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.

Studies of the spore walls of Agaricus bisporus and Agaricus campestris.

The composition and ultrastructure of spore walls of Agaricus bisporus and Agaricus campestris were compared by chemical and enzymatic assays and electron microscopy. Polymers of N-acetylglucosamine (chitin) and glucosamine (chitosan) were the major carbohydrate wall components of both species. The chitin to chitosan ratio in the spore walls of A. bisporus was about 0.38, while in A. campestris it was about 2.8 These polymers were associated with proteins, lipids (readily extractable and bound), melanin, and a low content of beta-glucan. The quantity of protein, total lipid, melanin, or beta-glucan was similar in spore walls of both species. With the electron microscopy, the spore walls appeared as two well-defined layers which may correspond to microfibrils of chitin and chitosan in which the electron-dense melanin was located in the external layer.

Giant diverticula of the colon.

A case of a gas-filled intra-abdominal abscess cavity is reported. The literature is reviewed for similar cases and with reference to the cause and differential diagnosis of abdominal air cysts.

Intrahepatic vascular division in the pig: basis for partial hepatectomies.

Transplantation of resected hepatic fragments, with the attendant vascular and biliary tract reconstruction, presents difficulties. We have studied the intraparenchymal vascular division in the pig with a view to performing partial hepatectomies with the greastest possible anatomical support. Forty-six molds of the various vascular territories were obtained from the 31 porcine livers. Each segment of the median lobe is dependent on the adjacent lateral lobe. Its intersegmental fissure is the obligatory site for parenchymal section to be continued through horizontal portion of portal vein, hepatic artery, and left hepatic duct. A right hemihepatectomy unfailingly results in the devitalization of the left side of the liver. If the goal of a hepatectomy is the transplantation of the resected fragment, it is recommended that the right side of the liver be utilized, as its more convenient extrahepatic vascular and biliary calibre will permit pedicular conservation and anastomosis.

Membrane protein synthesis in Micrococcus lysodeikticus and selective effect of chloramphenicol.

Micrococcus lysodeikticus cytoplasmic membranes labeled with ]-14C]arginine plus [-14C]-threonine were prepared and subjected to mild washing treatments to fractionate membrane proteins. Polyacrylamide gel electrophoresis of total membranes, in the presence of sodium dodecyl sulfate, results in the separation of 28-30 bands of labeled protein. Three peaks of protein show higher specific radioactivity than the others. Chloramphenicol at 100 mug/ml inhibits the incorporation of labeled precursors into membrane proteins by 45-70 percent, some of them being more affected by the antibiotic. From all available results, we suggest that the partial inhibitory effect shown by this antibiotic could be due to the existence of specific biosynthetic sites for some membrane proteins, which are differently affected by chloramphenicol.