Search PubMed⌕ Search

Biomedical subjects

T Ebihara

Publications and source records attributed to T Ebihara.

At least 55 records · Page 3Linked to original sources
PubMed1997

Muscarinic acetylcholine receptor-mediated induction of zif268 mRNA in PC12D cells requires protein kinase C and the influx of extracellular calcium.

The immediate-early gene zif268 (egr-1, NGFI-A, krox-24) encodes a transcription factor that has been proposed to play a role in differentiation and neuronal plasticity. zif268 mRNA is undetectable in unstimulated PC12D cells, a subline of PC12 characterized by accelerated differentiation in the presence of nerve growth factor, but is rapidly and robustly induced following exposure to muscarinic acetylcholine receptor (mAChR) agonists. Although PC12D cells express mRNAs for both m1 and m4 mAChR subtypes, induction of zif268 mRNA by mAChR agonists is apparently mediated exclusively by the m1 subtype because the induction is completely blocked by Dendroaspis angusticeps m1 toxin. Pretreatment of the cells with the specific protein kinase C (PKC) inhibitor GF109203X partially inhibits mAChR-mediated induction of zif268 mRNA. The remaining induction is blocked by chelation of extracellular calcium with EGTA. EGTA prevents the influx of calcium without blocking mAChR-mediated release of calcium from internal stores. These data indicate that both PKC and the influx of extracellular calcium play a role in the induction of zif268 mRNA following activation of the m1 mAChR. Transient increases in intracellular calcium levels resulting from the release of calcium from internal stores alone are not sufficient to induce zif268 mRNA. Rather, induction requires a prolonged elevation of intracellular calcium levels, which is sustained by the influx of extracellular calcium.

Animals↗
PubMed1997

[Specific modulation of vascular smooth muscle cell functions by docosahexaenoic acid].

There are increasing evidences that fish oil-enriched diets attenuate the progression of several types of human and experimental renal, intestinal and cardiovascular disorders including hypertension. Docosahexaenoic acid (DHA) may be one of the active biological component. We previously reported that dietary DHA suppressed the progression of hypertension in stroke-prone spontaneously hypertensive rats (SHRSP). The purpose of this study was to clarify the in vitro effect of DHA on vascular smooth muscle cell functions such as cell growth, hypertrophy, NO release, and intracellular Ca+2 dynamics which involves in the regulatory mechanisms of vascular tone. Addition of DHA to the culture medium of aortic smooth muscle cells isolated from SHRSP and normotensive Wistar Kyoto rats (WKY) had no significant effects on the cell growth, and cell hypertrophy induced by angiotensin II as measured by flow cytometer. DHA did not have a significant effect on interleukin-1 beta (10 ng/ml)-induced nitric oxide release from smooth muscle cells of SHRSP. However, the treatment of smooth muscle cells with DHA (30 microM) for 2 days significantly suppressed the increase in the intracellular Ca2+ concentration induced by 5-hydroxytryptamine, angiotensin II, depolarizing concentration of KCl, but not by thapsigargin. This suppression seems to be due to the suppression of Ca2+ influx, as determined by Mn2+ influx experiment. These results suggest that DHA specifically suppresses receptor-mediated Ca2+ influx in smooth muscle cells. This may be one of the mechanisms by which dietary DHA prevents the development of hypertension in SHRSP.

Animals↗
PubMed1996

Studies of autoantigens recognized by IgA anti-keratinocyte cell surface antibodies.

We have examined autoantigens for IgA anti-keratinocyte cell surface antibodies in 17 intercellular IgA vesiculopustular dermatosis (IAVPD) cases showing only IgA antibodies and 5 cases showing both IgG and IgA antibodies (G A cases). IAVPD cases were divided into two subtypes: (1) intraepidermal neutrophilic IgA dermatosis type showing pustule formation throughout the epidermis and IgA antibodies reactive with the entire epidermis and (2) subcorneal pustular dermatosis type containing IgA antibodies reactive with the uppermost portion of the epidermis. Most G A cases showed atypical clinical features. With immunoblot analysis of normal human epidermal extracts, IgA antibodies in these cases showed no specific reactivity with either pemphigus foliaceus antigen (desmoglein 1) or pemphigus vulgaris antigen (desmoglein 3), except that IgC antibodies in one G/A case each recognized one of the two antigens. With immunoblotting of desmosome enriched fraction obtained from bovine snout epidermis, IgA antibodies in 10 IAVPD and 3 G/A cases and IgG antibodies in 4 G/A cases showed reactivity with either desmoglein 1 or desmocollin another desmosomal cadherin. These results indicate that IAVPD and G/A cases are heterogeneous in terms of both clinical features and antigens and that the IgA autoantibodies in these cases may react with different antigens from those for IgG autoantibodies.

Animals↗
PubMed1996

Pemphigus: from immunofluorescence to molecular biology.

Since the discovery of autoantibodies in patients with pemphigus, pemphigus has been intensively studied by dermatologists and cutaneous or cellular biologists by means of various techniques including immunofluorescence, immunoelectron microscopy, immunoprecipitation, immunoblotting, and molecular biology. In this article, up-dated topics on pemphigus obtained by each individual technique are reviewed. In the course of immunofluorescence studies on unusual cases of blistering diseases, a new entity characterized by immunoglobulin A (IgA)-type autoantibodies directed against keratinocyte cell surfaces has been discovered. Immunoelectron microscopy using low temperature post-embedding gold labeling enabled us to quantitate binding sites of pemphigus autoantibodies within desmosomes at different levels of epidermis. Immunoprecipitation and immunoblot analyses allowed us to characterize antigen complexes in paraneoplastic pemphigus. Finally, approaches using molecular biology not only have given us a fundamental insight that pemphigus autoantigen is a cadherin-type cell adhesion molecule both in pemphigus vulgaris and pemphigus foliaceus, but also provided tools to develop novel diagnostic and therapeutic strategies.

Autoantibodies↗
PubMed1996

Angiotensin-converting enzyme inhibitor and danazol increase sensitivity of cough reflex in female guinea pigs.

To examine the mechanisms of an angiotensin-converting enzyme (ACE) inhibitor-induced cough in perimenopausal and postmenopausal women, cough responses to aerosols of capsaicin and citric acid were examined in four groups of female guinea pigs treated orally with danazol (D) (an agent decreasing plasma estrogen levels), cilazapril (C) (an inhibitor of ACE), both danazol and cilazapril (C+D), or without either drug (control group) for 4 to 5 wk. Capsaicin caused dose-dependent increases in the number of coughs in all four groups. C or D alone shifted dose-response curves to capsaicin (from 10(-7) M to 10(-3) M) to lower concentrations compared with the control, and C+D further shifted them. Likewise, the number of coughs induced by citric acid (3 x 10(-1) M; 2 min) was highest in animals treated with C+D and significantly higher in animals treated with C or D than in the control group. Aerosols of a selective substance P (SP) receptor antagonist FK 888 (10(-5) M; 2 min) inhibited capsaicin-induced cough in all four groups, and dose-response curves to capsaicin did not differ significantly at any concentrations among the four groups in the presence of FK 888 (p > 0.10). D decreased cyclic AMP levels in the trachea, irrespective of the combination of C. A beta 2-adrenoceptor agonist, procaterol, which is thought to inhibit SP release by elevation of cyclic AMP in sensory nerves, dose-dependently inhibited the number of coughs induced by capsaicin (10(-3) M) in animals treated with D. The present study suggests that SP is a common mechanism mediating increases in the sensitivity of cough reflex induced by both ACE inhibition and a decrease in plasma estrogen levels, and the additive effects of the two events may explain the high incidence of cough during ACE inhibitor therapy in perimenopausal and postmenopausal women.

Adrenergic beta-Agonists↗
PubMed1996

IgA antikeratinocyte surface autoantibodies from two types of intercellular IgA vesiculopustular dermatosis recognize distinct isoforms of desmocollin.

We previously proposed the term intercellular IgA vesiculopustular dermatosis (IAVPD) for cases showing IgA antikeratinocyte surface autoantibodies. This condition is divided into two subtypes: intraepidermal neutrophilic IgA dermatosis (IEN), showing pustule formation in the entire epidermis, and subcorneal pustular dermatosis (SPD) showing pustule formation in the uppermost epidermis. We have previously reported that serum from certain IAVPD patients reacts with bovine desmocollin (Dsc), a desmosomal cadherin. In this study we showed that two Dsc isoforms with a slightly different molecular weight were recognized by the serum from these patients. Further analysis revealed that serum from patients with the SPD type, which stained the cell surface in the uppermost epidermis with immunofluorescence, seem to react with Dsc1. By contrast, serum from patients with the IEN type, which stained the cell surface at all levels of the epidermis with immunofluorescence, seemed to react with Dsc3. This difference of distribution between the two distinct Dsc molecules may contribute to the different clinicopathological features between the IEN and SPD type of IAVPD.

Autoantibodies↗
PubMed1995

Role of substance P in cough during bronchoconstriction in awake guinea pigs.

To examine the role of substance P (SP) in cough during bronchoconstriction, we studied the effects of an aerosolized beta-adrenoceptor agonist, procaterol, and a specific inhibitor of SP (NK1) receptor, FK 888, on bronchoconstriction and cough induced by aerosols of histamine and acetylcholine (ACh) in unsensitized guinea pigs and by those of ovalbumin (OA) antigen in guinea pigs sensitized to OA. Intensity of bronchoconstriction was evaluated by the time to onset of bronchoconstriction after the inhalation of bronchoconstrictors. Both procaterol (10(-6) to 10(-4) M, 2 min) and FK 888 (10(-7) to 10(-5) M, 2 min) dose dependently decreased the number of coughs and increased the time to onset of bronchoconstriction induced by histamine (10(-2) M, 15 s). Procaterol attenuated histamine-induced cough only at the concentrations effective to inhibit bronchoconstriction. However, FK 888 at concentrations of 10(-7) and 10(-6) M decreased the number of coughs without effect on bronchoconstriction. Likewise, the inhibitory effects of procaterol (10(-5) M, 2 min) on the number of coughs were parallel to those on bronchoconstriction induced by ACh (10(-1) M, 15 s) and OA antigen (0.1% concentration, 30 s), but FK 888 (10(-6) M, 2 min) decreased the number of coughs without effect on bronchoconstriction induced by them. The number of coughs induced by histamine (10(-2) M, 15 s) was inhibited by systemic capsaicin treatment and enhanced by phosphoramidon (10(-5) M, 5 min) without effect on bronchoconstriction. (ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Familial linear and whorled nevoid hypermelanosis.

Two patients with familial linear and whorled nevoid hypermelanosis, a 33-year-old woman and her 3-month-old daughter, are described. These are the first cases of linear and whorled nevoid hypermelanosis of familial occurrence reported in the literature. Asymptomatic hyperpigmented macules in streaky configurations had appeared on the trunk and extremities of both patients several weeks after birth and then gradually spread. No previous inflammation or eruption was observed. Histologic examination revealed a slight increase in the number of melanocytes in the epidermis and an irregular basal melanosis. No pigmentary incontinence or melanophages were observed in the dermis. Ultrastructurally the only finding was an increase in the number of normal-appearing mature melanosomes in keratinocytes in the lesion. Chromosomal analysis of cultured peripheral blood lymphocytes and dermal fibroblasts from normal and pigmented skin revealed no evidence of mixoploidy or chimerism. An undescribed genetic abnormality is suggested as the cause.

Adult↗
PubMed1994

Unusual acantholytic bullous dermatosis associated with neoplasia and IgG and IgA antibodies against bovine desmocollins I and II.

There are unusual cases of pemphigus that have antibodies nonreactive with either pemphigus vulgaris or pemphigus foliaceus antigens. We describe a patient with an acantholytic bullous dermatosis and lung cancer with intercellular IgG and IgA antibodies that differed in specificity from those of pemphigus vulgaris and pemphigus foliaceus and reacted with bovine desmocollins I and II and recombinant desmocollin protein.

Adult↗
PubMed1994

Difference in binding sites of autoantibodies against 230- and 170-kD bullous pemphigoid antigens on salt-split skin.

The purpose of this study is to clarify a relationship between bullous pemphigoid autoantibodies against two major BP antigens, 230 kilodalton (kD) (BPAG1) and 180 kD (BPAG2) and their binding sites, using immunoblot analysis and indirect immunofluorescence on salt-split skin. Of the 135 sera obtained from patients in whom bullous pemphigoid had previously been diagnosed by clinical and immunopathologic criteria, all 52 sera recognizing only BPAG1 stained only the epidermal side of split skin (epidermal pattern). Of 24 sera recognizing only BPAG2, 20 showed the epidermal pattern and four stained both the epidermal and dermal sides (combined pattern). Of 42 recognizing both BPAG1 and BPAG2, 35 showed the epidermal pattern and seven showed the combined pattern. Of 17 that reacted with neither antigen, nine showed the epidermal pattern, four showed the combined pattern, and four stained only the dermal side (dermal pattern). Two of the four cases that showed a dermal pattern were retrospectively identified as epidermolysis bullosa acquisita. Immunoelectron microscopy confirmed that a serum with combined pattern bound to both intracellular and extracellular sites of hemidesmosomes. Our results suggest that autoantibodies that react solely with BPAG1 bind exclusively to the epidermal side of salt-split skin and never show either a combined or a dermal pattern, and that most antibodies against BPAG2 bind to the epidermal side. The combined pattern suggests the presence of autoantibodies against the extracellular epitopes of BPAG2 that are separated from the epidermis during the salt-splitting process.

Autoantibodies↗
PubMed1994

Cutaneous T-cell lymphoma with massive co-infiltration of polyclonal B cells.

A 76-year-old man presented with a 3-month history of a cutaneous nodule on the right thigh. The tumour was composed of CD3+, large atypical cells, and CD20+, small normal-appearing cells. Flow cytometry showed that CD20+ cells outnumbered CD3+ cells. By Southern blot hybridization analyses, the malignant cells were shown to be of T-cell origin, because of the presence of rearranged bands for the beta chain of the T-cell receptor, but not for the immunoglobulin heavy chain. This case represents a T-cell lymphoma intermingled with a large number of non-neoplastic B cells.

Aged↗
PubMed1994

Two different isoforms of desmocollin are recognized by autoantibodies in various types of pemphigus.

We have previously reported that, in addition to well-known pemphigus antigens (desmoglein and pemphigus vulgaris antigen), desmocollin (Dsc), another desmosomal cadherin, is recognized by certain pemphigus sera. Furthermore, we noticed that two Dsc species with a slightly different relative molecular weight were recognized by various pemphigus sera. This difference may contribute to the different clinicopathological features between the subcorneal pustular dermatosis type and the intraepidermal neutrophilic IgA dermatosis type of intercellular IgA vesiculopustular dermatosis.

Autoantibodies↗
PubMed1994

[Problems and solutions of home care for a terminal cancer patient--cooperation as a team approach].

In order to have a terminal cancer patient spending fulfilling remaining of his life, the role of home care is important. Caremark clinical team, consists of nurses, pharmacists and clinical coordinators (CC), provides home care service for patients. We have faced many problems regarding providing care for our cancer patients, especially terminal patients, and solved the problems in cooperation with the physicians. The main problems which we have faced with care for terminal cancer patients are as follows: (1) For emergency case, such as sudden changes in patient condition, if a hospital where the patient used to stay can not accept his return, our clinical coordinator makes a contact with closer hospital and asks them to hospitalize the patient. (2) Concerns of a patient and his family increase when his pain is getting severe. For this case, our nurse gives his caregiver training on treatment method, and normal pain management care for the patient. Also our pharmacist talks with the patient and his family and try to reduce the pain by using more suitable drugs at each conditions. (3) A patient with serious conditions which requires long term home care, his family and caregivers have more burdens. For this problem we suggests them to use high touch home care providers, and also our nurse provides psychological care (counseling). We have solved other problems in cooperation with each specialists, and we are confident that we are able to provide better home care service for our patients.

Female↗
PubMed1993

Detection of the 170-kDa bullous pemphigoid antigen by immunoprecipitation.

There has been controversy concerning the nature of the bullous pemphigoid (BP) antigen: immunoprecipitation identified BP antigen as a single, unique 230-kDa protein, whereas immunoblot analysis showed multiple antigen molecules, mainly 230- and 170-kDa proteins. In this study, to further characterize the 170-kDa protein, we have examined whether the 170-kDa protein is detected by immunoprecipitation. Extracts of human squamous cell carcinoma cells revealed the 170-kDa protein with immunoblot analysis. Although the conventional immunoprecipitation detected only the 230-kDa protein, some BP sera that detected the 170-kDa protein with immunoblotting also precipitated the 170-kDa protein with our modified immunoprecipitation, in which the cells were extracted with 1% sodium dodecylsulfate (SDS) buffer and reacted with the sera under reduced SDS concentration. The 170-kDa protein-specific BP sera clearly showed hemidesmosomal plaque staining with immunofluorescence of cultured cells. These results indicate that the 170-kDa protein is indeed one of the BP antigens and that the 230- and 170-kDa BP antigens are integrated in different ways in hemidesmosomes.

Autoantigens↗