Nemaline rod and degeneration of Z band of muscle cell in weightlessness at spaceflight.

There are some studies demonstrating the skeletal muscle degeneration associated with the degeneration of Z band and appearance of nemaline rods in experimental animals of the simulation model for spaceflight but not in human heart tissues. In the present study, therefore, we investigated the pathological changes or degeneration in left auricular heart muscles obtained during operations of mitral valves replacement using both electron and light microscopies. The degeneration of Z band even in the myofibrils of comparatively little damaged cell was found. Furthermore, nemaline rods were detected in most of the heart muscle cells. These results suggest that the existence of nemaline rods is involved in the cell injury in the heart muscle of patients with heart disease without nemaline myopathy. Further study is necessary to know whether the similar pathological findings are observed not only in the skeletal muscle but also in the cardiac muscle in experimental animals of the simulation model for spaceflight or in a prolonged spaceflight.

Immunoelectron microscopic localization of factor VIII-related antigen in the vascular endothelial cells of a patient with type 1 von Willebrand disease.

The intracellular localization of a factor VIII-related antigen in human umbilical veins derived both from a patient with 'severe Type 1' von Willebrand disease and from a normal full-term baby was investigated by immunoelectron microscopy. In normal vascular endothelial cells, the factor VIII-related antigen was detected in Weibel-Palade bodies. The endothelial cells of von Willebrand disease did not include these structures, but were filled with distended vesicles, in which the factor VIII-related antigen was found immunohistochemically. These results suggest that Type 1 von Willebrand disease causes dysfunction of blood coagulation by suppressing secretion of factor VIII-related antigen into the blood.

Synthesis and antibacterial activity of 2-(isoxazolidinio-5-yl)carbapenem derivatives.

The synthesis and antibacterial activity of the title compounds having an isoxazolidine ring at the C-2 position are described. These derivatives were synthesized by the 1,3-dipolar cycloaddition reaction of nitrone with 2-vinyl carbapenems. This 1,3-dipolar cycloaddition reaction proceeded regioselectively to give diastereomeric isomers of 2(-isoxazolidin-5-yl)carbapenems. It was ascertained that the antibacterial activity of 1 beta-methylcarbapenem derivatives was superior to that of the corresponding 1H-carbapenem derivatives, and between the 2-(isoxazolidin-5-yl)-1 beta-methylcarbapenems the antibacterial activity of the 5'R-isomer was slightly better than that of the 5' R-isomer slightly better than that of the 5' S-isomer.

Carbapenem and penem antibiotics. V. Synthesis and antibacterial activity of 2-functionalized-methyl 1-methylcarbapenems related to asparenomycins.

The synthesis of 1 alpha- and/or 1 beta-methylcarbapenems, 2-unsubstituted and 2-(5-methyl-1,3,4-thiadiazol-2-yl)thiomethyl derivatives having a 1-(hydroxy)methylethylidene or cyclic carbonate side chain at the C-6 position, is described. The in vitro antibacterial activities of these compounds and their corresponding 1-unsubstituted carbapenems are compared.

Carbapenem and penem antibiotics. VII. Synthesis and antibacterial activity of 1 beta-methyl-2-(quaternary heteroaromatic-thiomethyl) carbapenems.

The synthesis and antibacterial activity of a series of 1 beta-methylcarbapenems having quaternary heteroaromatic-thiomethyl groups at the C-2 position are described. Both 2-hydroxymethyl and 2-chloromethyl carbapenems (1 and 7) respectively served as the common key intermediates for the preparation of these compounds. Of these, the 4-pyridiniothiomethyl derivatives exhibited the best antibacterial properties and turned out to possess high in vivo efficacy as well.

Carbapenem and penem antibiotics. VI. Synthesis and antibacterial activity of 2-heteroaromatic-thiomethyl and 2-carbamoyloxymethyl 1-methylcarbapenems.

The synthesis and antibacterial activity of the 1-methylcarbapenems, 2-heteroaromatic-thiomethyl and 2-carbamoyloxymethyl derivatives having a 6-[(R)-1-hydroxyethyl] side chain, are described. The introduction of a methyl substituent at the C-1 position was accomplished by a newly developed procedure using crotyl halides and zinc dust. The 2-hydroxymethyl carbapenems as key intermediates allowed an easy entry into the preparation of title carbapenems.