloba L. After completion of root elongation, the vascular meristem gradually acquires cambial characteristics. Strips of the periclinal division of cells in transverse section are observed on the inner side of phloem when the primary xylem and phloem in the stele have been established. The strips are united into a continuous layer between phloem and xylem. In tangenital section, the procambium shows a homogeneous structure, which is initially composed of short cells with transverse end walls and subsequently, of long cells with tapering ends. Then, the procambium is organized into two systems of cells; axial strands of short cells with transverse end walls resulting from the sporadic transverse divisions of long cells, and long cells with tapering ends. Still later, the short cells are divided frequently in a trasverse plane exhibiting one or a few cells in width and several decades of cells in height, while the long cells are elongated. The frequency of transverse divisions of the short cells decreases in subsequent stages. Eventually, the short cells in axial strands are vertically separated from one another by the elongation of neighboring long cells and by the decrease in the frequency of transverse divisions of short cells themselves. Cambial initials occur in two forms; ray initials a few cells in height and one cell in width derived from the short cells, and fusiform initials with tapering ends derived from the long cells.     

In vitro shoot regeneration from leaf mesophyll protoplasts of hybrid poplar (Populus nigra x P. maximowiczii)

Summary Protoplasts were isolated from leaf mesophyll of hybrid poplar (Populus nigra X P. maximowiczii) with a mean yield of 10.4 x 10⁶ protoplasts per g fresh weight using 2.0% Cellulase Onozuka R-10, 0.8% Macerozyme R-10, 1.2% Hemicellulase, 2.0% Driselase, and 0.05% Pectolyase Y-23 with CPW salts solution containing 0.6 M mannitol, 0.002 M DTT, 3 mM MES at pH 5.6. A liquid plating method produced the highest frequency of dividing protoplasts (48.6%) using an MS medium without NH₄NO₃. The highest percent of colony formation was 22.8%, produced with fabric supported semi-solid (0.5% w/v) agar plating method using the same culture medium. Growing cell colonies and/or micro-calli were transferred to a fresh semisolid agar medium containing 0.44 M BAP and 9.0 M 2,4-D. Multiple shoots were produced from protoplast-derived callus after culture on MS medium containing 6.8 M zeatin. After root induction on half-strength MS medium that lacked growth regulators, shoots were transferred to pots containing artificial soil mix.Abbreviations CPW Cell and Potoplast Wash solution - LPM Liquid Plating Method - LDM Liquid Drop Method - HDM Hanging Drop Method - FSPM Fabric supported Semi-solid agar Plating Method - DTT Dithiothreitol - MES 2-(N-morpholino) ethane sulfonic acid - BAP 6-benzylaminopurine - 2,4-D 2,4-dichlorophenoxy acetic acid - NAA -naphthalene acetic acid - MS Murashige and Skoog (1962)     

Metacercarial infections of Paragonimus westermani in freshwater crabs sold in markets in Seoul

Status of metacercarial infections of Paragonimus westermani was observed in freshwater crabs, which were purchased at 3 markets in its peak season of 1990. All of 85 crabs were Eriocheir japonicus. No other species of Eriocheir were found. When crushed muscle and viscera was examined individually, the infection rate was 11.8%; and mean number of metacercariae was 2.1 per infected crab. Unless adequately cooked, freshwater crabs are still potential sources of human paragonimiasis.     

Component proteins in crude extract of adult Paragonimus westermani purified by immunoaffinity chromatography using monoclonal antibodies.

The nature of 2 component proteins in crude saline extract of adult Paragonimus westermani was investigated. By immunoaffinity chromatography using monoclonal antibodies (MAb) as ligands, the proteins were purified from the crude extract. Band 1 protein in disc-polyacrylamide gel electrophoresis (PAGE) was purified by PFCK-136 MAb. The protein, known to have molecular mass of 440 kDa, was composed of 23, 46 and 92 kDa subunits when observed by reducing SDS-PAGE and SDS-PAGE/immunoblot. This protein was originated from eggs of the worm as revealed by immunohistochemical staining with PFCK-136 Mab. Another affinity purified protein utilizing PFCK-44 MAb was the band 4 protein of 17 kDa in disc-PAGE. This was a monomer protein in reducing SDS-PAGE and SDS-PAGE/immunoblot. The protein was produced at intestinal epithelium of the worm.     

Triterpene glycosides from Schefflera octophylla.

In addition to 3-epi-betulinic acid, three triterpene glycosides were isolated from leaves of Schefflera octophylla. The structures of the glycosides have been determined as 28-O-[alpha-L-rhamnopyranosyl(1----4)-O-beta-D-glucopyranosyl(1----6)-be ta-D- glucopyranosides of 3 alpha-hydroxy-lup-20(29)-ene-23,28-dioic acid, 3 alpha,11 alpha- dihydroxy-lup20(29)-ene-23,28-dioic acid and 3-epi-betulinic acid by spectroscopic data and chemical transformations. The last two compounds were found for the first time in the plant kingdom.     

Application of a stability statistic to international maize yield trials

Summary Genotype x environment (GE) interaction encountered in experiments complicates genotype selection and varietal recommendation. The integration of yield and stability of genotypes into a single parameter may make selection and recommendation easier. Kang developed a rank-sum method that allows selection for both yield and the stability variance statistics ( _i ² or s _i ² ) of Shukla. The objective of this research was to compare the rank-sum selection method to selection based on yield alone in five international maize (Zea mays L.) yield trials. Ranks were assigned for yield (the highest mean yield received a rank of 1) and for _i ² and s _i ² (the lowest value received a rank of 1). The yield and _i ² ranks and/or the yield and s _i ² ranks for each genotype were summed. Each trial contained two reference entries (REs). Yield rank or rank-sum of each genotype was compared to yield rank or rank-sum of the best RE (BRE). GE interaction was significant for all trials. Heterogeneity in the GE interaction due to the linear effect of a covariate (differences in fertility and/or cultural practices) was significant in Trials 1, 2, and 5. Overall, in all trials, 29 genotypes were selected on the basis of yield alone. On the basis of _i ² and yield rank-sum, 32 genotypes were identified, with 11 being lower yielding than the 29 yield-based selections. On the basis of s _i ² and yield rank-sum, 31 genotypes were selected, with 11 being lower yielding than the yield-bases selections. Obviously, yield is sacrificed when the rank-sum method is used in the selection process. However, selection based on yield alone may not be adequate when GE interaction is significant because of testing in diverse environments.     

Changes in soil microflora associated with control of Sclerotium Rolfsii by Furfuraldehyde

The efficacy of 2‐furfuraldehyde for control of Sclerotium rolfsii was studied in laboratory and greenhouse experiments. Mycelial growth of the fungus was reduced proportionally with concentrations of 0.1–0.5 ml furfuraldehyde l^‐1 agar medium, and viability of sclerotia diminished on exposure to 2‐furfuraldehyde vapours. Detectable populations of bacteria and fungi, including Trichoderma spp., were reduced significantly (9=0.05) when furfuraldehyde was added to the agar used for soil dilution plates of untreated soil. Repeated treatments of natural soil with the fumigant significantly increased populations of Trichoderma spp. and bacteria, but diminished numbers of actinomycetes. Increasing dosages applied to soil artificially infested with S. rolfsii caused a reduction of disease on lentil, Lens culinaris. Results indicate that the compound, when applied to field soil, changes the composition of soil microflora and has potential for integrated control of S. rolfsii.     

A Comparison of the Efficacy of Nuclear Polyhedrosis and Granulosis Viruses in Spray and Bait Formulations for the Control of Agrotis segetum (Lepidoptera: Noctuidae) in Maize

Agrotis segetum nuclear polyhedrosis virus (AsNPV) and granulosis virus (AsGV), propagated in laboratory cultures of A. segetum in England and A. ipsilon in Spain, respectively, were applied to plots of maize plants at the one‐ to four‐leaf stage of growth. Plots were arranged in a 6 x 6 Latin square design and infested with second‐instar A. segetum larvae (the common cutworm). Each virus was applied in separate treatments by two application methods; as an aqueous spray containing 0.1% Agral as a wetting agent, and as a bran bait. The NPV was applied at a rate of 4 X 10¹² polyhedra/ha, and the GV at 4 X 10¹³ granules/ha. Soil and plants were sampled for larvae on three occasions following virus treatment: 24 h, 4 days and 11 days. The larvae were reared on diet in the laboratory, until death or pupation, to examine the rate and level of viral infection. Infection data showed 87.5% and 91% NPV infection and 12.5% and 55% GV infection in spray and bait treatments, respectively, in larvae sampled 24 h after treatment. In larvae sampled 4 days after treatment, the results were 78% and 100% NPV infection, and 13% and 6% GV infection. A total of only six larvae were retrieved on day 11. In both treatments larvae infected with AsNPV died significantly more rapidly and at an earlier instar than those infected with AsGV, indicating that AsNPV appears to have better potential as a control agent for A. segetum.