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Biomedical subjects

M Kohno

Publications and source records attributed to M Kohno.

At least 469 records · Page 26Linked to original sources

Effect of chronic treatment with angiotensin I converting enzyme inhibitors on circulating atrial natriuretic polypeptide in spontaneously hypertensive rats.

We have recently shown that circulating atrial natriuretic polypeptide (ANP) in adult spontaneously hypertensive rats (SHR) is higher than that in age-matched Wistar-Kyoto rats (WKY). The present experiment was designed to examine the possible effects of chronic treatment with angiotensin I converting enzyme inhibitors (ACEI) on plasma ANP levels in SHR. Captopril and enalapril lowered blood pressure and reduced relative ventricular weight in SHR but not to the level of WKY. Plasma ANP levels were decreased by captopril and enalapril compared with untreated SHR. These results suggest that the ANP release may be suppressed in ACEI-treated SHR compared with untreated SHR. We speculate that a reduction of cardiac overload by ACEI may in part explain the decline of circulating ANP.

Angiotensin-Converting Enzyme Inhibitors↗

A monoclonal antibody detecting a novel antigen expressed in the HTLV-I-infected cells.

A monoclonal antibody, FTF 148, was prepared by hybridizing murine myelomal cells (NS-1) and spleen cells of BALB/c mice immunized with cultured cells derived from an adult T cell leukemia (ATL) patient (KUT-2 cells). This monoclonal antibody reacted with all of the human T cell leukemia virus I (HTLV-I)-infected cell lines tested but did not react with other T cell lines derived from acute lymphocytic leukemia, Epstein-Barr virus-transformed B cell lines, or an erythroleukemic cell line. This monoclonal antibody was not directed to viral antigens because it reacted equally well with almost all KUT-2 and MT-1 cells, only 1% to 3% of which were ATL-associated antigen-positive. In contrast to interleukin 2 receptors expressed on both ATL cells and normal phytohemagglutinin-stimulated blasts, this antigen was not expressed on the latter cells. The antigen, mainly expressed on the cell membrane, was analyzed by metabolic labeling with 3H-leucine and surface labeling with 125I followed by cell lysis and immunoprecipitation with the FTF 148 antibody. The findings obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that p50 and p74 proteins were specifically precipitated and the antigen was also different from the product of the Xs gene of HTLV-I.

Antibodies, Monoclonal↗

Study of the biological activities of toxic shock syndrome toxin-1: II. Induction of the proliferative response and the interleukin 2 production by T cells from human peripheral blood mononuclear cells stimulated with the toxin.

Toxic shock syndrome toxin-1 (TSST-1) is an exotoxin produced by Staphylococcus aureus isolated from patients with toxic shock syndrome. We investigated the proliferative response of human lymphocytes and their interleukin 2 (IL-2) production after stimulation with TSST-1 in vitro. Human cord blood mononuclear cells (HCBM) and human peripheral blood mononuclear cells (HPBM) could proliferate with TSST-1 stimulation. T cell-depleted HPBM showed only a marginal response to this toxin. A IL-2-like factor with a molecular weight of 15-18 kD was obtained from the supernatants of TSST-1-stimulated HPBM cultures. The factor was absorbed by CTLL-2 cells but not by T cell-depleted murine spleen cells, indicating that it is IL-2. HPBM are very sensitive to TSST-1: a low concentration of TSST-1 (0.01 ng/ml in 36 h stimulation) and a short period of stimulation (8 h at 10 ng/ml of the toxin) were fully effective for HPBM to produce substantial amounts of IL-2. Removal of T cells abrogated the TSST-1-induced IL-2 production by HPBM. Reconstituted cell cultures of nylon wool column-passed T cells and macrophages produced IL-2 by TSST-1 stimulation and, furthermore, the accessory activity of the macrophages could be partially replaced by a macrophage-derived factor containing interleukin 1. These findings indicate that T cells require macrophages or IL-1 for TSST-1-induced production of IL-2. The roles of lymphokines, including IL-2, in the development of this illness are discussed.

Bacterial Toxins↗

Alteration of chemoreflex phrenic responses by oligomycin in the rabbit.

The effects of carotid chemoreceptor stimulation by intracarotid injections of sodium cyanide (NaCN, 30 micrograms), antimycin A (AMC, 10 micrograms) and dopamine (DA, 10 micrograms) on phrenic nerve activity were studied before and after oligomycin (200 micrograms) in the rabbit. The excitatory responses to NaCN and AMC were abolished after intracarotid administration of oligomycin, whereas the DA-induced phrenic depression was only slightly diminished. In addition, the effects of hypoxia on phrenic nerve activity were also studied before and after oligomycin (200 micrograms) in some animals with denervated one carotid sinus nerve. The hypoxia-induced phrenic excitation was greatly reduced after intracarotid administration of oligomycin. These results indicate that the chemoreflex phrenic responses induced by NaCN, AMC and hypoxia are probably related to the phosphate potential in the carotid body.

Animals↗

[A case report of hereditary angioedema and studies on the serum components of complement, C1-inactivator and proteinase inhibitors during edema attack].

Sixteen years old girl was admitted because of for the past ten years' frequent edema attack and abdominal pain. Laboratory examination revealed hypocomplementemia, marked depletion of the fourth component of complement and low level of C1-inactivator. Familial studies revealed that her mother was also hypocomplementemic and in low level of C1-inactivator. Serial studies performed on the alterlation of components of complement, C1-inactivator, alpha 1-antitrypsin, antithrombin III, and alpha 2-macroglobulin during edema attack. The fourth component of complement and C1-inactivator were markedly depleted in remission and attack. Remarkable depletion was found in antithrombin III and esterase inhibition activity of C1-inactivator during attack. In contrast, alpha 1-antitrypsin and alpha 2-macroglobulin did not change. The present study may explain that Hageman factor fragments, activated by C1s, promotes kinin generation via kalikrein activation. And the condition that complete functional deficiency of C1-inactivator was main role in this circuit. Fibrynolysis and late components of complement was less influence on edema attack.

Adolescent↗

ESR studies on the oxidation of N,N-dimethyl-p-anisidine and its analogues catalyzed by myeloperoxidase.

N,N-Dimethyl-p-anisidine (DMA) was used as a substrate to differentiate between the direct, or chloride-independent, and the indirect, or chloride-dependent, pathways characteristic of myeloperoxidase (donor: hydrogen-peroxide oxidoreductase, EC 1.11.1.7). The chemical oxidation by sodium hypochlorite and the horseradish peroxidase-catalyzed oxidation by H2O2 were also investigated for a comparison. The chemical oxidation of DMA by NaOCl (DMA/NaOCl = 1) gave the p-N,N-dimethylaminophenoxy radical at pH 5 and 7. p-Benzoquinone and formaldehyde were determined as stable end-products. On the other hand, the cation radical of DMA was detected and p-benzoquinone was not obtained in the horseradish peroxidase-H2O2-Cl- system. In the presence of Cl- the myeloperoxidase-catalyzed oxidation at pH 5 gave nearly the same result as did the oxidation by NaOCl, whereas in the absence of Cl- the result of the oxidation was similar to that of the horseradish peroxidase-catalyzed oxidation, except for a low yield of formaldehyde formation, which was ascribed to the decomposition of H2O2 by the catalase activity of myeloperoxidase. Although the myeloperoxidase-catalyzed oxidation of DMA at pH 7 in the presence of Cl- gave only the cation radical of DMA, a fairly large amount of p-benzoquinone was obtained as a product. This result indicates that the indirect chloride-dependent oxidation is also operating at pH 7. The reaction mechanism for the myeloperoxidase-catalyzed oxidation of DMA is proposed.

Aniline Compounds↗

Acute effects of sublingual isosorbide dinitrate on global and regional left ventricular diastolic filling in normal persons.

To study the acute effects of isosorbide dinitrate (ISDN) on global and regional left ventricular (LV) diastolic filling, gated radionuclide ventriculographic studies were conducted in 21 normal persons before and after sublingual administration of ISDN. ISDN treatment caused significant increases in ejection fraction and peak LV ejection rate and it caused a delay in occurrence of peak LV filling, without statistically significant changes in peak LV filling rate globally and regionally. The ratios of peak LV filling rate to peak LV ejection rate decreased significantly both globally and regionally. These alterations induced by ISDN could be interpreted as indicating a failure of improvement of the early diastolic filling despite increased systolic function and heart rate in the global left ventricle and in regions of the left ventricle. Furthermore, ISDN caused early diastolic asynchronous filling. There was a negative correlation between this early diastolic asynchronous filling and the ratio of global peak LV filling to global peak LV ejection rate (r = -0.66, p less than 0.001), indicating that administration of ISDN to normal persons may produce early diastolic asynchronous filling associated with failure of improvement of diastolic filling despite increased systolic function and heart rate.

Administration, Oral↗

Tetrahydroisoquinoline and 1-methyl-tetrahydroisoquinoline as novel endogenous amines in rat brain.

This is the first report to identify 1,2,3,4-tetrahydroisoquinoline and 1-methyl-1,2,3,4-tetrahydroisoquinoline as endogenous amines from non-treated rat brain. The detection was performed by coupled gas chromatography - multiple ion detection, using heptafluorobutyric anhydride and pentafluoropropionic anhydride as derivatizing reagents. These amines might be endogenous substances inducing parkinsonism.

Animals↗

Alpha-thrombin-induced tyrosine phosphorylation of 43,000- and 41,000-Mr proteins is independent of cytoplasmic alkalinization in quiescent fibroblasts.

Incubation of quiescent Chinese-hamster fibroblasts (CCL39) with alpha-thrombin, a potent mitogen for the cells, was found to stimulate the rapid phosphorylation of two 43,000-Mr and two 41,000-Mr proteins at tyrosine, threonine and/or serine, and two 63,000-Mr proteins at serine. Insulin, 12-O-tetradecanoylphorbol 13-acetate (TPA) and epidermal growth factor (EGF) are weak mitogens for cells; insulin and TPA did not stimulate the phosphorylation of those proteins significantly, whereas EGF stimulated their phosphorylation to the same extent as did alpha-thrombin. We analysed alpha-thrombin-induced protein phosphorylation at different external pH values in CCL39 and in the mutant derivative PS120, which lacks Na+/H+-antiport activity. We showed that cytoplasmic alkalinization, a common and early response to mitogens, is not required to trigger phosphorylation of 63,000-, 43,000- and 41,000-Mr proteins, either at tyrosine or serine and threonine residues. This finding contrasts with the phosphorylation of ribosomal protein S6, which takes place only at permissive pH for reinitiation of DNA synthesis. These results, demonstrating that phosphorylation of 63,000-, 43,000- and 41,000-Mr proteins and cytoplasmic alkalinization are not coupled, reinforce the idea that the site of action of intracellular pH controlling the commitment of G0/G1-phase-arrested cells to DNA synthesis might be restricted to mitogen-stimulated S6 phosphorylation.

Alkalies↗

An autoradiographic study of the spinofacial projection in the monkey.

The spinofacial projection was revealed using anterograde transport of radioactively labeled protein in the monkey. The projection arises from cells in the lateral part of the spinal dorsal horn (i.e. the lateral part of lamina V of Rexed) at the upper cervical cord, mainly C1 segment, ascends in the medial or ventromedial part of the anterior funiculus after crossing the anterior white commissure, then courses through the dorsolateral part of the inferior olivary complex. Finally, it terminates within the medial parts of the facial nuclei bilaterally, with the cells from the side ipsilateral to the injection contributing more heavily. Some fibers of this projection cross initially at spinal levels and recross again at levels through the rostral medulla and caudal pons.

Afferent Pathways↗

Interleukin 2 induces rapid phosphorylation of cellular proteins in murine T-lymphocytes.

When quiescent murine T-lymphocyte cells were stimulated by the addition of interleukin 2 (IL-2), they reinitiated DNA synthesis after a lag period of 5 h. Under these conditions, rapid but transient phosphorylation of two cellular proteins with Mr values of 27 000 and 26 000 was detected; maximal phosphorylation occurred within 10-15 min after the addition of IL-2. The protein of Mr 27 000 contained phosphoserine, while the protein of Mr 26 000 contained phosphothreonine.

Animals↗

Atrial natriuretic polypeptide in atria and plasma in experimental hyperthyroidism and hypothyroidism.

To investigate the involvement of thyroid hormone on the release of atrial natriuretic polypeptide (ANP), we have measured immunoreactive ANP in the atria and plasma of experimental hyperthyroid and hypothyroid rats. Plasma ANP was higher (p less than 0.05) in hyperthyroid rats and was lower (p less than 0.05) in hypothyroid rats than in euthyroid rats. ANP content and concentration in the atria were lower (p less than 0.01) in hyperthyroid rats than in hypothyroid rats. An inverse correlation was found between the plasma ANP and ANP concentration in the atria (n = 15, r = 0.60, p less than 0.01). The results indicate an increased systemic release of ANP from the atria in hyperthyroidism and a decreased systemic release in hypothyroidism.

Animals↗

Differential diagnosis of fever in systemic lupus erythematosus using discriminant analysis.

In an attempt to find a reliable method to assess fever in patients with systemic lupus erythematosus (SLE), a multifactorial analysis was applied to the routine laboratory examinations, including white blood cell count (WBC) and serum globulin fraction concentrations. During 74 febrile episodes, 49 SLE patients showed increased disease activity and the remaining 25 febrile episodes were due to intercurrent infection. The two different groups of fever episodes were clearly separated by a principal component analysis using five variables from the routine laboratory tests, including WBC, serum alpha-1, alpha-2, beta, and gamma globulins. Discriminant analysis showed that 95% of 74 febrile episodes could be correctly classified as to the cause of fever when a combination of WBC and alpha-2 globulin level was used as variables. A simple discriminant formula which we calculated was considered to be of practical use for the differentiation of the two clinical entities.

Alpha-Globulins↗

Primary malignant thymoma in a 6-year-old boy.

Although not uncommon in adults, thymomas are the least common mediastinal tumors in children. The behavior of these tumors in children is partially distinct with a much more rapid course and a poor prognosis. A symptom-free 6-year-old boy was treated for malignant thymoma detected incidentally on a chest X-ray in a school mass examination. At operation, the tumor was found to have already invaded the surrounding tissue. Complete removal at the base of the invasive tumor is the treatment of choice.

Child↗