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Biomedical subjects

M Yasuda

Publications and source records attributed to M Yasuda.

At least 433 records · Page 24Linked to original sources

In vitro production of feline IgG: quantification by an enzyme-linked immunosorbent assay (ELISA).

We report here on the development of a sensitive and convenient enzyme-linked immunosorbent assay (ELISA) for feline IgG by using commercially available reagents and optimizing their concentrations. The reagents employed include goat anti-cat IgG antibody and alkaline phosphatase-conjugated goat anti-cat IgG antibody. The assay described is sensitive, reproducible, and highly specific for feline IgG. The assay was applied for the measurement of feline IgG synthesized and secreted in vitro by peripheral blood mononuclear cells cultured with or without a polyclonal B-cell activator. The amounts of secreted IgG in the supernatants measured by an ELISA correlated well with the numbers of IgG-secreting cells which were induced upon stimulation with pokeweed mitogen and determined by a reverse hemolytic plaque assay.

Animals↗

[Morphological and immunohistochemical study on specimens of trophoblastic diseases in which the presence of a villous formation could not be established].

The histopathological discrimination between malignant trophoblastic diseases and benign trophoblastic diseases depends on the presence or absence of a villous structure. However, molar extravillous trophoblasts and cells in some placental site trophoblastic tumors (PSTT) of a benign nature, lack a villous structure. We therefore observed the morphology of trophoblastic cells which do not constitute a villous structure, including choriocarcinoma cells, and analyzed the location of placental proteins in these cells immunohistochemically. The results were as follows: 1. Molar extravillous trophoblasts were composed of large mononuclear cells and multinuclear cells. Most of them were positive for hPL and negative for hCG and SP1. 2. Choriocarcinoma consisted of cytotrophoblast-like cells, syncytiotrophoblast-like cells, large mononuclear cells and multinuclear cells resembling large mononuclear cells. HCG was noted in syncytiotrophoblast-like cells and large mononuclear cells, while hPL and SP1 were found only in syncytiotrophoblast-like cells. 3. PSTT was made up of large mononuclear cells and multinuclear cells which contained abundant hPL and very little hCG and SP1 or none at all. Molar extravillous trophoblasts were clearly distinguishable from choriocarcinoma cells in terms of their morphology and the location of placental proteins. In contrast, it seemed difficult to distinguish cells of PSTT from molar extravillous trophoblasts on a cell level.

Chorionic Gonadotropin↗

[Differential diagnosis of the early cancer: imaging diagnosis "CT"].

Computed tomography (CT) makes a significant contribution to the care of the patient with cancer, and is still expanding its usage in the diagnosis of the tumor. CT is considered to be an essential tool for the cancer of the pharynx and larynx, lung, liver, biliary tract, pancreas, kidney, adrenal gland, and ovary. We briefly describe the CT anatomy and oncologic pathology in these regions.

Carcinoma, Hepatocellular↗

[HLA-DP and HLA-DQ antigen expression on trophoblasts of normal human pregnancy and trophoblastic diseases].

A blocking antibody in pregnant sera seems essential in understanding why a fetus can survive as a semi-allograft in an immunologically competent mother. It has been demonstrated that blocking antibody is closely related to the paternal HLA-DR antigens. However, we previously reported that HLA-DR is not expressed on any trophoblast constituting the fetal frontier at the feto-maternal interface. The present study was then undertaken to clarify whether or not trophoblasts of normal pregnancy and trophoblastic diseases express HLA-DP or HLA-DQ antigens which are closely linked to HLA-DR as a haplotype. Materials were taken from ten pregnant uteri, ranging from 8 to 22 weeks of gestation, two uteri containing complete mole and two uteri each containing gestational choriocarcinoma. Curettage specimens obtained from three cases of complete mole and two cases of partial mole were also employed. Antigen expression was examined by an indirect immunoperoxidase technique using various monoclonal antibodies. From this immunohistochemical study, neither HLA-DP nor HLA-DQ seemed to be expressed on any trophoblast of normal pregnancy and trophoblastic diseases, which, together with the negative findings of HLA-DR on trophoblasts, may suggest that blocking antibody is not generated against HLA-D locus antigens on trophoblasts.

Female↗

Occurrence of spontaneous diabetes mellitus in a cynomolgus monkey (Macaca fascicularis) and impaired glucose tolerance in its descendants.

Spontaneous diabetes mellitus was diagnosed in a cynomolgus monkey. Clinical and pathological features, such as abnormal glucose tolerance, loss of insulin response, or degeneration of pancreatic beta-cells, resemble human noninsulin-dependent diabetes mellitus. Two descendants of the monkey have developed impaired glucose tolerance and insulin response. Genetic factors seem involved in the appearance of carbohydrate intolerance in this family group of monkeys.

Animals↗

[Regional left ventricular diastolic dysfunction in patients with apical hypertrophy].

Differences in cardiac function between the apical and the chordal parts of the left ventricle in apical hypertrophy (APH) were investigated by M-mode echocardiography. The subjects consisted of 10 patients with APH (APH Group) and 10 normal controls (N Group). The M-mode echocardiograms of the interventricular septum (IVS) and left ventricular posterior wall (LVPW), both in the apical and chordal parts were simultaneously recorded with the electrocardiogram and phonocardiogram. There were no significant differences in the blood pressures, heart rates, left ventricular end-diastolic internal diameters, and left ventricular end-systolic internal diameters between the APH Group and the N Group. The hypertrophy was localized to the IVS and LVPW of the apical part in the APH Group. In the chordal part, there were no significant differences in the peak negative dD/dt (-dD/dt) and the time to the peak filling rate (TPFR) between the APH Group and N Group. In the apical part, -dD/dt of the APH Group tended to increase compared with that of the N Group. The TPFR of the APH Group was significantly longer than that of the N Group (APH Group: 167 +- 33 msec and N Group: 126 +- 19 msec, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Detection of left ventricular thrombi after acute myocardial infarction using Ga-67-DFO-DAS-fibrinogen].

Ga-67-DFO-DAS-fibrinogen (Ga-fbg) scintigraphy, a new radiopharmaceutical method, was performed for detecting intraventricular thrombi following acute myocardial infarction in five patients. The thrombi in four of them were detected by two-dimensional echocardiography (2DE) and that in the fifth patient was suspected during magnetic resonance imaging. Imaging of the heart was performed using a scinticamera with a medium energy collimator and multiple views (anterior, LAO 30 degrees, LAO 45 degrees, and lateral) three and four days after the intravenous administration of Ga-fbg. By Ga-fbg scintigraphy, intraventricular thrombi were detected in four patients. The size of the thrombi visualized by Ga-fbg appeared larger than those by 2DE. In one patient examined again after anticoagulant therapy, a thrombus was missed by 2-DE, but it was detected by Ga-fbg, though the radioactivity of the thrombus decreased. We concluded that Ga-fbg scintigraphy is a very simple method and sufficiently useful for detecting active left ventricular thrombi and for monitoring the effect of anticoagulant therapy. It could be more sensitive than 2DE for determining the extent of an active intraventricular thrombus.

Adult↗

Nuclear ribonucleoprotein immune complexes in pericardial fluid of a patient with mixed connective tissue disease.

We performed immunopathologic studies of the pericarditis present in a patient with mixed connective tissue disease. A large number of nuclear RNP (nRNP) immune complexes (ICs) were found in the pericardial fluid, but not in the serum. The pericardial small vessels had no deposits of IgG. These results suggest that locally formed nRNP ICs were closely associated with the pathogenesis of pericarditis in this patient.

Adult↗

Streptonigrin and lavendamycin partial structures. Probes for the minimum, potent pharmacophore of streptonigrin, lavendamycin, and synthetic quinoline-5,8-diones.

The preparation and evaluation of 7-amino-5,8-dioxo-2-(2'-pyridyl)quinoline-6'-carboxylic acid (5a) and 7-amino-2-(2'-aminophenyl)-5,8-dioxoquinoline-5'-carboxylic acid (6a) constituting potential minimum, potent pharmacophores of streptonigrin (1a) and lavendamycin (2a), two structurally related naturally occurring antitumor antibiotics, are detailed. In contrast to observations associated with streptonigrin and lavendamycin in which the C-ring C-6' carboxylic acid potentiates the antitumor, antimicrobial, and cytotoxic properties of the naturally occurring, substituted 7-aminoquinoline-5,8-dione AB ring systems, the C-6'/C-5' carboxylic acid of 5a/6a diminishes the observed antimicrobial and cytotoxic properties of the 2-(2'-pyridyl)- and 2-(2'-aminophenyl)-7-aminoquinoline-5,8-diones. A direct comparison of the antimicrobial and cytotoxic properties of a complete set of streptonigrin and lavendamycin partial structures is detailed in efforts to define the role peripheral substituents play in potentiating the biological properties of the naturally occurring and synthetic agents bearing the 7-aminoquinoline-5,8-dione AB ring system and in efforts to define the minimum, potent pharmacophore of the naturally occurring antitumor antibiotics. The relationship of these observations to a chemical mechanism of cellular toxicity is discussed.

Animals↗

Suppressive effect on polyclonal B-cell activation of a synthetic peptide homologous to a transmembrane component of oncogenic retroviruses.

Purified feline leukemia virus, UV light-inactivated feline leukemia virus, and a synthetic peptide (CKS-17) homologous to a well-conserved region of the transmembrane components of several human and animal retroviruses were each studied for their effects on IgG production by feline peripheral blood lymphocytes. Using a reverse hemolytic plaque assay, both the viable virus and the UV-inactivated feline leukemia virus, but not the CKS-17, activated B lymphocytes to secrete IgG. When staphylococcal protein A, a polyclonal B-cell activator, was used to stimulate IgG synthesis by feline lymphocytes, the viable virus, the UV-inactivated virus, and the CKS-17 peptide each strongly suppressed IgG secretion without compromising viability of the lymphocytes. These findings suggest that the immunosuppressive influences of feline leukemia virus on immunoglobulin synthesis may reside in a conserved portion of the envelope glycoprotein that includes the region homologous to CKS-17.

Amino Acid Sequence↗

Cardiac function of patients with essential hypertension during exercise and isoproterenol infusion.

The left ventricular function of patients with essential hypertension was examined during exercise and isoproterenol (ISP) infusion echocardiography. Twenty-eight hypertensive patients without cardiac hypertrophy (Group NH), 20 patients with cardiac hypertrophy (Group HH), 7 patients with cardiac dilatation (Group D), and 13 normotensives (Group N), were studied during multistage exercise using a supine bicycle ergometer. In addition, 23 hypertensives (Group NH: 13 patients, Group HH: 10 patients) and 10 normotensives were studied during ISP infusion (0.005 microgram/kg/min, and 0.01 microgram/kg/min, respectively, for 5 min). To assess the left ventricular function, an M-mode echocardiogram was utilized at rest and during exercise and ISP infusion. At rest, the isovolumic relaxation time (IRT) of each hypertensive group was significantly longer than that of Group N. IRT of Group HH and Group D was significantly longer than that of Group NH. Only the shortening fraction (SF) of Group D was significantly smaller than that of Group N. During exercise the SF increased in all groups, and only the SF of Group D was significantly smaller than that of Group N at a load of 75 W as well as at rest. The SF of Group HH tended to be smaller. There was no significant difference in peak negative dD/dt (-dD/dt) between any of the groups at rest; however, the -dD/dt of Group HH was significantly smaller than that of Group N during ISP infusion. We concluded that left ventricular diastolic function was disturbed in each hypertensive group at rest. Diastolic dysfunction worsened in Group HH and Group D. Only the left ventricular systolic function of Group D was already depressed at rest. Furthermore, unmanifested systolic dysfunction of the left ventricle seemed to be present in Group HH, because SF during exercise tended to be smaller and -dD/dt during ISP infusion was significantly smaller than that of Group N.

Adult↗

Influence of inactivated feline retrovirus on feline alpha interferon and immunoglobulin production.

The effect of ultraviolet-inactivated feline leukaemia virus (UV-FeLV) on the development of feline immunoglobulin-secreting cells (ISC) was investigated using a reverse haemolytic plaque assay. Low concentrations of UV-FeLV at 2 X 10(-4) to 2.0 micrograms/ml stimulated the production of ISC. By contrast, the same concentration of UV-FeLV suppressed the development of pokeweed mitogen (PWM)-driven ISC. Maximum suppression of ISC occurred at 50 micrograms/ml of UV-FeLV. The generation of an interferon resistant to acid, heat and sodium dodecyl sulphate (SDS) in the media of lymphocyte cultures incubated with PWM was also significantly suppressed in the presence of 0.2 microgram/ml of UV-FeLV. These findings suggest that non-infectious viral particles appear to modify feline immunoglobulin and interferon-secreting systems.

Animals↗