Temperature changes caused by the difference in the distance between the ultrasound transducer and bone during 1†mhz and 3†mhz continuous ultrasound: a phantom study.

[Purpose] This study aimed to use a thermograph to observe temperature changes caused by different distances between an ultrasound transducer and bone during 1 MHz and 3 MHz continuous ultrasound emission on a phantom. [Materials and Methods] We observed the distribution of temperature elevations on a phantom consisting of pig ribs and tissue-mimicking material. One megahertz and 3 MHz ultrasound were delivered at 2.0 W/cm(2) for 5 minutes. To record the temperature changes on the phantom, we took a screenshot of the thermograph with a digital camera every 20 seconds. [Results] With 1 MHz ultrasound at the distances of 2 and 3 cm, the temperature elevation near the bone was higher than that near the transducer. However, with 3 MHz ultrasound, the temperature elevation was higher near the transducer rather than near the bone. At this point, we consider that there is a possibility of heat injury to internal organs in spite of there being no elevation of skin temperature. [Conclusion] When performing ultrasonic therapy, not only should the frequency be taken into consideration, but also the influence of the absorption coefficient and the reflection of the tissue. We visually confirmed the thermal ultrasound effect by thermography. Special attention to the temperature elevation of the internal organs is necessary to avoid injuries.

Spatial distribution of viruses associated with planktonic and attached microbial communities in hydrothermal environments.

Viruses play important roles in marine surface ecosystems, but little is known about viral ecology and virus-mediated processes in deep-sea hydrothermal microbial communities. In this study, we examined virus-like particle (VLP) abundances in planktonic and attached microbial communities, which occur in physical and chemical gradients in both deep and shallow submarine hydrothermal environments (mixing waters between hydrothermal fluids and ambient seawater and dense microbial communities attached to chimney surface areas or macrofaunal bodies and colonies). We found that viruses were widely distributed in a variety of hydrothermal microbial habitats, with the exception of the interior parts of hydrothermal chimney structures. The VLP abundance and VLP-to-prokaryote ratio (VPR) in the planktonic habitats increased as the ratio of hydrothermal fluid to mixing water increased. On the other hand, the VLP abundance in attached microbial communities was significantly and positively correlated with the whole prokaryotic abundance; however, the VPRs were always much lower than those for the surrounding hydrothermal waters. This is the first report to show VLP abundance in the attached microbial communities of submarine hydrothermal environments, which presented VPR values significantly lower than those in planktonic microbial communities reported before. These results suggested that viral lifestyles (e.g., lysogenic prevalence) and virus interactions with prokaryotes are significantly different among the planktonic and attached microbial communities that are developing in the submarine hydrothermal environments.

A Preliminary Evaluation of Energy Efficiency for Children with Cerebral Palsy for Driving A Manual Wheelchair and Walking: Use of the Total Heart Beat Index.

Aims: This study aims to compare the total heart beat index (THBI) in evaluating energy efficiency between using a manual wheelchair and walking for children with cerebral palsy (CP). Methods: The energy efficiency was measured in 21 participants with CP (mean age, 13.6 ± 3.4 years) who walk or drive a manual wheelchair using a square course. THBI was calculated as total number of heart beats during the exercise period/total distance traveled. Results: Significant differences in the THBI were observed between Gross Motor Function Classification System (GMFCS) levels III and IV (p = .049, effect size = 1.60). No significant differences in THBI were observed between GMFCS levels II and III or between GMFCS levels II and IV (p > .05). Conclusions: The energy efficiency of children with CP who use a manual wheelchair in this study was equal to or better than that for walking.

Factors affecting the self-rated health of elderly individuals living alone: a cross-sectional study.

OBJECTIVE: In Japan, the number of elderly individuals living alone is continuing to increase as society ages. Although studies have considered quality of life, life expectancy, and gender differences in elderly individuals living alone, only a few have considered the health and lifestyle of these individuals. Therefore, we aimed to investigate the factors that affect the self-rated health of elderly individuals living alone to understand this group and how best to offer them support. RESULTS: We include 113 individuals. There was a significant difference (P < 0.05) in some characteristics (e.g., age, chronic illness, frequency of hospital visits in 1 month, and caregivers), activities of daily living (e.g., motor tasks), and instrumental activities of daily living (e.g., household affairs, heavy housework, outdoor household, and outdoor activities).

Enhancement of skin permeation of ketotifen by supersaturation generated by amorphous form of the drug.

Pressure sensitive adhesive (PSA) matrices containing amorphous ketotifen were prepared and evaluated for enhanced skin permeability of the drug. A solvent casting method using silicone-typed PSA was employed, and n-hexane, an original solvent for the PSA and one more solvent, dichloromethane, tetrahydrofuran, acetone, ethyl acetate or toluene, were used for complete dissolution of ketotifen and high dispersion in an amorphous state of the drug. Presence of the amorphous form was judged based on the in vitro drug release rate from the matrix. As a result, dichloromethane and tetrahudrofuran were selected as appropriate dilution solvents. In vitro permeation experiments through excised hairless mouse skin revealed that the steady-state flux from the amorphous ketotifen-dispersed matrices was about five times greater than that of the crystalline ketotifen-dispersed matrices, and that the enhancement ratio was in good agreement with the solubility ratio of the amorphous to crystalline form of the drug. Comparison of the skin permeation profiles of amorphous ketotifen-dispersed matrices between two different drug contents suggested that the steady-state flux was not influenced by the drug content. In addition, at both drug contents, the period of the steady-state permeation coincided with the time until the amorphous drug was depleted from the matrix. These results suggest that the increase in skin permeation of ketotifen from PSA matrix was due to the supersaturation generated by amorphous form, and that the amorphous form was stable during the application period.

[Drug delivery systems for cancer chemotherapy].

Various types of drug delivery system (DDS) for antitumor drugs have been developed to reduce severe systemic toxicities and to enhance antitumor effects by improving their pharmacokinetics. In this paper, outlines are first given of the concept and design of DDS, focusing on polymeric antitumor drugs (macromolecular prodrugs) and then describing the superior DDS effects shown in preclinical studies of DE-310, a DDS optimized for the camptothecin analogue DX-8951. Clinical trials of DE-310 are now ongoing in the USA and Europe.

In vivo enhancement of transdermal absorption of ketotifen by supersaturation generated by amorphous form of the drug.

The enhancing effect of supersaturation generated by amorphous ketotifen in silicone pressure-sensitive adhesive matrices (PSA) on the transdermal absorption was evaluated in vivo using hairless rats, and it was compared with the increase of drug amount in skin tissues. The duration of the enhancing effect was also investigated in relation to the time how long supersaturation was maintained in PSA. PSA containing crystalline ketotifen (PSA-Crystalline) and that containing amorphous ketotifen (PSA-Amorphous) were prepared by the solvent casting method using n-hexane and dichloromethane, respectively. In vivo transdermal absorption was evaluated by measuring the amount of ketotifen in PSAs, the stratum corneum, and viable skin tissues after administration of PSAs on abdominal sites of hairless rats. The amount of ketotifen absorbed into the systemic circulation was calculated by subtracting the drug amount in whole skin tissues from the amount of the drug released from PSAs, then it was monitored for up to 23 h. In both types of PSA, a constant absorption rate was maintained for up to 23 h after 7-h lag time. The enhancement factor of PSA-Amorphous against PSA-Crystalline was approximately 7, which was in good agreement with the difference of drug amount in viable skin tissues. Time course of the drug amount in PSA-Amorphous suggested that the supersaturated level was gradually decreased after 10h, but the decline of the driving force from PSAs was supplemented by the drug release from the skin depot resulting in the constant absorption rate up to 23 h. These results suggest the usefulness of amorphous ketotifen to obtain enhanced transdermal absorption.

The effects of external heating on the permeation of oxybutynin through human epidermal membrane.

The transdermal delivery system (TDS) of oxybutynin (OXY) is widely used for the treatment of overactive bladder patients. This report aimed to assess the effect of external heating on the pharmacokinetics of OXY after transdermal administration. Franz-type diffusion cell experiments at room temperature, 36 and 45 degrees C were performed to estimate the permeations of OXY through human epidermal membrane with an isosorbide dinitrate (ISDN) formulation as a reference. The fluxes of OXY at 36 and 45 degrees C were only approximately 1.2-fold higher than that at room temperature, while those of ISDN with heating were more than 2.5 times as high as that without heating (p<0.001). These results indicate that the influence of heating on the permeation of OXY from the TDS of OXY may be minimal.