Biomedical subjects

H Mikawa

Publications and source records attributed to H Mikawa.

At least 73 records · Page 4Linked to original sources

PubMed1992

Anti-IgM but not anti-IgD antibodies inhibit cell division of normal human mature B cells.

Insolubilized anti-IgD antibody markedly increased DNA synthesis in and cell division of normal peripheral blood B cells (PBL-B) when used in combination with IL-4. Anti-IgM antibodies also induced DNA synthesis of PBL-B, but their ability to induce cell division was less than that of anti-IgD antibodies even when used in combination with IL-4. Moreover, anti-IgM antibodies inhibited cell division of PBL-B stimulated with insolubilized anti-IgD antibody plus IL-4 without affecting DNA synthesis. Anti-IgM antibodies also inhibited Staphylococcus aureus Cowan I-induced cell division of PBL-B without affecting DNA synthesis. These results indicate that cross-linkage of surface IgM (sIgM) in mature B cells generates negative signals to inhibit cell division of mature B cells. Because anti-IgD antibodies did not inhibit cell division at all, the role of sIgD in the regulation of cell division of mature B cells may be quite different from that of sIgM. IFN-alpha/beta promoted cell division of PBL-B stimulated with insolubilized anti-IgD antibody plus IL-4. They also counteracted the inhibitory effect of anti-IgM antibody on cell division of PBL-B.

Antibodies, Anti-Idiotypic↗

PubMed1992

Short stature with normal growth hormone and elevated IGF-I.

We report on a Japanese girl with short stature, malar hypoplasia, up-slanting palpebral fissures, blue sclerae and thin, stiff and slightly brownish hair. Short stature started in utero and her psychomotor development was normal. Menarche appeared at 13 years 8 months. Height at 14 years 5 months was 132 cm (-4.6 SD). Her growth hormone (GH) sleep pattern and responses to insulin, L-dopa, arginine, propranolol-glucagon and growth hormone-releasing hormone were normal. Plasma insulin-like growth factor I (IGF-I) was high (2170-4860 units/l) and increased from 4860 to 7080 units/l 20 h after biosynthetic GH injection. Gel infiltration patterns of the free and protein-bound IGF-I in plasma from the patient were not different from the controls; IGF-I fraction of the high and low molecular weight binding protein and the non-protein bound fraction were 75.5%, 15.8% and 8.7%, respectively. IGF-I from the patient showed normal bioactivities when determined by [35S]sulphate and [3H]thymidine uptake into cultured rat chondrocytes, and by [3H]thymidine and [3H]alpha-aminoisobutyric acid uptake into the patient's skin fibroblasts. IGF-I binding to cultured skin fibroblasts from the patient was comparable to that of controls. These results suggest that tissue specific defects of IGF-I receptors may be the cause of increased IGF-I levels in the patient.

Animals↗

PubMed1992

Regulation of the expression of leukocyte function-associated antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1) on a human eosinophilic leukemia cell line EoL-3.

The effects of several cytokines and phorbol myristate acetate (PMA) on LFA-1 and ICAM-1 expression on a human eosinophilic leukemia cell line, EoL-3, were investigated and compared with those of a human monocytic leukemia cell line, U937. EoL-3 cells expressed large amounts of LFA-1 and small amounts of ICAM-1, and their expression was regulated similarly in EoL-3 cells and U937 cells. Interferon-gamma (IFN-gamma) enhanced ICAM-1 expression but not LFA-1 expression, and PMA augmented both LFA-1 and ICAM-1 expression. IFN-gamma and PMA showed an additive effect on ICAM-1 expression. These results collectively suggest that expression of LFA-1 and ICAM-1 is regulated differently and that IFN-gamma and PMA regulate the expression through different mechanisms. PMA but not IFN-gamma induced homotypic adhesion of EoL-3 and U937 cells, suggesting that PMA but not IFN-gamma activated the adhesive function of these cells. Staurosporin, an inhibitor of protein kinases (PKs), partly suppressed IFN-gamma- and PMA-augmented expression of ICAM-1 on EoL-3 and U937 cells, but did not affect PMA-augmented LFA-1 expression, suggesting that staurosporin-sensitive PKs are involved in IFN-gamma- and PMA-augmented ICAM-1 expression but not in PMA-augmented LFA-1 expression. The role of protein kinase C (PK-C) in these mechanisms was not revealed because a PK-C inhibitor, H-7, did not show any definitive effect on IFN-gamma- and PMA-induced expression of LFA-1 and ICAM-1. Moreover, cyclic AMP (cAMP)- and cGMP-dependent pathways were not shown to be involved in the augmentation of the expression of these molecules.

Antigens, CD↗

PubMed1992

Eosinophil cationic protein inhibits immunoglobulin production and proliferation in vitro in human plasma cells.

The effect of eosinophil cationic protein (ECP) on immunoglobulin (Ig) production by and proliferation of human plasma cells was studied. ECP inhibited Ig production by and proliferation of the human plasma cell lines, IM-9 and AF-10, in a dose-dependent fashion. As little as 0.05 ng/ml ECP was found to be inhibitory, and the maximal inhibition was achieved at doses of 0.1-0.5 ng/ml ECP. This inhibition was not due to cytotoxicity, since viability was always greater than 98%. Kinetic experiments demonstrated that inhibition was observable after 24 hr of culture with ECP and that the inhibitory effect of ECP was reversible. The inhibitory effect of ECP could be blocked by anti-ECP serum, but not by control serum. Of the various cytokines tested, including interleukin (IL)-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6, interferon (IFN)-alpha, IFN-gamma, granulocyte-macrophage colony-stimulating factor (GM-CSF) and erythropoietin (Epo), IL-6 reversed the inhibition, while other cytokines failed to do so. ECP also inhibited Ig (IgG1, IgG2, IgG3, IgG4, IgM, and IgA) production by and proliferation of PCA-1+ plasma cells generated in vitro with a similar dose-response pattern. This inhibition also was blocked by anti-ECP serum but not by control serum, and was restored by IL-6. These results suggest that ECP may interact with IL-6 in controlling plasma cell responses.

Blood Proteins↗

PubMed1992

Morphological characteristics of the scalp far-field potentials evoked by median nerve stimulation in infants and children.

We investigated the somatosensory evoked potentials (SEPs) produced by median nerve stimulation in normal infants, children and adults, focussing upon the wave forms of the scalp far-field potentials (FFPs). In adolescents and adults, 3 or 4 positive FFPs preceded the widespread N18 component on the scalp, corresponding to P9, P11, P13 and P14 (or P13-14). In infants and children, however, the scalp FFPs often included 5 positive waves, the initial three of which were characteristically sharp and brief. This distinctive wave form, with 5 positive FFPs, was correlated with an Erb's potential having a bipeaked negative phase. We studied the temporal relationship of the 5 positive FFPs to the Erb's potential and the cervical SEPs and concluded that the initial 3 brief positive waves were produced by overlapping of a bipeaked "P9" and bipeaked "P11." Both "P9" and "P11" are stationary waves that are thought to originate in the first-order afferents, so they probably reflect the bipeaked appearance of the compound nerve action potential.

Action Potentials↗

PubMed1992

Inhibition of ongoing immunoglobulin production by eosinophil cationic protein.

The effect of eosinophil cationic protein (ECP) upon ongoing immunoglobulin (Ig) production and proliferation in human B cells was studied. ECP inhibited Ig production by the human lymphoblastoid cell lines, CBL and GM-1056, in a dose-dependent fashion. In contrast, proliferation was not affected. This ECP-induced inhibition of Ig production was specific, since inhibition was blocked by anti-ECP serum but not by control serum. Interleukin (IL)-4 did not affect Ig production by CBL or GM-1056 cells; however, IL-4 reversed ECP-induced inhibition of Ig production and this reverse was blocked by anti-IL-4 antibody but not by control antibody. In contrast, other cytokines, including IL-1 beta, IL-2, IL-3, IL-5, IL-6, interferon (IFN)-alpha, and IFN-gamma, failed to reverse inhibition. ECP also inhibited spontaneous Ig production (IgM, IgG1, IgG2, IgG3, IgG4, and IgA) by tonsillar large activated B cells without affecting proliferation. This inhibition was also blocked by anti-ECP serum but not by control serum and was reversed by IL-4 specifically. These results indicate that ECP may play an important role in B cell responses.

Antibody Formation↗

PubMed1992

Parathyroid hormone inhibits immunoglobulin production without affecting cell growth in human B cells.

The effect of parathyroid hormone (PTH) on immunoglobulin (Ig) production and proliferation in the human B-cell lines CBL, SKW, and CESS was studied. PTH inhibited Ig production from all the B-cell lines in a dose-dependent manner during 5 days of culture. As little as 0.1 ng/ml was inhibitory. PTH also inhibited Ig production from cell lines stimulated by vasoactive intestinal peptide (VIP), interleukin 2 (IL-2), and IL-6. This inhibition was not due to decreased cell growth since proliferation was not affected and cell viability was always greater than 98%. In contrast to PTH, inactivated PTH or triiodothyronine failed to affect Ig production. Inhibition by PTH was blocked by anti-PTH serum, but not by control serum. Of the various cytokines tested, IL-4 reduced the PTH-induced inhibition of Ig production, whereas other cytokines, including IL-1 beta, IL-3, IL-5, interferon alpha (IFN-alpha), IFN-gamma, and granulocyte-macrophage colony-stimulating factor (GM-CSF), failed to do so. The reducing effect of IL-4 was blocked by anti-IL-4 antibody but not by control antibody. Moreover, IFN-alpha and IFN-gamma, but not GM-CSF, overcame the reducing effect of IL-4. PTH also inhibited IgG, IgM, and IgA production by tonsillar B cells stimulated with Staphylococcus aureus Cowan strain I (SAC) and IL-6 without affecting proliferation. This inhibition was blocked by anti-IL-4 antibody but not by control antibody. These results indicate that, in addition to its regulatory effect on calcium metabolism, PTH also acts as an immunoregulatory factor, and that it interacts with the cytokine, IL-4.

Antibody Formation↗

PubMed1992

Adenosine inhibits divalent cation influx across human neutrophil plasma membrane via surface adenosine A2 receptors.

Adenosine and its analogues inhibited increases in divalent cation influx stimulated by platelet-activating factor (PAF) and formyl-methionyl-leucyl-phenylalanine (FMLP) in a dose-dependent fashion. This effect was antagonized by theophylline, an adenosine receptor antagonist. When extracellular adenosine was removed by adenosine deaminase, the effect of adenosine was completely abolished. Two adenosine analogues with different affinities for adenosine receptor subtypes, 5'-N-ethylcarboxamideadenosine (NECA) and L-N6-phenylisopropyladenosine (PIA), also inhibited divalent cation influx, NECA being more potent than PIA. These results suggest that adenosine and its analogues inhibit divalent cation influx across neutrophil plasma membranes via surface adenosine A2 receptors. Adenosine had little effect on the initial peaks of intracellular free calcium rises induced by chemoattractants, but it inhibited the subsequent rise in free calcium. Since calcium influx through the divalent cation channels or neutrophil plasma membranes is responsible for maintaining free calcium concentration following the initial peaks, we suggest that adenosine modulates neutrophil function by interfering with this calcium influx.

Adenosine↗

PubMed1992

Ring 14 chromosome with complex partial seizures: a case report.

A two-year-old girl was found to have a ring 14 chromosome: [46, XX, r(14) (P13 q32.3)]. Her development, including verbal ability, was retarded, her CT scan displayed a low density area anterior to the left temporal lobe, and she suffered from complex partial seizures. Focal central nervous system abnormalities may be present in patients with ring 14 chromosome, and their seizures are not exclusively of the primary generalized type. This is the first case with ring 14 chromosome and complex partial seizures.

Child↗

PubMed1992

Tyrosine phosphorylation of IgM- and IgD-associated molecules of a human B lymphoma cell line B104.

We investigated tyrosine phosphorylation and structural properties of the IgM-associated molecules in comparison with IgD-associated molecules in a recently established human surface IgM+, IgD+ B lymphoma cell line, B104, the growth of which was irreversibly inhibited by anti-IgM mAbs but not by anti-IgD mAbs. Tyrosine kinase activity and tyrosine phosphorylated proteins were detected in anti-IgM and anti-IgD immunoprecipitates from digitonin lysates of B104 cells with the use of an in vitro kinase assay followed by a re-immunoprecipitation experiment with anti-phosphotyrosine mAbs. Tyrosine phosphorylated proteins of 74, 58-44, 41, and 39 kDa were detected in anti-IgM immunoprecipitates, whereas tyrosine phosphorylated proteins of 74, 58-44, and 39 kDa, but not 41 kDa, were detected in anti-IgD immunoprecipitates. Crosslinking of surface IgM and surface IgD stimulated rapid tyrosine phosphorylation of different sets of proteins which included tyrosine-phosphorylated proteins of the same or similar molecular weights as those detected in the anti-IgM and anti-IgD immunoprecipitates respectively. After deglycosylation by N-glycosidase, both the IgM- and IgD-associated phosphoproteins (pp58-pp39) gave rise to the same three bands of 29, 27, and 26 kDa. Proteolytic peptide mapping of these three deglycosylated proteins showed that the primary structures of the IgM- and IgD-associated molecules are identical, suggesting that the IgM- and IgD-associated phosphoproteins (pp58-pp39) are the products of the same or closely related genes. One of the products, pp41, may be associated with IgM, but not with IgD, although the same gene product may be associated with IgD in a different glycosylation pattern.

Antibodies, Anti-Idiotypic↗

PubMed1992

Vasoactive intestinal peptide stimulates immunoglobulin production and growth of human B cells.

The effect of vasoactive intestinal peptide (VIP) on human lymphoblastoid B cell lines and tonsil B cells was studied. VIP increased immunoglobulin production and proliferation by lymphoblastoid B cell line, GM-1056, in a dose-dependent manner. As little as 10(-12) M of VIP was effective, and higher concentrations of VIP induced an approximately five-fold increase in IgA production. Moreover, this enhancement was blocked by VIP antagonist. Similarly, VIP enhanced IgM and IgG production by other lymphoblastoid B cell lines, CBL and IM-9, respectively. In contrast to VIP, another neuropeptide substance P (SP) or somatostatin failed to enhance immunoglobulin production and thymidine uptake. VIP also enhanced IgA production and thymidine uptake by purified tonsil B cells. However, in contrast to B cell lines, VIP failed to enhance IgM and IgG production by tonsil B cells. SP or somatostatin failed to enhance immunoglobulin production or thymidine uptake by tonsil B cells. These results indicate that VIP acts as B cell stimulatory factor and that VIP may also have preferential effect on IgA production on tonsil B cells.

B-Lymphocytes↗

PubMed1992

The inhibition of lymphocyte blastogenesis by asparaginase: critical role of glutamine in both T and B lymphocyte transformation.

L-Asparaginase has long been used in the treatment of acute lymphoblastic leukemia or malignant lymphoma in childhood. To determine cell type specific sensitivity to this drug, the L-asparaginase-mediated inhibition of blastogenesis of human peripheral T or B lymphocytes was compared. The rate of incorporation of [3H]-thymidine into the DNA of either T lymphocytes due to phytohemagglutinin (PHA) or B lymphocytes due to Staphylococcus aureus Cowan I (SAC) was measured by the addition of Escherichia coli L-asparaginase in the medium. The blastogenic response of either T or B lymphocytes was also determined in medium depleted of exogenous asparagine and/or glutamine, both of which are hydrolyzed by this enzyme. The in vitro blastogenesis of either human T lymphocytes due to PHA or B lymphocytes due to SAC was inhibited by the inclusion of asparaginase in the medium. The deprivation of exogenous asparagine did not have any inhibitory effect on the blastogenic response of both T and B lymphocytes to each mitogen. On the other hand, the glutamine concentration in the culture medium provided a critical influence on the proliferative response of T and B lymphocytes. The rate of incorporation of [3H]-thymidine into DNA was increased markedly as the concentration of glutamine was increased from 2(-7)-2 mmol/l. It is concluded that the mechanism of inhibition of PHA- or SAC-stimulated lymphocyte blastogenesis by L-asparaginase is not asparagine deprivation but glutamine deprivation. Glutamine, which is the most abundant amino acid, is thought to have an important role in the immune response of lymphocytes.

Asparaginase↗

PubMed1992

Alterations of benzodiazepine receptor binding in tremor rats with absence-like seizures.

Tremor rats begin to exhibit clinical or electrical absence-like seizures after 6 weeks of age, and by 14 weeks of age, all have seizures. Central-type benzodiazepine receptor binding was investigated in tremor rats and control rats, aged 4 weeks and 16 weeks. Significantly lower benzodiazepine receptor density and no differences in affinity were found in the hippocampus of the tremor rats in comparison with that of control rats at both ages. This abnormality is considered to be due to a tremor gene and may be the cause of absence-like seizures in tremor rats. A significantly lower receptor density was found in the cerebellum at 4 weeks of age in the tremor rats than in the control rats. These changes may be related to tremorous movements in the tremor rats. Receptor density was significantly lower in the brainstems of tremor rats and control rats at 16 weeks of age than at 4 weeks of age, and the decrease was more marked in control rats. These facts may reflect a reduced decrease in the response to the dysfunction of gamma-aminobutyric acidergic neurons, or the function of the gamma-aminobutyric acid/benzodiazepine receptor system may be secondarily increased to suppress seizures in 16-week-old tremor rats.

Animals↗

PubMed1992

Continuous, generalized, high-voltage fast activity and FIRDA in two children.

The EEG pattern of continuous, generalized, high-voltage fast rhythms without any reaction to eye-opening/closure, photic stimulation, or the sleep-awaking cycle was previously reported to be characteristic of infantile neuroaxonal dystrophy (INAD). However, we have observed such fast activity in one child with INAD and one with Menkes' kinky-hair syndrome. They both exhibited severe psychomotor disturbance, and their EEGs also included "frontal intermittent rhythmic delta activity (FIRDA)," a nonspecific EEG finding suggestive of organic encephalopathy. Since the continuous, generalized, high-voltage fast activity had features suggestive of spindles in both children, this EEG pattern is thought to actually represent "extreme spindles," and nonspecifically to indicate widespread organic brain damage.

Cerebral Cortex↗

PubMed1992

Recombinant human growth hormone stimulates B cell immunoglobulin synthesis and proliferation in serum-free medium.

In order to investigate the effects of growth hormone on human B cells, we studied immunoglobulin synthesis and [3H]-thymidine uptake by B cell lines, IM-9, GM-1056 and CBL, and purified tonsil B cells. Cells were cultured in a serum- and albumin-free medium, Cosmedium-001 to exclude interaction between a certain growth-promoting substance and any unknown substances that serum may contain. GH enhanced IgG synthesis and [3H]-thymidine uptake by IM-9 cells, IgA synthesis by GM-1056 cells and IgM synthesis by CBL cells in a dose-dependent fashion. This was not a non-specific effect of protein in GH, since equivalent or higher concentrations of proteins such as bovine serum albumin, interleukin-2, interleukin-5, granulocyte/macrophage colony-stimulating factor, or erythropoietin did not stimulate B cell lines. Moreover, the rabbit anti-GH antibody blocked the enhancing effect of GH, while normal rabbit antibody failed to do so. GH also enhanced immunoglobulin synthesis (IgG and IgM) and thymidine uptake by Staphylococcus aureus Cowan strain I-activated tonsil B cells. These results indicate that GH has a direct stimulating effect on B cells, and, in addition to its endocrinological function, GH may also act as an immunoregulatory cytokine.

B-Lymphocytes↗

PubMed1992

[Clinical evaluation of cefprozil in children].

Cefprozil (CFPZ, BMY-28100), a new oral cephalosporin, was evaluated for its efficacy and safety in 42 children with bacterial infections (Table 1), and the following results were obtained. 1. CFPZ was administered in 3 or 4 divided doses at daily dosages ranging from 15.3 to 60.0 mg/kg to 42 patients (19 cases of acute tonsillitis and/or laryngitis, pharyngitis, 13 cases of pneumonia, 2 cases each of suppurative cervical lymphadenitis and UTI, and 1 case each of scarlet fever, acute otitis media, suppurative parotitis, impetigo contagiosa, furuncle and acute enteritis) and the following clinical results were obtained: excellent; 24 cases, good; 14 cases, fair; 4 cases. The overall efficacy rate was 90.5% (Table 3). 2. MICs of CFPZ against 50 strains of isolated organisms are shown in Table 4. In 19 cases out of 28 cases examined, causative organisms were successfully eradicated and strain of Staphylococcus aureus was decreased in 1 case. 3. Diarrhea was observed in 2 cases (cases 8, 11). In case 8, the symptom disappeared spontaneously. Case 11 improved immediately after the administration of the drug was stopped. Among 39 children who went through laboratory tests, eosinophilia which seemed to be related to the administration of this drug was observed in 2 cases (cases 29, 38). Slight elevations of S-GOT and S-GPT were found in 1 case (case 22) (Table 7). 4. These data suggest that CFPZ is a safe and useful new antibiotic in the treatment of children with susceptible bacterial infections.

Administration, Oral↗

PubMed1992

Human B-cell growth-inhibitory activity of eosinophil cationic protein.

The effect of eosinophil cationic protein (ECP) upon proliferation of human B cell lines or purified B cells was studied. ECP inhibited proliferation of the human lymphoblastoid cell lines CBL and GM-1056 at doses of 0.1-5 ng/mL during 2-4 days of culture. The inhibitory effect of ECP was reversible and not due to toxic damage. Moreover, inhibition could be blocked by anti-ECP serum while the control serum failed to do so. Of various cytokines tested--including interleukin (IL)-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6; interferon (IFN)-alpha or IFN-gamma--IL-4 reduced the inhibition, while other cytokines failed to do so. The reduction of inhibition was specific to IL-4 since reduction by IL-4 was blocked by anti-IL-4 antibody but not by the control antibody. ECP also inhibited proliferation of tonsillar small resting B cells stimulated with anti-mu antibody plus low molecular weight B-cell growth factor (BCGF) or of large activated B cells. In contrast, ECP had no effect on proliferation of unstimulated small resting B cells. This inhibition was also reduced by IL-4 specifically. These results indicate that ECP may also act as a B-cell regulating factor.

B-Lymphocytes↗

PubMed1992

[Ischemic myocardial injury evaluated using positron emission tomography in children with coronary artery disease: comparison with thallium-201 SPECT].

Regional myocardial perfusion and glucose metabolism were evaluated by positron emission tomography (PET) in children with coronary artery disease. Also, PET findings were compared with those of thallium-201 myocardial single photon computed tomography (SPECT). The study patients consisted of 11 children ranging in age from 3 to 14 years. Ten patients had significantly stenotic coronary arterial lesions due to Kawasaki disease, and one patient had a left coronary artery with an anomalous origin from the pulmonary artery. Evaluation was made before and after surgical revascularization in 3 patients. Regional myocardial perfusion was assessed at rest using 13N-ammonia, and regional myocardial glucose metabolism was assessed at rest under fasting conditions using 18F-fluorodeoxyglucose (18FDG). SPECT was performed after dipyridamole infusion. Initial and delayed images were obtained 7 min and 3 hrs after dipyridamole infusion, respectively. Left ventricular myocardial images were categorized as the septal, anterior, lateral, apical, and inferior segments, and evaluation was made for each segment. A total of 70 myocardial segments in 11 patients were classified into 4 groups according to the PET findings: 1) segments with normal perfusion and without enhanced 18FDG uptake (normal segments; n = 55), 2) normal perfusion with enhanced 18FDG uptake (metabolically abnormal segments; n = 3), 3) hypoperfusion with enhanced 18FDG uptake (ischemic but viable segments; n = 9), and 4) hypoperfusion without enhanced 18FDG uptake (non-viable segments; n = 3). On SPECT, the numbers of myocardial segments showing no perfusion defects, complete redistribution, incomplete redistribution, and persistent perfusion defects were 38, 12, 14, and 6, respectively. Comparisons were made between PET findings and SPECT findings.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗