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Biomedical subjects

Y Chiba

Publications and source records attributed to Y Chiba.

At least 271 records · Page 15Linked to original sources
PubMed1988

Plasma collagen cofactor correlates with von Willebrand factor antigen and ristocetin cofactor but not with bleeding time.

Collagen cofactor (CCo), an activity of von Willebrand factor (vWF) which increases the rate of adhesion of human fixed washed platelets (FWP) to collagen, was measured in plasma from normal individuals and individuals with von Willebrand's disease (vWD). CCo in vWD plasma was compared to vWF antigen (vWF:Ag), ristocetin cofactor (RCo), factor VIII (VIII) coagulant activity (VIII:C) and the quantitative bleeding time. There was close correlation between CCo and VIII:C (r = 0.909), vWF:Ag (r = 0.975), and RCo (r = 0.936). However, there was no correlation between CCo and the quantitative bleeding time. Plasma CCo in type IIA vWD was markedly lower than vWF:Ag and the ratio of CCo/vWF:Ag was 0.08, which was less than a mean value of 0.92 in type I vWD. CCo activity in normal plasma was completely inhibited by monoclonal antibody CLB-RAg 201, an antibody that inhibits the binding of vWF to collagen, suggesting that the binding of vWF to collagen is required for the expression of CCo. Furthermore, the partial inhibition of CCo by monoclonal antibody CLB-RAg 35 that inhibits the binding of vWF to platelet in the presence of ristocetin, suggests that CCo is partly mediated through platelet membrane glycoprotein Ib. Large multimers of vWF:Ag in normal plasma were preferentially absorbed by collagen. These studies demonstrate that CCo is another functional activity of vWF and the measurement of CCo may be useful for the detection of new variant forms of vWD.

Antibodies, Monoclonal↗
PubMed1988

An autopsy case of congenital complete heart block in a newly born of a mother with systemic lupus erythematosus.

An autopsy case of congenital atrioventricular (AV) heart block is described. A newborn infant of a mother with systemic lupus erythematosus died 10 h after birth. Autopsy revealed hematoxylin bodies in the AV node, central fibrous body, and fibrous annulus of the heart. Also, immunoglobulin G (IgG) localization in the hematoxylin bodies was demonstrated by an immunoperoxidase technique. It is suggested that IgG or immune complexes crossed the placenta and that the immune deposition directly injured the cardiac conduction system, causing AV block.

Atrioventricular Node↗
PubMed1988

A case of hydrops fetalis due to placental chorioangioma.

A case of an infant born in association with a large chorioangioma of the placenta is reported. The mother was complicated with polyhydramnios and premature labor. The fetal complications were congestive heart failure and hydrops fetalis. This case serves to emphasize that it is necessary to examine the placenta in every perinatal autopsy case.

Female↗
PubMed1988

Occurrence of respiratory syncytial virus subgroup A and B strains in Japan, 1980 to 1987.

The subgroup characteristics of 71 strains of respiratory syncytial virus (RSV) isolated in Sapporo, Japan, during 5 epidemic years from 1980 to 1987 were determined by the use of 17 monoclonal antibodies (MAbs) raised against the RSV Long strain, which is now recognized as the prototype subgroup A strain. Nine of these MAbs immunoprecipitated the fusion protein (F), five immunoprecipitated the large glycoprotein (G), two immunoprecipitated the nucleoprotein (NP), and one immunoprecipitated the phosphoprotein (P). Based on the pattern of reaction of these MAbs to RSV isolates in an indirect immunofluorescence assay, we were able to distinguish two different subgroups. Subgroup A strains reacted to all 17 MAbs. Subgroup B strains reacted to none of the anti-G MAbs, eight of the nine anti-F MAbs, and all anti-NP and anti-P MAbs. Subgroup A included 38 (53.5%) isolates from every epidemic year. Subgroup B included 32 (45.1%) strains isolated in the last 4 epidemic years. One virus strain with an intermediate character of reactivity was isolated in 1983. From the first epidemic year, six subgroup A strains and no B strains were isolated. During the next three annual epidemics, subgroup B strains were predominantly isolated, i.e., 8 of 13, 10 of 13, and 13 of 17 strains. However, in the last epidemic year only one strain of 22 isolates belonged to subgroup B, and the remainder belonged to subgroup A. This variability of dominance in the occurrence of different RSV subgroup strains may suggest a possible role of the subgroup-specific immune response in RSV epidemics.

Antibodies, Monoclonal↗
PubMed1988

On a portable memory device for physical activities and informations of maternal perception.

The condition of patients must be known to attending doctors for adequate management of a disease, particularly of high risk pregnancy. For this purpose, we have developed a portable computerized disease condition memory device to record the physical activities with maternal perception of fetal movement and uterine condition in daily life, both at home and during work. This device taken out by the patient is a small battery-driven CMOS 8 bit computer system (size: 107 x 80 x 30 mm, 240 g) and is equipped with push-botton switches on the upper side and a mercury switch inside it. The time of maternal perception of fetal movement and uterine contraction are recorded by the patient pressing the corresponding switch. Meanwhile the mercury switch serves as a acceleration sensor and the physical activities were measured by counting ON-OFF actions of the mercury switch caused by her movements. Consequently, the device has recorded physical activities automatically by wearing this unit all day long. The continuously recordable time is more than two weeks. The evaluation about the sensitivity of physical activity measurement has indicated that the mercury switch sensor was well related to the oxygen consumption rate in rest and mild exercise. Using this device to five pregnant women, the data showed the quantitative difference in physical activities between rest in bed and normal home life, and daily changes could be clearly observed. From these results, the physical activities and the condition of the patient in daily life can be followed by this device.

Ambulatory Care Information Systems↗
PubMed1988

Effects of neuromedin B, gastrin-releasing peptide-10 and their fragment peptides on secretion of gastrointestinal and pancreatic hormones in dogs.

The effects of neuromedin B (NMB), gastrin-releasing peptide (GRP)-10 and their C-terminal fragment peptides on the pancreatic and gastrointestinal hormone release were studied in dogs. Intravenous bolus injections of NMB and GRP-10 (4.5 nmol/kg) into conscious dogs elicited a sharp and statistically significant rise in plasma gastrin and insulin levels, but only GRP-10 brought on a significant rise in the plasma glucagon and enteroglucagon levels. The degree of stimulation of gastrin and insulin secretion by NMB and GRP-10 was dose-dependent. With a dose of 4.5 nmol/kg, the minimum size of C-terminal fragment peptides of NMB and GRP-10 to stimulate gastrin secretion was NMB and GRP-10, respectively. Both NMB and GRP-10 (0.1-100 nmol/l) stimulated insulin release from the isolated canine pancreas. The glucagon release was stimulated by 10 and 100 nmol/l GRP-10 and was not stimulated by the same doses of NMB. The somatostatin release was not influenced by either peptide. It is concluded that 1) NMB and GRP-10 can stimulate gastrin and pancreatic hormone secretion, and the latter effect may be mainly due to a direct action on the islet cells; 2) the stimulatory effect of GRP-10 is stronger than that of NMB. The difference in the minimal active fragment between NMB and GRP-10 suggests that the amino acid of position 3 - NMB (Leu) and GRP-10 (His) - may play an important role in their biological activity.

Amino Acid Sequence↗
PubMed1988

Gentamicin dosing and pharmacokinetics in low birth weight infants.

Monitoring of serum gentamicin concentrations and one-compartment pharmacokinetic analysis were performed in 41 preterm low birth weight infants (20 with birth weight of less than 1,500 g and 21 with birth weight of greater than or equal to 1,500 g) in the first week of life. Our dosing regimens, which were 2.0 mg/kg every 24 hr for the less than 1,500 g group and 2.0 mg/kg every 12 hr for the greater than or equal to 1,500 g group, successfully achieved the desired peak (4-8 micrograms/ml; 87.8%) and trough (less than or equal to 3 micrograms/ml; 97.5%) concentrations on the 4th day of treatment. In a one-compartment pharmacokinetic analysis, a large intersubject variability of pharmacokinetic parameters were observed on the 1st day of treatment. When we compared the parameters of the 1st day with those of the 4th day, apparent decreases in Vd and TBC were observed. The mean values for TBC and T1/2 or Kd of the two birth weight groups were significantly different from each other on the 4th day of treatment, suggesting a less maturity of renal functions in the less than 1,500 g group. The modified method of Sawchuk and Zaske was proven impractical in predicting steady-state serum concentrations because of an underestimation probably caused by the dramatic alteration of Vd due to a diuresis soon after birth. Based on these results, we recommend the above-described dosing regimen and emphasize the importance of a close monitoring of serum gentamicin concentrations and toxicities, instead of the individualized dosing approach in low birth weight infants in the first week of life.

Bacterial Infections↗
PubMed1988

Intravital-microscopic observations on the intravascular behavior of blood cell components during dietary-induced hyperlipidemia in the male rabbit.

In normal male rabbits loaded dietary cholesterol, intravital-microscopy revealed a marked acceleration of intravascular adhesiveness of white blood cells and aggregability of red blood cells and a swarming of lipid-laden macrophages in connective tissue space concurrently with a systemic hyperlipidemia and anemia. Possible roles of the microcirculatory changes in the atherogenesis were discussed.

Animals↗
PubMed1988

[The course of pregnancy in patients with cardiac disease].

The outcome of 240 pregnancies in 202 patients with cardiac disease, who delivered between Jan. 1982 and Dec. 1987 at the National Cardiovascular Center was analyzed. Ninety-six patients had congenital heart disease. Forty-two had acquired valvular heart disease, 83 had cardiac arrhythmia, 7 had aortitis syndrome, 7 had cardiomyopathy and 2 had secondary angina pectoris. There was one case of each of the following cardiac diseases: Primary pulmonary hypertension, Marfan's syndrome and pericarditis. Nineteen of the above lapsed into congestive heart failure and there were two cases of maternal death. One was a case of primary pulmonary hypertension and the other had had an aortic valve replaced with a Bjork-Shiley prosthesis because of rheumatic valve disease. Another 16 mothers had artificial preterm delivery at a gestational age of 30 weeks to 36 weeks to reduce the risk of congestive heart failure. There were 5 cases of IUFD, three of which were attributed to maternal cardiac disease and another to fetal failure. Neonatal congenital heart disease was found in 8 cases. The percentage of IUGR, excepting twin pregnancies, was 14.8%.

Female↗
PubMed1988

[Surgical reconstruction for subclavian arterial obstruction at its origin].

The authors, having experienced 17 cases of subclavian arterial obstruction at its origin in Montpellier, France and in Japan, performed direct anastomosis between the divided end of the proximal subclavian artery and the ipsilateral common carotid artery (transposition technique) in 12 cases. Our series of 17 patients ranging in age from 30 to 73 years who were evaluated for variety of symptoms: 8 had subclavian steal syndrome; 12 had claudication of upper extremity; 1 had visual disturbance; 3 had vertigo; and 1 had ear throbbing. Twelve patients were treated surgically with division of the proximal subclavian artery and its anastomosis to the common carotid artery by means of supraclavicular cervicotomy. One was treated with carotid subclavian bypass grafting, and 4 were placed aorto-carotid-subclavian bypass grafting with median sternotomy because of the proximal occlusive lesions at the origins of common carotid and subclavian artery due to aortitis syndrome. All the patients were relieved from the symptoms which had been existed in pre-operative stage. The transposition technique is simple, effective and few complications.

Adult↗