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Biomedical subjects

Y Asai

Publications and source records attributed to Y Asai.

At least 181 records · Page 10Linked to original sources
PubMed1989

In vivo binding of circulating immune complexes by C3b receptors (CR1) of transfused erythrocytes.

The effects of packed erythrocyte transfusion with high CR1 activity on circulating immune complex concentrations were studied in 14 transfusion experiments involving 12 patients with immune complex related diseases. Before erythrocyte transfusion circulating immune complex concentrations ranged from 8 to 128 micrograms/ml. After transfusion (2-3 units) immune complex concentrations decreased depending on the levels of CH50 titres in the recipients. In 11 experiments, in which the patients' CH50 titres ranged from 21 to 44, immune complex concentrations decreased by 75-100% within five days. The CH50 titres were also decreased after erythrocyte transfusion but subsequently increased to initial ranges within 6-35 days. In three patients with low CH50 titres (1.0-10.0) decreases in immune complexes were not observed. Direct Coombs' tests for IgG and C3 were performed before and after erythrocyte transfusion to determine potential in vivo binding of circulating immune complexes. Thus in eight of 14 experiments, in which erythrocytes carried no IgG before packed erythrocyte transfusion, seven became Coombs' positive for IgG after the transfusion. In seven of 14 experiments, in which erythrocytes were negative for complement before transfusion, five became positive afterwards. Moreover, in 12 instances slight increases of CR1 activity of patients' erythrocytes were observed within eight days, which improved further within 35 days after erythrocyte transfusion. These studies suggest that transfusion of erythrocytes with high CR1 activity results in the removal of circulating immune complexes and that this process is dependent on complement consumption. These experiments support the hypothesis that erythrocyte-CR1 has a functional role in the removal of circulating immune complexes and may thereby inhibit the deposition of immune complexes within body tissue constituents.

Antigen-Antibody Complex↗
PubMed1989

Diagnosis of arteriosclerosis obliterans by impedance technique with special reference to relative blood flow of the lower extremity.

Simultaneous recordings of impedance cardiography of the chest and impedance plethysmography of the lower extremity were performed on 105 limbs with or without arteriosclerosis obliterans (ASO) documented by angiography. The ratios of blood flow to the lower extremity--leg stroke volume/cardiac stroke volume--(LSV/CSV) were 11.2 +/- 3.3% in normal male subjects, 11.1 +/- 5.5% in normal female subjects, and 3.1 +/- 1.2% in lower extremities with ASO, respectively. The normal value (range) for LSV/CSV calculated from the normal groups by the percentile method was between 4.9% and 17.8%, and the diagnostic accuracy of this value was 100% for sensitivity and 97.5% for specificity. LSV/CSV is a good index for the diagnosis of ASO and makes it possible to minimize error when expressed as an absolute value.

Arteriosclerosis Obliterans↗
PubMed1989

[Effectiveness of the bidirectional Glenn shunt for the univentricular heart].

Two cases underwent a modified Fontan operation with simultaneous superior vena cava-right pulmonary artery end-to-side anastomosis, which we called "bidirectional Glenn shunt". This anastomosis seems to be so effective for reduction of right arterial volume loading, and could proved life-saving in the case with the acute obstruction at the site of the right atriopulmonary artery anastomosis immediately after surgery.

Anastomosis, Surgical↗
PubMed1989

[Modified Fontan operation of single ventricle with D-TGA].

An 8-year-old boy who had previously received two systemic pulmonary shunts, underwent successfully direct anastomosis between SVC and right pulmonary artery (bidirectional Glenn shunt), and proximal side of SVC and main pulmonary artery. Post operative course was uneventful with pleural effusion during a shot period. Post operative right atrial pressure was 9/5 mmHg without evidence of live swelling.

Anastomosis, Surgical↗
PubMed1989

[Histopathological studies of periodontal tissue reactions to perforations in the furcation of dogs' teeth treated with cyanoacrylate cement (FH Cement)].

In the previous study (Shikwa Gakuho, 85: 413-451, 1985.), Morinaga reported on the histopathology of furcation perforations treated with ethyl cyanoacrylate and showed that, because of its properties, this material cannot be expected to effect a permanent blockade. It did not, however, irritate the wound. The purpose of this study is to investigate the effects of a new cyanoacrylate cement (FH Cement) when applied to furcation perforations. Subjects were 25 mandibular and maxilla premolars and molars obtained from 3 adult dogs. The method used in the study was as follows. After administration of pentobarbital-sodium general anesthesia, the pulp chamber was opened by means of a high-speed air turbine fitted with a diamond point. According to usual procedures, the pulp was removed, and the main root canal was filled. Next the floor of the pulp chamber was deliberately perforated by means of a 1mm round bur that had been previously sterilized in advance pouring a physiological sodium chloride solution at the same time. The perforated areas were then washed with a same solution, wiped, and dried with aseptic cotton pellets. They were then stuffed with cyanoacrylate cement. The cavity was lined with gutta-percha temporary stopping, and the remainder of the cavity was filled with silver amalgam. At periods of 1, 2, 4, 8 and 12 weeks after the operation, the animals were sacrificed by means of electricity under general anesthesia. The jaw bones were removed, fixed, decalcified, and embedded in celloidin. Longitudinal sections were stained with hematoxylin-eosin. Results 1. Periodontal tissues around perforated sites were healed by means of scar tissue, though suppuration occurred in a few cases. 2. Hard tissue was appended to the teeth in a small number of cases. 3. Repair of the alveolar bone was observed in the damaged site in about half of all cases. From the result mentioned above, cyanoacrylate cement (FH Cement) was seemed to did not close the site perforation for it self, but was not a stimulant to wound, in case of appropriate blockade.

Animals↗
PubMed1989

Ultrastructure of initial calcification on exposed human pulp applied with autogenous dentin fragments.

Initial calcification in human dental pulp has been studied with electron microscopy in 20 human teeth over a period of 21 days following pulp exposure and capping with autogenous dentin fragments. Five days after operation, dentin fragments were surrounded by degeneration cells and inflammatory cells. Occasionally a macrophage that had phagocytosed a dentin fragments was observed. Fourteen days after operation, osmiophilic needle-like crystalline structures were found in spherical bodies in the collagen fibrils or on the dentin surface. Ca and P were detected in these needle-like crystalline structures by energy dispersive X-ray analysis. They tended to increase in size and to fuse together to form mineralizing globules with the passage of time. Initial calcification around the dentin fragments developed various patterns, including spherical bodies in the collagen fibrils and direct apposition of needle-like crystals on the dentin fragments.

Adolescent↗
PubMed1988

[Clinical comparison of 99mTc-diethylenetriaminepentaacetic acid-human serum albumin (99mTc-HSA-D) and 99mTc-human serum albumin (99mTc-HSA) for cardiac blood pool imaging].

99mTc-HSA-D has been developed as a new blood pool scanning agent. Clinical comparison of 99mTc-HSA-D and 99mTc-HSA was made in 16 cases. The activity concentration of 99mTc in blood was measured during 2 hours after the injection in five cases. 99mTc-HSA-D showed higher concentration compared to 99mTc-HSA with the passage of time. Quantitative analysis of contrast between left ventricle and septum was performed on end diastolic frames of gated images 10 minutes after the injection. There was no obvious difference between 99mTc-HSA-D and 99mTc-HSA. The subjective comparison of detectability of lesions between the two agents was performed on three directional gated images. 99mTc-HSA-D was superior to 99mTc-HSA, because the images of the latter deteriorated with the passage of time. On anterior view images 1 hour after the injection, left ventricle/lung and abdominal aorta/background count ratios were greater for 99mTc-HSA-D in many cases. There was no obvious difference in liver/background and kidney/background count ratios between the two agents. Urinary excretion of 99mTc was considerably lesser for 99mTc-HSA-D. The results indicated that 99mTc-HSA-D was superior to 99mTc-HSA for cardiac blood pool imaging.

Aged↗
PubMed1986

Nucleotide sequence of a DNA segment promoting transcription in Pseudomonas putida.

A DNA segment that promotes gene expression in Pseudomonas putida was identified in pTN8, a mutant plasmid of an RP4-TOL recombinant. A promoter on the segment was cloned with a promoter-probe vector containing the xylE gene of the TOL plasmid. The xylE gene was expressed under the control of the promoter, and the gene product catechol 2,3-dioxygenase was constitutively synthesized. As analyzed by an S1 nuclease protection assay, the amount of mRNA produced in P. putida was more than that in Escherichia coli. Fine S1 nuclease mapping and reverse transcriptase mapping revealed three tandem transcription start sites in both P. putida and E. coli. The nucleotide sequence preceding the transcription start sites was determined; a part of this sequence contained a sequence homologous to E. coli promoter sequences. A tentative consensus sequence for P. putida constitutive promoters is proposed.

Base Sequence↗