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Biomedical subjects

Y Aoyagi

Publications and source records attributed to Y Aoyagi.

At least 19 recordsLinked to original sources
PubMed1992

Evaluation of morphological changes of the atherosclerotic aorta by enhanced computed tomography.

Enhanced and non-enhanced computed tomography (CT) were performed in 405 subjects (222 men; 183 women; mean age 57 years). Intimal atherosclerotic changes of the aorta were quantified by enhanced CT, revealing the atheromatous intima to be projecting and thick-walled, while non-enhanced CT demonstrated aortic calcification. We measured the degree of aortic intimal changes at various segments of the aorta. In 224 cases, CT was performed from the aortic root to the bifurcation of the abdominal aorta. Intimal changes were found predominantly at the aortic arch, the middle descending thoracic and the infrarenal abdominal aorta. As for the intimal changes, aortic calcification and aortic pulse wave velocity were significant atherosclerotic characteristics. The aortic diameter did not show a significant association with intimal change. Among the various atherosclerotic risk factors, intimal change was significantly associated with age, systolic blood pressure, serum total cholesterol and diabetes mellitus, whereas gender, diastolic blood pressure, relative weight and cigarette use were not significantly related. For coronary artery disease and arteriosclerosis obliterans, aortic intimal changes constituted a significant atherosclerotic feature. In cerebrovascular disease, however, aortic intimal change did not play a significant role.

Adolescent↗
PubMed1992

A case of cyclophosphamide-induced interstitial pneumonitis diagnosed by bronchoalveolar lavage.

A successfully treated case of cyclophosphamide pneumonitis, which developed during treatment for a leukemic phase of B-cell non-Hodgkin's lymphoma, is documented. Subtyping of lymphocytes in the peripheral blood and the bronchoalveolar lavage fluid easily excluded a possible diagnosis of pulmonary involvement of lymphoma. Bronchoalveolar lavage is a useful approach to determine the correct etiology of pneumonitis.

Aged↗
PubMed1992

Aging and muscle function.

Most of the available data on the aging of muscle function are cross-sectional in type. Static and dynamic muscle strength seem well preserved to about 45 years of age, but performance deteriorates by about 5% per decade thereafter. There is a parallel loss of lean tissue. Because muscle biopsy specimens are not always representative of an entire muscle, it is unclear whether there is a general hypotrophy or atrophy of the muscle fibres or a selective hypoplasia and degeneration of type II fibres associated with a loss of terminal sprouting. Other influences may include a deterioration of end-plate structures with impaired excitation-contraction coupling and impaired fibre recruitment. Both contraction time and half-relaxation time are prolonged with aging, and there is a decrease of maximal contraction velocity, more marked in the legs than in the arms. On the other hand, endurance at a fixed fraction of maximal force is increased. Potential factors leading to the enhanced endurance include a poorer maximal effort and an increased proportion of type I fibres; however, there is little evidence that muscle capillarity is altered. The loss of function is generally less in the arms than in the legs, but it remains unclear whether this is an inherent biological difference, or merely a reflection of differential changes in activity patterns between the upper and the lower limbs. The male/female strength ratio does not seem to change with age, but substantial slowing or reversal of the aging process is possible through appropriate activity programmes. The preservation of muscle function has important implications for the quality of life in the frail elderly, counteracting dyspnoea, stabilising joints and extending the period of independent living by up to 20 years.

Aging↗
PubMed1992

Unoperated thoracic aortic aneurysms: survival rates of the patients and determinants of prognosis.

The purpose of this study was to evaluate the long-term prognosis of unoperated thoracic aortic aneurysms, and to detect the risk factors which determine the prognosis of unoperated patients. The subjects were 52 unoperated patients with 58 thoracic aortic aneurysms (22 of the ascending aorta, 36 of the descending aorta or the aortic arch) and 38 with abdominal aortic aneurysms. The survival rates of the patients with ascending aortic aneurysms at 3 years and 5 years and those of the patients with descending aortic aneurysms at 5 years were significantly higher than those of the patients with abdominal aortic aneurysms. The risk factors for rupture of thoracic aortic aneurysms were the large size of aneurysms and non-management by the cardiologist and the risk factors for death unrelated to the aneurysms were patient age, male gender and non-management by the cardiologist.

Age Factors↗
PubMed1992

Establishment of a human hepatoblastoma model in athymic nude mice. Producibility of fatty acid-binding protein, alpha-fetoprotein, and alpha 1-acid glycoprotein.

An athymic nude mouse model of human hepatoblastoma, designated HBL-2, was established. HBL-2 produced alpha-fetoprotein (AFP) and the serum level in tumor-bearing mouse was roughly proportional to the tumor weight. Reactivity of AFP to Concanavalin A and Lens culinaris lectins indicated that it contained predominantly fucosylated, non-bisecting N-acetylglucosamine as a sugar moiety. Alpha 1-acid glycoprotein (AAG) was also found in both HBL-2 tumor extract and sera of tumor-bearing mice. The serum level, however, was not proportional to either the tumor weight or the value of the tumor extract. In addition, fatty acid-binding protein (FABP) was detected in approximately 40% of tumor cells and in tumor extract with polyclonal antibody against liver FABP. Thus, HBL-2 is an unique model of human hepatoblastoma, in that it produces FABP in addition to AAG and AFP.

Animals↗
PubMed1991

The usefulness of simultaneous determinations of glucosaminylation and fucosylation indices of alpha-fetoprotein in the differential diagnosis of neoplastic diseases of the liver.

The degrees of glucosaminylation (glucosaminylation index) and fucosylation (fucosylation index) of alpha-fetoprotein (AFP) were determined in serum samples of 351 patients with hepatocellular carcinoma (HCC), 47 with carcinoma metastatic to the liver from digestive organs, five with mixed cholangiocellular and HCC, and 176 with benign liver diseases. The glucosaminylation index of AFP in patients with carcinoma metastatic to the liver (42 +/- 23%, mean +/- SD) was significantly higher than that in patients with HCC (5 +/- 7%, P less than 0.001) or that in patients with benign liver diseases (2 +/- 4%, P less than 0.001). The fucosylation indices of AFP in patients with carcinoma metastatic to the liver, with HCC, and with benign liver diseases were 76 +/- 25%, 42 +/- 30%, and 4 +/- 6%, respectively. Thus, the fucosylation indices of AFP were high in two neoplastic liver diseases (carcinoma metastatic to the liver and HCC) and low in benign liver diseases, whereas the glucosaminylation indices were high in carcinoma metastatic to the liver but low in HCC and benign liver diseases. When the values of 30% and 80% were used as the level of the glucosaminylation and fucosylation indices, respectively, to discriminate carcinoma metastatic to the liver from HCC, 40 of 47 patients with carcinoma metastatic to the liver (85%) were able to be discriminated from HCC (sensitivity). The specificity, the positive predictive value, and the overall accuracy were 86% (302/351), 45% (40/40 + 47 + 3 - 2) and 86% (40 + 302/47 + 351), respectively. These data suggest that the combined information in these two indices provides a potent criterion for the diagnosis of neoplastic diseases of the liver.

Adenoma, Bile Duct↗
PubMed1991

Effects of the mammalian lignan, 2,3-dibenzyl-butane-1,4-diol, on contraction and Ca2+ mobilization induced by noradrenaline in rat aorta.

1. In rat aorta, 2,3-dibenzylbutane-1,4-diol (DBB) inhibited noradrenaline (NA)-induced contraction in a concentration-dependent manner. The inhibitory effect of DBB was observed in verapamil-pretreated muscle, and did not differ from that in the high K+ solution containing verapamil (1.0 microM). 2. DBB inhibited not only contraction, but [Ca2+]i elevation induced by NA (10 microM) with the same potency. 3. The inhibitory effect of DBB on NA-induced contraction was reversed by methylene blue (3.2 microM) and enhanced by M&B 22,948 (10 microM). 4. DBB (100 microM) alone increased cyclic GMP levels. This effect was attenuated by methylene blue (3.2 microM) and augmented by M&B 22,948 (10 microM). 5. From these results, the inhibitory effects of DBB on NA-induced contraction in rat aorta may be caused by an increase of cyclic GMP levels.

Animals↗
PubMed1991

Research note: beta-adrenergic agonist effects on liver and breast muscle protein synthesis in female chicks.

The effect of administration of clenbuterol, a beta-adrenergic agonist, on live weight gain and protein synthesis of liver and breast muscle was investigated in 32 White Leghorn chicks. Protein synthesis was measured by injection of [3H]phenylalanine in a wing vein using the flooding dose method. No significant changes in body weight gain were caused by dietary administration of the beta-agonist at .25 mg/kg of diet from 3 to 6 wk of age, but fat retention in the liver and breast muscle was significantly reduced by the drug treatment. No stimulating effect on protein synthesis of the beta-agonist administration was found either in the breast muscle or in the liver. Protein synthesis in the breast muscle was unchanged whereas that in the liver was reduced significantly by feeding clenbuterol.

Animals↗
PubMed1991

[Clinical significance of antibodies against calmodulin in patients with various liver diseases].

The sera from patients with various liver diseases were investigated for the antibody against calmodulin (CaM) extracted from bovine brain by the enzyme linked immunosorbent assay. The specificity and purity of CaM were confirmed by the Western blot technique using anti-CaM antibody (anti-CaM) positive sera. IgA class antibody was frequently detected in patients with hepatocellular carcinoma (HCC), autoimmune hepatitis (AIH) and chronic active hepatitis (CAH). On the other hand, IgG class antibody was very often present in patients liver cirrhosis, AIH and acute viral hepatitis (AVH). Sixty seven percent of patients with AVH in the acute phase were positive for IgM class anti-CaM and 33% of patients with AVH in the convalescent phase positive respectively. In AVH, the titer of anti-CaM reached its peak on 26.3 days after the onset. The titer of anti-CaM in fulminant hepatitis was higher than that in AVH. Seventy percent of type A hepatitis patients were positive for IgM class anti-CaM, 33% of type B and 33% of type non-A non-B. These results suggest that the frequency and titer of anti-CaM may depend upon the type of hepatitis and the degree of liver cell injury.

Autoantibodies↗
PubMed1990

Coronary artery calcification detected by CT: clinical significance and angiographic correlates.

Cardiac computed tomography (CT) to detect coronary calcification was performed on 161 patients undergoing coronary angiography for proven or suspected coronary artery disease. Among 108 patients in whom coronary calcifications was identified, 90% had significant coronary stenosis angiographically (greater than 75% stenosis), and 80% of 121 patients with significant coronary stenosis showed calcification by CT. The relationship between the calcification site and the significance in stenosis of each vessel was determined. Calcification was present in 133 arteries among 205 stenotic coronary arteries (sensitivity = 65%) as compared with 59 of 439 entire arteries with normal coronary angiograms (specificity = 87%). In the younger age group the sensitivity of calcification for stenosis of each coronary artery was lower and the specificity and predictive value were generally higher than those in the elderly group. These results demonstrate that CT is a valuable procedure for detecting coronary arterial disease, since this examination is easy to conduct, noninvasive, and widely applicable for screening a large population.

Adult↗
PubMed1990

A lectin-based monoclonal enzyme immunoassay to distinguish fucosylated and non-fucosylated alpha-fetoprotein molecular variants.

Purified alpha-fetoprotein (AFP), fucosylated AFP mixtures, and 40 sera from patients with AFP-producing hepatocellular carcinoma were analysed by monoclonal enzyme immunoassay (EIA) to distinguish fucosylated and nonfucosylated AFP molecular variants. FUC-AFP-25 was discriminated from FUC-AFP-75 by the EIA using monoclonal antibody 18H4 in the range of total AFP concentrations from 100 to 800 ng/mL. In addition, sera from 40 patients with hepatocellular carcinoma, with AFP concentrations from 100 to 1270 ng/mL and with fucosylated AFP from 0 to 100% by conventional cross immuno-affinoelectrophoresis, were also analysed by the present EIA. A statistically significant correlation was obtained between the data from the present EIA and from the conventional crossed immuno-affinoelectrophoresis in the range of fucosylated AFP more than 20% and the serum concentration of AFP more than 100 ng/mL. These results indicate that the present EIA is useful for clinical detection of hepatocellular carcinoma during the follow-up of patients with chronic liver diseases.

Antibodies, Monoclonal↗
PubMed1990

[Progression to ischemic heart disease in subjects with coronary calcification as evaluated by computed tomography].

It is well known that coronary artery calcification develops in patients with advanced coronary sclerosis. Currently, it can be easily detected by computed tomography (CT). We studied the correlation of CT-detected coronary calcification with its progression to myocardial infarction, and further with the prognosis in various patients who did not have symptoms suggesting ischemic heart disease. The subjects consisted of 241 patients (136 males, 105 females) with a mean age of 61 years, categorized as a calcified coronary artery group (82 patients) and a non-calcified coronary artery group (159 patients). In all the subjects nonenhanced serial cardiac-CT scans were performed with a GECT/T 9800 for detecting coronary calcification. The mean follow-up period was four years in both groups. Among the 82 patients with coronary calcification, four developed myocardial infarction (4.9%) and 14 patients died (17%). Among the 159 patients without coronary calcification, none progressed to myocardial infarction, but 17 patients died unrelatedly (11%). Although there was no significant difference in mortality between the two groups, there was a statistical significance (p less than 0.005) as to the incidence of progression to myocardial infarction. In males, there was no significant difference (13 vs 12%) in mortality between the two groups, but the calcified group had a higher incidence of progression to myocardial infarction than that of the non-calcified group (5.5 vs 0%). In females, the calcified group had higher mortality (26 vs 8.9%) and a more frequent incidence of myocardial infarction (3.7 vs 0%) than did the non-calcified group. In conclusion, patients with coronary artery calcification are likely to develop coronary artery disease rather rapidly, even though asymptomatic. Therefore, detection of coronary calcification by non-enhanced CT is helpful for estimating the prognosis of coronary artery disease.

Calcinosis↗
PubMed1990

[Hodgkin's disease associated with Tolosa-Hunt syndrome].

A thirty-eight-year-old man developed gradually progressing right retro-orbital pain, diplopia on the left lateral gaze, and left ptosis. On examination paresthesia was present on the first division of right trigeminal nerve. Orbital venography revealed obstruction of right superior orbital vein on the entering portion to the cavernous sinus. A daily administration of 30 mg of prednisolone resulted in a rapid improvement of the symptoms. Diagnosis of Tolosa-Hunt syndrome was made on the basis of neurological symptoms, roentgenographic findings and responsiveness to prednisolone. One year later, weakness of right leg accompanied with left cervical and axillary lymphadenopathy was developed. A biopsy specimen of cervical lymph node was identical with the Hodgkin's disease, lymphocyte predominance type. He was treated with COPP regimen; lymphadenopathy decreased in size. We reported a rare case of Hodgkin's disease preceded by Tolosa-hunt syndrome which might be caused by the extranodal lesions.

Adult↗
PubMed1990

Relationship between the starting age of training and physical fitness in old age.

The purpose of this study was to test the hypothesis that older persons can minimize the reduction in physical fitness with aging if they start training before approximately 50 years of age, beyond which strength decline has been reported to become more pronounced. Maximal values for isometric strength, dynamic strength and speed of movement of the biceps brachii and quadriceps muscles, back-lift strength, and predicted oxygen uptake (VO2max = VO2max) were measured in 39 male subjects who were 60-68 years old. Four groups were studied: T26, T45, T56, and untrained. The T26 group had been training (jogging 10 km.day-1, 5 days.wk-1 at 10 km.h-1) since before their mid-thirties (mean 26 years), the T45 group since their forties (mean 45 years), the T56 group since their fifties (mean 56 years), and the untrained group had never taken part in any systematic training. Collectively, the T26 and T45 groups had significantly (p less than 0.05) higher values for muscle strength, speed of contraction, and VO2max than the T56 and/or untrained group(s). However, no differences were observed between the T26 and T45 groups. The results support a relation between the starting age of training and the age-dependent decline of physical fitness. Thus, the hypothesis is accepted.

Adult↗
PubMed1979

alpha-Fetoprotein as a carrier protein in plasma and its bilirubin-binding ability.

The bilirubin-binding ability of human alpha-fetoproteins, which were purified from fetal cord serum and from ascites fluid of a hepatoma-bearing patient, was examined by the difference spectrum and the Jacobsen peroxidase methods. The difference spectrum observed as a result of the specific binding of bilirubin to alpha-fetoprotein had a maximum at 482 nm, and this pattern was quite similar to that observed for serum albumin. The result obtained by the difference spectrum method showed that 1 mol of each alpha-fetoprotein bound 1 mol of bilirubin at pH 8.3 and that the dissociation constants of the complexes of bilirubin with fetal alpha-fetoprotein and hepatoma-derived alpha-fetoprotein were 2.6 x 10(-7) and 5.0 x 10(-7) M, respectively. The Jacobsen enzymatic method using horseradish peroxidase gave the same values for molar binding ratios and similar dissociation constants, 7.1 x 10(-7) M for fetal alpha-fetoprotein and 7.4 x 10(-7) M for hepatoma-derived alpha-fetoprotein. These results indicate that alpha-fetoprotein may function as a carrier protein for bilirubin as has been shown for serum albumin.

Bilirubin↗
PubMed1978

Copper(II)-binding ability of human alpha-fetoprotein.

The copper(II)-binding ability of human alpha-fetoproteins, which were purified from umbilical cord serum and from ascites fluid of a hepatoma-bearing patient, was examined by equilibrium dialysis and gel filtration methods. The pH dependence of the copper(II)-binding ability of alpha-fetoprotein was quite similar to that of albumin. Alpha-fetoprotein bound 1 mol of copper(II) ion per mol of protein above pH 6.0 and 0.5 mol of copper(II) ion at pH 5.4, which is close to the pK value of the imidazole group of histidine. Photooxidation of alpha-fetoprotein in the presence of methylene blue resulted in the loss of the copper(II)-binding ability of the protein in parallel with the destruction of the histidyl residues. A synthetic amino-terminal undecapeptide of alpha-fetoprotein also bound copper(II) ion. These results indicate that the histidyl residue at the amino-terminal region of alpha-fetoprotein plays an important role in the copper(II)-binding ability of the protein.

Carcinoma, Hepatocellular↗