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Biomedical subjects

Y Tabata

Publications and source records attributed to Y Tabata.

At least 199 records · Page 11Linked to original sources
PubMed1982

Intermittent vascular access for extracorporeal circulation in conscious rats: a new technique.

A new technique is described for repeated intermittent access to the systemic circulation in fully conscious rats for infusion or extracorporeal circulation. The femoral artery and vein of each rat were cannulated. The cannulas were then passed subcutaneously and exteriorized through the skin of the tail 2 cm from its base. The exposed cannulas were protected by a special plastic device. This new approach did not immobilize the rat except during access to the circulation; even then, only the distal portion of the tail was immobilized, thus allowing the animal to move freely. This way repeated access to the systemic circulation was easily achieved in the fully conscious rat.

Animals↗
PubMed1980

Effect of splenectomy on reticuloendothelial function and survival following sepsis.

It is well known that splenectomy causes immunologic impairment and increases susceptibility to infection; however, the time course of reticuloendothelial depression and of alterations in hepatic and pulmonary retention of injected lipid emulsion following splenectomy is not known. To determine this, rats were splenectomized and reticuloendothelial function evaluated at various intervals following splenectomy by measuring the intravascular clearance of 131I-triolein gelatinized lipid emulsion. The intravascular clearance (T/2) and lung uptake of the lipid emulsion increased and hepatic uptake of emulsion decreased 4 to 8 hours following splenectomy. One day followng splenectomy, although the T/2 appeared normal, the lung uptake was 1,123% higher and hepatic uptake was still 33% lower than control. The T/2 and hepatic retention returned to normal 2 days following splenectomy; however, the lung retention was higher than controls even 10 days following splenectomy. In another set of experiments, splenectomy was performed following which sepsis in rats was produced by cecal ligation and puncture. Ten hours following cecal ligation and puncture, the gangrenous cecum was removed and survival was measured over 5 days. The mortality rate in these animals was 57% (12/21) compared to 0% (0/8) in nonsplenectomized cecal ligated and punctured animals. These results suggest that splenectomy may not only have deleterious effects in terms of the host defense system, but may also cause prolonged pulmonary changes.

Animals↗
PubMed1977

[Improvement of resolution of positron annihilation radiation energy spectrum measurement by data analysis (author's transl)].

Recently much attention is being paid to positron annihilation radiation energy spectrum measurement as a simple method that gives information about the momentum distribution of an annihilating pair. However, this method has a disadvantage that it is sensitive to drifts of the measuring system and the resolution is still insufficient. We have succeeded to reduce the influence of the drifts to a negligibly small degree by using, in addition to the necessary procedure for a temperature control and stabilizing of AC power lines, a compensation technique in data analysis. We have further attempted to improve the resolution by deconvolution processing. By these procedures, we have been able to separate a narrow component which has not otherwise been resolved directly from the spectrum. The resolution attained by this way is 0.43 keV (FWHM), and is two- or three-fold superior to those ever reported.

Models, Theoretical↗
PubMed1976

Changes in amplitude of the EEG induced by a photic stimulus.

Occipital EEG responses to a single photic flash were studied by using a complex demodulation technique. Individual EEGs were first digitally filtered by making use of the Ormsby band-pass filter. Envelopes of the alpha (8-12 c/sec) and of the low frequency (3-7 c/sec) activities were obtained in terms of the demodulation calculation. Both individual and averaged data of raw, filtered, and demodulated EEGs were utilized for the present study. Two typical kinds of EEG responses were observed. One showed clearly the blocking as well as the enhancement of the alpha activity. The alpha activity first exhibited a reduction in amplitude in the range 50-200 msec after the stimulus (the minimum amplitude at about 150 msec). Then an evocation, rather than merely a recovery, of the alpha was observed in the range 500-800 msec (maximum amplitude at about 650 msec). The other typical example showed the low frequency evoked potential prominently. This response appeared almost locked to the stimulus and showed roughly a bi-phasic pattern in the time range where the alpha blocking took place (30-200 msec). Phases of the evoked low frequency component were almost locked to the stimulus but no distinct phase coherence was observed for the enhanced alpha wavetrains. Detection by demodulation of the phase change of the alpha was critical for a single EEG. It is pointed out that changes of the alpha must be studied on individual EEGs.

Adult↗