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Biomedical subjects

A Mizuno

Publications and source records attributed to A Mizuno.

At least 289 records · Page 16Linked to original sources
PubMed1985

Blow-out fracture of the orbit in 4 children.

4 cases of blow-out fractures of the orbit in children are presented. Four 6- to 12-year-old boys were successfully operated on via an orbital and transsinus approach. As material for restoration of the broken orbital floor, Silastic was used in 3 patients.

Child↗
PubMed1985

[Application of a response duration schedule in rats to evaluate visual and/or auditory threshold].

Determination of visual and auditory thresholds was carried out under a response duration schedule of tone and/or light-dipper presentation. This schedule enabled an exact assessment of visual and auditory sensitivities, since the direction and distance from the rat to the sound or light sources were constant, and the rat could thus acquire the conditioned behavior in a short time. The rat has to put its nose into the hole and hold it there until a conditioned stimulus (tone and/or light) was presented. The animal could get water-reinforcement by taking its nose out from the hole during the period of conditioned stimulus. To determine the visual threshold, the intensity of light was reduced, from 100 Lx (starting point) by 10 Lx steps in each trial, until the subject made 10 non-response trials (i.e., no dipper approach within 1.0 sec after the light onset) among 10 trials. In terms of auditory threshold, the intensity of 3, 7 and 10 KHz pure tone was reduced, from 90 dB by 10 or 2 dB steps in each trial, until the subject made 10 non-response trials among 10 trials. The light or tone intensity that prolonged the response latency 2 times compared to normal rats was taken as the threshold. The visual sensitivity in the rats suffering from alkaline-burn on its corneas decreased about 14 Lx. The auditory thresholds in rats were 19.5 +/- 1.3, 37.5 +/- 1.8 and 54.6 +/- 1.3 dB at 10, 7 and 3 KHz, respectively. The auditory sensitivity in the rats with cotton-stuffed ears and pierced eardrums decreased about 6 and 12 dB, respectively.

Animals↗
PubMed1985

2',3'-Cyclic nucleotide 3'-phosphohydrolase in acrylamide-induced optic neuropathy in rabbit.

The in vivo effects of acrylamide on the nerve tissues of the rabbit optic pathway were examined. The optic nerve of acrylamide-treated rabbits showed inflammatory changes and degeneration. The decrease of myelin was observed with myelin stain. The activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase (EC.3.1.4.37) which is firmly bound to myelin was markedly diminished by acrylamide intoxication.

2',3'-Cyclic Nucleotide 3'-Phosphodiesterase↗
PubMed1985

Focal experimental demyelination in monkey optic nerve by lysophosphatidylcholine.

The optic nerve of 2 adult male Macaca fuscata was exposed and lysophosphatidylcholine dissolved in saline at 2% was slowly injected into the nerve at about 5 mm posteriorly from the eyeball. This procedure produced a focal lesion of demyelinating plaque. Klüver-Barreras and Bodian stain for myelin and axon revealed demyelination with myelin ovoids and relatively well preserved axons in the focal plaque. It was thought that this lesion would be an experimental model of the demyelinating lesion of retrobulbar optic neuritis.

Animals↗
PubMed1985

[Coronary artery imagings by intraoperative two-dimensional echocardiography].

Using a new diagnostic ultrasonographic apparatus for tomographic imagings during surgery, we attempted to image the coronary arteries to delineate vascular lesions. Twenty patients were studied, including four with ischemic heart disease, eight with valvular disease, and eight with congenital anomalies. A T-shaped, 7.5 MHz electronically-focused linear array scanner sterilized with formalin gas was placed directly over the exposed surface of the heart. Echocardiograms of the coronary systems were obtained in the following selected planes. Plane 1: With the scanner probe on the main pulmonary artery, the main trunk of the left coronary artery (LMT) was imaged; Planes 2 and 3: Tomographic imaging of the left anterior descending artery (LAD) was accomplished with the probe of the scanner applied to the anterior interventricular sulcus; Planes 4 and 5: For imaging the right coronary artery (RCA), the scanner probe was placed over the right atrioventricular groove. The LMT and its branches (LAD and the circumflex branch, Cx) were readily visualized echocardiographically in plane 1 in nearly all cases examined. Satisfactory imagings of the RCA were also easily achieved in planes 4 and 5. Nevertheless, attempts to image the LAD in planes 2 and 3 entailed some difficulty. Echograms of adult patients were of higher intensity and brighter, with an increased prominence of the intima of the coronary arteries, compared to those of children. The echocardiographic features in coronary artery stenosis were remarkably consistent with the angiographic findings in respect to the location of stenotic lesions. Advantages of echographic observations of the coronary arteries using this noninvasive procedure lie not only in providing accurate information as to the site of stenosis but in delineating the morphologic features of the vessel wall, as well. Using this procedure optimal sites for vascular graft sutures in cases requiring aorto-coronary bypass surgery may be appropriately selected, hence this is a valuable diagnostic aid to increase the safety of surgical procedures.

Adult↗
PubMed1985

[Evaluation of regurgitant fraction of aortic regurgitation by means of pulsed Doppler echocardiography as compared with cine angiography].

The regurgitant fraction (RF) of aortic regurgitation (AR) was calculated using pulsed Doppler echocardiography (PDE), and the results were compared with those of aortography. Two-dimensional echocardiography (2DE), PDE and cine angiography were performed for 33 patients, including nine in whom aortic regurgitation (AR) was ruled out by contrast 2DE and 24 in whom AR was confirmed by aortography (AOG). The latter were subdivided into six of Sellers' degree I, seven of degree II, eight of degree III and three of degree IV. Sampling was obtained from the main pulmonary artery, the left ventricular outflow tract, and the mean circulation velocity (f1) was calculated from the power spectrum wave pattern obtained from each source. With the following formula, Qp (pulmonary arterial blood flow), Qs (left ventricular ejection blood flow) and RF [= (Qs--Qp)/Qs] were calculated, and compared with the findings obtained from invasive methods: (formula; see text) (L = vascular diameter; theta = angle of incidence; C = velocity of sound; fo = oscillating frequency; ET = ejection time; HR = heart rate) A correlation of r = 0.81 was found between Qp calculated with PDE and right cardiac output (CO) by the thermodilution method. A correlation of r = 0.66 was observed between Qs and left ventricular ejection volume obtained from left ventriculography using Dodge's method. Comparison of RF using Sellers' classification with AOG revealed that the RF in the group uncomplicated with AR was 0.14 +/- 0.10, and Sellers' degrees I, 0.27 +/- 0.08; II, 0.36 +/- 0.04; III, 0.53 +/- 0.05; and IV, 0.64 +/- 0.06, indicating consistency with severity and RF.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve Insufficiency↗
PubMed1984

Raman spectroscopic evidence for the microenvironmental change of some tyrosine residues of lens proteins in cold cataract.

Reversible "cold cataract" phenomenon of a SD-strain rat lens (29 days old) was studied by Raman spectroscopy in the temperature range of 35-17.5 degrees C. Cold cataract appeared in the lens nucleus below 26 degrees C. The Raman spectra did not show any detectable change in the 300-800 cm-1 and 900-4000 cm-1 regions as the temperature decreased. However lens opacification caused a significant change in the intensity ratio of tyrosine doublet near 840 cm-1, suggesting that some tyrosine residues in lens proteins undergo a change in their hydrogen bonding environment during the cold cataract formation. It was also found that the intensity ratio of the tyrosine doublet band provides a practical indicator of phase transition temperature of cold cataract.

Animals↗
PubMed1984

Clinical evaluation of the microporous hollow fiber oxygenator.

This report concerns a clinical evaluation for a newly devised hollow fiber oxygenator, Capiox II. It functions on a one-pump system, and is simple to set up and operate. This equipment was used for 118 patients undergoing cardiac surgery at Tokyo University Hospital from February 1982 through February 1983. The gas transfer capacity proved to be satisfactory. The employment of an air-oxygen blender prevented overoxygenation, and reasonable levels of PaO2 and PaCO2 were demonstrated with a FiO2 0.7, V/Q ratio 0.7 at normothermia. The destruction of platelets was much less with the use of this oxygenator, as compared to findings with the BOS-10. Hemolysis by Capiox II appeared to be lower than that by BOS-10, but the difference was not statistically significant. Differences were distinct in the amount of microbubbles; strikingly, no bubble was evidenced in Capiox II by the ultrasound bubble detector, during general procedures. We conclude that Capiox II is of excellent clinical value, and should be used especially for infants as well as adult patients with possible long perfusions. The merits and demerits of this equipment are given attention.

Adolescent↗
PubMed1984

Effects of glutamic acid, kainic acid and aspartic acid on GABA release from rat retina degenerated by kainic acid.

The effects of L-glutamic acid (Glu), kainic acid (KA) and L-aspartic acid (Asp) on 14C-GABA release from the rat retina degenerated by KA were investigated. In the normal rat retina, Glu initially enhanced GABA release and subsequently inhibited it. Both KA and Asp did not have dual effects; KA enhanced GABA release, while Asp inhibited it. In the KA-degenerated retina, the stimulatory effect of Glu or KA on GABA release was markedly suppressed, while the inhibitory effects of Glu or Asp were preserved.

Animals↗
PubMed1984

Infrared spectroscopic analysis of materials from calcified epithelioma.

An infrared spectrum of the calcified epithelioma excised from the eyelid of a three-year old girl was observed. Main absorption peaks were assigned as proteins and calcium phosphate. The crystallinity of calcium phosphate was 41%. The relative content of proteins and calcium phosphate was monitored as 7.4:1, reproducing the spectrum of the calcified epithelioma with a mixture of keratin and calcium phosphate. An epithelioma taken from the trunk of a 41-year-old man showed no calcification and the infrared spectrum of this epithelioma showed no absorption peaks of calcium phosphate.

Adult↗
PubMed1984

Influence of messenger RNA secondary structure on translation efficiency.

Two genes for human immune interferon (hIFN-gamma), synthetic (GIFs) and cDNA prepared from mRNA (GIFm), have been expressed in E. coli under the control of the trp promoter. The expression level of GIFs was 100-fold lower than that of GIFm. Secondary structure analysis of two genes' mRNA surrounding Shine-Dalgarno (SD) sequence showed the presence of a 8 base-pair stable stem structure preceding SD sequence in GIFs mRNA, but not in GIFm mRNA. Expression of a GIFs gene, in which the stem structure was rendered unstable by changing two bases, became 100 times greater than that of the original GIFs.

Base Sequence↗