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11.
The effects of in vivo ultrasound irradiation of the spleen on immunological functions were assessed with an in vitro natural killer (NK) cell cytotoxic assay. Anesthetized hamsters were exposed to 1 MHz ultrasound at intensity levels currently being used clinically for therapeutic diathermy and hyperthermia (1-5 W/cm2, for 500 sec with constant beam scanning). Hyperthermic levels in the spleen ranged from 38-43 degrees C. Significant depression of natural killer (NK) cell activity was seen 4 h after spleen irradiation as compared to sham irradiated and normal animals. A return towards normal levels was observed in experimental groups at 24 h after exposure. Sham and normal animals were not significantly different in NK activity, indicating no significant stress-related immunosuppressive effects due to handling. Differential leukocyte counts taken for each exposure condition showed significant lymphopenia at 4, 8, and 16 h after exposure, near normal levels at 24 h, and complete recovery by 48 h. The number of circulating mononuclear cells at 4 h showed a dose-related suppression as the exposure intensities were increased. 相似文献
12.
Katherine J. Devonald Winthrop J. Harewood David A. Ellwood Andrew F. Phippard 《Journal of medical primatology》1996,25(5):339-345
Normal biometric ranges for fetal growth in a captive breeding baboon (Papio hamadryas) colony are described. Measurements include crown-rump length, biparietal diameter, binocular distance, head circumference, abdominal circumference, femur length and amniotic fluid index. The pattern of fetal growth is compared with other baboon subspecies and man. The uses and limitations of such data for breeding colony management and optimum utilisation of experimentally derived data are discussed. 相似文献
13.
For measuring the length of root samples, the use of a three-dimensional (3D) scanner is proposed to address the problem of a too low resolution. The scanner's high resolution (up to 354 pixels per cm) enables in the resulting grey-value image very thin roots (diameter 100 m) to be segmented from the background by a simple thresholding operation. After skeletonizing, total length of the roots is calculated by multiplying the number of skeleton pixels by a correction factor. A comparison with the modified Newman Line-Intersect Method showed a correlation of r=0.98. Besides its superior resolution, an advantage of this type of scanner is its focusing depth, which allows root samples to be recorded on the scanbed similarly to a camera-oriented system. 相似文献
14.
An important new artefact in cytopathology is described. the initial observation of the artefact followed contamination of a breast fine needle aspiration (FNA) sample by ultrasound gel which was used to localize the lesion. the changes proved reproducible ex vivo. the changes varied depending on the conditions and degree of contamination, and ranged from cell swelling to leakage of nuclear chromatin and cell lysis. This artefact is discussed in the context of other major sources of cytology artefact. Pathologists and radiologists should beware of the detrimental effects of ultrasound gel on cytology specimens. 相似文献
15.
Donat-P. Häder 《Journal of biological physics》1993,19(2):95-108
A three-dimensional model of the flagellateEuglena gracilis was developed to simulate phototaxis and movement in space. The simulation of the phototactic behavior was compared with thein vivo behavior in order to determine the mechanism of orientation with respect to light. Phototactic behavior with respect to one light source, can be explained by the shading hypothesis as well as by a dichroic orientation of the absorbing vectors of the photoreceptor pigments. In contrast, the behavior of the cells when exposed to two perpendicular light beams is not compatible with the shading hypothesis. Likewise, the phototactic orientation of stigmaless cells cannot be accounted for on the basis of the shading hypothesis. In contrast, simulations andin vivo observations of the behavior under polarized light strongly indicate the validity of the dichroic orientation of the photoreceptor pigments. 相似文献
16.
17.
本文研究了超声波和相转移催化剂在Reimer—Tiemann反应中的应用,提出了超声波和相转移催化下Reimer—Tiemann反应的机理。研究结果表明:在超声波和相转移催化剂的共同作用下,二氯卡宾形成十分迅速,羟基苯甲醛产率显著提高,反应时间成倍缩短。 相似文献
18.
Junichiro J. Kazama Takashi Aikata Masaaki Arakawa Hidehiro Ozawa 《Biotechnic & histochemistry》1994,69(6):324-328
We describe a new technique for immunohistochemical and enzyme-histochemi-cal double staining using confocal laser scanning microscopy in the reflection mode. As an example, we investigated the immunoreactivity for Spot 35-calbindin-D28K, a vitamin D-dependent calcium binding protein, and the enzyme activity for ma+-ATPase in the rat kidney. The lead precipitation method for Ca2+-ATPase was initially used to process kidney slices. Each specimen was then dehydrated and embedded in a water soluble resin. Thin sections were cut from the resin block, and an indirect immunocolloidal gold method with silver enhancement for Spot 35-calbindin-D28K antigen was carried out on the glass slides. Results were then observed by confocal laser scanning microscopy in the reflection mode. The three-dimensional distribution of the reaction products was detected by serial optic slice images. Lead phosphate particles, which represented the location of Ca2+-ATPase, were distributed deep in the section. The most intense signals from the silver partkles were detected from the surface slice of the section. A stereoscopic image generated from the serial optic slices clearly showed the differences in their distribution. 相似文献
19.
The three-dimensional structure of habitats is a critical component of species' niches driving coexistence in species-rich ecosystems. However, its influence on structuring and partitioning recruitment niches has not been widely addressed. We developed a new method to combine species distribution modelling and structure from motion, and characterized three-dimensional recruitment niches of two ecosystem engineers on Caribbean coral reefs, scleractinian corals and gorgonians. Fine-scale roughness was the most important predictor of suitable habitat for both taxa, and their niches largely overlapped, primarily due to scleractinians' broader niche breadth. Crevices and holes at mm scales on calcareous rock with low coral cover were more suitable for octocorals than for scleractinian recruits, suggesting that the decline in scleractinian corals is facilitating the recruitment of octocorals on contemporary Caribbean reefs. However, the relative abundances of the taxa were independent of the amount of suitable habitat on the reef, emphasizing that niche processes alone do not predict recruitment rates. 相似文献
20.
Shuhei Takatsuka Takeshi Kubota Yuta Kurashina Sho Kurihara Motoki Hirabayashi Masato Fujioka Hirotaka James Okano Hiroaki Onoe 《Biotechnology and bioengineering》2023,120(8):2371-2377
Adeno-associated virus (AAV)-based gene therapy holds promise as a fundamental treatment for genetic disorders. For clinical applications, it is necessary to control AAV release timing to avoid an immune response to AAV. Here we propose an ultrasound (US)-triggered on-demand AAV release system using alginate hydrogel microbeads (AHMs) with a release enhancer. By using a centrifuge-based microdroplet shooting device, the AHMs encapsulating AAV with tungsten microparticles (W-MPs) are fabricated. Since W-MPs work as release enhancers, the AHMs have high sensitivity to the US with localized variation in acoustic impedance for improving the release of AAV. Furthermore, AHMs were coated with poly-l -lysine (PLL) to adjust the release of AAV. By applying US to the AAV encapsulating AHMs with W-MPs, the AAV was released on demand, and gene transfection to cells by AAV was confirmed without loss of AAV activity. This proposed US-triggered AAV release system expands methodological possibilities in gene therapy. 相似文献