The
Reference Center in Japan collected 427
clinical isolates between 2008 and 2016, including 7 representative isolates from corresponding outbreaks. The collection included 419
isolates, of which ...372 belonged to serogroup 1 (SG1) (87%) and the others belonged to SG2 to SG15 except for SG7 and SG11, and 8 isolates of other
species (
,
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, and
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isolates were genotyped by sequence-based typing (SBT) and represented 187 sequence types (STs), of which 126 occurred in a single isolate (index of discrimination of 0.984). These STs were analyzed using minimum spanning tree analysis, resulting in the formation of 18 groups. The pattern of overall ST distribution among
isolates was diverse. In particular, some STs were frequently isolated and were suggested to be related to the infection sources. The major STs were ST23 (35 isolates), ST120 (20 isolates), and ST138 (16 isolates). ST23 was the most prevalent and most causative ST for outbreaks in Japan and Europe. ST138 has been observed only in Japan, where it has caused small-scale outbreaks; 81% of those strains (13 isolates) were suspected or confirmed to infect humans through bath water sources. On the other hand, 11 ST23 strains (31%) and 5 ST120 strains (25%) were suspected or confirmed to infect humans through bath water. These findings suggest that some ST strains frequently cause legionellosis in Japan and are found under different environmental conditions.
serogroup 1 (SG1) is the most frequent cause of legionellosis. Our previous genetic analysis indicated that SG1 environmental isolates represented 8 major clonal complexes, consisting of 3 B groups, 2 C groups, and 3 S groups, which included major environmental isolates derived from bath water, cooling towers, and soil and puddles, respectively. Here, we surveyed clinical isolates collected from patients with legionellosis in Japan between 2008 and 2016. Most strains belonging to the B group were isolated from patients for whom bath water was the suspected or confirmed source of infection. Among the isolates derived from patients whose suspected infection source was soil or dust, most belonged to the S1 group and none belonged to the B or C groups. Additionally, the U group was discovered as a new group, which mainly included clinical isolates with unknown infection sources.
An attempt to measure the negative ion density in an O
2/Ar electron cyclotron resonance (ECR) plasma is made with two methods. The first one is to estimate the density ratio of negative ions to ...positive ions, α, from the reduction rate of the ion and electron saturation current obtained with the Langmuir probe. The second one is to calculate α from the measured phase velocity of the fast mode of ion acoustic waves (IAWs). The IAWs are launched along magnetic fields using a wire-antenna where positive pulse voltages are applied, and are detected as a fluctuation of ion saturation current. As a result, α<0.3 is found. It is also found that α obtained with both methods agree qualitatively. Furthermore, the spatial distribution and the gas mixture ratio dependence of α are investigated. It is found that α has the optimum value at the gas mixture ratio of 15%, and that α near the wall is larger than that in the center region.
Numerous options are available for rehabilitation of chronic facial nerve paralysis, ranging from simple slings to complex procedures such as microneurovascular tissue transfer. Microneurovascular ...muscle transfer is generally indicated: 1) if the patient desires dynamic facial reanimation, particularly restoration of involuntary emotional facial expressions; 2) in the absence of distal facial nerve fibers or motor endplate function; 3) with an associated large soft tissue defect in the cheek; and 4) when other dynamic reanimation procedures have not been successful. The most commonly used free flaps for facial reanimation are gracilis, latissimus dorsi and inferior rectus abdominus muscle. When successfully performed free flaps yield excellent functional and aesthetic results in facial reanimation.
A late afterglow period of cryogenic plasma with density less than 10/sup 8/ cm/sup -3/ in 4.2-K helium gas is measured, where the plasma is lost mainly through ambipolar diffusion. We fabricate a ...large stainless-steel cylindrical discharge vessel of 16.6 cm in diameter and 8.2 cm in length. The vessel is a TE/sub 011/ mode cavity with resonant frequency 2.85 GHz and Q-value larger than 3000. The diffusion length of the cavity, 2.1 cm, is much larger than those previously reported on cryogenic plasmas. A high-voltage pulse of 15 kV, 600 A with duration 2.5 /spl mu/ s is applied between tungsten needle electrodes to produce a plasma repeatedly. Gas pressure is varied from 0.08 to 1.1 torr. Temporal changes in plasma density and electron-atom momentum transfer collision frequency are measured by an improved method of microwave interferometer including the cavity. The plasma decay with time constant on the order of 1 s is observed. We can see very slowly fading fluorescent light with our naked eyes. The decay time is increased, if gas temperature is cooled below 4.2 K.
Using the patch-clamp technique, we have identified an intermediate conductance Ca2+-activated K+ channel from bullfrog (Rana catesbeiana) erythrocytes and have investigated the regulation of channel ...activity by cytosolic ATP. The channel was highly selective for K+ over Na+, gave a linear I-V relationship with symmetrical 117.5 mM K+ solutions and had a single-channel conductance of 60 pS.
1. Two independent methods were used, in man, to assess changes in presynaptic inhibition of I a terminals at the onset of
selective voluntary contractions: (1) measurement of the amount of ...heteronymous monosynaptic I a facilitation (from the quadriceps
muscle to soleus motoneurones) to provide an assessment of the amount of ongoing presynaptic inhibition exerted on the I a
fibres responsible for the facilitation; (2) measurement of the inhibition of H reflexes 40-60 ms after a short vibration
to the tibialis anterior tendon to estimate the excitability of the interneurones mediating presynaptic inhibition from tibialis
anterior I a afferents to the I a afferents of the test H reflex (soleus or quadriceps). 2. At the onset of an isolated voluntary
plantar flexion of the foot (gastrocnemius-soleus contraction) the heteronymous facilitation from quadriceps to soleus was
increased, reflecting a decreased presynaptic inhibition of the quadriceps I a terminals on soleus motoneurones. Vibratory
inhibition of the soleus H reflex was decreased, reflecting an inhibition of transmission of presynaptic inhibition to homonymous
soleus I a afferent terminals. 3. At the onset of the same gastrocnemius-soleus contraction there was, on the contrary, an
increased vibratory inhibition of the quadriceps H reflex indicating a facilitation of transmission of presynaptic inhibition
to homonymous quadriceps I a afferent terminals. 4. At the onset of an isolated voluntary knee extension (quadriceps contraction)
the opposite pattern was seen: the heteronymous facilitation from quadriceps to soleus was decreased and the vibratory inhibition
of a soleus H reflex was increased, whereas the vibratory inhibition of the quadriceps H reflex was decreased. 5. These results
indicate that presynaptic inhibition of I a afferent terminals on motoneurones of contracting muscles is decreased, permitting
I a activity to contribute to excitation of voluntarily activated motoneurones. On the contrary, presynaptic inhibition of
I a fibres to motoneurones of muscles not involved in the contraction is increased. It is argued that the former must be supraspinal
in origin. 6. It is concluded that the control of presynaptic inhibition of I a fibres at the onset of movement may be organized
so as to aid in achieving selectivity of muscle activation, i.e. so as to increase motor contrast.
Cerebral amyloid angiopathy (CAA) due to beta -amyloid (A beta ) is one of the specific pathological features of familial Alzheimer's disease. A beta mainly consisting of 40- and 42-mer peptides (A ...beta 40 and A beta 42) exhibits neurotoxicity and aggregative abilities. All of the variants of A beta 40 and A beta 42 found in CAA were synthesized in a highly pure form and examined for neurotoxicity in PC12 cells and aggregative ability. All of the A beta 40 mutants at positions 22 and 23 showed stronger neurotoxicity than wild-type A beta 40. Similar tendency was observed for A beta 42 mutants at positions 22 and 23 whose neurotoxicity was 50-200 times stronger than that of the corresponding A beta 40 mutants, suggesting that these A beta 42 mutants are mainly involved in the pathogenesis of CAA. Although the aggregation of E22G- A beta 42 and D23N-A beta 42 was similar to that of wild-type A beta 42, E22Q- A beta 42 and E22K-A beta 42 aggregated extensively, supporting the clinical evidence that Dutch and Italian patients are diagnosed as hereditary cerebral hemorrhage with amyloidosis. In contrast, A21G mutation needs alternative explanation with the exception of physicochemical properties of A beta mutants. Attenuated total reflection-Fourier transform infrared spectroscopy spectra suggested that beta -sheet content of the A beta mutants correlates with their aggregation. However, beta -turn is also a critical secondary structure because residues at positions 22 and 23 that preferably form two-residue beta -turn significantly enhanced the aggregative ability.
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