Predictive factors for walking in acute stroke patients: a multicenter study using classification and regression tree analysis.

[Purpose] Walking ability should be predicted as early as possible in acute stroke patients. The purpose is to construct a prediction model for independent walking from bedside assessments using classification and regression tree analysis. [Participants and Methods] We conducted a multicenter case-control study with 240 stroke patients. Survey items included age, gender, injured hemisphere, the National Institute of Health Stroke Scale, the Brunnstrom Recovery Stage for lower extremities, and "turn over from a supine position" from the Ability for Basic Movement Scale. The National Institute of Health Stroke Scale items, such as language, extinction, and inattention, were grouped under higher brain dysfunction. We used the Functional Ambulation Categories to classify patients into independent (four or more the Functional Ambulation Categories; n=120) and dependent (three or fewer the Functional Ambulation Categories; n=120) walking groups. A classification and regression tree analysis was used to create a model to predict independent walking. [Results] The Brunnstrom Recovery Stage for lower extremities, "turn over from a supine position" from the Ability for Basic Movement Scale, and higher brain dysfunction were the splitting criteria for classifying patients into four categories: Category 1 (0%), severe motor paresis; Category 2 (10.0%), mild motor paresis and could not turn over; Category 3 (52.5%), with mild motor paresis, could turn over, and had higher brain dysfunction; and Category 4 (82.5%), with mild motor paresis, could turn over, and no higher brain dysfunction. [Conclusion] We constructed a useful prediction model for independent walking based on the three criteria.

Effects of diagonally aligned sitting training with a tilted surface on sitting balance for low sitting performance in the early phase after stroke: a randomised controlled trial.

PURPOSE: To clarify the effects of diagonally aligned sitting training using a tilted surface on sitting balance for patients with low sitting performance in the early phase after stroke. MATERIALS AND METHODS: This was an assessor-blinded randomised controlled trial. The experimental group used a surface tilted 10° backward and down toward the most affected side; the control group trained on a horizontal surface. Both groups were asked to move their trunk diagonally forward toward the least affected side. Participants performed the activity 40 times/session for seven sessions over 8 days. Sitting performances were assessed using the function in sitting test (FIST), subjective postural vertical (SPV) on the diagonal plane, and trunk impairment scale (TIS). RESULTS: Thirty-three stroke patients were randomly allocated into two groups. Treatment effects differed significantly: mean differences between groups for FIST (total score, static, dynamic, scooting, and reactive) were 8.96, 2.35, 3.01, 1.27, and 1.72 points, for the mean SPV value was 1.82°, and for the TIS (total score and static) were 1.87 and 1.58 points, respectively. These results were more favourable in the experimental group. CONCLUSIONS: Diagonally aligned sitting training on a tilted surface improves sitting balance and modulates the SPV compared with a horizontal surface.

Effects of performing a lateral-reaching exercise while seated on a tilted surface for severe post-stroke pusher behavior: A case series.

Background: For patients with severe post-stroke pusher behavior (PB), acquiring a vertical posture involves correcting paretic-sided body tilt to the non-paretic side. Active lateral sitting training may facilitate improvement in postural orientation for patients with PB. However, its effect on patients with severe PB remains unclear.Objective: To determine the effect of performing a lateral-reaching exercise in patients with severe PB seated on a tilted surfaceMethods: Three patients with severe PB due to right hemispheric stroke participated in our study. Using a single-case design, the intervention's effect was verified using the applied behavior analysis method. Conventional physical therapy was performed for 1 h at baseline and at follow-up. During the intervention, lateral sitting training on a tilted surface was performed 40 times per session (total, 2 sessions). PB was assessed using the Scale for Contraversive Pushing and the Burke Lateropulsion Scale, and patient-reported fear of falling. The Function in Sitting Test (FIST) and the Trunk Control Test (TCT) were administered.Results: PB improved in all patients post-intervention and persisted at follow-up. Fear of falling during the passive sitting task while moving toward the non-paretic side disappeared post-intervention and at follow-up. FIST and TCT scores improved in 2 patients.Conclusion: The lateral sitting exercise reduced severe PB in all patients; however, sitting balance and trunk performance did not improve in 1 patient. Future studies to examine the adaptability of this task and long-term effects are needed.

Factors Influencing Sitting Ability During the Acute Post-Stroke Phase: A Multicenter Prospective Cohort Study in Japan.

OBJECTIVES: Sitting ability during the acute phase after stroke is a useful indicator of functional outcomes; however, factors that affect this ability have not been evaluated. Therefore, this study aimed to identify and evaluate factors that affect sitting ability in the acute phase after stroke. MATERIALS AND METHODS: This multicenter prospective cohort study included hemispheric stroke patients who underwent an inpatient rehabilitation program after acute stroke from five acute care hospitals. The effect of age, sex, lesion side, etiology, consciousness disorder, stroke and dementia history, stroke-related complications, National Institutes of Health Stroke Scale score, hemiparalysis, turn-over movement from the supine position and sit-up movement, and Scale for Contraversive Pushing on the "remain sitting" item in the revised version of the Ability of Basic Movement Scale at the time of acute hospital discharge were investigated. Factors affecting sitting ability were identified using binomial logistic regression analysis. RESULTS: We included 293 stroke patients. Age (odds ratio: 0.943, 95% confidence interval: 0.910-0.977, p=0.001), National Institutes of Health Stroke Scale score (odds ratio: 0.862, 95% confidence interval: 0.811-0.916, p<0.001), and Scale for Contraversive Pushing score (odds ratio: 0.543, 95% confidence interval: 0.419-0.705, p<0.001) were identified as independent predictors of sitting ability at the time of hospital discharge (median; 23.0 days). CONCLUSIONS: Older patients and those with high Scale for Contraversive Pushing and National Institutes of Health Stroke Scale scores experienced difficulties in regaining sitting ability. These results may guide physical therapy for patients with impaired sitting ability due to hemispheric stroke.

Starting position effects in the measurement of the postural vertical for pusher behavior.

Pusher behavior (PB) is a severe lateral postural disorder that involves a disturbed subjective postural vertical (SPV) in the frontal plane. SPV is measured by determining the mean value and standard deviation of several trials beginning on both the contralesional- and ipsilesional-tilted positions. However, the postural representation, when passively tilted to the contralesional versus ipsilesional position, is different between patients with and without PB. Therefore, we hypothesized that SPV dependence on the starting position will be influenced by PB. For 53 patients with hemispheric stroke enrolled, SPV was measured using a non-motorized vertical board with eyes closed. The mean value (tilt direction) and standard deviation (variability) were calculated in four trials, each from two positions, with the patient tilted to the contralesional position (SPV-CL condition) and then to the ipsilesional position (SPV-IL condition). Patients were categorized into the non-pusher (n = 29) and pusher (n = 24) groups. In the SPV-CL trials, the tilt direction was significantly tilted contralesionally for the pusher group (- 6.3° ± 1.6°) compared with that for the non-pusher group (- 2.2° ± 1.8°; p < 0.001), with no significant difference in variability between the groups. In the SPV-IL trials, the tilt direction was not significantly different between the groups, but the variability was significantly higher in the pusher group (4.8° ± 2.0°) than in the non-pusher group (2.2° ± 1.3°; p < 0.001). The dependence of tilt direction and variability of SPV on the starting position in patients with PB differed from those noted in patients without PB. These results may help explain this abnormal posture and optimize neurological rehabilitation strategies for PB.

Influence of unilateral spatial neglect on vertical perception in post-stroke pusher behavior.

Pusher behavior (PB) impairs verticality in the frontal plane and is often associated with unilateral spatial neglect (USN). However, it is unclear whether USN affects verticality among patients with PB. We aimed to clarify the characteristics of verticality among PB, with and without USN. The study included 43 patients with right hemisphere stroke, including 12 without PB or USN, 10 with only USN, 10 with PB only, and 11 with PB and USN, and 15 age-matched healthy individuals. The subjective visual vertical (SVV), subjective postural vertical with eyes closed (SPV), and subjective postural vertical with eyes open were assessed. Under each condition, the mean (tilt direction) and standard deviation (variability) across trials were calculated. The variability of SVV was significantly greater among patients with only USN (6.9°±5.9°) or those with PB and USN (7.6 ± 4.3°). On SPV, the contralesional tilt was significantly greater, with higher variability, in patients with only PB (-2.2°±1.1° and 6.3°±1.4°, respectively) and those with PB and USN (-2.1°±2.0° and 6.6°±2.0°, respectively) than in the other groups. In patients with PB, SVV differed depending on the presence of USN, but it was suggested that SPV might not be affected by USN. These findings are important to plan PB treatment.

Test-retest reliability of and age-related changes in the subjective postural vertical on the diagonal plane in healthy subjects.

The subjective postural vertical (SPV) reflects gravity perception when the eyes are closed. Changes in the SPV on both the frontal and sagittal planes occur in response to neurological disorders and aging; however, these changes on the diagonal plane are unclear. Here we examined test-retest reliability (n=16) of and age-related changes (n=38) in the SPV on the diagonal plane. Subjects sat on an electrical vertical board (EVB), which was used to measure the SPV on the diagonal plane. An experimenter controlled and moved the EVB seat at a constant speed on the diagonal plane and measured the seat's tilt using a digital inclinometer when subjects verbally reported that they had reached a true vertical position. Measurement was performed for eight trials, and the mean (tilt direction) and standard deviation (variability) were calculated. To determine test-retest reliability, the same experimenter repeatedly measured the SPV 1 week later. To assess age-related changes, tilt direction and variability were compared between the young (n=20) and elderly (n=18) groups. Test-retest reliability on the right and left diagonal planes was 0.61 or more. Moreover, tilt direction on the right diagonal plane - but not on the left diagonal plane - indicated a significant diagonally backward deviation in the elderly group compared with that in the young group. Variability was significantly higher in the elderly group on both planes. SPV measurement on the diagonal plane was indicated, and age-related changes were identified. Thus, future studies should assess the potential clinical applications of SPV in neurological disorders.

The effects of aging on the subjective vertical in the frontal plane in healthy adults.

[Purpose] To determine age-related differences in the subjective vertical in the frontal plane in healthy adults. [Subjects and Methods] The subjects were 26 healthy adults. For the subjective visual vertical (SVV), subjects were presented with a visual indicator in front of them that was rotated. For the subjective postural vertical-eyes open (SPV-EO) and subjective postural vertical (SPV), subjects sat in a seating device that was tilted right or left. The subjects gave a signal when they perceived true verticality. Each task was performed eight times. The items examined were the mean (tilt direction) and standard deviation (variability) of the eight trials, then the mean of four trials that started from the right or left side position. These items were compared between the young (age: 22-30 years [range]) and elderly (age: 60-74 years) groups. [Results] As for variability, the elderly group demonstrated significantly higher values of SPV-EO and SPV. As for the starting point effect, the elderly group demonstrated greater bias toward the starting direction than did the young group in SPV-EO and SPV in frontal plane. [Conclusion] The postural vertical was shown to change with age. Consideration of age-related changes and the starting point effect was indicated to be important.

Sonographic findings of immunoglobulin G4-related sclerosing sialadenitis.

PURPOSE: We evaluated the sonographic findings of immunoglobulin G4-related sclerosing sialadenitis (IgG4-SS). METHODS: Nineteen patients with IgG4-SS and 12 healthy volunteers (controls) were enrolled. The following sonographic features were evaluated: (1) enlargement of the submandibular gland by measurement of the longitudinal diameter and thickness; (2) the contour texture of the submandibular gland (smooth or rough); (3) the internal echo texture, categorized into three sonographic patterns (homogeneous, multiple hypoechoic nodule, and diffuse hypoechoic); and (4) quantitative color Doppler signaling. RESULTS: The longitudinal diameter and the thickness (mean ± SD) of the submandibular gland were significantly greater in patients than in controls (p = 0.005 and p < 0.001, respectively). Contour roughness was seen in 62.9 and 8.3 % of patients and controls (p < 0.001), respectively. Homogeneous echo textures alone were seen in controls, whereas multiple hypoechoic nodule patterns were seen in 60 % of the patients, and diffuse hypoechoic patterns were seen in 40 %. Color Doppler signaling (mean ± SD) was significantly higher in patients as compared with controls (p < 0.001). CONCLUSION: Patients could be distinguished from healthy volunteers using four distinctive sonographic findings, suggesting that ultrasonography would be a useful diagnostic tool for IgG4-SS.

Comprehensive assessment of impaired peripheral and coronary artery endothelial functions in smokers using brachial artery ultrasound and oxygen-15-labeled water PET.

BACKGROUND: Comprehensive evaluation of endothelium-dependent and endothelium-independent vascular functions in peripheral arteries and coronary arteries in smokers has never been performed previously. Through the use of brachial artery ultrasound and oxygen-15-labeled water positron emission tomography (PET), we sought to investigate peripheral and coronary vascular dysfunctions in smokers. METHODS AND RESULTS: Eight smokers and 10 healthy individuals underwent brachial artery ultrasound at rest, during reactive hyperemia [250mmHg cuff occlusion (flow-mediated dilatation (FMD)], and following sublingual nitroglycerin (NTG) administration. Myocardial blood flow (MBF) was assessed through O-15-labeled water PET at rest, during adenosine triphosphate (ATP) administration, and during a cold pressor test (CPT). Through ultrasound, smokers were shown to have significantly reduced %FMD compared to controls (6.62±2.28% vs. 11.29±2.75%, p=0.0014). As assessed by O-15-labeled water PET, smokers were shown to have a significantly lower CPT response than were controls (21.1±9.5% vs. 50.9±16.9%, p=0.0004). There was no relationship between %FMD and CPT response (r=0.40, p=0.097). Endothelium-independent vascular dilatation was similar for both groups in terms of coronary flow reserve with PET (p=0.19). Smokers tended to have lower %NTG in the brachial artery (p=0.055). CONCLUSIONS: Smokers exhibited impaired coronary endothelial function as well as peripheral brachial artery endothelial function. In addition, there was no correlation between PET and ultrasound measurements, possibly implying that while smokers may have systemic vascular endothelial dysfunction, the characteristics of that dysfunction may be different in peripheral arteries and coronary arteries.

Accurate quantitative measurements of brachial artery cross-sectional vascular area and vascular volume elastic modulus using automated oscillometric measurements: comparison with brachial artery ultrasound.

Increasing vascular diameter and attenuated vascular elasticity may be reliable markers for atherosclerotic risk assessment. However, previous measurements have been complex, operator-dependent or invasive. Recently, we developed a new automated oscillometric method to measure a brachial artery's estimated area (eA) and volume elastic modulus (V(E)). The aim of this study was to investigate the reliability of new automated oscillometric measurement of eA and V(E). Rest eA and V(E) were measured using the recently developed automated detector with the oscillometric method. eA was estimated using pressure/volume curves and V(E) was defined as follows (V(E)=Δ pressure/ (100 × Δ area/area) mm Hg/%). Sixteen volunteers (age 35.2±13.1 years) underwent the oscillometric measurements and brachial ultrasound at rest and under nitroglycerin (NTG) administration. Oscillometric measurement was performed twice on different days. The rest eA correlated with ultrasound-measured brachial artery area (r=0.77, P<0.001). Rest eA and VE measurement showed good reproducibility (eA: intraclass correlation coefficient (ICC)=0.88, V(E): ICC=0.78). Under NTG stress, eA was significantly increased (12.3±3.0 vs. 17.1±4.6 mm(2), P<0.001), and this was similar to the case with ultrasound evaluation (4.46±0.72 vs. 4.73±0.75 mm, P<0.001). V(E) was also decreased (0.81±0.16 vs. 0.65±0.11 mm Hg/%, P<0.001) after NTG. Cross-sectional vascular area calculated using this automated oscillometric measurement correlated with ultrasound measurement and showed good reproducibility. Therefore, this is a reliable approach and this modality may have practical application to automatically assess muscular artery diameter and elasticity in clinical or epidemiological settings.

Reliability of peripheral intraneural microhemodynamics evaluation by using contrast-enhanced ultrasonography.

PURPOSE: The purpose of the study was to validate the reliability of quantitative intraneural enhancement patterns by using contrast-enhanced ultrasonography (CEUS). METHODS: Nine asymptomatic wrists underwent a total of three CEUS examinations each conducted at 1-month intervals. The CEUS enhancement pattern of median nerves was quantitatively evaluated. The area under the time-intensity curve was calculated by placing the regions of interest at the proximal, center, and distal regions of the median nerve. An intra-class correlation coefficient for intra-observer, inter-observer, and inter-examination reproducibility was calculated. RESULTS: The intra- and inter-observer reproducibility was almost perfect. Inter-examination reproducibility of the proximal, center, and distal regions was 0.891, 0.614, and 0.535, respectively. In this study, we found that the reproducibility of the distal and center regions of the median nerve in the carpal tunnel was lower than that of the proximal region. CONCLUSION: High intra-observer, inter-observer, and inter-examination reproducibility of CEUS was obtained in the evaluation of the intraneural enhancement pattern when the region of interest was placed in the proximal region of the median nerve.

Overweight causes left ventricular diastolic asynchrony and diastolic dysfunction: a study based on speckle tracking echocardiography in healthy subjects.

BACKGROUND: Left ventricular (LV) diastolic dysfunction is often observed in healthy subjects and can be a cause of heart failure with preserved ejection fraction (EF). We aimed to investigate the role of LV diastolic asynchrony as a cause of diastolic dysfunction in healthy subjects. METHODS: In 40 healthy subjects, two-dimensional speckle tracking imaging (2DSTI) was performed to measure the peak early diastolic longitudinal strain rates (Esr) of the apical, mid-ventricular, and basal segments of the septum and posterior wall. A mean value of the Esr of the 6 segments (mEsr) was calculated. The time from aortic valve closure to the Esr was measured for each segment, and the standard deviation (SDTEsr) was calculated. The peak global early diastolic strain rate (gEsr) was measured with a region of interest (ROI) on the whole LV myocardium. LV flow propagation velocity (FPV) was measured using conventional Doppler techniques. RESULTS: SDTEsr was not correlated with age, but was significantly correlated with body mass index (BMI) (r = 0.41, p < 0.01). Although no significant correlation was observed between mEsr and FPV, gEsr and SDTEsr significantly correlated with FPV (r = 0.41, p < 0.01; r = -0.54, p < 0.001). As a result of the multiple regression analysis, SDTEsr was the single determinant of FPV. CONCLUSIONS: Diastolic asynchrony, associated with overweight but not with aging, may contribute to diastolic dysfunction in healthy subjects.

Early diastolic mitral annular velocity at the interventricular septal annulus correctly reflects left ventricular longitudinal myocardial relaxation.

AIMS: Early diastolic mitral annular velocity (e') obtained by tissue Doppler imaging (TDI) is widely used to evaluate left ventricular (LV) diastolic function based on the assumption that it reflects myocardial relaxation in the long-axis direction. In this study, we aimed to determine whether or not e' truly reflects early diastolic longitudinal myocardial relaxation, and which is the most useful for evaluating LV diastolic function among e' measured at the interventricular-septal annulus (IS-e'), that measured at the lateral annulus (LW-e') or their mean value (M-e'). METHODS AND RESULTS: IS-e', LW-e', and M-e' were measured using colour TDI in 15 patients with hypertrophic cardiomyopathy, 13 patients with hypertension, and 19 control subjects. Using two-dimensional speckle-tracking imaging, early diastolic myocardial strain rates (SR(E)) were measured for the IS (IS-SR(E)), LW (LW-SR(E)), and entire LV myocardium (G-SR(E)). IS-e' was excellently correlated with IS-SR(E) (r = 0.90, P < 0.001); the correlation was better than that between LW-e' and LW-SR(E) (r = 0.75, P < 0.001). IS-e' and M-e' were well correlated with G-SR(E) (r = 0.88, P < 0.001 and r = 0.86, P< 0.001, respectively) and with LV early diastolic flow propagation velocity (FPV) (r = 0.77, P < 0.001 and r = 0.78, P < 0.001, respectively). The correlations of LW-e' to G-SR(E) (r = 0.80, P < 0.001) and FPV (r = 0.75, P < 0.001) did not reach this level. CONCLUSION: IS-e' well reflected LV longitudinal myocardial relaxation and LV diastolic function, and was found to be more useful in evaluating LV diastolic function than LW-e'.

Development of new functional nanostructures consisting of both DNA duplex and quadruplex.

The sequence specificity of a duplex and the cation dependent self-assembly of a G-quadruplex were combined to design rationally DNA G-quadruplex arrays connected by duplexes.

Angiotensin II receptor blocker, valsartan, increases myocardial blood volume and regresses hypertrophy in hypertensive patients.

BACKGROUND: Although a reduction in myocardial blood volume (MBV), an in vivo index of the myocardial microvasculature, measured by myocardial contrast echocardiography in patients with hypertension (HT), can be demonstrated, it is still unknown whether a decreased MBV can be improved by antihypertensive treatment. METHODS AND RESULTS: Eleven HT patients (mean age 58 years, 7 men) with left ventricular hypertrophy (LVH) and 10 age- and sex-matched normal controls were studied. Harmonic power Doppler images were acquired at end-diastole of every 6(th) beat and MBV was calculated as 10(X/10)x100%, where X (dB) is myocardial contrast intensity minus the contrast intensity of the adjacent intracavity blood pool. Baseline blood pressure (BP) and left ventricular mass index (LVMI) in the HT patients were higher and MBV was lower than in the controls (2.52 +/-0.37% vs 3.31 +/-0.61%, P<0.01). MBV did not correlate with mean BP, but was inversely correlated with LVMI (r=0.61, P<0.01). After treatment with valsartan for 6 months, LVMI significantly decreased and MBV increased (2.72 +/-0.26%, P<0.05 vs baseline) in the patients with HT. There was a significant inverse correlation between the changes in MBV and those of LVMI (r=0.62, P<0.05), but not between MBV and mean BP. CONCLUSIONS: Valsartan, an angiotensin II receptor blocker, corrected the decreased MBV in association with regression of LVH in patients with HT.

Right ventricular diastolic dysfunction in patients with left ventricular hypertrophy: analysis of right ventricular myocardial relaxation using two-dimensional speckle tracking imaging.

BACKGROUND: Although several previous studies have suggested the presence of right ventricular (RV) diastolic dysfunction in patients with hypertrophic cardiomyopathy (HCM) and those with hypertensive left ventricular hypertrophy (HT-LVH), the mechanisms are still unclear. This study aimed to clarify the relationship between the RV global diastolic dysfunction in these patients and the regional myocardial diastolic function, including synchronicity of the interventricular septum and RV free wall. METHODS: In 20 age-matched patients with HT-LVH, 20 patients with HCM and 22 control subjects without pulmonary hypertension, RV isovolumic relaxation time (IRTR) was measured using continuous-wave Doppler echocardiography. The early diastolic peak strain rate (E SR) and time from QRS to E SR (T-E SR) were measured in the apical, mid-ventricular and basal segments of the interventricular septum and RV free wall using two-dimensional speckle tracking imaging (2DST). RESULTS: IRTR was more prolonged both in HT-LVH and in HCM than in the controls. The averaged septal E SR was reduced both in HT-LVH and in HCM (P < 0.0001, respectively), but the averaged RV free wall E SR was decreased only in HCM (P = 0.0007). E SR averaged for six septal and RV free wall segments was correlated with IRTR (r = -0.46, P = 0.0001). Neither intergroup difference nor correlation with IRTR was observed in a coefficient of variation of T-E SR for the six segments. CONCLUSIONS: RV global diastolic function is impaired in patients with HT-LVH and HCM due to relaxation abnormalities, not an asynchrony, of the myocardium surrounding the RV cavity. The detection of RV free wall relaxation abnormality using 2DST may be useful to differentiate HCM from HT-LVH.

N-terminal region of ZW10 serves not only as a determinant for localization but also as a link with dynein function.

ZW10 interacts with dynamitin, a subunit of the dynein accessory complex dynactin, and functions in termination of the spindle checkpoint during mitosis and in membrane transport between the endoplasmic reticulum (ER) and Golgi apparatus during interphase. Its associations with kinetochores and ER membranes are mediated by Zwint-1 and RINT-1, respectively. A previous yeast two-hybrid study showed that the C-terminal region of ZW10 interacts with dynamitin, and part of this region has been used as an inhibitor of ZW10 function. In the present study, we reinvestigated the interaction between ZW10 and dynamitin, and showed that the N-terminal region of ZW10 is the major binding site for dynamitin and, like full-length ZW10, could potentially move along microtubules to the centrosomal area in a dynein-dynactin-dependent manner. Competitive binding experiments demonstrated that dynamitin and RINT-1 occupy the same N-terminal region of ZW10 in a mutually exclusive fashion. Consistent with this, over-expression of RINT-1 interfered with the dynein-dynactin-mediated movement of ZW10 to the centrosomal area. Given that the N-terminal region of ZW10 also interacts with Zwint-1, this region may be important for switching partners; one partner is a determinant for localization (kinetochore and ER) and the other links ZW10 to dynein function.

Development of molecular logic gates using the structural switch of telomere DNAs.

Telomere DNAs consisting of double-stranded G-rich and C-rich sequences are particularly promising as scaffolds for molecular devices because they form high-ordered structures and have a highly polymorphic nature depending on surrounding factors. Based on the structural polymorphism of telomere DNAs, excellent molecular devices such as molecular motors and switches have been reported. Here we found that the dynamic structural conversion of telomere DNAs can be controlled by both monovalent cations (M(+)) and pH (H(+)). Based on this conversion, we propose a new concept of molecular logic gates in response to the surrounding conditions (M(+) and H(+)) with fluorescence intensity changes as the output signal.