1 Department of Molecular Biology
and 2 Department of Internal Medicine, School of Medicine, Keio University, Shinanomachi, Shinjuku-ku, Tokyo 160
3 Department of Microbiology, Yakult Institute for ...Microbiological Research, Kunitachi-shi, Tokyo 186
and 4 Department of Microbiology
and 5 Department of Internal Medicine, School of Medicine, Tokai University, Boseidai, Isehara, Kanagawa 259-11, Japan
In order to elucidate the ecological role of bacteriophages in the human intestine, we analysed the numbers of coliphages and of coliphage strains present in faecal samples collected from healthy individuals and from patients with certain intestinal diseases. The isolated phages were grouped according to their serological properties. The samples with low phage titres, observed in both healthy subjects and patients, contained mainly temperate phages (many were related to ø80 and ), and those with higher titres, observed in patients, contained virulent phages. From successive surveys of coliphages and their host, Escherichia coli , in faecal samples of each subject, it was concluded that temperate phages are maintained in the human intestine through spontaneous induction of lysogenic bacteria. Qualitative and quantitative differences existed between phages isolated from faecal samples from healthy subjects and from patients. Simultaneous changes in the distribution patterns of coliphages and of the clinical symptoms were observed in a continuous survey of a leukaemic patient in a protective environmental ward.
Keywords: coliphage distribution, temperate phages, virulent phages, phage ecology
Present address: Department of Microbiology, School of Medicine, Tokai University, Boseidai, Isehara, Kanagawa 259-11, Japan.
Received 13 January 1983;
accepted 20 May 1983.
Leucine dehydrogenase (
l-leucine: NAD
+ oxidoreductase, deaminating, EC 1.4.1.9) was purified to homogeneity from the crude extract of an alkaliphilic halophile,
Natronobacterium magadii MS-3, with ...a yield of 16%. The enzyme had a molecular mass of about 330
kDa and consisted of six subunits identical in molecular mass (55
kDa). The enzyme required a high concentration of salt for stability and activity. It retained the full activity after heating at 50
°C for 1
h and about 50% activity after being kept at 30
°C for 2 months in the presence of 2.5
M NaCl. The enzyme required NAD
+ as a coenzyme and showed maximum activity in the presence of more than 3
M salt, as CsCl, RbCl, NaCl, or KCl. In addition to
l-leucine,
l-valine and
l-isoleucine were also good substrates in the oxidative deamination. In the reductive amination, 2-keto analogs of branched-chain amino acids were substrates. The Michaelis constants were 0.69
mM for
l-leucine, 0.48
mM for NAD
+, 4.0
mM for 2-ketoisocaproate, 220
mM for ammonia, and 0.02
mM for NADH in the presence of 4
M NaCl. The
K
m for
l-leucine depended on the concentration of salt and increased with decreasing salt concentration. The
N. magadii enzyme was unique in its halophilicity among leucine dehydrogenases studied so far.
The interaction cross-sections (σ I ) of neutron-rich Na isotopes, 23-35 Na, on C target have been measured at 250A MeV using the RI beam factory (RIBF) at RIKEN. Mass dependence of σ I for 27-35 Na ...suggests monotonic growth of the skin thickness. The root-mean-square nuclear matter radii (r m ) of 23-35 Na were deduced from observed σ I via a Glauber-type calculation. These r m are in a good agreement with the theoretical prediction by relativistic mean field model (RMF). r m of 33-35 Na were determined for the first time.
The relationship between the seasonal prevalence of the predacious coccinellid Pseudoscymnus hareja and the mulberry scale Pseudaulacaspis pentagona in tea fields was investigated using sticky traps ...set inside tea bushes. Crawlers (newly-hatched larvae) and winged adult males of P. pentagona and adults of P. hareja were captured in large numbers. The number of trapped P. hareja adults reached a peak 0 to 15 days (average: 6.9 days) after the peak in the number of P. pentagona crawlers in each tea field. P. hareja adults captured in this period are considered to have visited tea fields to prey on P. pentagona larvae and to deposit their offspring (larvae), which primarily consume P. pentagona larvae. Another relatively lower peak in P. hareja adults was found 0 to 14 days (average: 6.6 days) after the peak in the number of P. pentagona adult males. P. hareja adults trapped in this period are suggested to be those that had spent their larval period feeding on P. pentagona larvae and male pupae in tea fields. Thus, the seasonal occurrence of P. hareja adults in tea fields is associated with that of P. pentagona larvae as the main prey of P. hareja larvae.
We examined the distribution of calpains I and II in human hematopoietic system cell lines by Western and Northern blot analyses
and enzyme activity assay. Expression of calpain I, a low ...Ca(2+)-requiring cysteine protease, was observed in all human T-cell
lines tested. By contrast, expression of calpain II, a high Ca(2+)-requiring form, in human T-cells was closely correlated
with human T-cell leukemia virus type I (HTLV-I) infection, which is known to result in the expression of adult T-cell leukemia-associated
antigens, interleukin-2 (IL-2) receptor alpha, and Ca(2+)-dependent cell proliferation. Specific expression of calpain II
in HTLV-I-infected cells occurred at the mRNA level. Furthermore, expression of calpain II in human natural killer-like cells
was augmented by HTLV-I pX gene transfection. In HTLV-I-infected cells, the trans-acting transcriptional activation of the
long terminal repeat and control elements for the IL-2 receptor alpha, c-fos, and granulocyte-macrophage colony-stimulating
factor genes by the Tax from the pX gene is already known. Our results suggest that the similar trans-activation occurs to
the calpain II gene in HTLV-I-infected hematopoietic system cells.
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