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Biomedical subjects

Y Sakamoto

Publications and source records attributed to Y Sakamoto.

At least 487 records · Page 27Linked to original sources
PubMed1989

Measurement of postoperative intraocular lens tilting and decentration using Scheimpflug images.

A three-dimensional, in vivo method for determining the position of implanted intraocular lenses (IOLs) using an image-processing technique has been developed. Two images of the anterior segment of the eye with an implanted IOL were photographed with a Scheimpflug camera at slit-lamp angles of 90 degrees and 180 degrees. After geometrical correction, the contours of the original images were enhanced using binarization and curve-fitting techniques. These images afforded calculation of the angle of tilt of the IOL optic axis relative to a standard reference line which connected the center of anterior corneal surface curvature with the geometrical center of the pupil. The extent and direction of IOL decentration could also be shown. The IOL image in the posterior chamber was expressed as a wire-frame figure. This method provides several kinds of biometry in pseudophakic eyes.

Anterior Eye Segment↗
PubMed1989

Comparative study of the sugar chains of gamma-glutamyltranspeptidases purified from human hepatocellular carcinoma and from human liver.

The sugar chains of gamma-glutamyltranspeptidases, purified from human hepatoma and from normal human liver, were released quantitatively as oligosaccharides by hydrazinolysis. Comparative study of their structures revealed that the following structural alterations are induced by hepatocyte carcinogenesis: 1) high mannose type sugar chains are detected in the hepatoma enzyme but not in the normal liver enzyme; 2) abnormal biantennary sugar chains containing C-2,4 outer chain branches newly appeared; 3) the total amounts of tri- and tetraantennary sugar chains containing C-2,6 outer chain branches increased up to three times.

Carbohydrates↗
PubMed1989

A novel enzyme immunoassay for conidia of Fusarium oxysporum f.sp. cucumerinum F504.

This study was undertaken to develop a new tool to study fusarial diseases of plants. Micro- and macro-conidia of a strain (F504) of Fusarium oxysporum were isolated and antiserum against the conidia was elicited in rabbits. A highly specific and sensitive competitive-type enzyme-linked immunosorbent assay (ELISA) for conidia of the strain was developed using the antiserum with beta-D-galactosidase-labeled anti-rabbit IgG as the secondary antibody and conidia fragments of the strain as antigen attached to Amino-Dylark solid-phase balls. The assay was highly specific to conidia of the strain F504, while conidia-free hypha of the strain F504 as well as all other microorganisms tested including nine other strains of Fusarium species showed little cross-reactivity. Application of the ELISA to following the growth rates of conidia in hyphae of the strain F504 under several conditions are also reported.

Animals↗
PubMed1989

The biphasic change of cytosolic acetyl-CoA hydrolase in rat liver during 3'-methyl-4-dimethylaminoazobenzene hepatocarcinogenesis.

When Donryu male albino rats were given diet containing 0.06% 3'-methyl-4-dimethyl-aminoazobenzene (3'-Me-DAB) for 20 weeks, the activity of cytosolic acetyl-CoA hydrolase in their livers decreased to about one-third the initial level in week 2, returned to the control level in week 7, and then decreased again to about one-tenth of the control in week 20. These changes in enzyme activity were parallel with changes in the amount of enzyme protein determined by ELISA. In 3'-Me-DAB-resistant rats, however, the enzyme activity and enzyme protein remained within the normal range during administration of 3'-Me-DAB-containing diet for 20 weeks and no tumors were detectable macroscopically. Interestingly, the biphasic change in this enzyme activity was inversely associated with the well known change of gamma-glutamyltranspeptidase activity during azo-dye-induced hepatocarcinogenesis.

Acetyl-CoA Hydrolase↗
PubMed1989

Phenotypes of infiltrating cells in trehalose dimycolate-induced interstitial pneumonitis.

Trehalose dimycolate is a glycolipid component of the cell walls of mycobacteria, nocardia, and corynebacteria. When trehalose dimycolate is injected into certain strains of mice, they develop interstitial pneumonitis that is characterized by mononuclear cell infiltration of the alveolar walls, intra-alveolar hemorrhages, and in some animals, granuloma formation. The disorder is seldom fatal, and in approximately 4 weeks, the lungs are normal. There is strong evidence that T lymphocytes are essential for production of interstitial pneumonitis by trehalose dimycolate, but little is known about the mechanisms of lung injury in this model. The experiments described in this report were conducted to identify the roles of the various cells that accumulate in the lungs of mice with this form of interstitial pneumonitis. We found that Mac3+ macrophages were the first cells to appear in the alveolar walls. Increases in the number of L3T4+ T lymphocytes, Lyt2+ T lymphocytes, and surface-immunoglobulin-positive lymphocytes followed, but significant increases in the number of lymphoid cells were not observed until day 7, when the pulmonary lesions were well developed. Treatment of the mice with cyclophosphamide or anti-T-cell sera significantly reduced the number of lymphoid cells in the alveolar walls but did not affect the number of Mac3+ cells and did not affect development of intra-alveolar hemorrhages. Treatment with poly(I.C) significantly decreased the number of Mac3+ cells in the lungs, and these mice did not develop pulmonary hemorrhages. We conclude that although development of pulmonary lesions in trehalose dimycolate-treated mice is a T-cell-dependent process, macrophages are also essential and are more directly involved in production of the lung injury. We postulate that the lung lesions are the direct effect of macrophage-produced cytokines, such as tumor necrosis factor.

Animals↗
PubMed1989

Chronic cervical cord compression: clinical significance of increased signal intensity on MR images.

Magnetic resonance (MR) imaging was performed in 668 patients with chronic compressive lesions of the cervical spinal canal. High signal intensity was observed within the spinal cord on T2-weighted or proton density spin-echo images in 99 patients (14.8%). Frequency of this finding was directly proportional to severity of clinical myelopathy and degree of spinal canal compression seen on MR images. Patients with a high-signal-intensity area responded less favorably than those without to surgical or medical treatment. More than 60% of the patients had this finding when grade of myelopathy or degree of canal compression was moderate to marked. Among 10 patients who received contrast material during MR imaging, one patient had definite enhancement and another had questionable enhancement in the high-signal-intensity area. The finding disappeared after decompressive surgery and medical treatment in some cases: Three of four of the patients who underwent surgery showed good clinical improvement. High signal intensity of the spinal cord produced by compressive lesions appears to be an important indicator for predicting prognosis.

Adolescent↗
PubMed1989

Direct inhibitory effect of high glucose in mesenteric artery on glucose absorption from isolated perfused rat intestine.

To study whether glucose level in mesenteric artery has some direct effect on the intestinal glucose absorption, the rat small intestine was isolated and vascularly and luminally perfused. The vascular perfusate consisted of Krebs-Ringer bicarbonate buffer (KRB) containing 4% dextran, 0.5% albumin and 1-28 mM glucose, and the luminal perfusate consisted of KRB containing 18 mM glucose. Glucose absorption rate was decreased in a dose-dependent manner by the increasing concentration of glucose in the vascular perfusate within a range of 1-28 mM, but not changed by the addition of fructose to the vascular perfusate. It is suggested that glucose in the mesenteric artery has a direct inhibitory effect on the intestinal glucose absorption, not through a change of osmotic pressure.

Animals↗
PubMed1989

Interaction of rat liver glucocorticoid receptor with histones.

The activated glucocorticoid-receptor complexes (GRC) from rat liver bind tightly to histone (from calf thymus)-agarose and cannot be eluted with 3 M KCl or 50% ethylene glycol, but can be eluted with 20 mM pyridoxal 5'-phosphate (PALP). Purified activated GRC were found to have much higher affinity for histones H3 and H4 (arginine-rich histones) than for histones H2A and H2B (slightly lysine-rich histones) and to have negligible affinity for histone H1 (lysine-rich histone). The GRC bound to immobilized histones could be eluted with PALP, but not with its related compounds, such as pyridoxamine, pyridoxamine 5'-phosphate, pyridoxal, and pyridoxine, suggesting a specific effect of PALP. Not only activated GRC but also unactivated GRC were found to bind to immobilized histones. However, from their profiles of elution from a histone-agarose column by 20 mM PALP, the activated GRC seemed to have higher affinity than unactivated GRC for histone. Our results suggest that the binding of GRC to histones could be associated with a mechanism for alteration of the chromosome structure by the hormonal signals, before the binding of the GRC to a specific sequence of DNA in regulatory elements of glucocorticoid-responsible genes.

Animals↗
PubMed1989

Properties of an adenosine triphosphate-stimulated factor that enhances the nuclear binding of activated glucocorticoid-receptor complex: binding to histone-agarose.

Recently we have purified and characterized a factor in rat liver cytosol that enhances nuclear binding of the activated glucocorticoid-receptor complex in the presence of ATP [an ATP-stimulated translocation promoter (ASTP)]. It has a mol wt of 93,000, S value of 6.5, and pI of 4.5. Here we report studies on the binding of ASTP to histones from calf thymus. Higher salt concentrations were required to disrupt the binding of ASTP to histone-agarose than to disrupt its binding to the anion exchanger diethylaminoethyl-cellulose (half-maximal concentration for inhibition: 200 mM vs. 60 mM KCl). ATP decreased the binding of ASTP to histone-agarose in a dose-dependent fashion, but ADP and AMP had no appreciable effect on the binding. Pyridoxal 5'-phosphate (10 mM) inhibited the binding of ASTP to histone-agarose, whereas 10 mM pyridoxal, pyridoxamine 5'-phosphate, pyridoxamine, and pyridoxine were not inhibitory. ASTP did not bind to histone-agarose that had been pretreated with pyridoxal 5'-phosphate and then reduced with sodium borohydride. In contrast, ASTP pretreated in the same way could bind to histone-agarose. Therefore, modification of lysine residues of histones by pyridoxal 5'-phosphate (Schiff base) presumably inhibited the binding of ASTP to the immobilized histone. Competition experiments with various histones (H1, H2A, H2B, H3, and H4) indicated that ASTP bound to the arginine-rich histones H3 and H4, with preference for H4. These observations together suggest that lysine residues in H4 and H3 are essential for the binding of ASTP to histone. The implications of this interaction are discussed.

Adenosine Triphosphate↗
PubMed1989

Establishment of a cell line producing bone morphogenetic protein from a human osteosarcoma.

A human osteosarcoma cell line was established from a biopsy specimen from a 13-year-old girl. The osteosarcoma tissue was maintained in athymic nude mice (Balb C nu/nu) by serial transplantation for three years. The tumor was excised from a host mouse and digested with collagenase. The isolated cells were cultured by 98 passages in 14 months, and clones of osteosarcoma cells were obtained by limiting dilution. A clone named human osteosarcoma cell 6 (H-OS-6) that showed the osteoblastic phenotypes of productions of bone morphogenetic protein (BMP) and alkaline phosphatase and a response to human parathyroid hormone (h-PTH 1-34) was selected. The morphology of its chromosomes indicated its human origin. This human osteosarcoma cell line is unique in producing BMP under in vitro conditions.

Adolescent↗
PubMed1989

[Combination chemotherapy with bronchial arterial infusion (BAI) and systemic chemotherapy in advanced non-small cell lung cancer].

Five patients of advanced non-small cell lung cancer with atelectasis and/or poor performance status were treated with combination MVP therapy consisting of bronchial arterial infusion (BAI) using cisplatin (50 mg) and simultaneous systemic MVP therapy. The tumor size reduced more than 50% in three patients, and less than 25% in one patient. In another patient the tumor size was not measurable. Four of five patients showed disappearance of atelectasis, and three of four patients showed improvement of performance status. Average time taken was 13 and 17 days, respectively. We expect that combination MVP therapy has beneficial effects not only for relieving local symptoms and improving performance status within shorter period, but also achieving a better prognosis.

Aged↗
PubMed1989

[A family of pseudocholinesterase deficiency (silent type II)].

We report here a case of pseudocholinesterase (E.C. 3.1.1.8) deficiency, silent type II. The proband was a 29-year-old healthy man. His parents were cousins. A family study revealed that 9 out of 17 members of family investigated (paternal side 6, maternal side 3) concentrations. Serum cholinesterase activity were correlated well with serum albumin concentrations in both healthy people and patients with chronic liver diseases. The ratio of cholinesterase activity to albumin concentrations in serum was found more useful to detect heterozygous pseudocholinesterase deficiency than the serum cholinesterase activity alone. Both the dibucaine number and the fluoride number were within normal range in all family who showed low cholinesterase activity in serum. The amount of immunoreactive substance in serum against anticholinesterase antibody was normal in the proband as well as his family, while it was about twice of the value expected from their activity in those who had low ratio of serum cholinesterase activity to albumin concentrations. These results altogether suggested that the proband was a case of homozygous pseudocholinesterase deficiency, silent type II.

Adult↗
PubMed1989

[Noninvasive evaluation of changes in stroke volume and left ventricular filling dynamics. Produced by atrioventricular interval manipulation].

To evaluate the effects of atrioventricular pacing interval on hemodynamics, we studied the changes in stroke volume and left ventricular filling dynamics in fourteen consecutive patients with implanted atrioventricular pacemakers using a Doppler echocardiographic technique. Twelve patients had sick sinus syndrome and 2 had complete atrioventricular block. Stroke volume was determined as the time-velocity integral of the pulsed Doppler recordings at the aortic annulus multiplied by the area of the aortic annulus obtained by 2-dimensional echocardiography. Left ventricular filling velocity was measured at the mitral annulus by the pulsed Doppler technique to provide the time-velocity integral of rapid filling (TVI-R) and that of atrial filling (TVI-A). No significant change in stroke volume was noted during the atrioventricular interval manipulation. TVI-R was greater with short atrioventricular intervals than that with the long atrioventricular intervals. On the contrary, TVI-A was greater with long atrioventricular intervals than that with short atrioventricular intervals. These results suggested that there is a compensatory mechanism in the left ventricular filling dynamics to keep the stroke volume constant despite the change in the atrioventricular interval. However, in patients with high atrial filling to rapid filling ratio (A/R), the stroke volume varied with change of atrioventricular interval, suggesting that the compensatory mechanism was not sufficient in such patients. We conclude that Doppler echocardiography is a useful, noninvasive technique to assess the changes in the hemodynamics produced by atrioventricular interval manipulation in patients with implanted atrioventricular pacemakers.

Adult↗
PubMed1989

[A clinical evaluation of rush immunotherapy in adult patients with severe bronchial asthma].

Rush immunotherapy (RIT) using house dust (HD) antigen were performed in ten adult patients with chronic severe bronchial asthma who had mite allergy. All cases have reached to the maintenance dose of 10(-1) X 0.50 ml within 10 days and been able to introduce maintenance therapy smoothly. After the RIT, remarkable improvement of asthmatic symptom was seen in 4 cases and one of them was considered to be completely cured of the asthma. Although side effects such as local skin reaction, rhinorrhea and asthmatic attack were seen, severe side effect was not observed at all. IgE-RAST scores for both HD and mite were unchanged before and after RIT. On the other hand, the values of specific IgG4 for both HD and mite antibody were significantly increased 2 or 4 weeks after RIT. These results indicated that RIT can be performed safely and securely, and rapid immunological response as well as clinical effectiveness are able to be expected for adult severe asthmatics.

Adolescent↗