Mono-ADP-ribosylation is a posttranslational modification of proteins employed by a variety of bacterial ADP-ribosylating toxins to modify the metabolism of target cells. The ADP-ribosyltransferases of bacterial toxins, in general, use NAD as a substrate for covalent modification by ADP-ribose to certain GTP-binding proteins (G proteins) as signal transducers resulting in altered enzymatic activity of the membrane enzymes as effectors. Such a mechanism has the potential of being of importance in the physiological regulation of cellular metabolism, particularly if the process is reversible. These ADP-ribosylating toxins are characterized in Table 1.

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Clinical isolates of Branhamella catarrhalis from patients with respiratory infections were used in this study. Electron microscopic observation after treating Branhamella catarrhalis with immune serum and ruthenium red revealed the capsule. In the phagocytosis test, most organisms were not ingested by human polymorphonuclear neutrophils in the presence of normal rabbit serum (NRS), while organisms were primarily cell associated and apparently ingested in the presence of immunized rabbit serum (IRS). The capsule may be one of the virulence factors in this bacteria. This study demonstrates the possible presence of a capsule in Branhamella catarrhalis.

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Many electron-dense granules were found in the nucleoid area of Pseudomonas aeruginosa strain K by electron microscopy with the technique of the freeze-substitution method. These granules contained phosphorus and calcium as determined by X-ray microanalysis. The size and the numbers of the granules decreased when the bacteria was cultured in the medium from which phosphate-containing compounds were depleted. From these observations we concluded that the granule was a phosphate-containing granule and possibly a polyphosphate granule. The excellent preservation of the fine structures by the freeze-substitution technique enables us to show very small polyphosphate granules in the nucleoid area of the bacterial cells which cannot be revealed by the conventional chemical fixation method. As we could not see the granules in other bacteria cultured in nutrient medium such as Serratia, Escherichia, Bacillus and Vibrios, the accumulation of the phosphate granules in Ps. aeruginosa might be a unique character of this bacteria and might be related to the growing capability of this bacteria in extremely low nutrient supply.

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The community surveillance of respiratory virus infections performed during 1985-1987 in Sendai and 1988-1990 in Yamagata has identified a total of five herald waves of influenza virus infections: A/H3N2 virus infections in 1985 and 1989, A/H1N1 virus infections in 1986 and 1988, and type B virus infections in 1989. To investigate the antigenic and genetic relationships between the herald wave and epidemic strains, influenza A/H1N1 viruses isolated during the 1986 and 1988 herald waves were compared with those isolated during the 1986-1987 and 1988-1989 epidemic seasons, respectively, utilizing hemagglutination inhibition tests with anti-hemagglutinin monoclonal antibodies and oligonucleotide mapping of total viral RNAs. The results showed that multiple variants differing in antigenic and genetic properties were cocirculating during the 1986 herald wave as well as during each of the two epidemics (only one strain was isolated in the 1988 herald wave). It was also observed that viruses which had the antigenic and/or genetic characteristics closely similar to those of the viruses circulating in the 1986 and 1988 herald waves, were isolated during the winters of 1986-1987 and 1988-1989, respectively.

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We observed the effects of a chinese herb medicine Sho-saiko-to on the lethal and antitumor activities of recombinant human tumor necrosis factor (rhTNF) administered in mice. Sho-saiko-to was noted to protect the rhTNF-induced lethality in galactosamine-hypersensitized mice, and also Sho-saiko-to pretreated mice was protected against the decrease of rectal temperature after rhTNF administration. On the other hand, there was a remarkable enhancement of antitumor activity of rhTNF by Sho-saiko-to pretreatment. These results suggest that Sho-saiko-to drug may protect mice from severe shock syndrome induced by rhTNF.

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A method is described in which cells of Staphylococcus aureus can be converted to vesiculated large bodies of L-form. When coccal cells were incubated in a liquid growth medium containing D-cycloserine, N-acetylmuramidase and subtilisin, a large number of vesiculated large bodies were formed. Electron microscopy revealed that development of internal vesicles arose after 6hr of incubation. When growth inhibitory concentrations of rifampicin, novobiocin, or chloramphenicol were added to the culture at 6hr of incubation, small-sized nonvesiculated bodies were produced instead of vesiculated forms. The viability of cultures was reduced by rifampicin and novobiocin but not by chloramphenicol.

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Clumping and fibrinogen-binding activities of 4 Staphylococcus aureus strains (Cowan I, Newman D2C, Wood 46 and NCTC 5655) were assayed with a semiquantitative clumping test and an enzyme-linked immunosorbent assay (ELISA), respectively. Distinct positive clumping was detected with whole cells of the 3 strains except Wood 46. Amounts of fibrinogen required for a definite clumping depended greatly on strains as well as on their growth phases. On the other hand, fibrinogen-binding activities were detected both in culture supernatants and in cell lysates of all the 4 strains, and the levels were rather comparable with one another and relatively steady through their growth cycles. No significant correlation was thus found among expression behavior of clumping and fibrinogen-binding activities.

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