Hypotensive actions of some analogues of platelet-activating factor (PAF) with higher potencies than natural PAF

Substituents on the nitrogen atom of the phosphorylcholine moiety of natural C16 platelet-activating factor (PAF) were modified or replaced by more bulky groups, and their hypotensive activities were examined with rats. As a result, it was found that N-methylpiperidine and N-methylpyrrolidine analogues were 3-10 times more potent than natural C16-PAF.     

Isolation,Identification and Substrate Assimilation Specificity of Some Aromatic Hydrocarbon Utilizing Bacteria

As a result of screening isoalkyl or isoalkenyl substituted aromatic hydrocarbon assimilating microorganisms, 19 strains of isopropylbenzene assimilating bacteria were isolated. Thirteen of these strains were found to grow on α-methylstyrene and all 4 strains tested were also found to grow on isobutylbenzene.

Among them, 2 strains (S107B1 and S182BI) were selected for further study and were identified as Ps. convexa and Ps. ovalis, respectively.

Furthermore, some examined aromatic hydrocarbon utilizing bacteria were classified into two groups by differences in substrate assimilation specificity.     

Virulence in Mice of Orientia tsutsugamushi Isolated from Patients in a New Endemic Area in Japan

Four strains of Orientia tsutsugamushi (KN-1, KN-2, KN-3 and GJ-1) isolated from patients in an area of Gifu Prefecture, Japan, in which tsutsugamushi disease is newly endemic, were examined for their virulence in mice. Among these, KN-1 (identified as Kawasaki type), GJ-1 (identified as Kuroki type) and KN-2 strains were found to be non-lethal for BALB/c mice as well as CH3/HeJ mice, even with high doses (10⁶ × being the 50% mouse infectious dose). On the other hand, the KN-3 strain was found to be sufficiently virulent to kill BALB/c mice. Among the prototype strains (Gilliam, Karp and Kato), the Karp and Kato strains exhibited high virulence to mice, while the Gilliam strain killed only a susceptible strain of mouse. BALB/c mice infected with KN-1 and KN-2 strains showed significant splenomegaly and moderate ascites accumulation in the first week of infection, while these symptoms became prominent during the second week of infection using KN-3, Karp and Kato strains. After infection with the GJ-1 strain, these symptoms were not observed. Antibody responses induced by infections with highly virulent strains were lower than that with low or intermediate virulent strains.