Globule Leukocyte And Mast Cell in Bile Ducts of Cattle Naturally Infected with Liver Flukes

In n previous report dealing with the pathology of bovine fascio-liasis the author described an unknown cell type in the epithelium of bile ducts. The histological and histochemical investigations published in this paper suggest that the cell may be considered a globule leukocyte. Globule leukocytes are rare in uninfected livers but are occurring in abundance in main bile ducts of cattle with spontaneous fascioliasis and also in small perilobular ducts in dicrocoeliasis. Liver fluke infection causes an increase in the population of subepithelial mast cells. Mast cell and globule leukocyte present similarities In their cytochemical properties. However, at low pH toluldinc blue shows a stronger but Alcian blue a weaker affinity for mast cells than for globule leukocytes.     

Simultaneous Display of Multiple Foreign Peptides in the FliD Capping and FliC Filament Proteins of the Escherichia coli Flagellum

The bacterial flagellum is composed of more than 20 different proteins. The filament, which constitutes the major extracellular part of the flagellum, is built up of approximately 20,000 FliC molecules that assemble at the growing distal end of the filament. A capping structure composed of five FliD molecules located at the tip of the filament promotes polymerization of FliC. Lack of FliD leads to release of the subunits into the growth medium. We show here that FliD can be successfully used in bacterial surface display. We tested various insertion sites in the capping protein, and the optimal region for display was at the variable region in FliD. Deletion and/or insertion at other sites resulted in decreased formation of flagella. We further developed the technique into a multihybrid display system in which three foreign peptides are simultaneously expressed within the same flagellum, i.e., D repeats of FnBPA from Staphylococcus aureus at the tip and fragments of YadA from Yersinia enterocolitica as well as SlpA from Lactobacillus crispatus along the filament. This technology can have biotechnological applications, e.g., in simultaneous delivery of several effector molecules.     

Determination of taxonomic resolution capacity of conventional one-dimensional SDS-polyacrylamide gel electrophoresis of whole-cell proteins using Enterobacteriaceae

The capacity of one-dimensional SDS-PAGE of whole bacterial cells to both separate and cluster taxonomic units is studied using members of Enterobacteriaceae as test material. The results show that intraspecies variation can be detected and on the other hand the degree of taxonomic divergence which still can be grouped together is determined. In addition the system has high tolerance to changes in cell culture conditions making the usage of SDS-PAGE suitable for applications where rapid and reliable bacterial identification is needed.     

The root-knot nematode resistance gene (Mi) in tomato: construction of a molecular linkage map and identification of dominant cDNA markers in resistant genotypes

A dominant allele at the Mi locus on chromosome 6 of tomato (Lycopersicon esculentum Mill) confers resistance to three species of root-knot nematodes (Meloidogyne). The resistance, which is associated with a localized necrotic response, was originally introduced into tomato from the wild species Lycopersicon peruvianum. As a step towards the molecular cloning of Mi, we have identified closely linked DNA markers from both cDNA and genomic DNA libraries as restriction fragment length polymorphisms (RFLPs). DNA from tomato populations segregating for nematode resistance was analyzed to generate a high-resolution genetic map of this region. Additional information on gene order was obtained by comparing the size of the introgressed L. peruvianum chromosomal segment within a collection of nematode-resistant tomato lines. Among the four cDNA markers that are tightly linked to Mi, three are dominant, i.e. L. peruvianum-specific. One cDNA marker corresponds to a gene family comprising 20-30 members, one of which is diagnostic for all nematode-resistant genotypes tested. The presence of non-homologous sequences around the Mi gene may contribute to the suppression of recombination in this region of the genome in crosses heterozygous for Mi. The potential of 'walking' from closely linked markers to Mi is discussed.     

In Vitro Adhesion of N2-Fixing Enteric Bacteria to Roots of Grasses and Cereals

Nitrogen-fixing Klebsiella and Enterobacter strains isolated from several plants were assayed for fimbriae and for adhesion to plant roots in vitro. All eight Klebsiella strains formed type 3 fimbriae, and five strains also formed type 1 fimbriae; all 21 Enterobacter strains had type 1 fimbriae. Three strains of Klebsiella carrying either type 1, type 3, or no fimbriae were used as model organisms in developing an in vitro adhesion test. Adhesion was assayed with bacterial cells labeled with [³H]leucine. Fifteen N₂-fixing strains and the three model strains were compared for adhesion to the roots of seven grasses and five cereals. Type 3-fimbriated Klebsiella strains adhered better than the other strains, and type 3 fimbriae appeared to be major adhesins for the Klebsiella strains. Although variations between plants were observed, no host specificity for bacterial adhesion was found.     

Complementation and regulatory interaction between two cloned fimbrial gene clusters of Escherichia coli strain KS71

Summary Complementation experiments with cloned DNA fragments encoding either the KS71A, the KS71B or the KS71C fimbriae of the pyelonephritogenic Escherichia coli strain KS71 were used to localise the P-fimbrillin genes and to demonstrate regulatory interactions between the cloned genes. The structural genes of the KS71A and KS71B fimbriae were located within a common 1.1 kilobase pair ClaI-SmaI fragment, and it was shown that the gene clusters for these fimbriae could complement each other in trans. The gene cluster encoding the KS71C fimbriae did not complement for the other KS71 fimbriae. A DNA fragment, located near the KS71A fimbrillin gene, was found to enhance the production of the KS71B fimbriae in trans.     

Pancreatic Duct Obstruction in the Pig: Light Microscopy of Chronic Pancreatitis

Morphological changes of pancreatic tissue in young pigs caused by surgical ligation of the main pancreatic duct are described. Nineteen animals from 6 to 7 weeks in age were operated on and necropsied 3 or 6 to 8 weeks later. Twelve pigs developed a pronounced chronic pancreatitis with complete exocrine insufficiency. Of the 7 animals failing to develop ectasia of pancreatic ducts, 2 died due to surgical complications. In addition, 3 pigs were sham-operated and served as controls. In macroscopical studies it was observed that in the pronounced pancreatitis cases the ligated duct was greatly dilated by a clear watery fluid. Only remnants of pale and firm grandular tissues were seen around the ectatic ducts. Microscopically, typical changes of chronic pancreatitis were noted. Complete disappearance of acini was followed by ductular cell proliferations. Glandular tissues were divided into lobuli by fibrotic tissues and fat cells. The wall of the main pancreatic duct was greatly thickened and fibrotic, presenting intensely proliferating ductular cells and round cell infiltrates. Furthermore, enlarged endocrine islets surrounded by connective tissue fibres were seen.     

Strain while skiing and hauling a sledge or carrying a backpack

Eight soldiers on skis transported three loads of different weights on the level, uphill and downhill. The load was placed either on a cargo sledge or in a backpack or divided between the sledge and the backpack. The sledge had a new type of haulage-shaft, which was fixed to both sides of the pelvis. A service belt spread the pull over the whole upper body. The physical stain of different transport methods and the serviceability of the sledge was studied by measuring heart rate (HR), oxygen consumption, ventilation, and perceived exertion. The results indicate that both absolute and relative strain were systematically lower when pulling the load on the sledge than when carrying it in the backpack and on the sledge. HR when pulling a load equal to the human body weight on the sledge was on average 133 beats X min-1; HR was significantly higher 144 beats X min-1 when the load was divided between backpack and sledge. At the lower load level the differences between the transport methods were not significant for HR, oxygen consumption or ventilation. Uphill travel increased oxygen consumption by about 50% over that on the level. Perceived exertion at all load levels was significantly lower with the sledge than with the backpack alone or in combination. The estimated maximal allowable working time emphasized the advantage of the sledge and the importance of high physical working capacity. The maneuverability of the sledge with the new haulage shaft was good and the braking mechanisms worked well.(ABSTRACT TRUNCATED AT 250 WORDS)