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Short-term synaptic plasticity (SSP) is a basic mechanism for temporal processing of neural information in synaptic transmission. Facilitation, the fastest component of SSP, has been extensively investigated with regard to Ca 2+ signaling and other relevant substances. However, systematic analyses on the slower components of SSP, originated by Magleby and Zengel, have remained stagnant for decades, as few chemicals directly modifying these slower components have been identified. In combination with refined experimental protocols designed to study the stimulation frequency-dependence of SSP and botulinum neurotoxins A and C (BoNT-A and BoNT-C), we investigated SSP of frog neuromuscular transmission to clarify the roles of synaptosomal-associated protein of 25 kDa (SNAP-25) and syntaxin, SNARE proteins exclusively participating in vesicular events including docking, priming and exocytosis. We found that BoNT-A treatment eliminated slow potentiation, and BoNT-C poisoning abolished intermediate augmentation, two components of SSP. Fast facilitation was maintained after double poisoning with BoNT-A and -C, but the postsynaptic response became biphasic. A novel depression, termed repression, emerged by double poisoning. Repression was different from depletion because it developed even at a low-frequency stimulation of 1 Hz. We conclude that SNAP-25 and syntaxin not only play roles as cooperative exocytotic machinery, but also have roles in SSP., (Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.)

Methodologies beyond the Born-Oppenheimer (BO) approximation are nowadays important to explain high precision spectroscopic measurements. Most previous evaluations of the BO correction are, however, focused on light-element molecules and based on a nonrelativistic Hamiltonian, so no information about the BO approximation (BOA) breakdown in heavy-element molecules is available. The present work is the first to investigate the BOA breakdown for the entire periodic table, by considering scalar relativistic effects in the Diagonal BO correction (DBOC). In closed shell atoms, the relativistic EDBOC scales as Z(1.25) and the nonrelativistic EDBOC scales as Z(1.17), where Z is the atomic number. Hence, we found that EDBOC becomes larger in heavy element atoms and molecules, and the relativistic EDBOC increases faster than nonrelativistic EDBOC. We have further investigated the DBOC effects on properties such as potential energy curves, spectroscopic parameters, and various energetic properties. The DBOC effects for these properties are mostly affected by the lightest atom in the molecule. Hence, in X2 or XAt molecule (X = H, Li, Na, K, Rb, and Cs) the effect of DBOC systematically decreases when X becomes heavier but in HX molecules, the effect of DBOC seems relatively similar among all the molecules.

The efficacy of 1% chlorhexidine-gluconate ethanol and 10% povidone-iodine for skin antisepsis of central venous catheter (CVC) sites were compared among hematology patients. The CVC site colonization rates of those groups were 11.9% and 29.2%, respectively, and the catheter-associated blood stream infections were 0.75 and 3.62 per 1,000 catheter-days, respectively. One percent chlorhexidine-gluconate ethanol was superior to povidone-iodine to reduce skin colonizers at CVC sites even when catheters were used for long duration., (Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.)

We analyse the folding and unfolding of an RNA hairpin using a conventional zipping model that includes both the free energy for RNA binding and the elastic free energy of the system. Unfolding under isotonic conditions (where we control the applied load) is known to occur at a well-defined critical load. In marked contrast, we find that unfolding under isometric conditions (where we control the extension of the hairpin) produces a series of sharp peaks in the average load as the stem of the hairpin starts to unzip base by base. A peak occurs when the elastic energy stored in the unzipped arms of the hairpin becomes so large that it is energetically favourable for the next base pair to unzip: the consequent increase in the contour length of the unzipped arms reduces their elastic energy and causes the average load to fall abruptly. However, as the contour length of the unzipped arms increases, the peaks become less distinct. Moreover, when we include the long DNA/RNA handles that have been used in single-molecule experiments, the unzipping of individual base pairs cannot be resolved at all. Instead, with the hairpin in the folded state, the average load increases with extension until the elastic energy stored in the handles makes it energetically favourable for the hairpin to unzip over a narrow range of extensions. The resultant yield point produces a mechanical hysteresis loop with a negative slope, as observed experimentally. Unfolding of the hairpin is also affected by the elastic energy stored in a compliant force transducer. We find that short, stiff handles and a stiff force transducer could improve the resolution of mechanical experiments on single molecules.

Diurnal variations in serum iron concentration were examined to investigate the influence of sampling time in hemodialysis (HD) patients and healthy subjects. The serum iron concentration and TIBC of HD patients decreased significantly (p<0.01, p<0.01 respectively) compared to those of healthy subjects. Inversely, the serum ferritin concentration of HD patients increased significantly (p<0.01) compared to that of healthy subjects. These findings show the disturbance of iron transport system: under such condition intracellural iron transition out into peripheral blood stream is low in HD patients. Serum iron concentration in samples collected in the evening decreased significantly both in HD patients (p<0.05) and in healthy subjects (p<0.01). Diurnal variations in serum iron concentration reveal almost similar decrement in both groups. In HD patients, serum iron concentration of the blood samples collected on the third day morning after HD and second day morning after HD was examined to see the influence from changes of circulating plasma volume. The serum iron concentration and Hct value in the second day sampling increased significantly compared to the third day sampling (p<0.01, p<0.01 respectively). In addition, the serum iron concentration corrected by Hct in the second day sampling increased significantly (p<0.01) compared to the third day sampling. We conclude from our results that diurnal variations of serum iron concentration vary in sampling time in HD patients as well as in healthy subjects. We also deduct that there may be other factors concerning changes in circulating plasma volume.

The antibacterial activity of meropenem (MEPM) and other parenteral antibiotics against clinical isolates of 2655 strains including 810 strains of Gram-positive bacteria, 1635 strains of Gram-negative bacteria, and 210 strains of anaerobic bacteria obtained from 30 medical institutions during 2009 was examined. The results were as follows; (1) MEPM was more active than the other carbapenem antibiotics tested against Gram-negative bacteria, especially against enterobacteriaceae and Haemophilus influenzae. MEPM was also active against most of the species tested in Gram-positive and anaerobic bacteria, except for multidrug resistant strains including methicillin-resistant Staphylococcus aureus (MRSA). (2) MEPM maintained potent and stable antibacterial activity against Pseudomonas aeruginosa. The proportion of MEPM-resistant strains to ciprofloxacin-resistant strains or imipenem-resistant strains were 53.1% and 58.0% respectively. (3) The proportion of extended-spectrum beta-lactamase (ESBL) strains was 3.1% (26 strains) in enterobacteriaceae. And the proportion of metallo-beta-lactamase strains was 2.0% (6 strains) in P. aeruginosa. (4) Of all species tested, there were no species except for Bacteroides fragilis group, which MIC90 of MEPM was more than 4-fold higher than those in our previous study. Therefore, there is almost no significant decrease in susceptibility of clinical isolates to meropenem. In conclusion, the results from this surveillance study suggest that MEPM retains its potent and broad antibacterial activity and therefore is a clinically useful carbapenem for serious infections treatment at present, 14 years passed after available for commercial use in Japan.

Hybrisep is an in situ hybridization (ISH) method to detect phagocytosed bacteria in peripheral blood neutrophils and macrophages. We report 10 actual clinical cases tested using Hybrisep with new DNA probes, and the data were compared to the actual blood culture results. A normal Hybrisep strategy employs 5 DNA probes to detect the following bacterial DNA: "SA" probe for S. aureus, "SE" for S. epidermidis, "PA" for P. aeruginosa, "EF" for E. faecalis, and "EK" for E. coli, E. cloacae, and K. pneumoniae. Six newly designed DNA probes were used in this study: "GB" probe for 49 common bacteria, "SP" for S. pneumoniae, "BF" for B. fragilis, "HI" for H. influenzae, "GC" for Candida species, and "CA" for C. albicans. Three cases were positive on ISH, but all their blood cultures were negative. One case showed a positive blood culture, but was negative on ISH. In another 6 cases, both were negative. We postulated that empirical therapy of antibiotics resulted in only positive ISH. Cases only showing a positive outcome on blood culture might be due to a diminished phagocytic function during patients' severe disease conditions. In conclusion, ISH with Hybrisep has clinical advantages such as being able to defect causative pathogens even after the use of antibiotics, and facilitates more rapid identification than routinely performed bacterial cultures only.

We analyzed 4 cases that were not determined as incidents and another 7 cases determined as incidents, found at the department of clinical laboratory of us from April 2009 to March 2010. The former cases were, excess values of LD, and Cl, and glucose leveled as 0 mg/dl incorrectly, and misdirected blood samples at the ER. Our routine equipment and sample flow did not detect these false values. Resetting for auto dilution system and secondary check by every worker were reconsidered for these measurements. Antiseptic drug usage was notified by clinicians, and actually affected to the excessive Cl value. Real incidents were, two unprocessed samples, leakage of a sample, missing processes that caused delay of clinical practice, mixed up sample labels, a lost narcotic patch during cardiac ultrasonography. A lack of checking, carelessness, and accidental mistakes were reevaluated and reminded for workers on the duties. Also inadequate pharmaceutical knowledge and responsibilities of this section might severely affect on these lessons. Efforts were taken so that all workers shared the accurate information. Code blue cases are defined here as those of life-threatening events and sudden vital changes occurred in highest emergency, involve all health care workers, patients, and families. It is very important here to keep regular trainings for workers to cope with such events as well as preemptive assessments on environment and underlying risks in our laboratory. In line with the continuous advances in clinical medicine, medical safety managements are growing issues. To achieve safer environment and minimize various type of risks in the hospital, these incidents are to be assessed and reported regularly.

We need to attend to a patient face to face in the physiological function testing room and the central blood-drawing room of the central clinical laboratory in a hospital. Recently, there have been some problems and troubles experienced by medical staff because patients may have had some over-expectations regarding our medical service and their sense of entitlement may have been unrealistic. We report some problems experienced in our Central Clinical Laboratory and hospital, and describe some solutions. If a medical staff member gets into trouble with a patient because of some difference in awareness between him/her and the patient, we should take prompt action regarding these claims and be considerate to the patient. However, we have to take a tough stance against some severe cases, for example violence and intemperate language directed toward medical staff. One of the most important things is to investigate complaints against us, and, through this, keep on improving. Another important thing is to disseminate information among central clinical laboratory teams liaising with nursing and other departments. Therefore, we can establish a good trusting relationship between patients and staff, and consequently our patient service will improve.

When a two-headed molecular motor such as kinesin is attached to its track by just a single head in the presence of an applied load, thermally activated head detachment followed by rapid re-attachment at another binding site can cause the motor to 'hop' backwards. Such hopping, on its own, would produce a linear force-velocity relation. However, for kinesin, we must incorporate hopping into the motor's alternating-head scheme, where we expect it to be most important for the state prior to neck-linker docking. We show that hopping can account for the backward steps, run length and stalling of conventional kinesin. In particular, although hopping does not hydrolyse ATP, we find that the hopping rate obeys the same Michaelis-Menten relation as the ATP hydrolysis rate. Hopping can also account for the reduced processivity observed in kinesins with mutations in their tubulin-binding loop. Indeed, it may provide a general mechanism for the breakdown of perfect processivity in two-headed molecular motors.

There exist inter-laboratory differences in measurements of rheumatoid factor (RF) and antinuclear antibodies (ANA), leading to a misdiagnosis of rheumatoid arthritis (RA) and other collagen diseases. This study was carried out to bring the positivity of RF and ANA of different reagents into accord by standardizing their data. The titer and cutoff value was inconsistent among the 17 different kits. We found a possibility in standardization of RF by a new concept in cooperation with Japanese Committee for Clinical Laboratory Standards (JCCLS). Sera from 1300 healthy subjects and 79 RA patients were measured for RF by 17 different RF kits, and sera with a little deviation among the kits were selected. Panels for detection of RF positive rate in healthy subjects were made from the pooled sera. The cutoff value in 5% positive in the panel was defined tentatively as 15 IU/ml. The 100 IU/ml was also able to become in general accord by adjusting the individual data using pooled RF-positive reference sera. The nationwide survey of immunofluorescence ANA (IF-ANA) was performed in 41 laboratories using 6 pooled sera. The reported titer was fairly different among laboratories, and a striking discrepancy was found for low-titer samples. When the titer was corrected by simultaneously measured reference serum, inconsistency of ANA titer among different laboratories was mostly compensated. Here, we propose a new method for standardization of RF and also try to standardize the positivity of RF and IF-ANA by providing pooled reference sera.

Objective: Methicilllin-resitant Staphylococcus aureus (MRSA) is still the most important bacterium for hospital infection control, and is known to exhibit beta-lactam resistance. Moreover, the increase in PBP2'-producing methicillin-resistant coagulase-negaive Staphylococcus (MR-CNS), especially methicillin-resistant S. epidermidis (MRSE) has been problematic. In this study, we investigated the induction of PBP2' by MPIPC, other antibiotics and disinfectants in MRSE., Materials and Methods: The bacterial strains used were MRSE isolated in our clinical laboratory. MRSA-LA 'Seiken' was used for the detection of PBP2'. To investigate induction of PBP2' by MPIPC in MRSE, MRSE was cultured on the medium containing MPIPC at 11 different concentrations from 0.0001 to 6 microg/ml, and PBP2' induction was investigated. Strains in which no induction was noted at a low MPIPC concentration were cultured with other antibiotic discs and discs impregnated with various disinfectants, and PBP2' was detected in colonies that grew around the disc and PBP2' induction was investigated., Results: In the culture on MPIPC-supplemented medium, PBP2' was detected in all strains at 0.01-6 microg/ml. At 0.001 and 0.0001 microg/ml, 8/10 and 4/10 were positive, respectively. Addition of another beta-lactam, particularly cephem antibiotics, induced PBP2' in some strains that were negative at 0.0001 microg/ml. In cultures with disinfectants, inhibition zones were noted, but no PBP2' was induced., Conclusion: PBP2' was induced by a low beta-lactam and was not by disinfectants in MRSE.

Conventional kinesin (Kinesin-1) is a microtubule-based molecular motor that supports intracellular vesicle/organelle transport in various eukaryotic cells. To arrange kinesin motors similarly to myosin motors on thick filaments in muscles, the motor domain of rat conventional kinesin (amino acid residues 1-430) fused to the C-terminal 829 amino acid residues of catchin (KHC430Cat) was bacterially expressed and attached to catchin filaments that can attach to and arrange myosin molecules in a bipolar manner on their surface. Unlike the case of myosin where actin filaments move toward the center much faster than in the opposite direction along the catchin filaments, microtubules moved at the same speed in both directions. In addition, many microtubules moved across the filaments at the same speed with various angles between the axes of the microtubule and catchin filament. Kinesin/catchin chimera proteins with a shorter kinesin neck domain were also prepared. Those without the whole hinge 1 domain and the C-terminal part of the neck helix moved microtubules toward the center of the catchin filaments significantly, but only slightly, faster than in the opposite direction, although the movements in both directions were slower than those of the KHC430Cat construct. The results suggest that kinesin has substantial mechanical flexibility within the motor domain, possibly within the neck linker, enabling its interaction with microtubules having any orientation., (Copyright 2008 Wiley-Liss, Inc.)

It has been found in in vitro experiments that cytoskeletal filaments driven by molecular motors show finite diffusion in sliding motion even in the long filament limit [Imafuku, Y. et al. Biophys. J. 1996, 70, 878-886. Noda, N. et al. Biophysics 2005, 1, 45-53]. This anomalous fluctuation can be evidence for cooperativity among the motors in action because fluctuation should be averaged out for a long filament if the action of each motor is independent. In order to understand the nature of the fluctuation in molecular motors, we perform numerical simulations and analyze velocity correlation in three existing models that are known to show some kind of cooperativity and/or large diffusion coefficient, i.e., the Sekimoto-Tawada model [Sekimoto, K.; Tawada, K. Phys. Rev. Lett. 1995, 75, 180], the Prost model [Prost, J. et al. Phys. Rev. Lett. 1994, 72, 2652], and the Duke model [Duke, T. Proc. Natl. Acad. Sci. U.S.A. 1999, 96, 2770]. It is shown that the Prost model and the Duke model do not give a finite diffusion in the long filament limit, in spite of the collective action of motors. On the other hand, the Sekimoto-Tawada model has been shown to give a diffusion coefficient that is independent of filament length, but it comes from the long time correlation whose time scale is proportional to filament length, and our simulations show that such a long correlation time conflicts with the experimental time scales. We conclude that none of the three models represent experimental findings. In order to explain the observed anomalous diffusion, we have to search for a mechanism that will allow both the amplitude and the time scale of the velocity correlation to be independent of the filament length.