Seventy-nine ambulatory patients with acute lower respiratory tract infection were evaluated for Legionella pneumophila by acute and convalescent antibody titers. None of the patients met the ...traditional criteria for the diagnosis of acute infection caused by Legionella pneumophila. Currently accepted criteria for diagnosing legionellosis by serologic means may or may not be applicable to mild respiratory tract infections.
We have observed the
ηπ
+
π
− and
ηπ
0
π
0 decay modes of the
E meson in
pp
annihilation at rest into
π
+
π
−
π
0
π
0
η. The mass and width of the
E meson are 1409 ± 3 and 86 ± 10 MeV. The production ...and decay branching ratio is
B(
pp → Eππ)B(E → ηππ) = (3.3 ± 1.0) × 10
−3
. With a spin-parity analysis we determine that
J
P
= 0
−. The observation of the
ηπ
0
π
0 decay mode establishes that
E is isoscalar (
C = +1). We find that
E decays to
η(
ππ)
s
(where (
ππ)
s
is an S-wave dipion) and
πa
0(980)(→
πη) with a relative branching ratio of (78 ± 16) %. Using the
K
Kπ
production and decay branching ratio measured earlier we determine that
BE → K
Kπ
BE → ηππ
= 0.61 ± 0.19
. A comparison with observations in radiative
J
Ψ
decays suggests that
E and
ι
η
(1416)
are identical.
As recently reported, Sarcocystis gigantea lectin (SGL) is a powerful mitogen and a polyclonal activator (Syn. S. ovifelis) of human peripheral B-cells. In the present study we investigated the ...reactivity of human T-helper (CD4) and T-suppressor (CD8) cells to SGL. Mononuclear cells (MNCs) from five newborns and six adults were examined cytofluorometrically for the expression of cell-surface differentiation and activation antigens using a set of seven monoclonal antibodies. In all, 96% of cord-blood and 81% of adult CD4 cells expressed receptors for interleukin-2 (Tac+) after 64 and 164 h microgram/ml). The percentages of neonatal and adult Tac+ CD8 cells amounted to 67% and 59%, respectively. Major histocompatibility complex (MHC) class II antigens identified using the monoclonal anti-human leukocyte antigen (HLA)-DR antibody L243 were expressed on 30% (CD4) and 44% (CD8) of adult T-cells. Neonatal HLA-DR+ T-lymphocytes were not detectable. In parallel, functional tests were performed to examine cell proliferation and MNC antibody production.
The annihilation
pp → Φγ
has been investigated with the Crystal Barrel detector at LEAR for antiprotons stopped in liquid hydrogen. The observed branching ratio
BR(
pp → Φγ = (1.7 ± 0.4) · 10
−5
is ...almost two orders of magnitude higher than expected from the OZI-rule. As a by-product, the branching ratios
BR(
pp → K
LK
S) = (9.0 ± 0.6) · 10
−4
and
BR(
pp → Φπ
0) = (5.5 ± 0.7) · 10
−4
have been measured.
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