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Biomedical subjects

K Hayashida

Publications and source records attributed to K Hayashida.

At least 271 records · Page 15Linked to original sources

Visualization of right atrial thrombus associated with constrictive pericarditis by indium-111 oxine platelet imaging.

A right atrial thrombus is not often seen and only a few reports of visualization have been described. We report a 44-yr-old man who had a large atrial thrombus associated with constrictive pericarditis. Two-dimensional echocardiography and computed tomography showed a large right atrial mass. Indium-111 oxine platelet deposition was demonstrated on the surface of thrombus by platelet imaging. Platelet imaging was useful for differential diagnosis from cardiac tumor, and as an indication for surgical treatment, since right atrial thrombus may have a high risk of pulmonary embolism or severe right heart failure.

Adult↗

[Lymphocyte subsets and response of breast cancer and benign mammary disease to PHA].

The lymphocyte counts, subsets and response to PHA in the peripheral blood of patients with breast cancer (stage I-III) and with a benign mammary disease have been evaluated. In the breast cancer cases, the lymphocyte counts and stimulation index of PHA increased gradually as the stages advanced but there was no statistical significance. The ratio and number of OKT 4 positive lymphocytes were significantly lower in patients with breast cancer (stage I) between 40 and 59 years old than in patients with benign mammary diseases between the same ages. This impairment of OKT 4 in breast cancer (stage I) cases was considered as either a cause of the carcinoma or as a reflection of the environment of steroid hormones.

Antigens, Surface↗

[Pre- and post-operative right ventricular functions in valvular heart diseases: the significance of noninvasive assessment].

This investigation was undertaken to evaluate right ventricular function in valvular heart diseases by calculating right ventricular ejection fraction (RVEF) from first-pass radionuclide angiography (RNA). One hundred cases of valvular heart disease were examined by RNA, 93 of whom underwent cardiac catheterization and contrast left ventriculography, preoperatively. Fifty of the 100 cases were examined by RNA; 18 by cardiac catheterization post-operatively. The results were as follows: 1. In 49 cases of mitral valve disease, there was a correlation (r = -0.75) between pulmonary artery mean pressure (PAm) and RVEF. This suggested that afterload of left atrial pressure elevation induced a decrease in RVEF. 2. Although PAm did not increase so much in aortic valve disease, RVEF decreased in some cases, especially in those having massive aortic stenosis or regurgitation. In 22 cases of aortic regurgitation which had normal PAm and a left ventricular-aortic systolic pressure gradient less than 50 mmHg, there was a correlation (r = -0.69) between the RVEF and the left ventricular end-diastolic volume index (LVEDVI). 3. Although post-operative RVEF did not improve significantly in mitral valve disease, it increased significantly in the early post-operative period in aortic valve disease. Also, the increase in RVEF and the decrease in LVEDVI seemed to correlate closely in aortic valve disease. It was speculated that pre-operative decrease of RVEF is derived from a deformity of the RV caused by pressure from the enlarged or thickened LV, and that post-operative increase of RVEF is dependent upon a decrease of LV size and volume.

Erythrocytes↗

Human lymphocytes synthesize C-reactive protein.

We obtained evidence for the synthesis and secretion of C-reactive protein (CRP) by peripheral mononuclear cells in culture. Human mononuclear cells isolated from peripheral blood, after depletion of platelets, were cultured in glutamine-depleted RPMI 1640 supplemented with [3H]glutamine in the presence of 10-O-tetradecanoyl-phorbol-13-acetate (TPA). Anti-CRP antiserum was added to the culture medium, and the resultant immunoprecipitate was analyzed in SDS-polyacrylamide gel electrophoresis (SDS-PAGE). The immunoprecipitate consisted of CRP, heavy and light chains of IgG, and only the CRP protein band had radioactivity, indicating that CRP was synthesized by mononuclear cells. In the populations of mononuclear cells, T-cell preparations mainly synthesized CRP, under stimulation of a factor derived from activated monocytes. Studies using the inhibitors of phospholipid metabolism suggested that generation of the monocyte factor was relevant to metabolites of an arachidonate cascade.

B-Lymphocytes↗

Expression of rat alpha 2-macroglobulin gene during pregnancy.

Rat alpha 2-macroglobulin (alpha 2M) is a typical acute phase protein, the concentration of which in serum increases more than 100-fold after inflammation. It is also known that the protein increases during pregnant (and neonatal) stages. Using a specific cDNA probe, expression of the alpha 2M gene during pregnancy was studied at the mRNA level. During inflammation, the liver is almost the only organ producing alpha 2M, but during pregnancy the placenta and uterus were found to be major organs producing a large amount (70-80% of that of inflamed liver) of alpha 2M mRNA at days 12-15. The yolk sac, maternal liver and fetal (or neonatal) liver also produced a small but significant amount (5-20% of that of inflamed liver) of the mRNA. Southern blotting analysis showed that only one copy of the alpha 2M gene was present in a haploid rat genome. These results indicated that a single alpha 2M gene has the ability to respond to two completely-different physiological states.

Animals↗

Age-specific prevalence of hepatitis B e antigen (HBeAg) and antibody to HBeAg (anti-HBe) among asymptomatic hepatitis B surface antigen (HBsAg) carriers in Okinawa and Kyushu, Japan.

A total of 1,741 asymptomatic hepatitis B surface antigen (HBsAg) carriers in two areas (Okinawa and Kyushu) in Japan were surveyed for the presence of hepatitis B e antigen (HBeAg) and the corresponding antibody (anti-HBe) to determine the age-specific prevalence of these markers and the mean age of carriers with HBeAg. Prevalence of HBeAg was significantly higher in Kyushu (36.4% of 755 carriers) than in Okinawa (20.0% of 986 carriers) (P less than 0.001). The mean age of carriers with HBeAg was 25.5 years in Kyushu and 16.1 years in Okinawa, suggesting that HBeAg converted to anti-HBe earlier in Okinawa than in Kyushu. In contrast, the prevalence of anti-HBe was significantly higher in Okinawa (74.6% of 986) than in Kyushu (56.3% of 755) (P less than 0.001). The prevalence of HBeAg decreased with age up to 40-49 years of age and then increased in both areas. Prevalence of anti-HBe was inversely related to the prevalence of HBeAg in both areas. These data suggest that HBeAg and anti-HBe are chronological markers of chronic hepatitis B virus infection and that the duration of HBeAg persistence can be different in different area, even in the same country.

Age Factors↗

Hypercapnic and hypoxic ventilatory responses during growth.

Cross-sectional studies on hypercapnic and hypoxic ventilatory chemosensitivities were performed in 71 children ranging in age from 7 to 18 yrs. The subjects were classified into 6 successive 2-year age groups. CO2 ventilatory response was measured by rebreathing 5% CO2 in O2, a slight modification of the method originally proposed by Read. The results were evaluated when the CO2-ventilation feedback control system was supposed to have attained the open-loop condition. Hypoxic ventilatory response was measured by the isocapnic progressive hypoxia test. To obtain good reproducibility in the ventilatory response, end-tidal PCO2 was maintained at 5 mmHg higher than the resting condition throughout the test. Normalized ventilatory responses to CO2 by body surface area (S/BSA) progressively decreased from the 7-8 through the 11-12 yr groups, and then tended to decrease further in a more gradual manner with increasing age. This trend was very similar to the normalized CO2 output (VCO2/BSA), but did not parallel so closely the normalized O2 intake (VO2/BSA). When ventilatory and metabolic parameters were normalized by body weight (BW), or the lean body mass (LBM), qualitatively similar relationships between CO2 sensitivities and metabolic parameters were also obtained. Contrary to the hypercapnic response, hypoxic ventilatory chemosensitivities were not significantly different among the 6 different age groups. We concluded that normalized hypercapnic chemosensitivity decreased during growth and corresponded well with decreased CO2 output per unit body mass.

Adolescent↗

Polymorphonuclear leukocytes and the induction of alpha 2-macroglobulin synthesis.

Peritoneal exudate-polymorphonuclear leukocytes (PMNLs) secreted a factor, PMN factor (PMN-F), which stimulated hepatocytes to synthesize alpha 2-macroglobulin (a2M), in vitro. The synthesis of a2M was enhanced by the factor in the presence of dexamethasone (Dex), and the effect was dose-dependent. After harvesting from the peritoneal exudate, PMNLs released the factor within 1 hr of the incubation. Physicochemical properties of the factor were as follows: nondialyzable, heat-labile, stable in wide pH change, inactivated by a protease inhibitor, aprotinin, and apparent molecular weight being 12,000-21,000, determined by gel filtration. Treatment of PMNLs with zymosan resulted in increases in the activity of lysosomal enzymes but not that of the factor. These results indicate that the factor is a protease other than lysosomal enzymes.

Animals↗