Emergence of a unique O3:K6 clone of Vibrio parahaemolyticus in Calcutta, India, and isolation of strains from the same clonal group from Southeast Asian travelers arriving in Japan

Active surveillance of Vibrio parahaemolyticus infection among hospitalized patients in Calcutta, India, was initiated in January 1994. The incidence of cases of V. parahaemolyticus infection suddenly increased in February 1996 and has remained high since then. One hundred thirty-four strains of V. parahaemolyticus isolated from January 1994 to August 1996 were examined for serovar, the presence of the thermostable direct hemolysin gene (tdh) and tdh-related hemolysin genes (trh1 and trh2), production of urease, and antibiogram. Strains of the O3:K6 serovar appeared for the first time in February 1996. The O3:K6 serovar strains accounted for 50 to 80% of the strains isolated during the high-incidence period (February to August 1996). All of the serovar O3:K6 strains carried the tdh gene but not the trh genes and did not produce urease. All of the isolates except two were sensitive to all of the antibiotics tested. These and the results of analysis by an arbitrarily primed PCR method indicated that the O3:K6 serovar strains belong to a unique clone. When the O3:K6 serovar strains, isolated from travelers arriving in Japan from Southeast Asian countries, were compared by the arbitrarily primed PCR method, the strains isolated between 1982 and 1993 were distinct from Calcutta O3:K6 while the strains isolated in 1995 and 1996 were indistinguishable from the Calcutta O3:K6 strains. The results suggest that this unique O3:K6 clone may have become prevalent not only in Calcutta but also in Southeast Asian countries very recently. Not only the O3:K6 strains but also the non-O3:K6, tdh-bearing strains isolated in 1996 produced thermostable direct hemolysin at high levels, and thus the level of hemolysin produced does not appear to have influenced the high incidence of serovar O3:K6 strains.     

Giant retroperitoneal hematoma in a patient with von Recklinghausen's disease]

A 51-year-old male of von Recklinghausen's disease presented with huge retroperitoneal hematoma caused by spontaneous arterial rupture. He died of uncontrollable hemorrhage during the operation. Gross appearance of aorta, renal artery, celiac artery, pulmonary artery and lumbar artery were extremely fragile, and there was a complete rupture between aorta and lumbar artery. On the microscopic examination, significant medial dysplasia were demonstrated in these arteries. Arterial stenosis is well-known vascular complication in von Recklinghausen's disease. Spontaneous rupture of major artery, however, has been extremely uncommon. This is the 26th case reported in the world literature, and 21th case in the Japanese literature.     

Structure-activity relationships of spontaneous nitric oxide releasers, FK409 and its derivatives

(+/-)-(E)-4-Ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide (FK409) shows both potent in vitro vasorelaxant and antiplatelet activities via nitric oxide (NO) generated spontaneously from the compound. In this study, we measured spontaneous NO-releasing rates of a series of FK409 derivatives, of which chain lengths or substituents were systematically modified, in sodium-phosphate buffer solution at pH 7.4. Furthermore, we studied their in vitro antiplatelet and vasorelaxant effects to evaluate relationships between spontaneous NO-releasing activities of FK409 analogs and their biological activities. FK409 derivatives were found to possess different spontaneous NO-releasing rates and biological activities according to their structural modification. In addition, these studies revealed a close correlation between NO-releasing rates of FK409 derivatives and their in vitro antiplatelet activities in human platelet-rich plasma, whereas the in vitro vasorelaxant activities of these compounds in isolated rat aorta did not correlate with the rates of NO liberation. The vasorelaxant effects were supposed to be affected by the structural properties of FK409 derivatives as well as their NO-releasing abilities.     

Potent preventive action of alpha-carotene against carcinogenesis: spontaneous liver carcinogenesis and promoting stage of lung and skin carcinogenesis in mice are suppressed more effectively by alpha-carotene than by beta-carotene

Although beta-carotene has been considered to be a key cancer preventive agent in green and yellow vegetables, other types of carotenoids, such as alpha-carotene, may also contribute to anticarcinogenic action, since these carotenoids usually coexist with beta-carotene and are detectable in human blood and tissues. In this study, we compared the inhibitory effect of natural alpha-carotene, obtained from palm oil, with that of beta-carotene on spontaneous liver carcinogenesis in C3H/He male mice. The mean number of hepatomas per mouse was significantly decreased by alpha-carotene supplementation (per os administration in drinking water at a concentration of 0.05%, ad libitum) as compared with that in the control group (P < 0.001, Student's t test). On the other hand, beta-carotene, at the same dose as alpha-carotene, did not show any such significant difference from the control group. Furthermore, we also compared the antitumor-promoting activity of alpha-carotene with that of beta-carotene against two-stage mouse lung carcinogenesis (initiator, 4-nitroquinoline 1-oxide; promoter, glycerol). alpha-Carotene, but not beta-carotene, reduced the number of lung tumors per mouse to about 30% of that in the control group (P < 0.001, Student's t test). The higher potency of the antitumor-promoting action of alpha-carotene compared to beta-carotene was confirmed in other experimental systems; e.g., alpha-carotene was also found to have a stronger effect than beta-carotene in suppressing the promoting activity of 12-O-tetradecanoylphorbol-13-acetate on skin carcinogenesis in 7,12-dimethylbenz[a]anthracene-initiated mice. These results suggest that not only beta-carotene, but also other types of carotenoids, such as alpha-carotene, may play an important role in cancer prevention.     

Report on Microgravity Experiments of Dynamic Surface Deformation Effects on Marangoni Instability in High-Prandtl-Number Liquid Bridges

This paper reports an overview and some important results of microgravity experiments called Dynamic Surf, which have been conducted on board the International Space Station from 2013 to 2016. The present project mainly focuses on the relations between the Marangoni instability in a high-Prandtl-number (Pr=?67 and 112) liquid bridge and the dynamic free surface deformation (DSD) as well as the interfacial heat transfer. The dynamic free surface deformations of large-scale liquid bridges (say, for diameters greater than 10 mm) are measured with good accuracy by an optical imaging technique. It is found that there are two causes of the dynamic free surface deformation in the present study: the first is the time-dependent flow behavior inside the liquid bridge due to the Marangoni instability, and the second is the external disturbance due to the residual acceleration of gravity, i.e., g-jitter. The axial distributions of DSD along the free surface are measured for several conditions. The critical parameters for the onset of oscillatory Marangoni convection are also measured for various aspect ratios (i.e., relative height to the diameter) of the liquid bridge and various thermal boundary conditions. The characteristics of DSD and the onset conditions of instability are discussed in this paper.     

Growth of amorphous carbon nanotube from poly(tetrafluoroethylene) and ferrous chloride

The formation process of an amorphous carbon nanotube (α-CNT) from poly-(tetrafluoroethylene) using ferrous chloride was investigated by observing the TEM images of the isolated intermediates and conducting in situ TEM observation of its formation. These observations revealed unique features of the nanotube growth process through a series of steps; the growth of the core whisker, the deposition of amorphous carbon fragments onto the core whisker, and the disappearance of the core whisker, leaving the α-CNT. Such a unique process suggests a new method of controlling the carbon nano structure through the deposition of carbon over the core whisker template. The stable fluoride form of the core whisker is a key to preparing the amorphous carbon wall on its surface.     

Structural significance of the geminal-dimethyl group of (+)-trans-verbenyl acetate,sex pheromone mimic of the American cockroach

The significance of the geminal dimethyl group at C-6 of (+)-trans-veibenyl acetate (Ib), a sex pheromone mimic of the American cockroach, was investigated. Our interest was first directed to eliminating either methyl group of the geminal dimethyl group. Consequently, alcohols (IIIa and IVa) possessing a monomethyl group at C-6 were successfully obtained. Acetate (IVb) and propionate (IVc) of alcohol (IVa) possessing only a C-9 methyl group induced sex pheromonal activity at the 0.5 (IVb) and 0.02 mg (IVc) dose levels, respectively, while acetate (IIIb) of a alcohol (IIIa) with only C-8 methyl group was inactive. Alcohol (Va), which has an ethyl group at the C-6 instead of C-9 methyl, was also synthesized and converted into its acetate (Vb), which showed no activity. From these results, the significance of the dimethyl group is discussed relative to spatial requirements of the molecule for the receptor space. The M/F ratio in EAG was also evaluated for the synthesized esters. The M/F ratio index represented well the potency of pheromonal activity.