Ultraconformable Capacitive Strain Sensor Utilizing Network Structure of Single-Walled Carbon Nanotubes for Wireless Body Sensing

Capture and real-time recording of precise body movements using strain sensors provide personal information for healthcare monitoring and management. To acquire this information, a sensor that conforms to curved irregular surfaces, including biological tissue, is desired to record complex body movements while acting like a second skin to avoid interference with the movements. In this study, we developed a thin-film-type capacitive strain sensor that is flexible and stretchable on the surface of a living body. We fabricated conductive polymeric ultrathin films ("nanosheets") comprising polystyrene-block-polybutadiene (SB) elastomers and single-walled carbon nanotubes (SWCNTs) (i.e., SWCNT-SB nanosheets) via gravure coating; the SWCNT-SB-coated nanosheets were used as the flexible electrode in a capacitive strain sensor. The dielectric (DE) layer was then prepared using the silicone elastomer Ecoflex 00-30 because its Young's modulus is comparable to that of the epidermis. The normalized capacitance changes (ΔC/C0) in the sensor increased with increasing tensile strain over a range from 0-100%, indicating that the proposed sensor can measure the strain of biological movements, including those of skin and blood vessels. To improve sensor conformability further, the effect of sensor thickness on the gauge factor (GF) was investigated using thinner DE layers by focusing on their flexural rigidity. As a result, the GF increased from 0.64 to 1.13 as the DE layer thickness decreased from 260 to 40 μm. Finally, we evaluated the fabricated sensor's signal stability and mechanical durability, including during wireless sensing when applied to human skin and a vascular model. The ΔC/C0 values varied in response to the bending motion of a finger, dilation of a blood vessel, and the swallowing movement of the throat. These results indicate that our capacitive strain sensor is conformable and functional on biological tissue to enable monitoring of dynamic biological movements (e.g., pulse rate and arterial dilation) without wearer discomfort.

Flexible Electrohydrodynamic Fluid-Driven Valveless Water Pump via Immiscible Interface

The conventional electrohydrodynamic (EHD) pump is limited to pumping functional and dielectric liquids, which restricts its applications in fields like microfluidics, food safety, and materials production. In this study, we present a flexible water pump driven by EHD fluid, achieved by integrating valveless elements into the fluidic channel. Our approach leverages the water-EHD interface to propel the immiscible aqueous liquid and reciprocate this process using the nozzle-diffuser system. All components of the water pump are digitally fabricated and assembled. The valveless parts are created using a laser cutting machine. Additionally, we develop a model for the EHD pump and nozzle-diffuser system to predict the generated flow rate, considering factors such as the asymmetrical performance of the EHD pump, pulse frequency, applied voltage, and structural parameters. Finally, we experimentally characterize the flow rates of both the EHD pump and water pump and apply the newly developed device to air bubble manipulation and droplet generation. This research broadens the range of specialized liquids pumped by EHD pumps to include other aqueous liquids or mixtures.

Pocketable and Smart Electrohydrodynamic Pump for Clothes

Seamlessly fusing fashion and functionality can redefine wearable technology and enhance the quality of life. We propose a pocketable and smart electrohydrodynamic pump (PSEP) with self-sensing capability for wearable thermal controls. Overcoming the constraints of traditional liquid-cooled wearables, PSEP with dimensions of 10 × 2 × 1.05 cm and a weight of 10 g is sufficiently compact to fit into a shirt pocket, providing stylish and unobtrusive thermal control. Silent operation coupled with the unique self-sensing ability to monitor the flow rate ensures system reliability without cumbersome additional components. The significant contribution of our study is the formulation and validation of a theoretical model for self-sensing in EHD pumps, thereby introducing an innovative functionality to EHD pump technology. PSEP can deliver temperature changes of up to 3 °C, considerably improving personal comfort. Additionally, the PSEP system features an intuitive, smartphone-compatible interface for seamless wireless control and monitoring, enhancing user interaction and convenience. Furthermore, the ability to detect and notify users of flow blockages, achieved by self-sensing, ensures an efficient and long-term operation. Through its blend of compact design, intelligent functionality, and stylish integration into daily wear, PSEP reshapes the landscape of wearable thermal control technology and offers a promising avenue for enhancing personal comfort in daily life.

A DIY Fabrication Approach of Stretchable Sensors Using Carbon Nano Tube Powder for Wearable Device

Soft robotics and wearable devices are promising technologies due to their flexibility. As human-soft robot interaction technologies advance, the interest in stretchable sensor devices has increased. Currently, the main challenge in developing stretchable sensors is preparing high-quality sensors via a simple and cost-effective method. This study introduces the do-it-yourself (DIY)-approach to fabricate a carbon nanotube (CNT) powder-based stretchable sensor. The fabrication strategy utilizes an automatic brushing machine to pattern CNT powder on the elastomer. The elastomer ingredients are optimized to increase the elastomer compatibility with the brushing method. We found that polydimethylsiloxane-polyethyleneimine (PDMS-PEIE) is 50% more stretchable and 63% stickier than previously reported PDMS 30-1. With these improved elastomer characteristics, PDMS-PEIE/multiwalled CNT (PDMS-PEIE/MWCNT-1) strain sensor can realize a gauge factor of 6.2-8.2 and a responsivity up to 25 ms. To enhance the compatibility of the powder-based stretchable sensor for a wearable device, the sensor is laminated using a thin Ecoflex membrane. Additionally, system integration of the stretchable sensors are demonstrated by embedding it into a cotton-glove and a microcontroller to control a virtual hand. This cost-effective DIY-approach are expected to greatly contribute to the development of wearable devices since the technology is simple, economical, and reliable.

Soft Mango Firmness Assessment Based on Rayleigh Waves Generated by a Laser-Induced Plasma Shock Wave Technique

Many methods based on acoustic vibration characteristics have been studied to indirectly assess fruit ripeness via fruit firmness. Among these, the frequency of the ₀S₂ vibration mode measured on the equator has been examined, but soft-flesh fruit do not show the ₀S₂ vibration mode. In this study, a Rayleigh wave is generated on a soft mango fruit using the impulse excitation force generated by a laser-induced plasma shock wave technique. Then, the flesh firmness of mangoes is assessed in a non-contact and non-destructive manner by observing the Rayleigh wave propagation velocity because it is correlated with the firmness (shear elasticity), density, and Poisson's ratio of an object. If the changes in the density and Poisson's ratio are small enough to be ignored during storage, then the Rayleigh wave propagation velocity is strongly correlated to fruit firmness. Here, we measure the Rayleigh wave propagation velocity and investigate the effect of storage time. Specifically, we investigate the changes in firmness caused by ripening. The Rayleigh wave propagation velocity on the equator of Kent mangoes tended to decrease by over 4% in 96 h. The Rayleigh wave measured on two different lines propagated independent distance and showed a different change rate of propagation velocity during 96-h storage. Furthermore, we consider the reliability of our method by investigating the interaction of a mango seed on the Rayleigh wave propagation velocity.

Autonomous oil flow generated by self-oscillating polymer gels

The previously reported gel and polymer actuators require external inputs, such as batteries, circuits, electronic circuits, etc., compared with autonomous motions produced by the living organisms. To realize the spontaneous motions, here, we propose to integrate a power supply, actuators, and control into a single-component self-oscillating hydrogel. We demonstrate self-actuating gel pumps driven by the oscillatory Belousov-Zhabotinsky (BZ) reaction without electronic components. We have developed the volume oscillation of gels synchronized with the BZ reaction (BZ gel). Since the self-actuating gel pumps are driven by chemo-mechanical energy from BZ gels, the self-actuating gel pumps don't require complex wiring designs, energy supply, and assembling. The mechanical work generated by BZ gels is extremely small. We formulated the thermodynamic cycle of BZ gels and maximized mechanical work. We found that pre-stretched BZ gel shows larger mechanical works. We physically separated the BZ gels and working fluid to create practical pumps. By using optimizing mechanical generated by BZ gels, we demonstrated the self-actuating gel pumps that transfer mechanical work through a stretchable elastomer membrane.

A Deformable Motor Driven by Dielectric Elastomer Actuators and Flexible Mechanisms

Soft robots with dynamic motion could be used in a variety of applications involving the handling of fragile materials. Rotational motors are often used as actuators to provide functions for robots (e.g., vibration, locomotion, and suction). To broaden the applications of soft robots, it will be necessary to develop a rotational motor that does not prevent robots from undergoing deformation. In this study, we developed a deformable motor based on dielectric elastomer actuators (DEAs) that is lightweight, consumes little energy, and does not generate a magnetic field. We tested the new motor in two experiments. First, we showed that internal stress changes in the DEAs were transmitted to the mechanism that rotates the motor. Second, we demonstrated that the deformable motor rotated even when it was deformed by an external force. In particular, the rotational performance did not decrease when an external force was applied to deform the motor into an elliptical shape. Our motor opens the door to applications of rotational motion to soft robots.

Large deformation of self-oscillating polymer gel

A self-oscillating gel is a system that generates an autonomous volume oscillation. This oscillation is powered by the chemical energy of the Belousov-Zhabotinsky (BZ) reaction, which demonstrates metal ion redox oscillation. A self-oscillating gel is composed of Poly-N-isopropylacrylamide (PNIPAAm) with a metal ion. In this study, we found that the displacement of the volume oscillation in a self-oscillating gel could be controlled by its being subjected to a prestraining process. We also revealed the driving mechanism of the self-oscillating gel from the point of view of thermodynamics. We observed that the polymer-solvent interaction parameter χ is altered by the redox changes to the metal ion incorporated in the self-oscillating gel. The prestraining process leads to changes in χ and changes in enthalpy and entropy when the self-oscillating gel is in a reduced and oxidized state. We found that nonprestrained gel samples oscillate in a poor solution (χ>0.5) and prestrained gel samples oscillate in a good solution (χ<0.5).

Hemispherical breathing mode speaker using a dielectric elastomer actuator

Although indoor acoustic characteristics should ideally be assessed by measuring the reverberation time using a point sound source, a regular polyhedron loudspeaker, which has multiple loudspeakers on a chassis, is typically used. However, such a configuration is not a point sound source if the size of the loudspeaker is large relative to the target sound field. This study investigates a small lightweight loudspeaker using a dielectric elastomer actuator vibrating in the breathing mode (the pulsating mode such as the expansion and contraction of a balloon). Acoustic testing with regard to repeatability, sound pressure, vibration mode profiles, and acoustic radiation patterns indicate that dielectric elastomer loudspeakers may be feasible.

Effect of 1,25-dihydroxycholecalciferol on the duodenal villi and alkaline phosphatase in the developing chick embryo

Administration of 1,25-(OH)2D3 to developing 14-day chick embryo gave precocious induction of alkaline phosphatase in 20-day chick embryonic duodenum. 1,25-(OH)-2D3-induced alkaline phosphase involved in changes in Km and Vmax values. Furthermore, polyacrylamide gel disc electrophoresis of n-butanol-solubilized alkaline phosphatase from control and 1,25-(OH)2D3-treated chick embryonic duodenum revealed that 1,25-(OH)2D3 involved the transformation of neuraminidase-resistant fast migrating form to the neuraminidase-sensitive faster migrating one. Scanning electron microscopic data showed that the injection of 1,25-(OH)2D3 stimulated the elongation of duodenal microvilli, although there was no effect on the duodenal absorptive epithelial cell height.

Establishment of one-axis vibration test system for measurement of biodynamic response of human hand-arm system

Prolonged exposure to hand-arm vibration (HAV) due to use of hand-held power tools leads to an increased occurrence of symptoms of disorders in the vascular, neurological, and osteo-articular systems of the upper limbs called hand-arm vibration syndrome (HAVS). Biodynamic responses of the hand-arm system to vibration can be suggestive parameters that give us better assessment of exposure to HAV and fundamental data for design of low-vibration-exposure power tools. Recently, a single axis hand-arm vibration system has been installed in the Japan National Institute of Occupational Safety and Health (NIOSH). The aims of this study were to obtain the fundamental dynamic characteristics of an instrumented handle and to validate the performance and measurement accuracy of the system applied to dynamic response measurement. A pseudo-random vibration signal with a frequency range of 5-1,250 Hz and a power spectrum density of 1.0 (m/s2)2/Hz was used in this study. First the dynamic response of the instrumented handle without any weight was measured. After this measurement, the dynamic response measurement of the handle with weights mounted on the handle was performed. The apparent mass of a weight itself was obtained by using the mass cancellation method. The mass of the measuring cap on the instrumented handle was well compensated by using the mass cancellation method. Based on the 10% error tolerance, this handle can reliably measure the dynamic response represented by an apparent mass with a minimum weight of 2.0 g in a frequency range of 10.0 to 1,000 Hz. A marked increase in the AM magnitude of the weights of 15 g and 20 g in frequency ranges greater than 800 Hz is attributed not to the fundamental resonance frequency of the handle with weights, but to the fixation of the weight to the measuring cap. In this aspect, the peak of the AM magnitude can be reduced and hence should not be an obstacle to the biodynamic response measurement of the human hand-arm system. On the basis of the results obtained in this study, we conclude that this hand-arm vibration test system can be used to measure biodynamic response parameters of the human hand-arm system.

Is the degree of fetal hepatosplenomegaly with transient abnormal myelopoiesis closely related to the postnatal severity of hematological abnormalities in Down syndrome?

We present three cases of transient abnormal myelopoiesis associated with trisomy 21 in which hepatomegaly was apparent during the fetal period. In the first case, the fetal hepatosplenomegaly was severe, multiple organ failure occurred in the neonatal period and death ensued at 4 weeks of age. In the second case, the hepatomegaly was moderate, and with conservative treatment in the neonatal period the outcome was good. In the third case, hepatomegaly was mild and improved spontaneously, and the hematological abnormalities required only conservative treatment in the neonatal period. Our experience raises the question of whether fetal hepatosplenomegaly is a predictor of transient myeloproliferative disorder with trisomy 21 and whether the degree of fetal hepatomegaly is a marker for the neonatal severity of hematological abnormalities.

Effects of calcium hydroxide on physical and sealing properties of canal sealers

AIM

To investigate whether Ca(OH)2 in four different agents alters the physical properties (Exp. I) and sealing ability (Exp. II) of root canal sealers.

EXPERIMENT

(Exp. I) Calcipex (Nippon Sika-Yakuhin, Shimonoseki, Japan), Vitapex (Neo-Dental, Tokyo, Japan), Calkyl (Showa Yakuhin, Tokyo, Japan), and Ca(OH)2 were used as Ca(OH)2 agents. Four sealers were tested for flow, working time, setting time, and film thickness: Canals (Showa Yakuhin), Canals-N (Showa Yakuhin), Ketac -Endo (Espe, Seefeld, Germany), and Sealapex (Kerr, Romulus, MI, USA). Each Ca(OH)2 agent was added to 10 vol.% of each sealer, and the mixture and controls without a Ca(OH)2 agent were tested according to ISO specifications. Measurements were compared using Student's t-tests (P < 0.05). (Exp. II) After removing Ca(OH)2 agents applied to the root canals of 100 extracted human teeth, canals were filled with sealer. Controls were filled with each sealer without Ca(OH)2 agents. Sealing ability was evaluated using distance of dye penetration from the apices. Dye penetration data were compared using analysis of variance and post hoc Newman-Keuls test (P < 0.05).

RESULTS

Ca(OH)2 agents influenced the physical properties of the sealers. Flow and setting time met ISO requirements, but film thickness and working time did not. Apical sealing ability of all four sealers was influenced by Ca(OH)2 agents. The sealing ability of Sealapex improved with all Ca(OH)2 agents. The physical and sealing abilities varied among the other sealers.

CONCLUSIONS

Contact with Ca(OH)2 agents left on the canal wall caused considerable changes to the sealing ability of sealers.

Changes in enamel surface roughness and adhesion of Streptococcus mutans to enamel after vital bleaching

OBJECTIVES

The purpose of this in vitro study was to observe the influence of vital bleaching on changes to the enamel surface and adhesion of Streptococcus mutans to tooth enamel.

METHODS

The coronal part of each of 70 extracted third molars was cut in half, with either the buccal or lingual half used for experiments or controls. Experimental halves were assigned to the following conditions: (A) enamel was bleached 1, 3 or 5 times using a bleaching material with or without etching; or (B) etched condition without bleaching. All control samples were kept intact in physiological saline solution. Surface roughness (Ra; roughness center-line average: microm) of enamel was measured for 35 pairs of specimens. TS broth culture medium containing 3% glucose was inoculated with S. mutans and cultured for 72 h before adding the other 35 pairs of specimens. Under scanning electron microscopy, the number of S. mutans colonies was counted and statistically analysed.

RESULTS

Compared to controls, bleached enamel displayed increased colonies of S. mutans. Repeated bleaching further increased bacterial adhesion and maximal colonies counts were found under conditions of five bleaching treatments plus etching (p</=0.01). Compared to controls, roughness increased after etching. However, no linear correlation was found between number of S. mutans colonies and roughness.

CONCLUSION

We conclude that both surface roughness and adhesion of S. mutans to the enamel surface increase after bleaching.

Identification of a novel fusion gene, TTL, fused to ETV6 in acute lymphoblastic leukemia with t(12;13)(p13;q14), and its implication in leukemogenesis

ETS variant gene 6 (ETV6)/translocation, ETS, leukemia (TEL)-involving chromosomal translocations are frequently observed in various hematologic neoplasms. We describe here a novel ETV6-involving translocation, t(12;13)(p13;q14), found in the case of acute lymphoblastic leukemia, in which ETV6 fused with a previously unknown gene, named Twelve-thirteen Translocation Leukemia gene (TTL), at 13q14. TTL was weakly but ubiquitously expressed in normal human tissues as detected by reverse transcribed-PCR. Three TTL splicing forms were identified, TTL-T from a human testis cDNA library, with an open-reading frame of 402 bp encoding 133 amino acids (aa), and TTL-B1 and -B2 from a human brain cDNA library. These proteins have no homology to known proteins. In leukemic cells from the patient, both reciprocal fusion transcripts, ETV6/TTL and TTL/ETV6, were expressed. The predominant fusion transcript, TTL/ETV6-1, encodes a predicted 530 aa fusion protein containing 89 aa of the N-terminal TTL fusing to the helix-loop-helix domain and ETS-binding domain of ETV6. Although the function of TTL is yet to be elucidated, our findings will provide another insight into the molecular pathogenesis of leukemia having ETV6-involving translocations.

Resting energy expenditure among Japanese

1. Resting energy expenditure (REE) provides appropriate basic data for the calculation of energy requirements. 2. The REE of 6498 subjects according to sex and age (1 year stratification), with a minimum of 10 subjects per group, was measured systematically using the easy portable calorimeter (Metavine; Vine, Tokyo, Japan). 3. The REE or the REE/kg according to age and sex was observed to obtain the amount of standard deviation (20-25%). 4. The REE/kg for male and female subjects was maintained at a steady level after the age of 15 years and was estimated to be around 29 kcal/kg.

Intubating laryngeal mask airway size selection: a randomized triple crossover study in paralyzed, anesthetized male and female adult patients

We determined the optimal size of intubating laryngeal mask airway (ILM) for ventilation and blind tracheal intubation in men and women. We also determined the distance the tracheal tube needs to protrude beyond the distal aperture to ensure that the cuff is through the vocal cords. Fifty male and 50 female anesthetized, paralyzed patients (ASA physical status I or II, aged 18-80 yr) were studied. Three operators (A, B, and C) were involved for the purposes of blinding. The size 3, 4, or 5 ILM was inserted into each patient in random order by Operator A, and the quality of ventilation was scored (adequate, suboptimal, or failed) by Operator B. The fiberoptic position (correct, too shallow, or too deep) and the distance between the distal aperture and the vocal cords was determined by Operator B. A single attempt at blind intubation was made by Operator C. Operators B and C were blinded to the size of the ILM. Operator C was also blinded to the information recorded by Operator B. All ILMs were inserted into the laryngopharynx at the first attempt. For men and women, the ventilation score was smaller for the Size 3 than the Size 4 or 5 (all: P < 0.002). For men, correct positioning was less common with the Size 3 than the Size 4 or 5 (both: P < 0.02). For women, correct positioning was similar among sizes. For men, tracheal intubation was successful less frequently with the Size 3 (84%) than the Size 4 (100%) or 5 (98%) (both: P < or = 0.01). For women, tracheal intubation success was similar among sizes (Size 3, 4, and 5: 86%, 96%, and 92%, respectively). Intubation was always successful if the ILM was correctly positioned and always failed if it was too shallow or deep. In both male and female patients, the distance between the distal aperture and the vocal cords increased with increasing ILM size (all: P < 0.04) and patient height (P < 0.0001) and was always longer for men (all: P < 0.0001). The overall mean distance (95% confidence interval) that the tracheal tube needed to protrude was 10-12 cm (8-13 cm) in men and 8-11 cm (8-12 cm) in women. We conclude that for men, the Size 4 and 5 ILMs are better than the Size 3 for ventilation and blind intubation. For women, the Size 4 and 5 ILMs are better than the Size 3 for ventilation, but there is no difference among sizes for blind intubation. The length the tracheal tube must protrude from the distal aperture to ensure that the cuff is completely through the vocal cords is 8-13 cm, depending on ILM size, the tracheal tube size, and the sex and height of the patient.

IMPLICATIONS

For men, the Size 4 and 5 intubating laryngeal mask airways are better than the Size 3 for ventilation and blind tracheal intubation. For women, the Size 4 and 5 are better than the Size 3 for ventilation, but there is no difference among sizes for blind intubation. The length the tracheal tube must protrude from the distal aperture of the intubating laryngeal mask airway to ensure that the cuff is completely through the vocal cords is 8-13 cm, depending on the size of the mask and tracheal tube and on the sex and height of the patient.

Notch1 inhibits differentiation of hematopoietic cells by sustaining GATA-2 expression

Notch signaling is involved in cell fate decisions in many systems including hematopoiesis. It has been shown that expression of an activated form of Notch1 (aNotch1) in 32D mouse myeloid progenitor cells inhibits the granulocytic differentiation induced by granulocyte colony-stimulating factor (G-CSF). Results of the current study show that aNotch1, when expressed in F5-5 mouse erythroleukemia cells, also inhibits erythroid differentiation. Comparison of the expression levels of several transcription factors after stimulation for myeloid and erythroid differentiation, in the presence or absence of aNotch1, revealed that aNotch1 did not change its regulation pattern with any of the transcription factors examined, except for GATA-2, despite its inhibitory effect on differentiation. GATA-2 was down-regulated when the parental 32D and F5-5 were induced to differentiate into granulocytic and erythroid lineages, respectively. In these induction procedures, however, the level of GATA-2 expression was sustained when aNotch1 was expressed. To ascertain whether maintenance of GATA-2 is required for the Notch-induced inhibition of differentiation, the dominant-negative form of GATA-3 (DN-GATA), which acted also against GATA-2, or transcription factor PU.1, which was recently shown to be the repressor of GATA-2, was introduced into aNotch1-expressing 32D (32D/aNotch1) cells that do not express GATA family proteins other than GATA2. Both DN-GATA and PU.1 reversed the phenotype of 32D/aNotch1 inducing its differentiation when G-CSF was added. Furthermore, enforced expression of HES-1, which is involved in Notch signaling, delayed differentiation of 32D, and again this phenotype was neutralized by DN-GATA. These results indicate that GATA-2 activity is necessary for the Notch signaling in hematopoietic cells.

Changes in molecular weight of hyaluronan and hyaluronidase activity in uterine cervical mucus in cervical ripening

BACKGROUND

This study was undertaken to investigate changes in the forms of hyaluronan and hyaluronidase activity in cervical mucus during cervical ripening.

METHODS

Uterine cervical mucus was obtained from 57 pregnant women (25 at preterm gestation, ten at term gestation, 11 within 1 week before labor, and 11 during the first stage of labor). We determined 1) concentration of hyaluronan, 2) hyaluronidase activity, and 3) molecular weight of hyaluronan in cervical mucus. Data are presented as mean and range.

RESULTS

The hyaluronan concentration in mucus in the 1st stage of labor (1.58 microg/ml, 0.46-23.96) was significantly (p<0.05) higher than that in all other groups (preterm: 0.29, 0.10-0.88; term: 0.24, 0.11-0.80; within 1 week before labor: 0.30, 0.18-0.62). Hyaluronidase activity both within 1 week before labor group (3.03 min., 1.12-3.95) and in 1st stage of labor group (3.52, 0.43-5.15) was significantly (p<0.05) higher than that in preterm group (1.70, 0.00-5.47). The molecular weight of hyaluronan in cervical mucus in the 1st stage of labor (0.97x106, 0.86-1.41) was significantly (p<0.05) lower than in the preterm and term groups (preterm: 1.60, 1.21-2.20, term: 1.41, 1.21-2.20). There was a significant correlation between hyaluronidase activity and molecular weight of hyaluronan (p<0.05, r=-0.41, n=23).

CONCLUSION

These findings suggest that either hyaluronidase or low-molecular weight hyaluronan could be one of the most important regulators in the process of cervical ripening.

Calcium concentration and pH of the periapical environment after applying calcium hydroxide into root canals in vitro

The purpose of the present study was to determine both calcium concentration and pH in the periapical region after application of 1 of 4 different calcium hydroxide preparations into experimental root canals. Fifty root canal models were divided into five groups: group 1--calcium hydroxide was mixed with distilled water at a powder/water weight ratio of 38%; group 2--calcium hydroxide was mixed with distilled water at 44%; group 3--calcium hydroxide was mixed with distilled water at 50%; group 4--calcium hydroxide powder only was used; and group 5-the control group, in which nothing was applied to the canals. All samples were immersed in distilled water maintained at 37 degrees C. Calcium concentration and pH of the distilled water were measured after 3 days, 7 days, and then at weekly intervals up to 15 wk, during which time the storage medium was renewed after each measurement. Calcium concentration and the change in pH of the distilled water were statistically quicker and greater in groups 1 to 3 (mixture groups) than group 4 (powder only) (p < 0.05). The highest calcium concentration (peak Ca2+ release) was observed after 3 days for the mixture groups, whereas that for the powder only group was found at 7 days. Peak pH change was found after 14 days for the mixture groups, whereas that for the powder only group was found at 49 days. After peaking, all groups showed a decline of the pH over time. These results suggest that the time required for optimum intracanal activity when using calcium hydroxide mixtures is at least 2 wk.

The influence of two concentrations of sodium hypochlorite on human blood: changes in haemolysis, pH and protein

AIM

To evaluate the in vitro effect of 2.5% and 5.0% sodium hypochlorite (NaOCl) on human blood.

METHODOLOGY

Each concentration of NaOCl was reacted with human blood for 5 min at volume ratios of 1 : 1, 1 : 6, 1 : 12, each creating changes in colour, pH and temperature. Reaction suspensions were separated by centrifugation, and absorption measurements made for separated bilirubin, Fe, and protein supernatants. Each supernatant was desalted, lyophilized, and treated by SDS polyacrylamide gel electrophoresis (SOS-PAGE).

RESULTS

Increased ratios and concentrations of NaOCl caused an increase in both pH and temperature. Protein supernatants tended to decompose on SDS-PAGE. Supernatants showed increased decolourisation with 5.0% NaOCl. Concentrations of bilirubin, Ferrum and protein in supernatants decreased with increased NaOCl concentration. NaOCl had an effect on the protein component in blood.

CONCLUSIONS

These data suggest that changes in molecular structure are due to the chemical effects of NaOCl. Protein bands tended to show low molecular weight, suggesting that haemoglobin components effect the oxidation-reduction reaction.

Genotyping of Pneumocystis carinii f. sp. hominis isolates in Japan based on nucleotide sequence variations in internal transcribed spacer regions of rRNA genes

Genotyping of Pneumocystis carinii (Pc) isolated from 24 bronchoalveolar lavage (BAL) fluid specimens in Japan was examined based on nucleotide sequence variations in internal transcribed spacer regions 1 and 2 (ITS1 and ITS2, respectively) of rRNA genes. We found 11 ITS1 genotypes including 2 novel ones and 11 ITS2 genotypes including 3 new ones. Combining the ITS1 and ITS2 genotypes resulted in 30 ITS genotypes, of which 10 are newly described in this report. Two or more genotypes in ITS regions in a specimen were observed in 16 of 24 patients. Our results will be of help for the epidemiological investigation of Pc infection.

The walking bleach procedure: an in vitro study to measure microleakage of five temporary sealing agents

The purpose of this study was to compare the in vitro sealing capacity of five materials, each used as a temporary sealing agent for the walking bleach technique. All teeth received traditional biomechanical root canal instrumentation, after which the walking bleach agent was placed in the pulp chamber space. The occlusal access was sealed with one of five temporary materials: two hydraulic filling materials, a photoactivated resin composite, a zinc oxide-eugenol cement, and a zinc oxide phosphate cement with/without the placement of a piece of rubber sheet that was placed as a barrier to isolate filling material from the bleaching agent. All teeth were stored in a 1% solution of Alcian blue with thermal cycling stress. After 1 wk, they were sectioned longitudinally, and ranked by graded scores of 0 to 3, according to the degree of the dye penetration. Significantly less dye microleakage was observed in the two hydraulic materials than in the photoactivated resin. Both zinc oxide-eugenol and zinc phosphate cements showed a considerable amount of microleakage. There were no significant differences between the groups with and without a rubber sheet. Our data demonstrate that hydraulic filling materials provide the most favorable cavosurface seal when they are firmly packed into the cavity space to prevent microleakage.

Vitamin E modified cellulose membrane

There has been a demand for hemodialysis membranes of better biocompatibility, the use of which would reduce the incidence of complications in patients who have been under long hemodialysis treatment. We developed a surface modification technique consisting of forming efficiently a synthetic polymer layer on the inside of the regenerated cellulose hollow fiber without impairing fiber performance. Our newly developed membrane has excellent biocompatibility by modifying the inner surface and by immobilizing vitamin E (alpha-tocopherol), which serves as an antioxidant, to the modified surface.

Relationship between mutations in dihydropteroate synthase of Pneumocystis carinii f. sp. hominis isolates in Japan and resistance to sulfonamide therapy

We examined mutations in the dihydropteroate synthase (DHPS) genes of Pneumocystis carinii f. sp. hominis (P. carinii) strains isolated from 24 patients with P. carinii pneumonia (PCP) in Japan. DHPS mutations were identified at amino acid positions 55 and/or 57 in isolates from 6 (25.0%) of 24 patients. The underlying diseases for these six patients were human immunodeficiency virus type 1 infection (n = 4) or malignant lymphoma (n = 2). This frequency was almost the same as those reported in Denmark and the United States. None of the six patients whose isolates had DHPS mutations were recently exposed to sulfa drugs before they developed the current episode of PCP, suggesting that DHPS mutations not only are selected by the pressure of sulfa agents but may be incidentally acquired. Co-trimoxazole treatment failed more frequently in patients whose isolates had DHPS mutations than in those whose isolates had wild-type DHPS (n = 4 [100%] versus n = 2 [11.1%]; P = 0.002). Our results thus suggest that DHPS mutations may contribute to failures of co-trimoxazole treatment for PCP.

Binding of Delta1, Jagged1, and Jagged2 to Notch2 rapidly induces cleavage, nuclear translocation, and hyperphosphorylation of Notch2

Delta1, Jagged1, and Jagged2, commonly designated Delta/Serrate/LAG-2 (DSL) proteins, are known to be ligands for Notch1. However, it has been less understood whether they are ligands for Notch receptors other than Notch1. Meanwhile, ligand-induced cleavage and nuclear translocation of the Notch protein are considered to be fundamental for Notch signaling, yet direct observation of the behavior of the Notch molecule after ligand binding, including cleavage and nuclear translocation, has been lacking. In this report, we investigated these issues for Notch2. All of the three DSL proteins bound to endogenous Notch2 on the surface of BaF3 cells, although characteristics of Jagged2 for binding to Notch2 apparently differed from that of Delta1 and Jagged1. After binding, the three DSL proteins induced cleavage of the membrane-spanning subunit of Notch2 (Notch2(TM)), which occurred within 15 min. In a simultaneous time course, the cleaved fragment of Notch2(TM) was translocated into the nucleus. Interestingly, the cleaved Notch2 fragment was hyperphosphorylated also in a time-dependent manner. Finally, binding of DSL proteins to Notch2 also activated the transcription of reporter genes driven by the RBP-Jkappa-responsive promoter. Together, these data indicate that all of these DSL proteins function as ligands for Notch2. Moreover, the findings of rapid cleavage, nuclear translocation, and phosphorylation of Notch2 after ligand binding facilitate the understanding of the Notch signaling.

Effect of canal drying methods on the apical seal

The purpose of this study was to observe the seal obtained in human root canals under different in vitro treatment conditions. Root canals of freshly extracted human maxillary incisors received traditional biomechanical preparation and irrigation with 10% NaClO, followed by a final rinse of distilled water. Teeth were divided into four groups. In group 1, each root canal was dried with one paper point. In group 2, each root canal was dried with four paper points. Group 3 was dried with four paper points, followed by a gentle burst of warm air. Group 4 was dried using four paper points, followed by an internal 200 degrees C heat probe. Twenty canals in each group were filled with a gutta-percha cone and a zinc oxide-eugenol sealer, whereas 20 were filled with a glass ionomer sealer. All teeth were immediately immersed in India ink for 1 or 4 wk. The teeth were cleared, and the dye penetration-leakage measured with an accuracy of +/- 0.01 mm. Optimum sealing conditions were observed when the canal was dried with paper points and a 200 degrees C probe. There were no significant differences between 1 and 4 wk immersion. Glass ionomer sealer appeared more susceptible to the wet condition of the root canal walls than zinc oxide-eugenol sealer. An additional 40 teeth were prepared in the same manner as the dye penetration tests to observe the drying conditions of the root canal walls, and the moisture inside the canals was measured to an accuracy of 0.0001 g. The highest degree of internal canal wall dryness was found in group 4.

Mouse jagged1 physically interacts with notch2 and other notch receptors. Assessment by quantitative methods

The Delta/Serrate/LAG-2 (DSL) domain containing proteins are considered to be ligands for Notch receptors. However, the physical interaction between DSL proteins and Notch receptors is poorly understood. In this study, we cloned a cDNA for mouse Jagged1 (mJagged1). To identify the receptor interacting with mJagged1 and to gain insight into its binding characteristics, we established two experimental systems using fusion proteins comprising various extracellular parts of mJagged1, a "cell" binding assay and a "solid-phase" binding assay. mJagged1 physically bound to mouse Notch2 (mNotch2) on the cell surface and to a purified extracellular portion of mNotch2, respectively, in a Ca(2+)-dependent manner. Scatchard analysis of mJagged1 binding to BaF3 cells and to the soluble Notch2 protein demonstrated dissociation constants of 0.4 and 0.7 nM, respectively, and that the number of mJagged1-binding sites on BaF3 is 5,548 per cell. Furthermore, deletion mutant analyses showed that the DSL domain of mJagged1 is a minimal binding unit and is indispensable for binding to mNotch2. The epidermal growth factor-like repeats of mJagged1 modulate the affinity of the interaction, with the first and second repeats playing a major role. Finally, solid-phase binding assay showed that Jagged1 binds to Notch1 and Notch3 in addition to Notch2, suggesting that mJagged1 is a ligand for multiple Notch receptors.

Mutation analysis of the WT1 gene in myelodysplastic syndromes

The WT1 tumor suppressor gene was examined for mutations in a panel of 44 patients with myelodysplastic syndromes (MDS) including acute myelogenous leukemias (AML) secondary to MDS, using polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) analysis and sequencing analysis. A WT1 mutation was detected in one out of 17 cases of AML secondary to MDS. This mutation exists upstream of the zinc finger region and is predicted to produce a truncated WT1 protein lacking the zinc finger region. No mutations were detected in 27 MDS patients who had not progressed to AML. This is the first report of analysis for WT1 mutations in a large number of MDS patients, suggesting that WT1 mutations are uncommon in MDS. Abnormalities in this gene may, however, contribute to a small proportion of cases showing progression from MDS into AML.

[Clinical efficacy of fosfomycin in combination with sulbactam/cefoperazone in the treatment of severe infections complicated to blood dyscrasia. Working Group of Kanto Combination Therapy for FOM + SBT/CPZ]

In the treatment of severe infections complicated to blood dyscrasia, the efficacy and usefulness of fosfomycin (FOM) in combination with sulbactam (SBT)/cefoperazone (CPZ) were compared between patients receiving FOM in the first followed by SBT/CPZ (Group A) and those receiving both drugs simultaneously (Group B). The following results were obtained. 1. The efficacy rate was 56.3% for Group A and 47.9% for Group B, with no significant difference. 2. The efficacy for patients suspected of the presence of septicemia, the efficacy rate was 57.9% for Group A and 54.3% for Group B, with no significant difference. 3. As for underlying disease, patients with acute myelogenous leukemia were most prevailing. In these patients, the efficacy rate was 57.1% for Group A and 27.3% for Group B, with no statistically significant difference. However, the efficacy rate tended to be higher in Group A. 4. The administration of antibiotics was effective to restore the neutrophil count to 501/microliters or higher in 77.8% and 45.5% of the cases for Groups A and B, respectively, with significantly higher efficacy for Group A. 5. In the safety evaluation a total of 115 cases were included. Side effects and laboratory abnormalities were seen in 3 cases each, but none of them were serious in degree. From these results, it was confirmed that the combination therapy consisting of administration of FOM followed by SBT/CPZ with some interval is effective for severe infections complicated to blood dyscrasia.

Secretion of tetrain, a Tetrahymena cysteine protease, as a mature enzyme and its identification as a member of the cathepsin L subfamily

A protease in the culture medium of Tetrahymena pyriformis was purified to homogeneity. The purified protease had an apparent molecular mass of 28 kDa on SDS/PAGE. The amino acid sequences of the N-terminal and internal peptides of the protease showed complete identity with those of tetrain, an enzyme previously reported as a Tetrahymena cysteine protease but not characterized in detail. Two overlapping cDNA clones for tetrain were sequenced, and the nucleotide sequence predicts that these clones encode a 330-amino acid protein composed of a 16-residue N-terminal signal sequence followed by a 103-residue propeptide and a 211-residue mature protease. The primary structure and enzymatic properties support the conclusion that tetrain belongs to the cathepsin L subfamily. Immunoblotting analyses showed that mature tetrain was found exclusively in the culture medium. Immunofluorescence microscopy demonstrated that tetrain was concentrated in or around the food vacuoles of cells in the late logarithmic phase, but the staining of food vacuoles was not obvious in the stationary phase. These results suggest that tetrain is synthesized at the logarithmic phase and is secreted into the culture medium as a mature form.

Frameshift mutations of the hMSH6 gene in human leukemia cell lines

Defects in DNA mismatch repair mechanisms, including frameshift mutations of the hMSH6 and hMSH3 genes at their (C)8 and (A)8 tracks, respectively, have been shown to be associated with human malignancies. To clarify the possible involvement of these mutations in hematopoietic malignancies, we screened a total of forty-four human leukemia and lymphoma cell lines for mutations in the hMSH6 and hMSH3 genes, as well as in other genes required for DNA replication or repair, by polymerase chain reaction single-strand conformation polymorphism analysis and sequencing analysis. Frameshift mutations at the (C)8 track of the hMSH6 gene were detected in two cell lines established from lymphoid leukemias. These two cell lines had no wild-type alleles, and both of them showed microsatellite instability. This is the first report that describes mutations and inactivation of the hMSH6 gene in hematological malignancies, suggesting that defects of the hMSH6 gene may be associated with development of hematological malignancies.

Release of a newly-identified cysteine protease, tetrain, from Tetrahymena into culture medium during the cell growth

Protease activity in the culture medium of Tetrahymena pyriformis markedly increased during the growth of the ciliate. The protease activity in the culture medium was purified by sequential column chromatographies. The purified protease had an apparent molecular mass of 28 kDa. N-terminal amino acid sequencing analysis suggested that the protease is a mature form of cysteine protease. Requirements of free sulfhydryl groups for activity and sensitivity to N-tosyl-L-phenylalanine chloromethyl ketone and Na-p-tosyl-L-lysine chloromethyl ketone also indicated that the protease is a member of the papain family of cysteine proteases. The protease was designated as tetrain. Immunoblotting analyses showed that tetrain was present in higher amount in the culture medium in the stationary phase than in the logarithmic phase. Tetrain has high activities at neutral to alkaline pH values. This suggests that tetrain has functional roles in the culture medium in the stationary phase, because the pH of the culture medium became alkaline with the progress of Tetrahymena growth.

Malignant hyperthermia induced by general anesthesia for bone marrow harvesting

We present a case of a bone marrow donor who developed rhabdomyolysis, acute renal failure and pulmonary edema following an apparently uneventful general anesthesia for bone marrow harvesting. Because malignant hyperthermia (MH) was suspected, he was treated with dantrolene, fluid loading, and continuous hemodiafiltration along with symptomatic supportive care. He made a full recovery and was discharged 3 weeks after harvest. Although the incidence of MH is low, marrow donation involves the risks of anesthesia as is seen in this case. Close monitoring is required to prevent life-threatening complications associated with the bone marrow harvesting procedure.

Mutations and loss of expression of a mismatch repair gene, hMLH1, in leukemia and lymphoma cell lines

Defects in genes involved in DNA mismatch repair have been detected in both hereditary and sporadic tumors of colon, endometrium, and ovary and suggested to be associated with tumorigenesis. To investigate disruptions of the mismatch repair system in hematological malignancies, we examined alterations of the human mutL homologue 1 (hMLH1) gene, a member of the mismatch repair gene family, in a total of 43 human leukemia and lymphoma cell lines, by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and sequencing analyses. Mutations of the hMLH1 gene were detected in three cell lines established from lymphoid leukemias. Moreover, Northern and Western blot analyses showed that expression of hMLH1 transcript or protein was abrogated in these three leukemia cell lines. Further studies for microsatellite loci showed that these cell lines without hMLH1 expression showed microsatellite instability. This is the first report that describes mutations and inactivation of the hMLH1 gene in human leukemia cells, suggesting that disruption of DNA mismatch repair system may play an important role in the development of human lymphoid leukemias.

A rare case of cardiac sarcoidosis in a patient with progressive systemic sclerosis, Sjogren's syndrome, and polymyositis

A 56-year-old woman with overlap syndrome of progressive systemic sclerosis (PSS), Sjogren's syndrome, and polymyositis is reported. She developed complete atrioventricular (AV) block and progressive bilateral hilar adenopathy, and was diagnosed as having sarcoidosis by histological examination of the hilar lymph nodes biopsied thoracoscopically. Although coexistence of one or two autoimmune diseases with sarcoidosis is not uncommon, coexistence of three or more autoimmune diseases with sarcoidosis is rare. To our knowledge, the described case is the first case in which the three above-mentioned autoimmune diseases were accompanied by myocardial sarcoidosis.

Dietary maltitol increases calcium content and breaking force of femoral bone in ovariectomized rats

Maltitol is a disaccharide alcohol generated by hydrogenation of maltose and exhibiting resistance to intestinal disaccharidases. We demonstrated previously that maltitol stimulates transepithelial transport of calcium in the ileum, accompanied by an elevation of intestinal calcium absorption as well as calcium retention in the body. In this study, we examined whether the maltitol-induced increase in intestinal calcium absorption leads to an alteration of the physical properties of bones in rats subjected to ovariectomy. We used this study as a simulation model for postmenopausal females who are at risk for osteoporosis. Following the intake of a low-calcium diet for 28 d ovariectomized rats were fed diets containing either 10% maltose (control) or 10% maltitol, together with increased amounts of calcium (0.3% in Experiment 1 and 1.2% in Experiment 2) for 21 d. Balance studies performed during the final 5-d (Experiment 1) or 2-d (Experiment 2) period of the experiments showed that maltitol increased intestinal calcium absorption and retention. The breaking force of femoral bones was significantly elevated (by 5-7%) in animals fed the maltitol diet compared with that in rats fed the maltose diet. The calcium content in the femoral bones as well as the mineral bone density of the tibial metaphysis was also elevated in rats fed the maltitol diet. These results indicate that maltitol stimulates the intestinal absorption of dietary calcium leading to an increase in calcium content in the bone, and coinciding with the elevation of the breaking strength of the bone in ovariectomized rats.

A study of the apical microleakage of a gallium alloy as a retrograde filling material

The feasibility of utilizing mercury-free Gallium alloy GF for retrograde filling was investigated by comparing apical microleakage in 184 extracted human teeth. The teeth were divided into four experimental and two control groups. Three experimental groups were apical cavity retrofillings with the Gallium alloy GF, a mercury-containing amalgam, and a glass ionomer. The fourth experimental group was filled with gutta-percha and heat-burnished after apicoectomy. After 24 h, 1 wk, 4 wk, and 12 wk immersion in dye solution, the roots were vertically sectioned, and the deepest point of dye penetration was recorded. The glass ionomer showed the least leakage, followed by the amalgam group and the gallium group (no significant difference). The gutta-percha heat-burnished group displayed the greatest leakage. Gallium alloy GF was shown to have an equivalent sealing potential to dental amalgam for a retrograde filling material.