Biomedical subjects

M Nagashima

Publications and source records attributed to M Nagashima.

At least 235 records · Page 13Linked to original sources

PubMed1990

Both epidermal dendritic cell populations, Langerhans' cells and Thy 1+ dendritic cells are simultaneously stained by an Lyt-1 monoclonal antibody.

Both Langerhans' cells (LC) and Thy 1+ dendritic epidermal cells (DEC) are bone marrow-derived epidermal cells that are thought to play an important role in immune responses. Despite their several similarities, the surface phenotypes of both cells appear to be almost mutually exclusive. We found that an anti-Lyt-1.2 monoclonal antibody that recognizes solely an epitope on certain T cells can crossreact with a shared epitope on both cell types. The morphological details of LCs and Thy 1+ DECs stained by the anti-Lyt-1.2 MAb was superior to those stained by either anti-I-A or anti-Thy-1 MAb. The availability of this MAb enables us to simultaneously view both cell populations in the same sections.

Animals↗

PubMed1990

[A case report of Ebstein's anomaly treated with Carpentier's procedure].

A 42-year-old male patient was admitted with congestive heart failure. Echocardiogram and cardiac angiogram revealed Ebstein's anomaly and severe tricuspid valve incompetence. He underwent Carpentier's procedure for the treatment of Ebstein's anomaly. Carpentier's procedure consists of the following two new points; (1) the right atrium and atrialized ventricle is plicated longitudinally; (2) the anterior leaflet and the posterior leaflet of tricuspid valve are transposed with a clockwise rotation to the level of the normal tricuspid anulus. Compared with Hardy's procedure (transverse plication), longitudinal plication preserves the cavity and the function of the right ventricle and excludes atrialized chamber. In our case, there is a trivial residual regurgitation of tricuspid valve postoperatively, but the patient's clinical status has improved remarkably. We conclude that Carpentier's procedure is an effective operation for Ebstein's anomaly.

Adult↗

PubMed1990

[A case report of definitive repair for pulmonary atresia and intact ventricular septum associated with aortic valve regurgitation].

A successful definitive repair for a 10-year-old girl with pulmonary atresia and intact ventricular septum (PA.IVS) associated with aortic valve regurgitation is described. The Fontan type repair was not indicated in this case because of the left ventricular dysfunction due to aortic valve regurgitation and inadequate size of the pulmonary artery. Therefore, right ventricular outflow tract reconstruction, Glen shunt and aortic valve replacement were performed despite severe hypoplastic right ventricle (RVEDVI; 33% of normal) and restrictive tricuspid valve (TVD; 48% of normal). Postoperatively, good result was obtained. There is general agreement that biventricular repair could be safely performed using Glenn shunt, when RVEDVI is above 40% of normal and TVD is above 50% of normal in a patient with PA.IVS. Moreover recently including our case, several successful repairs for PA.IVS with more hypoplastic right ventricle and tricuspid valve have been reported. So it is suggested that the right ventricular outflow tract reconstruction and Glenn shunt can be reliably applied for PA.IVS with more hypoplastic right ventricle and more restrictive tricuspid valve. To our knowledge, this is the first successful report of definitive repair (right ventricular outflow tract reconstruction, Glenn shunt and AVR) for PA.IVS associated with AR.

Aortic Valve↗

PubMed1989

Effect of disopyramide on initiation of atrial fibrillation and relation to effective refractory period.

Electrophysiologic studies were performed before and after intravenous administration of disopyramide (2 mg/kg) to 40 patients with either documented or suspected atrial fibrillation (AF). In control studies, sustained AF (greater than 1 minute), nonsustained AF (1 to 60 seconds) and no AF were found in 14, 18 and 8 patients, respectively. After disopyramide, the ability to initiate AF was totally lost in 18 patients (group A), while 22 patients (group B) showed sustained AF (11 patients) or nonsustained AF (11 patients). The effective refractory period of the atrium was 232 +/- 41 ms in the control study and 266 +/- 49 ms after disopyramide. Atrial functional refractory periods before and after disopyramide were 282 +/- 43 and 317 +/- 48 ms, respectively. The differences and ratios of the refractory periods after and before disopyramide were higher in group A than in group B (p less than 0.001). The prolongation of atrial refractoriness after disopyramide was important to suppress the initiation of AF in group A. In some group B patients, on the other hand, the initiation of AF was promoted after disopyramide. Disopyramide may alter the atrial electrophysiologic substrate required for AF initiation.

Atrial Fibrillation↗

PubMed1989

Transmembrane TGF-alpha precursors activate EGF/TGF-alpha receptors.

TGF-alpha and EGF are structurally related factors that bind to and induce tyrosine autophosphorylation of a common receptor. Proteolytic cleavage of the transmembrane TGF-alpha precursor's external domain releases several TGF-alpha species. However, membrane-bound TGF-alpha forms remain on the surface of TGF-alpha-expressing cell lines. To evaluate the biological activity of these forms, we modified two cleavage sites in the TGF-alpha precursor coding sequence, making processing into the 50 amino acid TGF-alpha impossible. Overexpression of this cDNA in a receptor-negative cell line, partial purification, and N-terminal sequence analysis indicate the existence of two transmembrane TGF-alpha forms. These solubilized precursors induce tyrosine autophosphorylation of the EGF/TGF-alpha receptor in intact receptor-overexpressing cells, and anchorage-independent growth of NRK fibroblasts. Cell-cell contact between TGF-alpha precursor-overexpressing cells and cells expressing high numbers of receptors also resulted in receptor activation. These findings suggest a role for transmembrane TGF-alpha forms in intercellular interactions in proliferating tissues.

Animals↗

PubMed1989

Fixed drug eruption. Expression of epidermal keratinocyte intercellular adhesion molecule-1 (ICAM-1).

The pathogenic mechanism of preferential localization to certain skin sites of fixed drug eruption lesions has remained unknown. Skin biopsy specimens were obtained from four patients with fixed drug eruptions at various time points after final exposure to the causative drug and were studied immunohistologically using monoclonal antibodies to intercellular adhesion molecule-1 (ICAM-1), lymphocyte function-associated antigen-1, and HLA-DR. The expression of ICAM-1 by keratinocytes was confined exactly to the involved epidermis. In contrast, the expression of HLA-DR by keratinocytes was observed not only in the involved epidermis but also in the uninvolved epidermis, although to a lesser extent. In general, the intensity of expression of ICAM-1 by keratinocytes correlated well with the degree of epidermal invasion of lymphocytes but not with the degree of dermal lymphocytic infiltration. Interestingly, in fixed drug eruption lesions, basal keratinocytes still showed intense reactivity for ICAM-1 6 to 10 days after final exposure to the causative drug, at which time the expression of HLA-DR was already down-modulated. Such a strong dissociation between the expression of ICAM-1 and HLA-DR on lesional keratinocytes was never observed at any time in the normal skin of control patients challenged with dinitrochlorobenzene. These results suggest that localized misregulated expression of ICAM-1 by the keratinocytes may be one factor that explains the preferential site-specificity characteristic of fixed drug eruptions.

Adult↗

PubMed1989

Occurrence of yawning and decrease of prolactin levels via stimulation of dopamine D2-receptors after administration of SND 919 in rats.

SND 919 [S)-2-amino-4,5,6,7-tetrahydro-6-propylamino-benzothiazole) is expected to have a potent and selective dopamine D2-receptor agonistic activity. From this information, the present study was performed to investigate effects of SND 919 on yawning behavior and prolactin secretion in rats. Subcutaneous injections of SND 919 (25-500 micrograms/kg, s.c.) elicited yawning responses. Its dose-response curve was bell-shaped with maximal effects at a dose of 100 micrograms/kg. Yawning behavior was also evoked by the putative dopamine autoreceptor agonists, talipexole (6-allyl-2-amino-5,6,7,8-tetrahydro-4H-thiazolo [4,5-d]azepine) (B-HT 920) (5-100 micrograms/kg, s.c.) and (+)-3-PPP ((+)-3-(3-hydroxyphenyl)-N-n-propylpiperidine) (5-15 mg/kg, s.c.). The yawning induced by SND 919 (100 micrograms/kg, s.c.) as well as talipexole (25 micrograms/kg, s.c.) was inhibited by pretreatment with dopamine D2-receptor antagonists such as spiperone (0.5 mg/kg, i.p.) and YM-09151-2 (cis-N-(1-benzyl-2-methylpyrrolidin-3-yl)-5-chloro-2-methoxy-4-met hylamino- benzamide) (0.1 mg/kg, i.p.), or the muscarinic receptor antagonist, scopolamine (0.5 mg/kg, i.p.). However, the yawning was not affected by the dopamine D1-receptor antagonist, SCH 23390 (R(+)-8-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepine-7-o l) (0.5 mg/kg, i.p.). Stereotypy such as licking and biting was not observed following the administration of SND 919, talipexole and (+)-3-PPP. Administration of SND 919, talipexole or (+)-3-PPP in respective yawn-inducing doses caused a reduction in both the basal prolactin levels and the alpha-methyl-p-tyrosine-induced hyperprolactinemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

Involvement of central beta-adrenoceptors in the regulation of yawning responses.

A behavioral study was performed in an attempt to understand the role of central beta-adrenoceptors in yawning in rats. Yawning was evoked by apomorphine and piribedil, mixed dopamine D1/D2-receptor agonists, but not by SK&F 38393 [1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8-diol], a dopamine D1-receptor agonist. The apomorphine-induced yawning was increased by pindolol, propranolol, indenolol, alprenolol and bukumolol which block the central beta-adrenoceptors, but not by the peripheral beta-adrenoceptor antagonists, carteolol and atenolol. These beta-adrenoceptor antagonists given alone did not elicit yawning. Conversely, the yawning was inhibited by salbutamol, a beta-adrenoceptor agonist, without being affected by prazosin, an alpha-adrenoceptor antagonist. The combined administration of SK&F 38393 and the beta-adrenoceptor antagonists did not induce yawning. The yawning elicited by either apomorphine or piribedil in combination with pindolol was suppressed by spiperone and YM-09151-2 [cis-N-(1-benzyl-2-methyl-pyrrolidin-3-yl)-5- chloro-2-methoxy-4-methylamino-benzamide], dopamine D2-receptor antagonists, and scopolamine, a muscarinic receptor antagonist, but not by SCH 23390 [R(+)-8-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3- benzazepine-7-ol], a dopamine D1-receptor antagonist. Physostigmine or pilocarpine induced yawning, which was also enhanced by pindolol and propranolol. This enhanced yawning was inhibited by scopolamine, but not by spiperone, YM-09151-2 and SCH 23390.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗

PubMed1989

Potentiation by serotonergic inhibition of yawning induced by dopamine receptor agonists in rats.

Low doses of the dopamine D2-receptor agonist, B-HT 920 (25 micrograms/kg, SC), and the dopamine D1/D2-receptor agonists, apomorphine (50 micrograms/kg, SC) and piribedil (1 mg/kg, SC), evoked yawning. However, the dopamine D1-receptor agonist, SK&F 38393 (2 mg/kg, SC), failed to induce yawning. The yawning responses induced by B-HT 920, apomorphine or piribedil were markedly increased without eliciting stereotypy by pretreatment with reserpine (5 mg/kg, IP, 24 hr). These yawning responses were also enhanced by p-chlorophenylalanine (PCPA) (300 mg/kg, IP, 72 hr), but not by alpha-methyl-p-tyrosine (300 mg/kg, IP, 6 hr). The yawning induced by B-HT 920 given alone and in combination with reserpine or PCPA was inhibited by spiperone (0.5 mg/kg, IP) or scopolamine (0.5 mg/kg, IP), but not by SCH 23390 (0.5 mg/kg, IP). The present results suggest that yawning is evoked by stimulation of dopamine D2-receptors having a high affinity and consequent muscarinic activation, and that the yawning induced by dopamine receptor agonists is potentiated by decreases in serotonergic neuron activity.

Animals↗

PubMed1989

Interferon-gamma as adjuvant therapy for resistant warts.

A patient who for 26 years had common warts, which were resistant to various treatment modalities, was treated with a single intralesional injection of interferon-gamma after dinitrochlorobenzene immunotherapy, because immunologic studies indicated she had failed to respond to prior treatment modalities as a result of a functional impairment of her cellular immune response. Within 1 to 2 days, not only the wart injected with interferon-gamma, but also other warts, became erythematous and swollen, giving a lichen planus-like appearance. Without additional injections of interferon-gamma, all warts disappeared completely, leaving slight pigmentation. Interferon-gamma would be most effective when used with, rather than instead of, other immunotherapy.

Biopsy↗

PubMed1989

Mobile schwannoma of the cauda equina diagnosed by magnetic resonance imaging.

Three cases of a mobile cauda equina schwannoma, preoperatively diagnosed by magnetic resonance imaging, are described. When dealing with tumors of the cauda equina, it is important to carry out a second magnetic resonance imaging scan after changes in posture, bearing in mind the possibility of mobility of the tumor.

Adult↗

PubMed1989

In vitro migration of L3T4+ cloned T cells to epidermis: possible role for keratinocyte-derived factors.

Three types of L3T4+ cloned T cells with different antigen specificities, auto-, allo-, and antigen-reactive, were characterized with respect to their migratory potential using an in vitro migration assay under agar gel. Autoreactive T cells, BB5, and alloreactive T cells, SK 1, both of which have been proved to be epidermotropic in vivo, showed specific directional migration to the epidermis, whereas no directional migration was seen with non-epidermotropic cloned T cells and freshly isolated lymph node T cells. Both BB5 and SK 1 cells were equally attracted to all the epidermal fragments tested regardless of their I-A antigens. The directional migration of BB5 cells to the epidermis was significantly inhibited by the co-cultivation with the epidermis, but not the dermis. Studies with cell lines, the conditioned media (CM), and recombinant interleukin (IL) 1, 2, and 3 revealed that BB5 cells were chemotactically attracted to a transformed keratinocyte cell line PAM212 and, to a lesser extent, to the CM from PAM212 and IL-2, but not to IL-1 and IL 3. These results suggest that epidermotropic T cells may be preferentially trapped in an area with a high concentration of keratinocyte-derived growth factors as well as IL-2.

Animals↗

PubMed1989

Differential expression of lymphocyte function-associated antigen 1 (LFA-1) on epidermotropic and non-epidermotropic T-cell clones.

Various T-cell surface molecules are involved in T-cell adhesion, which is an essential requirement for epidermotropic migration of T cells. Our previous studies demonstrated that certain T-cell clones can migrate into the epidermis upon their intradermal inoculation into the footpads of recipient mice with relevant antigens, while other T-cell clones, despite their identical antigen specificities and functions, are non-epidermotropic. We therefore tested whether the differences in epidermotropism of these T cells could reside in the different levels of expression of T-cell surface molecules such as CD3, CD4, CD2, and lymphocyte function associated antigen 1 (LFA 1). The results of flow cytometric analysis showed that LFA-1 was preferentially expressed on the surface of epidermotropic T-cell clones, while non-epidermotropic T-cell clones were negative or very weakly positive for LFA-1 with one exception. After exposure to phorbol ester, epidermotropic clones with high levels of LFA-1 did not show any further up-regulation of LFA-1. In contrast, under identical conditions, significant up-regulation of LFA-1 was observed on non-epidermotropic T cells with low levels of LFA-1. However, even after exposure to phorbol ester, these T cells remained non-epidermotropic. These results suggest that the presence of high levels of LFA-1 on T cells is absolutely necessary for their epidermotropic migration, but its up-regulation is neither necessary nor sufficient to trigger the epidermotropic migration. High levels of LFA-1, regardless of cell activation, may be required to mediate stable cell adhesions leading to epidermotropic migration.

Animals↗

PubMed1989

Dopamine receptor blocking action of a dibenzothiepin derivative isofloxythepin in rats.

1. Subcutaneous injection of isofloxythepin or haloperidol inhibited exploratory behaviour, methamphetamine (3 mg/kg)-induced hyperactivity and bromocriptine (15 mg/kg)-induced yawning, and also elicited catalepsy. 2. Isofloxythepin and haloperidol increased concentrations of dihydroxyphenylacetic acid in the striatum and elevated serum prolactin levels. 3. The results suggest that isofloxythepin, as well as haloperidol, blocks the action of the dopamine D2-receptors in the striatum, nucleus accumbens and pituitary.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1989

Expression of the Arthrobacter viscosus penicillin G acylase gene in Escherichia coli and Bacillus subtilis.

The penicillin G acylase gene cloned from Arthrobacter viscosus 8895GU was subcloned into vectors, and the recombinant plasmids were transferred into Escherichia coli or Bacillus subtilis. Both E. coli and B. subtilis transformants expressed the A. viscosus penicillin G acylase. The enzyme activity was found in the intracellular portion of the E. coli transformants or in the cultured medium of the B. subtilis transformants. Penicillin G acylase production in the B. subtilis transformants was 7.2 times higher than that in the parent A. viscosus. The A. viscosus penicillin G acylase was induced by phenylacetic acid in A. viscosus, whereas the enzyme was produced constitutively in both the E. coli and B. subtilis transformants carrying the A. viscosus penicillin G acylase gene.

Amidohydrolases↗

PubMed1989

Psoriasis and lichen planus: coexistence in a single patient. Are both diseases mutually exclusive?

The coexistence of psoriasis and lichen planus has been rarely reported, although both diseases are relatively common and have some features in common. A rare case of simultaneous occurrence of both diseases is presented. Spontaneous improvement of psoriasis occurred during the development of lichen planus and a subsequent disappearance of the lichen planus was associated with an exacerbation of the psoriasis. The clinical courses of the two diseases may not be independent of each other, but be affected by common factors. Immunohistochemical studies with lesional skin suggested local production of interferon-gamma, which may in part explain the improvement of the psoriasis during the development of lichen planus. Based on these immunohistochemical findings, we discuss a putative role for these lymphokines in the pathogenesis of the two diseases.

Adult↗

PubMed1989

[Successful treatment of cheilitis granulomatosis with potent inhibitors of mediator release--possible involvement of mast cells in the pathogenesis].

We report two cases of patients with cheilitis granulomatosis treated successfully with tranilast and ketotifen, both of which are known to be potent inhibitors or mediator release from mast cells. In one patient, complete resolution of the lesion occurred after 1 year of therapy. In another patient, the lesion also showed consistent, if not complete, improvement during the course of therapy. Because of the mechanism of the action, these agents have been widely used as therapeutic modalities for mast-cell-related diseases. We therefore measured numbers of mast cells in the lesions of cheilitis granulomatosis, in comparison with those in mucous cyst and lichen planus. Light microscopy of toluidine-blue-stained sections showed that mast cells, particularly those with ongoing degranulation, increased in number in the reticular dermis of the lesions of cheilitis granulomatosis. These findings suggest that mediators released from mast cells may be critical for the granulomatous inflammation in cheilitis granulomatosis.

Adolescent↗

PubMed1989

[Clinical evaluation of perioperative myocardial infarction as a complication of valve replacement].

Perioperative myocardial infarction (PMI) is a well-known complication of coronary artery surgery, but rarely encountered in valvular surgery. We have experienced 6 cases of valve replacement with PMI, using blood cardioplegia since 1979. Those patients (5 men, one woman; mean age 47 +/- 8 years) had no previous angina, and preoperative CAG revealed no significant stenosis. Three patients were reoperative cases. A diagnosis of PMI was established by the following criteria; an abnormal increase in maxCPK-MB (greater than 150 IU/l), new Q waves at ECG, positive 99mTc-PYP scan (grade 3-4). The area of PMI was inferior in 4 patients, posterior in one, and anterior infarction was seen in only one case. Three cases required IABP, but all 6 cases showed good exercise capacity by Treadmill exercise test in late stage. Several factors are thought to be the cause of PMI at valvular surgery; such as coronary air embolism, perioperative coronary spasm, inappropriate topical hypothermia, etc. Prognosis is not necessarily poor, however much attention should be paid to prevent PMI in valve replacement.

Adult↗