Basement-membrane components associated with the extracellular matrix of the lymph node

Summary Lymph nodes contain an extensive array of extracellular matrix fibers frequently referred to as reticular fibers because of their reticular pattern and positive reaction with silver stains. These fibers are known to contain primarily type-III collagen. In the present study, frozen and plastic-embedded sections of mouse and human lymph nodes were subjected to immunostaining with a panel of monospecific antibodies directed against type-IV collagen, type-III collagen, laminin, entactin, and heparan sulfate proteoglycan. Immunofluorescent staining revealed that, in addition to being uniformly stained with antibodies to type-III collagen, these fibers also stained positively with antibodies to type-IV collagen and to other basement-membrane-specific components. Furthermore, the basement-membrane-specific antibodies stained the outer surface of individual fibers. These same type-III collagen-rich fibers were distinct from blood vascular basement membranes since they did not react with antibodies to factor VIII-related antigen, an endothelial-cell-specific marker. The role of these basement-membrane-specific components associated with the reticular fibers of lymphoid tissue is unknown. However, it is possible that the ligands promote attachment of reticular fibroblasts as well as macrophages and lymphocytes to the extracellular matrix fibers.     

The importance of Paracallisoma coecus and myctophid fishes to nesting fork-tailed and Leach's storm-petrels in the Queen Charlotte Islands, British Columbia

The diet of fork-tailed (Oceanodroma furcata) and Leach's storm-petrel(O.leucorhoa) was studied at Petrel Island, a small island northof Hippa Island in the Queen Charlotte Islands, British Columbiain 1983. The diet of the two storm-petrel species consistedmostly of the amphipod Paracallisoma coecus and fish. Most fisheswhich could be identified were myctophids, and may have beenacquired by storm-petrels at night. Fishes increased while P.coecusdeclined in importance as a food over the nestling season ofthe storm-petrels. The amount of oil also declined in the Leach'sstorm-petrel diet over the season. Since P.coecus contains muchoil, the seasonal decline of both P.coecus and oil was probablyassociated. Other less important foods were jellyfishes, copepods,isopods, euphausiids, shrimp, squid and octopus. Jellyfishes(Velella velella) only occurred in the diet of Leach's storm-petrels,which may relate to that storm-petrel feeding in open oceanwhere V. velella occurs most frequently. The most numerous copepodwas Neocalanus cristatus, which was only observed in the storm-petreldiet early on during the study period. An abyssal copepod, Bathycalanusbradyi, and the isopod Cirolana californiensis (tentativelyidentified, the latter only previously known from sea canyonsoff California) were surprising food items of storm-petrels.Most euphausiid prey consisted of Thysanoessa spinifera andEuphausia pacifica.     

Ac transposition in transgenic tomato plants

Summary As an initial step towards developing a transposon mutagenesis system in tomato, the maize transposable element Ac was transformed into tomato plants via Agrobacterium tumefaciens. Southern analysis of leaf tissue indicated that in nine out of eleven transgenic plants, Ac excised from the T-DNA and reintegrated into new chromosomal locations. The comparison of Ac banding pattern in different leaves of the same primary transformant provided evidnece for transposition during later stages of transgenic plant development. There was no evidence of Ds mobilization in tomato transformants.     

Salicyloylaspartate as an endogenous component in the leaves of Phaseolus vulgaris

An amide conjugate of o-methoxybenzoic acid and aspartic acid has been isolated from bean leaves. After extraction and methylation of plant material, this compound was isolated as two isomeric monoethyl monomethyl esters. The ethylation of the aspartyl carboxyl groups was shown to be a likely result of an extraction procedure utilising acidified ethanol, the methylation of the aromatic hydroxy of the methoxy group to be due to the derivatisation procedure. Studies with pentafluorobenzylation confirmed that the endogenous compound is o-hydroxybenzoylaspartate.     

Simultaneous degradation of the herbicides 2,4-dichlorophenoxyacetic acid and 2-(2-methyl-4-chlorophenoxy)propionic acid by mixed bacterial cultures

The simultaneous degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-(2-methyl-4-chlorophenoxy)propionic acid (mecoprop) was achieved by two mixed cultures in the absence of any additional carbon or energy substrates. Mecoprop was not completely degraded by either of the two cultures, nor did addition of 2,4-D affect the degradation of mecoprop. The cultures completely degraded 2,4-D, and the degradation was uninfluenced by the addition of mecoprop. Nearly complete dechlorination of the mixture of two herbicides was achieved by both cultures, on the basis of the total amount of the two herbicides degraded. During the course of the reaction, however, the expected values of chloride were not met. Cell growth continued after the degradation of the parent substrates ceased. Although the mecoprop degradation did not continue to completion, spectral and growth data indicated that the metabolites which had accumulated during the reaction were degraded upon further incubation.     

The equine protease inhibitory system (Pi): Abnormal expressions of PiF,PiL, and PiS

Three cases of abnormal expression of the equine protease inhibitory alleles, Pi F, L, and S₁, were observed following the examination of 30,000 plasma samples by one-dimensional acid (pH 4.6) polyacrylamide gel electrophoresis. Characterization of the abnormal proteins in terms of isoelectric point, molecular mass, inhibitory spectra, and sialic acid content was performed using one- and two-dimensional electrophoretic techniques. The Pi F and S₁ abnormalities were postulated to be the result of amino acid substitutions causing alterations in the processing of the carbohydrate side chains. No explanation could be offered for the Pi L abnormality other than a charge shift mutation. Abnormal types, F*, L*, and S*₁ behaved as alleles but the distribution of L* in offspring from one stallion (present in only 6 of 83 offspring) differed significantly from expectation.This work was supported by a grant from the Australian Stud Book, Alison Road, Randwick, N.S.W. 2031.     

Salinity tolerance of Mytilocypris henricae (Chapman) (Crustacea,Ostracoda)

Salinity tolerance, and the effects of temperature upon it, of the Australian ostracod Mytilocypris henricae (Chapman) was determined in direct transfer experiments using adults. Animals were subjected to a combination of 11 salinities (ranging between 0.0 g · 1^–1 and 45.0 g · 1^–1) and 4 temperatures (10, 15, 20 and 25 °C). Survival was analysed using two statistical techniques: the logit linear model and the proportional hazards model. Results show that both salinity and temperature have a significant effect on survival, but there is no significant interaction between temperature and salinity.     

Cellular systems for the study of the biosynthesis of polyamines and ethylene,as well as of virus multiplication

Leaves of Chinese cabbage from healthy plants or from those infected with turnip yellow mosaic virus yield protoplasts which convert methionine to protein, S-adenosylmethionine, decarboxylated S-adenosylmethionine, spermidine, spermine and 1-aminocyclopropane-1-carboxylate. The enzyme spermidine synthase is entirely cytosolic and has been purified extensively. An inhibitor of this enzyme, dicyclohexylamine, blocks spermidine synthesis in intact protoplasts, and in so doing stimulates spermine synthesis. Aminoethoxyvinylglycine blocks the conversion of S-adenosylmethionine to 1-aminocyclopropane-1-carboxylate, the precursor to ethylene, in protoplasts. This inhibitor markedly stimulates the synthesis of both spermidine and spermine. Essentially all the protoplasts obtained from new leaves of plants infected 7 days earlier are infected. On incubation, such protoplasts convert exogenous methionine to viral protein and viral spermidine whose specific radioactivity is twice that of total cell spermidine. Exogeneous spermidine is also converted to cell putrescine and viral spermidine and spermine. Normal and virus-infected cells are being studied for their content of phenolic acid amides of the polyamines.