Fibrillization Process of Human Amyloid-Beta Protein (1-40) under a Molecular Crowding Environment Mimicking the Interior of Living Cells Using Cell Debris

Molecular crowding environments play a crucial role in understanding the mechanisms of biological reactions. Inside living cells, a diverse array of molecules coexists within a volume fraction ranging from 10% to 30% v/v. However, conventional spectroscopic methods often face difficulties in selectively observing the structures of particular proteins or membranes within such molecularly crowded environments due to the presence of high background signals. Therefore, it is crucial to establish in vitro measurement conditions that closely resemble the intracellular environment. Meanwhile, the neutron scattering method offers a significant advantage in selectively observing target biological components, even within crowded environments. Recently, we have demonstrated a novel scattering method capable of selectively detecting the structures of targeted proteins or membranes in a closely mimicking intracellular milieu achieved utilizing whole-cell contents (deuterated-cell debris). This method relies on the inverse contrast matching technique in neutron scattering. By employing this method, we successfully observed the fibrillization process of human amyloid beta-protein (Aβ 1-40) under a molecular crowding environment (13.1% w/v cell debris, Aβ/cell debris = ~1/25 w/w) that closely mimics the interior of living cells. Aβ protein is well known as a major pathogenic component of Alzheimer's disease. The present results combining model simulation analyses clearly show that the intracellular environment facilitates the potential formation of even more intricate higher-order aggregates of Aβ proteins than those previously reported.

Characterization of Localization, Ligand Binding, and pH-Dependent Conformational Changes of Two Chemosensory Proteins Expressed in the Antennae of the Japanese Carpenter Ant, Camponotus Japonicus

Camponotus japonicus uses basiconic antennal sensilla (s. basiconica) to sense a colony-specific blend of species-specific cuticular hydrocarbons (CHCs). The inner portion of the s. basiconica is filled with sensillar lymph and chemosensory proteins (CSPs) presumed to transport CHCs to olfactory neuron receptors. Although 12 CSPs have been found in C. japonicus antennae, we focused on CjapCSP1 and CjapCSP13. The molecular basis of CSP1 function was explored by observation of its structure in solution at pH 4.0 and 7.0 through circular dichroism (CD) and X-ray solution scattering. Although the secondary structure did not vary with pH change, the radius of gyration (Rg) was larger by 5.3% (0.74 Å increase) at pH 4.0 than at pH 7.0. The dissociation constant (K_d) for CjapCSP1 measured with a fluorescent probe, 1-N-phenylnaphthylamine, was larger at pH 4.0 than at pH 7.0, suggesting that acidic pH triggers ligand dissociation. In contrast to CjapCSP1, the Rg of CjapCSP13 was slightly smaller at pH 4.0 than at pH 7.0. Western blotting and immunohistochemistry with protein-specific antisera revealed that both CjapCSP1 and CjapCSP13 are detected in the antennae, but differ in their specific internal localization. Binding to four compounds, including the ant CHC (z)-9-tricosene, was examined. Although both CjapCSP1 and CjapCSP13 bound to (z)-9-tricosene, CjapCSP13 bound with higher affinity than CjapCSP1 and showed different binding properties. CjapCSP1 and CjapCSP13 are synthesized by the same cells of the antenna, but function differently in CHC distribution due to differences in their localization and binding characteristics.

Short-Distance Intermolecular Correlations of Mono- and Disaccharides in Condensed Solutions: Bulky Character of Trehalose

Organisms with tolerance to extreme environmental conditions (cryptobiosis) such as desiccation and freezing are known to accumulate stress proteins and/or sugars. Trehalose, a disaccharide, has received considerable attention in the context of cryptobiosis. It has already been shown to have the highest glass-transition temperature and different hydration properties from other mono- and disaccharides. In spite of the importance of understanding cryptobiosis by experimentally clarifying sugar-sugar interactions such as the clustering in concentrated sugar solutions, there is little direct experimental evidence of sugar solution structures formed by intermolecular interactions and/or correlation. Using a wide-angle X-ray scattering method with the real-space resolution from ∼3 to 120 Å, we clarified the characteristics of the structures of sugar solutions (glucose, fructose, mannose, sucrose, and trehalose), over a wide concentration range of 0.05-0.65 g/mL. At low concentrations, the second virial coefficients obtained indicated the repulsive intermolecular interactions for all sugars and also the differences among them depending on the type of sugar. In spite of the presence of such repulsive force, a short-range intermolecular correlation was found to appear at high concentrations for every sugar. The concentration dependence of the observed scattering data and p(r) functions clearly showed that trehalose prefers a more disordered arrangement in solution compared to other sugars, that is, bulky arrangement. The present findings will afford a new insight into the molecular mechanism of the protective functions of the sugars relevant to cryptobiosis, particularly that of trehalose.

Conformational selection of the intrinsically disordered plant stress protein COR15A in response to solution osmolarity - an X-ray and light scattering study

The plant stress protein COR15A stabilizes chloroplast membranes during freezing. COR15A is an intrinsically disordered protein (IDP) in aqueous solution, but acquires an α-helical structure during dehydration or the increase of solution osmolarity. We have used small- and wide-angle X-ray scattering (SAXS/WAXS) combined with static and dynamic light scattering (SLS/DLS) to investigate the structural and hydrodynamic properties of COR15A in response to increasing solution osmolarity. Coarse-grained ensemble modelling allowed a structure-based interpretation of the SAXS data. Our results demonstrate that COR15A behaves as a biomacromolecule with polymer-like properties which strongly depend on solution osmolarity. Biomacromolecular self-assembly occurring at high solvent osmolarity is initiated by the occurrence of two specific structural subpopulations of the COR15A monomer. The osmolarity dependent structural selection mechanism is an elegant way for conformational regulation and assembly of COR15A. It highlights the importance of the polymer-like properties of IDPs for their associated biological function.

Direct Evidence for the Effect of Glycerol on Protein Hydration and Thermal Structural Transition

The mechanisms of protein stabilization by uncharged solutes, such as polyols and sugars, have been intensively studied with respect to the chemical thermodynamics of molecular crowding. In particular, many experimental and theoretical studies have been conducted to explain the mechanism of the protective action on protein structures by glycerol through the relationship between hydration and glycerol solvation on protein surfaces. We used wide-angle x-ray scattering (WAXS), small-angle neutron scattering, and theoretical scattering function simulation to quantitatively characterize the hydration and/or solvation shell of myoglobin in aqueous solutions of up to 75% v/v glycerol. At glycerol concentrations below ∼40% v/v, the preservation of the hydration shell was dominant, which was reasonably explained by the preferential exclusion of glycerol from the protein surface (preferential hydration). In contrast, at concentrations above 50% v/v, the partial penetration or replacement of glycerol into or with hydration-shell water (neutral solvation by glycerol) was gradually promoted. WAXS results quantitatively demonstrated the neutral solvation, in which the replacement of hydrated water by glycerol was proportional to the volume fraction of glycerol in the solvent multiplied by an exchange rate (β ≤ 1). These phenomena were confirmed by small-angle neutron scattering measurements. The observed WAXS data covered the entire hierarchical structure of myoglobin, ranging from tertiary to secondary structures. We separately analyzed the effect of glycerol on the thermal stability of myoglobin at each hierarchical structural level. The thermal transition midpoint temperature at each hierarchical structural level was raised depending on the glycerol concentration, with enhanced transition cooperativeness between different hierarchical structural levels. The onset temperature of the helix-to-cross β-sheet transition (the initial process of amyloid formation) was evidently elevated. However, oligomerization connected to fibril formation was suppressed, even at a low glycerol concentration.

Frozen State of Sephadex® Gels of Different Crosslink Density Analyzed by X-ray Computed Tomography and X-ray Diffraction

Water in Sephadex^® (crosslinked dextran) gels is known to indicate different freezing behavior which is dependent on the density of the crosslinks, and water in a Sephadex^® G25 gel remains partially unfrozen during cooling and crystallizes during rewarming. The mechanism of anomalous ice crystallization during rewarming is still unclear. The objective of this study is to observe the ice grains that form in Sephadex^® beads and to comprehend their frozen state with a focus on the ice crystallization during rewarming. Sephadex^® beads containing 50 wt % water were prepared and used for the measurements. The observation of the ice grains was carried out by using synchrotron radiation-sourced X-ray CT (computed tomography). XRD (X-ray diffraction) analysis was also conducted to investigate the frozen state. As a result, ice grains that were larger than ~1 μm were hardly observed after the slow cooling of Sephadex^® beads, except in the G25 beads. However, at the occurrence of ice crystallization during rewarming, ice grains that were larger than 10 μm appeared in the G25 beads. Using XRD, it was found that small incomplete ice crystals were formed in G25 beads and the presence of glassy water was indicated in the gel. In conclusion, the size and distribution of ice grains that formed in Sephadex^® beads were different depending on the density of the crosslinks.

Towards a unified model of neutrino-nucleus reactions for neutrino oscillation experiments

A precise description of neutrino-nucleus reactions will play a key role in addressing fundamental questions such as the leptonic CP violation and the neutrino mass hierarchy through analyzing data from next-generation neutrino oscillation experiments. The neutrino energy relevant to the neutrino-nucleus reactions spans a broad range and, accordingly, the dominant reaction mechanism varies across the energy region from quasi-elastic scattering through nucleon resonance excitations to deep inelastic scattering. This corresponds to transitions of the effective degree of freedom for theoretical description from nucleons through meson-baryon to quarks. The main purpose of this review is to report our recent efforts towards a unified description of the neutrino-nucleus reactions over the wide energy range; recent overall progress in the field is also sketched. Starting with an overview of the current status of neutrino-nucleus scattering experiments, we formulate the cross section to be commonly used for the reactions over all the energy regions. A description of the neutrino-nucleon reactions follows and, in particular, a dynamical coupled-channels model for meson productions in and beyond the [Formula: see text](1232) region is discussed in detail. We then discuss the neutrino-nucleus reactions, putting emphasis on our theoretical approaches. We start the discussion with electroweak processes in few-nucleon systems studied with the correlated Gaussian method. Then we describe quasi-elastic scattering with nuclear spectral functions, and meson productions with a [Formula: see text]-hole model. Nuclear modifications of the parton distribution functions determined through a global analysis are also discussed. Finally, we discuss issues to be addressed for future developments.

Different views on treatment decisions by first-year interprofessional healthcare students

This study explored ethical treatment decisions of healthcare professional students beginning their education. As part of a first-semester modern medicine and bioethics course, 311 students watched and discussed, in interprofessional groups, a video titled Dax's Case: Who Should Decide? regarding the treatment of a life-threatening infectious disease against Dax's wish. The students then discussed and made their decision regarding treating or not. Their decisions, recorded on a worksheet, were classified as "will treat" or "won't treat." Professional groups' decision patterns were compared using the chi-square test. Overall, 151 (71%) opinions from students were classified as "will treat," and 61 (29%) as "won't treat." Nursing students were more likely to decide "won't treat" (in line with Dax's preference); however, the majority of other professions' students favoured treatment (against Dax's wish). Given the students' limited exposure to profession-specific education, our preliminary study supports the notion that healthcare profession students hold different values that align with their chosen profession at the start of their studies.

Potentially inappropriate medications in elderly Japanese patients: effects of pharmacists' assessment and intervention based on Screening Tool of Older Persons' Potentially Inappropriate Prescriptions criteria ver.2

WHAT IS KNOWN AND OBJECTIVES

The Screening Tool of Older Persons' Potentially Inappropriate Prescriptions (stopp) criteria were updated in 2014 (stopp criteria ver.2), but few studies have evaluated the usefulness of stopp criteria in elderly patients. This prospective observational study evaluated the prevalence of potentially inappropriate medications (PIMs), and the efficacy of hospital pharmacists' assessment and intervention based on stopp criteria ver.2.

METHODS

The study was conducted at three medical units of Kobe University Hospital between April 2015 and March 2016. Pharmacists assessed and detected PIMs based on stopp criteria ver.2 and considered the patient's intention to change the prescription at the time of admission of each patient. If the pharmacists judged that benefits outweighed risks of prescription change and the patients consented to change the medications, they recommended the doctor to change the prescription. If there was a risk of exacerbation of disease by the change of medications and the pharmacists judged it to be difficult to adjust medications during hospitalization or the patients did not consent to change the medications, they did not recommend to change it. The pharmacists and the doctors discussed and finally decided whether to change the PIMs or not. The number of patients prescribed PIMs, the number and contents of PIMs, and the number of medications changed after pharmacists' intervention were calculated.

RESULTS

Totally, 822 new inpatients aged ≥65 years prescribed ≥1 daily medicine were included. Their median (interquartile range) age was 75·0 (71·0-80·0) years, and 54·9% were male. According to the criteria, 346 patients (42·1%) were prescribed ≥1 PIMs. Patients prescribed PIMs took significantly more medications than others: 10·0 (7·0-13·0) vs. 6·0 (4·0-9·0), P < 0·001. The total number of PIMs was 651%, 47·6% of which (n = 310) were recommended the doctors to change, and 292 of 651 PIMs (44·9%) were finally discontinued/changed after pharmacists' assessment and intervention. PIMs related to benzodiazepines, including Z-drugs, were most frequent, with a detailed classifications as follows (changed/total): (i) benzodiazepines for 4 or more weeks (75/205), (ii) drugs that predictably increase the risk of falls in older people (benzodiazepines) (30/67) and (iii) drugs that predictably increase the risk of falls in older people (hypnotic Z-drugs) (15/31).

CONCLUSION

Over 40% elderly patients were prescribed PIMs, and pharmacists' assessments and interventions based on stopp criteria ver.2 were useful in detecting and correcting prescription of PIMs.

Intact attentional orienting towards inverted faces revealed by both manual responses and eye-movement measurement in individuals with Williams syndrome

BACKGROUND

Individuals with Williams syndrome (WS) exhibit atypical attentional characteristics when viewing faces. Although atypical configural processing of faces has been reported in WS, the relative strengths of configural and local feature information to capture visual attention in WS remains unclear. We previously demonstrated that attentional capture by target-unrelated upright faces differs depending on what response is measured. Whereas eye movements reflected subtle atypical attentional properties at the late stage of visual search, manual responses could not capture the atypical attentional profiles towards target-unrelated upright faces in individuals with WS. Here we used the same experimental paradigm to assess whether sensitivity to configural facial information is necessary for capturing attention in WS.

METHODS

We measured both eye movements and manual responses from 17 individuals with WS and 34 typically developing children and adults while they were actively involved in a visual search task with an inverted face distractor. Task measures (reaction time and performance accuracy) and gaze behaviour (initial direction of attention and fixation duration) were analysed for each stimulus.

RESULTS

When the target and the inverted face were displayed in the same search array, reaction times and accuracies in individuals with WS showed similar tendencies as typical controls. Analysis of task and gaze measures revealed that attentional orienting towards inverted faces was not atypical.

CONCLUSION

Although individuals with WS exhibited atypical gaze behaviour towards upright faces in our previous study, this unusual behaviour disappears if the faces are upside down. These findings suggest that local feature information alone (e.g. eyes) does not contribute to the heightened attention to faces, but configural information appears necessary for drawing attention to faces in individuals with WS, at least in the current experimental paradigm.

Changes in Interface Pressure under Elastic and Short-Stretch Bandages during Posture Changes and Exercise

Objective:

To evaluate the pressure under short-stretch and elastic bandages.

Design:

Prospective study in 20 healthy volunteers, comparing the two different kinds of bandages.

Setting:

Department of Surgery, Aichi Prefectural College of Nursing, Nagoya, Japan.

Main outcome measures:

Pressure measurements were made beneath the bandages with different initial pressures of 10, 20, 30, 40, 50, 60, and 70 mmHg, during supine resting, standing, tip-toe exercise and walking.

Results:

Short-stretch bandages showed a significant increase in pressure during standing and exercise at lower initial pressures compared with elastic bandages. In analysing the pressure waveform during tip-toe exercise and walking, a significantly greater pressure difference between muscle contraction and relaxation was noted for short-stretch bandages compared with elastic bandages at any initial pressures.

Conclusions:

Short-stretch bandages produce a higher working pressure and a larger pressure difference during exercise. However, the effect depends on the initial pressures at the time of application. In clinical practice, prevention of a decrease in pressure with time and uniform application of bandages are important.

Clinical Significance of Corona Phlebectatica Associated with Varicose Veins

Objective:

To investigate the clinical significance of corona phlebectatica.

Design:

Clinical and plethysmographic evaluation of corona phlebectatica associated with primary varicose veins.

Setting:

Department of Surgery, Aichi Prefectural College of Nursing, Nagoya, Japan.

Main outcome measures:

In 411 limbs with greater saphenous incompetence, including 101 with skin changes and 310 without skin changes, clinical analysis and plethysmographic evaluation using the photoplethysmographic technique were carried out.

Results:

In 204 of 411 limbs, corona phlebectatica was observed, including 75 coloured red and 129 coloured blue. Blue coronas were observed significantly more often then red coronas in limbs with skin changes. The half refilling time in limbs with skin changes was significantly shorter than that in limbs without skin changes. In limbs without skin changes, limbs with blue coronas showed a significantly shortened half refilling time than those with red coronas.

Conclusions:

Blue coronas are a strong indicator of the presence of prolonged venous hypertension in varicose veins.

Interface Pressure under Elastic Stockings with Compression Pads during Posture Changes and Exercise

Objective:

To quantify the influence of posture and exercise on the interface pressure obtained under elastic stockings with compression pads.

Design:

Interface pressure measurement and plethysmographic evaluation of elastic stockings with and without compression pads.

Setting:

Department of Surgery, Aichi Prefectural College of Nursing, Nagoya, Japan.

Main outcome measures:

Pressure measurements in 24 volunteers were obtained beneath elastic stockings, elastic bandages and short-stretch bandages during supine resting, standing, tip-toe exercise and walking, and the effect of elastic stockings on the muscle pump of the leg was evaluated by strain-gauge plethysmography in 40 limbs with varicose veins.

Results:

Without compression pads, only short-stretch bandages showed a significant increase in pressure during standing and exercise. When pads were used, however, elastic stockings and bandages also showed a significant increase. With pads, significant improvement in the expelled volume during exercise was observed by strain-gauge plethysmography.

Conclusions:

Interface pressure under elastic materials during posture and exercise is similar to that under short-stretch bandages when compression pads are used, and pads effectively augment the muscle pump.

A comparison of physical methods for prophylaxis of deep vein thrombosis on augmentation of venous flow velocity and reduction of calf volume

Objective: This study was designed to determine the optimal physical methods for promoting venous return of the leg.

Methods: Ten healthy volunteers were investigated in the supine position on a couch, and their peak femoral venous velocity and calf muscle volume were determined using duplex ultrasound and strain gauge plethysmography,respectively,before and during deep respiration, limb elevation, calf squeezing and various types of leg exercises.

Results: Deep respiration showed the smallest effect on both percentage increase of peak flow velocity and expelled volume. Elevation of the leg showed the same effect on the expelled volume as calf muscle squeezing and ankle movement, while the former showed significantly less effect than the latter on the percentage increase of peak flow velocity. In both dorsal flexion of the ankle and squeezing at the calf, the stronger of each procedure caused more effective changes in haemodynamics. Ankle exercise was more effective in promoting venous return in the calf muscle than wiggling the toes, making circling movements with the feet or alternately flexing and spreading the toes.

Conclusions: Ankle exercise or calf muscle squeezing, performed maximally,may be the first recommendation for reducing venous stasis at the calf muscle and prophylaxis of deep vein thrombosis..

Effect of protein-encapsulation on thermal structural stability of liposome composed of glycosphingolipid/cholesterol/phospholipid

We have studied the thermal structural stability of liposomes encapsulating proteins by using synchrotron radiation small- and wide-angle X-ray scattering (SR-SWAXS). Liposomes are known to be effective drug-delivery systems (DDSs) because they can reduce drug toxicity due to biodegradability and biocompatibility and can offer promising carriers of various types of drugs. However, in spite of numerous studies of liposomes, physicochemical characteristics of liposomes entrapping proteins are rarely known. The liposome studied is characterized by the lipid composition (mixture of acidic glycosphingolipid (ganglioside)/cholesterol/phospholipid). Gangliosides are one of the major constituents of so-called lipid rafts playing the role of a platform of cell-signaling. We have found that the encapsulation of proteins elevates the thermal transition temperature of the liposome membrane and suppresses the deformation of its shape. The present results suggest that not only membrane proteins, but also water-soluble proteins affect liposome stability through the revalence between osmotic pressure and membrane elasticity. In addition, we have found the presence of the size-effect depending on the molar content of gangliosides in the liposome, indicating the ability of ganglioside molecule controlling both the size and effective surface charge of the liposome. The present results would have significance from two different points of view. One is the confinement effect of proteins within a limited space like cell, and the other is a stability of a new type of DDS using gangliosides. Due to the intrinsic properties, gangliosides are expected to be promising agents for targeting and long-circulation properties of liposomal DDSs.

ASAXS measurements with soft (tender) X-rays to control the contrast

The structure and properties of thin soft matter materials might be better examined in detail by scattering measurements when the contrast between the materials and penetration depth are tunable. In the so-called tender X-ray region, there are several elements of interest for small-angle scattering measurements, such as Mg, Al, Si, P, and S. We worked on GISAXS measurements at K absorption edges of Si and P to control contrast and penetration depth for thin block copolymer (SEBS) samples and phospholipid alloy systems comprising of phospholipid (PC, DPPC), cholesterol, and ganglioside, and SAXS at Al for Al alloys. The photon energy used in the present measurements is soft enough to give large anomalous effect in the real part of refractive indices for light elements, yet hard enough so that the scattering vector required for nanostructure analysis can be covered. By choosing the photon energy at the K absorption edge of Si, the contrast between Si substrate and polymer thin film can be suppressed, thereby suppressing dynamical effect in GISAXS intensity caused by reflected beam[1]. Combined with the depth sensitive analysis, this is useful to examine the nanostructures that are changing with the distance from the surface. Concerning the contrast change inside the thin films, change of the GISAXS intensities from PC (phosphatidylcholine)-cholestrol-ganglioside (GD1) films spin-cast on Si substrates have been examined at the K absortpion edge of P [2]. ASAXS for P has been examined by Stuhrmann and coworkers[3], but the number of works after them is not large. Present measurements using image plates showed that the hexagonal phase appearing in dried phospholipid alloy films suggests a contrast reversal with the photon energy.

Conformational characterization of a protein complex involving intrinsically disordered protein by small-angle neutron scattering using the inverse contrast matching method: a case study of interaction between α-synuclein and PbaB tetramer as a model chaperone

Cumulative genomics and proteomics data have now highlighted the presence of intrinsically disordered proteins (IDPs), which are devoid of stable secondary or tertiary structures under physiological conditions. While the flexible nature of IDPs precludes their study by crystallographic methods, IDP interactions with their cognate proteins, during which the IDPs often form their secondary structures, have been characterized by nuclear magnetic resonance (NMR) spectroscopy. In view of this, a complementary small-angle neutron scattering (SANS) technique has been developed for probing IDP conformations in larger protein complexes. As a model interaction system, α-synuclein (αSN) bound to an archaeal homotetrameric chaperone, PbaB, was analyzed. To selectively observe the SANS profile of αSN in the complex, the bacterially produced PbaB was fractionally (75%) deuterated using D2O and deuterated glucose for contrast matching to approximately 100% D2O solvent. By employing 75%-deuterated PbaB, the conformational changes of αSN upon capture by this tetrameric chaperone were successfully observed with minimal background scattering. Together with the present NMR data, the SANS data reveal that the PbaB tetramer grasps the N-terminal segments of αSN, disrupting the residual ordered structure in this region, while leaving the remaining regions flexible within a slightly reduced conformational space.

Structure of liposome encapsulating proteins characterized by X-ray scattering and shell-modeling

Lipid liposomes are promising drug delivery systems because they have superior curative effects owing to their high adaptability to a living body. Lipid liposomes encapsulating proteins were constructed and the structures examined using synchrotron radiation small- and wide-angle X-ray scattering (SR-SWAXS). The liposomes were prepared by a sequential combination of natural swelling, ultrasonic dispersion, freeze-throw, extrusion and spin-filtration. The liposomes were composed of acidic glycosphingolipid (ganglioside), cholesterol and phospholipids. By using shell-modeling methods, the asymmetric bilayer structure of the liposome and the encapsulation efficiency of proteins were determined. As well as other analytical techniques, SR-SWAXS and shell-modeling methods are shown to be a powerful tool for characterizing in situ structures of lipid liposomes as an important candidate of drug delivery systems.

An automated rapid detection system using the quenching probe method for detecting interleukin 28B and inosine triphosphatase single nucleotide polymorphisms in chronic hepatitis C

Single nucleotide polymorphisms (SNPs) in the interleukin 28B gene (IL28B) are good pretreatment predictors of anti-hepatitis C virus (HCV) therapy with interferon. SNPs of the inosine triphosphatase (ITPA) gene are associated with reduced haemoglobin levels during treatment with ribavirin. The i-densy™ (Arkray, Inc.), which is based on the quenching probe (QP) method, automatically detects target genes in blood samples by fluorescence quenching within 100 min. Using a QP and primer set, a gene amplification response is generated that can quickly and easily detect a specific gene's arrangement by fluorometry. The present study was conducted to compare the utility of i-densy (QP method) with that of conventional direct sequencing (DS) for detecting SNPs in the IL28B and ITPA genes in chronic hepatitis C patients. Between June 2011 and January 2012, 73 consecutive patients underwent genotyping of IL28B, and 54 patients underwent genotyping of ITPA. All of the patients were seropositive for HCV-RNA. The IL28B and ITPA genotypes were tested for bi-allelic polymorphisms in rs8099917 (T/T, T/G and G/G; minor allele, G) and rs1127354 (C/C, C/A and A/A; minor allele, A), respectively. The results obtained with the QP method were identical to those obtained with the conventional DS method. The frequency of the IL28B genotypes TT, GT and GG were 74%, 24.7% and 1.4%, respectively, and those of the ITPA genotypes CC, AC and AA were 68.5%, 29.6% and 1.9%, respectively. These results indicate that the i-densy using the QP method can automatically, quickly and easily identify genotypes of IL28B and ITPA.

Effect of gaiters on muscle pump activity in healthy volunteers

OBJECTIVES

Exercise of the leg with external limb compression has been reported to be useful for preventing and reducing leg oedema. The aim of this study was to investigate the effects of leg gaiters on calf muscle pump activity.

METHODS

Continuous measurements of the interface pressure at the leg during exercise and determination of the femoral venous velocity at the groin during exercise were carried out in healthy volunteers with elastic stockings alone, leg gaiters alone and gaiters over the elastic stockings.

RESULTS

The greatest pressure difference between muscle contraction and relaxation during exercise was observed when gaiters were applied over the elastic stockings at the calf. Gaiters alone without elastic stockings led to a significantly greater pressure difference between muscle contraction and relaxation during exercise than elastic stockings alone (P < 0.01). A significantly higher value of the peak flow velocity of the femoral vein was observed with the combined use of gaiters and elastic stockings than the single use of elastic stockings.

CONCLUSIONS

Leg gaiters have a beneficial effect of augmenting venous femoral blood flow during calf muscle pump activity in volunteers with a normal valve function of leg veins.

Interface pressure is affected by slippage of bandages at thigh

AIM

Very little is known about how compression bandages lose interface pressure. We hypothesized that the loss of interface pressure is correlated with the slippage of the bandages, and studied the interface pressure and slippage of three bandages over 8 hours.

METHODS

Twenty-Seven legs from 27 healthy volunteers were bandaged with short stretch bandages (SS), cohesive short stretch bandages (CS), and long stretch bandages (LS). Pressure sensors were placed above the ankle (B1), below the knee (D), and mid thigh (F). Interface pressures in a sitting position were recorded at the beginning, and 4 and 8 hours later. In 17 legs, the pressure sensor sites were marked, and their heights were measured on standing upright.

RESULTS

SS and CS lost interface pressure quickly, but LS maintained pressure better than SS and CS at all sites. There was no pressure difference between SS and CS at the lower leg. However, CS maintained pressure better than SS at the mid thigh (44.6% vs. 54.4% pressure loss at 8 hours, respectively. P=0.037). There was a tendency toward less slippage with CS than SS at the mid thigh. In CS and LS, there was a linear correlation between the slippage of bandages and the interface pressure at the mid thigh (P <.01, in both).

CONCLUSION

The interface pressure may be affected by the slippage of bandages at the thigh, but not at the lower leg. Cohesive short stretch bandages may exert their beneficial impact at the thigh.

Development of separated elastic stockings

Objectives

To investigate the acceptability of newly developed separated elastic stockings, which are divided into two portions at the ankle.

Methods

The difficulty in putting on and taking off stockings was compared between the original or modified separated stockings with various techniques in order to reduce the shift of the stockings and current non-separated stockings in healthy volunteers and patients with lymphoedema by applying both stockings alternately. In the modified model, the shift during daily activities was measured in healthy volunteers and patients with lymphoedema.

Results

The two items, ‘easier compared with non-separated stockings’ and ‘much easier’, were chosen at rates of 75% and 81% for putting on and taking off stockings for the original separated stockings and 75% and 75% for the modified separated stockings, respectively. Complaints during daily activities with the modified type to the stockings decreased as compared with the original type. The shift of stockings after an average 11-hour application was 1.6 ± 3.0 SD mm (range: 0–10 mm).

Conclusions

Modified separated elastic stockings are easier to put on and take off compared with current non-separated stockings, and they can be used safely because of their low-level shift during daily activities.

Interface pressure and stiffness in different combinations of compression material

Objectives

To compare the interface pressure and stiffness between various combinations of compression material.

Methods

Using a stiffness-determining device, the interface pressure and stiffness were determined in several combinations of five elastic stockings and two elastic bandages.

Results

In the double stockings system, the interface pressure increased significantly and the highest stiffness was observed in double short-stretch stockings. When short-stretch bandages were applied over either short- or long-stretch stockings, a significant increase in stiffness was observed at any initial pressure compared with the single use of short-stretch stockings. In double bandage systems, when short-stretch bandages were applied over either short- or long-stretch bandages, the stiffness increased significantly. When long-stretch bandages were used over short-stretch bandages, the stiffness decreased significantly.

Conclusions

The stiffness is changeable according to the combinations of material, such as double stockings, double bandages and the wearing of bandages over stockings. The use of short-stretch bandages as the outside layer produces the highest stiffness at a high initial pressure.

Development of a device to determine the stiffness of elastic garments and bandages

Objective

To evaluate the reliability of a newly developed stiffness-determining device, composed of a leg mannequin and air-pack type analyser, for measuring the interface pressure.

Method

The correlation of stiffness values obtained employing the Hohenstein method and this new method was investigated using 17 different brands of medical elastic compression stocking.

Results

A significant correlation in stiffness values using the two methods was obtained ( P < 0.01). When this new method was applied to the bandages, the stiffness was significantly correlated with the initial pressure when assessing both short-stretch and long-stretch bandages. On the comparison of stiffness values between elastic stockings and bandages with the same initial pressure, the short-stretch bandages showed a predominantly higher value than long-stretch bandages and stockings ( P < 0.01).

Conclusion

The reliability of this new method, which can be easily applied to not only elastic stockings but also elastic bandages, was verified. In clinical practice, the compression pressure should be selected in consideration of the prospective stiffness.

Improvement of a three-dimensional measurement system for the evaluation of foot edema

BACKGROUND/AIMS

This study investigated the accuracy and usefulness of a newly improved three-dimensional measurement system for measuring the volume and circumference at the foot as well as at the calf and ankle.

METHODS

Regarding the newly improved device, halogen light was projected from four directions instead of the conventional two directions. The circumference and volume were measured in the morning and evening with and without elastic stockings in 23 healthy subjects.

RESULTS

The average circumference at the foot calculated using the 'average method', in which the circumference of the foot was measured in 10 places every 1 mm and the values were averaged, significantly increased in the evening compared with in the morning. When stockings were applied, the significant differences in the circumference or volume between the morning and evening disappeared at all sites of the leg.

CONCLUSION

The newly improved three-dimensional measurement system incorporating the halogen light from four directions, in which the foot circumference was calculated using an 'average method', was reliable and useful for evaluating edema at the foot as well as at the calf and ankle. The beneficial effect of elastic stockings on edema prevention was observed at all sites of the leg.