Chemical components and their locations in the Verticillium fungicola cell wall.

The chemical structure of cell walls and fractions of Verticillium fungicola, a pathogen of Agaricus bisporus, as well as their corresponding ultrastructures were studied. There are at least three chemically distinct types of carbohydrate polymers: one yielding mannose with lower amounts of galactose and glucose (glucogalactomannan), another one composed mainly of glucose (glucan), and a third one containing only N-acetylglucosamine (chitin). Attempts were made to locate these materials in situ by comparing electron micrographs of shadowed and sectioned cell walls, and also by indirect immunofluorescence. It was shown that none of these polymers constituted a completely physically distinct layer, but there seem to be different solubility properties in the outer, inner, and intermediate layers. It was also shown that fibrillar material (chitin) embedded in cementing glucan constituted the residual inner fraction of the original wall material. Indirect immunofluorescence showed the location of a significant amount of glucogalactomannan on the surface of the walls in which rodlet structures were visualized by electron microscopy.

Chemical analysis of the lamella walls of Agaricus bisporus fruit bodies.

Purified lamella wall fragments of Agaricus bisporus fruit bodies were analyzed and shown to consist of neutral sugars (46.5%), hexosamines (31.7%), proteins (9.5%), some lipid material (10.0%), and ash (1.4%). The cell walls were fractionated on the basis of their polysaccharide solubility in water and alkaline solutions. The isolated fractions, using methylation analysis, exhibited striking chemical structural differences compared with the same fractions obtained from the corresponding vegetative cells and fruit bodies (stipe and pileus) walls. The structural differences detected in the wall seem to correspond to the ultimate differentiation of the mycelium inside the fruit body of A. bisporus.

News & notes: production, purification, and properties of an endo-1, 3-beta-glucanase from the basidiomycete Agaricus bisporus.

Agaricus bisporus H 25 produced extracellular endo-1, 3-beta-glucanase when grown in a static culture at 25 degrees C in a minimal synthetic medium supplemented with A. bisporus cell walls plus fructose. Endo-1,3-beta-glucanase was purified 17.85-fold from 20-day-old culture filtrates by precipitation at 80% ammonium sulfate saturation, Sephadex G-75 gel filtration, and preparative PAGE followed by electroelution. The purified enzyme yielded a single band in both native and SDS-polyacrylamide gels with a molecular mass of 32 kDa (SDS-PAGE) and 33.7 kDa (MALDI-MS), showing an isoelectric point of 3.7. The enzyme was active against beta-1,3- linkages and, to a lesser extent, against beta-1,6-, exhibiting an endohydrolytic mode of action and a glycoprotein nature. Significant activities of the endo-glucanase against laminarin and pustulan were observed between pH 4 and 5.5, and between 40 degrees and 50 degrees C for laminarin, and between 30 degrees and 50 degrees C for pustulan. The optimum pH and temperature were 4.5 and 45 degrees C for both substrates.

Enzymic activity of the mycoparasite Verticillium fungicola on Agaricus bisporus fruit body cell walls.

The in vitro production of different hydrolytic enzyme activities by Verticillium fungicola, a mycoparasite of Agaricus bisporus fruit bodies, was examined in cultures grown with various carbon sources (glucose, fructose, sucrose and A. bisporus cell walls). Several of the identified enzymes were influenced by the carbon source. The results of A. bisporus cell wall digestion by these enzymes in vitro have been compared with V. fungicola infection of A. bisporus fruit bodies in vivo. Evidence supporting mycoparasite enzymic action on the host cell walls is presented.

New contributions to the wall polysaccharide structure of vegetative mycelium and fruit body cell walls of Agaricus bisporus.

Significant differences in chemical composition and structure of wall polysaccharides were found in Agaricus bisporus vegetative mycelium in comparison with the fruit body mycelium. Chemical fractionation of the walls demonstrated distinct percentages of the successively solubilized polysaccharides in both walls, and different proportions of their respective sugar monomers. Permethylation of isolated fractions also showed striking differences relative to the sugar linkages between the two types of walls studied. Furthermore, infrared spectrophotometry exhibited a distinct polysaccharidic configuration in several fractions. All the described differences were correlated with the transition of vegetative mycelial walls to the fruiting stage of differentiation.

Chemical and Structural Differences in Cell Wall Polysaccharides of Two Monokaryotic Strains and Their Resulting Dikaryon of Agaricus bisporus

Compatible monokaryotic strains of Agaricus bisporus ATCC 36975 and 36976 and the resulting dikaryon of their mating were grown in a liquid medium, and their respective cell walls were prepared. Significant differences were not found in the gross chemical composition of the three hyphal types. However, the neutral carbohydrate composition of the complete walls and their fractions was found to be somewhat different in each strain. More consistent differences were encountered in the chemical structure of the distinct polysaccharidic wall fractions in the three types of organisms. Some of these structural wall differences can be considered as characteristic markers for differentiating the mono- and dikaryotic types of A. bisporus.

Percutaneous catheterization of the gallbladder with ultrasonic guidance.

We have described a case in which the gallbladder was catheterized by the Seldinger technic, using ultrasonic guidance. The biliary tree was flushed until clear and free passage of bile into the duodenum occurred. Thick inspissated bile can cause intrinsic echoes in the gallbladder that can be mistaken for gallstones.

Ultrasound diagnosis of the hyperextended head in breech presentation.

Hyperextension of the fetal head in the breech presentation can be diagnosed by ultrasound. Straightening of the fetal spine and the widest diameter of the skull posterior to the long axis of the spine is diagnostic. Face presentation should also be diagnosable by these criteria.

T-tube tract dilatation for removal of large biliary stones.

A technique used for removal of residual biliary tract stones, too large to be withdrawn through a T-tube tract, is reported. Telescoping Teflon catheters were used in one patient to dilate the tract sufficiently to remove the stone with the Dormia type wire basket.