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T Nishikawa

Publications and source records attributed to T Nishikawa.

At least 145 records · Page 8Linked to original sources
PubMed2000

Subepidermal blistering disease with autoantibodies against a novel dermal 200-kDa antigen.

A number of autoimmune subepidermal blistering diseases are characterized by the distinct autoantigens of the cutaneous basement membrane zone. Recently, a few cases with autoantibodies against a novel 200-kDa dermal protein have been reported. We collected nine cases of subepidermal blistering disease with IgG antibodies against this 200-kDa antigen. In this report, we describe the clinical and immunological appearances in these cases. Five cases showed bullous pemphigoid-like features, one case resembled dermatitis herpetiformis, and another case showed mixed features of bullous pemphigoid and linear IgA bullous dermatosis. It was interesting to note that psoriasis coexisted in four cases. By indirect immunofluorescence on 1 M NaCl split skin, IgG antibodies from all sera reacted with the dermal side of the split. By immunoblot analysis, IgG antibodies recognized a 200-kDa protein of dermal extract. IgG affinity-purified antibodies on the 200-kDa immunoblot membrane stained the dermal side of 1 M NaCl split skin. Various examinations suggested that the 200-kDa antigen is not identical to any chains of laminins-1, -5 or -6. This autoimmune subepidermal blistering disease against the dermal 200-kDa protein may form a new distinct entity, which often associates with psoriasis.

Adult↗
PubMed2000

Effects of oral clonidine premedication on side effects of intravenous ketamine anesthesia: a randomized, double-blind, placebo-controlled study.

STUDY OBJECTIVE: To determine the effects of oral clonidine premedication on hemodynamic changes during the entire course of ketamine anesthesia and incidence of postoperative adverse reactions. DESIGN: Randomized, prospective, double-blind, placebo-controlled study. SETTING: Department of Anesthesiology, University of Tsukuba Hospital, Ibaraki, Japan. PATIENTS: 39 ASA physical status I and II patients undergoing superficial surgeries. INTERVENTIONS: Placebo, clonidine 2.5 micrograms/kg, and clonidine 5 micrograms/kg groups received respective doses of oral clonidine 90 minutes prior to surgery. Anesthesia was induced with ketamine 2 mg/kg intravenously (i.v.), trachea was intubated, and anesthesia was maintained with 67% nitrous oxide, oxygen, and supplemental ketamine (1 mg/kg) when systolic blood pressure and heart rate (HR) exceeded 180 mmHg and 100 bpm, respectively. MEASUREMENTS AND MAIN RESULTS: In the clonidine 2.5 micrograms/kg group, HR response to tracheal intubation was significantly less, while in the clonidine 5 micrograms/kg group both mean arterial pressure and HR responses were significantly suppressed, compared with the placebo group. Intraoperative coefficients of variations of HR were significantly less in both clonidine groups than the placebo group. Incidence of nightmare and degree of salivation were significantly less in the clonidine 5 micrograms/kg group than in the placebo group. CONCLUSION: Oral clonidine 2.5 micrograms/kg and clonidine 5 micrograms/kg attenuates cardiostimulatory effects, while clonidine 5 micrograms/kg was associated with reduced incidence and severity of nightmare and salivation attributable to i.v. ketamine.

Administration, Oral↗
PubMed2000

Expression and activity of dehydroepiandrosterone sulfotransferase in human gastric mucosa.

Dehydroepiandrosterone sulfotransferase (DHEA-ST) is a key enzyme in the formation of Dehydroepiandrosterone sulfate (DHEAS) and is thought to be involved in the conversion of various substances such as bile acids and cholesterol. The existence of DHEA-ST in the small intestine in addition to the adrenal gland and liver in adult humans was recently reported. As the sulfotransferases can act on toxic or potentially toxic substances to reduce their biological activity, we attempted to clarify the significance of DHEA-ST in gastrointestinal tract. We examined surgically resected human stomach for the presence of DHEA-ST and attempted to determine its possible biological significance. DHEA-ST activity ranged widely from 6 to 84 pmoles/mg protein/90 min in 7 cases. Immunoblotting revealed one single band of a 35-kDa protein corresponding to the moleculr weight of DHEA-ST. Both DHEA-ST immunoreactivity and mRNA hybridization signals were localized in parietal cells of the gastric glands. The results of our present study demonstrated that the sulfation of DHEA by DHEA-ST occurs in the gastric glands. The localization of DHEA-ST in parietal cells suggests that this enzyme is correlated to mucosal function in the human stomach in addition to detoxification of exogenous substances.

Adult↗
PubMed2000

Clarithromycin suppresses bronchial hyperresponsiveness associated with eosinophilic inflammation in patients with asthma.

BACKGROUND: Although long-term administration of 14-membered macrolide antibiotics is a therapeutic alternative in asthma, both its pharmacologic mechanism of action and association with the pathogenesis of asthma remain obscure. OBJECTIVE: This study investigated the suppressive effect of clarithromycin on airway responsiveness to methacholine provocation testing and examined whether chrarithromycin's antiasthmatic activity is associated with a reduction in eosinophilic inflammation. METHODS: For 8 weeks, patients received 200 mg of clarithromycin or identical-appearing placebo twice daily. We assessed the effects of treatment with clarithromycin on bronchoconstriction precipitated by inhalation of methacholine in 17 adults with mild or moderate bronchial asthma who were in stable clinical condition. A double-blind, randomized, crossover design was used. Eosinophil counts and eosinophilic cationic protein (ECP) levels were determined in blood and sputum samples obtained on the morning of the methacholine provocation testing day. RESULTS: After 8 weeks of treatment with clarithromycin, patients' symptoms, blood and sputum eosinophils counts and sputum ECP levels were significantly decreased compared with both placebo and baseline. Furthermore, values of PC20 methacholine improved in all patients after clarithromycin treatment. CONCLUSIONS: Clarithromycin has a bronchial anti-inflammatory effect associated with decreased eosinophilic infiltration. This study suggests interesting therapeutic possibilities for bronchial asthma that warrant further trials.

Adult↗
PubMed2000

Additive effects of combined treatment with etidronate and alfacalcidol on bone mass and mechanical properties in ovariectomized rats.

The present study was undertaken to evaluate the effects of combined treatment with intermittent cyclical etidronate and daily alfacalcidol on the mass and the mechanical properties of bone in ovariectomized rats, and to compare the effects with those of single treatments. Seventy 14-week-old female rats underwent ovariectomy (ovx) or sham operation, and were assigned to seven groups (n = 10 each): sham-operated; ovx; ovx treated with etidronate; ovx treated with 0.1 microg/kg alfacalcidol; ovx treated with 0.2 microg/kg alfacalcidol; ovx treated with etidronate and 0.1 microg/kg alfacalcidol; and ovx treated with etidronate and 0.2 microg/kg alfacalcidol. One week after the operation, etidronate (4 mg/kg per day) was intermittently injected into rats for 2 weeks followed by a 10 week period of no treatment, and alfacalcidol was administered orally every day. After 24 weeks of treatment, all single and combined treatments increased the bone mineral densities (BMDs) of the proximal tibiae, midfemurs, and the fourth and fifth vertebral bodies, which had been decreased by ovx. Combined treatment groups showed higher BMDs than single treatment groups, and the effects were almost equal to the addition of those of respective single treatment groups. The combined treatment also showed additive effects on the mechanical properties of both midfemurs and L4 vertebral bodies. The increases in mechanical properties were proportional to those in BMDs. Analyses of microcomputed tomography images and histology confirmed the strong effects of combined treatments on both trabecular and cortical bone mass without impairment of mineralization or connectivity. We conclude that the combined treatment with etidronate and alfacalcidol additively increases the mass of bone with normal quality, resulting in bone strengthening in ovx rats.

Animals↗
PubMed2000

Polymorphisms in the TNFA promoter region is not associated with palmoplantar pustulosis.

Polymorphisms of the 5'-flanking promoter/enhancer region of the TNAFA gene were determined in 80 Japanese patients with pulmoplantar pustulosis (PPP). The 5'-flanking region of the TNFA gene from -1107 to 66 was amplified by polymerase chain reaction (PCR) method. Nucleotide sequencing data from the PCR products revealed that 5 single nucleotide polymorphisms at position 1031, -863, -857, -307 and -237. None of the nucleotide substitutions were significantly increased in PPP patients when compared with those in controls. To clarify the linkage among the neighboring genetic marker, we analyzed the association between the polymorphisms in the TNFA promoter region and the NcoI polymorphism in the first intron of the TNFB gene as well as HLA-DR9. The genotype at 1031C is strongly associated with TNFB1 and negatively associated with TNFB2 which is reported to be associated with PPP. These data indicate that TNFA gene centromeric to TNFB is not associated with PPP and the susceptible gene of PPP is located between TNFB and HLA-B.

Genotype↗
PubMed2000

Development of chimeric molecules for recognition and targeting of antigen-specific B cells in pemphigus vulgaris.

Pemphigus vulgaris (PV) is an autoimmune blistering disease characterized by circulating pathogenic IgG antibodies against desmoglein 3 (Dsg3). The purpose of this study was to develop chimeric molecules for specific recognition and elimination of autoimmune B cells in PV. Mouse hybridoma cell lines producing anti-Dsg3 antibody (5H10, 12A2) were developed as an in vitro model system for targeting B cells. Dsg3-GFP, a baculoprotein containing the entire extracellular domain of Dsg3 fused with green fluorescence protein, recognized and targeted the hybridoma cells through their surface immunoglobulin receptors in an antigen-specific way. The epitopes of these monoclonal antibodies were mapped on the amino terminal EC1 and part of EC2, a region considered functionally important in cadherins. Chimeric toxin molecules containing the mapped region (Dsg3deltaN1) and modified Pseudomonas exotoxin were produced in bacteria (Dsg3deltaN1-PE40-KDEL, PE3 7-Dsg3deltaN1-KDEL) and tested in vitro on hybridoma cell lines. The chimeric toxins, but not Dsg3deltaN1 alone, showed dose-dependent toxic activity with a reduction in hybridoma cell number to 40-60% of toxin-negative control cultures, compared with little or no effect on anti-Dsg3-negative hybridoma cells. Furthermore, these toxins showed toxic effects on anti-Dsg3 IgG-producing B cells from Dsg3deltaN1-immunized mice, with a 60% reduction in cell number compared with Dsg3deltaN1 alone. Thus, specific recognition and targeting of antigen-specific B cells in PV was demonstrated; this strategy may hold promise as a future therapeutic option for PV and other autoimmune diseases.

ADP Ribose Transferases↗
PubMed2000

Dissociation of intra- and extracellular domains of desmosomal cadherins and E-cadherin in Hailey-Hailey disease and Darier's disease.

In order to clarify the pathomechanism of acantholysis in Hailey-Hailey disease (HHD) and Darier's disease (DD), the distribution of desmosomal and adherens junction-associated proteins was studied in the skin of patients with HHD (n = 4) and DD (n = 3). Domain-specific antibodies were used to determine the cellular localization of the desmosomal transmembrane glycoproteins (desmogleins 1 and 3 and desmocollin), desmosomal plaque proteins (desmoplakin, plakophilin and plakoglobin) and adherens junction-associated proteins (E-cadherin, alpha-catenin, beta-catenin and actin). A significant difference in staining patterns between intra- and extracellular domains of desmosomal cadherins and E-cadherin was demonstrated in acantholytic cells in both HHD and DD, but not in those in pemphigus vulgaris and pemphigus foliaceus samples used as controls. In acantholytic cells in HHD and DD, antibodies against attachment plaque proteins and intracellular epitopes of desmosomal cadherins exhibited diffuse cytoplasmic staining, whereas markedly reduced staining was observed with antibodies against extracellular epitopes of the desmogleins. Similarly, membrane staining of an intracellular epitope of E-cadherin was preserved, while immunoreactivity of an extracellular epitope of E-cadherin was destroyed. While the DD gene has been identified as ATP2A2, the gene for HHD has not been clarified. The dissociation of intra- and extracellular domains of desmosomal cadherin and E-cadherin is characteristic of the acantholytic cells in HHD and DD, and not of pemphigus. This common phenomenon in HHD and DD might be closely related to the pathophysiological mechanisms in both conditions.

Acantholysis↗
PubMed2000

Epidemiological study of human herpesvirus-6 and human herpesvirus-7 in pityriasis rosea.

BACKGROUND: Pityriasis rosea (PR) is a common papulosquamous skin disorder that is suspected to have an infectious aetiology. OBJECTIVES: We aimed to study the role of human herpesvirus (HHV)-7 and HHV-6 in the pathogenesis of PR. METHODS: We performed seroepidemiological studies (indirect immunofluorescence test) and polymerase chain reaction (PCR) analysis for HHV-6 and HHV-7 in patients with PR. Seventy-two serum samples and 37 samples of peripheral blood mononuclear cells (PBMC) from 44 patients with PR were obtained. Twenty-five patients with other skin disorders such as drug eruption, urticaria or herpes zoster were studied as controls in the PCR analysis. RESULTS: HHV-7 DNA was detected in 13 of 30 (43%) samples of PBMC of the patients with PR and 14 of 25 (56%) samples of PBMC of controls. HHV-6 DNA was detected in six of 29 (21%) patients with PR and nine of 23 (39%) controls. Thus there was no difference in the prevalence of HHV-6 or HHV-7 in PBMC between patients with PR and those with other skin disorders. In the seroepidemiological study, two cases of at least a fourfold rise in titre and five cases of a fourfold decrease in titre to HHV-7 antibody, and two cases of a fourfold rise in titre and two cases of a fourfold decrease in titre to HHV-6 antibody, were observed in 24 patients with PR. This seroepidemiological study revealed antibody responses consistent with active infection in several PR patients, but the greater proportion of the patients had no definite increase in the antibody titres. CONCLUSIONS: We conclude that HHV-7 and HHV-6 may play a part in some patients with PR, but that other causative agents may exist. Further analyses are needed to determine the causative agents of PR.

Adolescent↗
PubMed2000

Therapeutic effect of intracolonically administered nuclear factor kappa B (p65) antisense oligonucleotide on mouse dextran sulphate sodium (DSS)-induced colitis.

Cytokines such as IL-1, tumour necrosis factor-alpha (TNF-alpha), IL-6 and IL-8 are increased in inflamed colonic mucosa after administration of mouse DSS. Nuclear factor kappaB (NF-kappaB) is a transcription factor which regulates the expression of these cytokine genes. The effect of intracolonically administered NF-kappaB (p65) antisense phosphorothioate oligonucleotide was examined in mouse DSS-induced colitis using drinking water containing 5% DSS. When antisense oligonucleotide was given on day 0, the disease activity index (DAI) representing clinical symptoms improved and the histological score decreased; furthermore, IL-1, IL-6, and TNF-alpha concentrations in rectal mucosa were lower compared with the control group. Clinical and histological improvement was also observed when antisense oligonucleotide was begun on day 2 but not on day 7. In addition, the distribution of antisense oligonucleotides was investigated by confocal laser microscopy. In colonic mucosa, oligonucleotides were predominantly localized to cells in the lamina propria, but also in the epithelium. Western blot analysis using homogenized rectal mucosa showed the decreased expression of NF-kappaB p65 in the antisense oligonucleotide-treated group, although it was increased in the colitis group. These results suggest that intracolonic administration of NF-kappaB antisense oligonucleotide may be effective in ulcerative colitis.

Administration, Oral↗
PubMed2000

Enprostil, a prostaglandin-E(2) analogue, inhibits interleukin-8 production of human colonic epithelial cell lines.

We previously reported that intracolonic administration of enprostil, a prostaglandin-E(2) (PGE(2)) analogue, had therapeutic effects on acute colitis induced in rodents by dextran sulfate sodium (DSS). In addition, production of growth-regulated gene product/cytokine-induced neutrophil chemoattractant-1 [GRO/CINC-1; an interleukin(IL)-8 like cytokine] was suppressed in the inflamed tissues. In the present study we used a human colon cancer cell line (HT-29) to investigate enprostil effects on the IL-8 production of intestinal epithelial cells stimulated by various stimulants. In a MTT assay, concentrations of enprostil >10(-5)M had cytotoxitic effects on HT-29 cells. Furthermore, 10(-6) M enprostil suppressed IL-8 production in HT-29 cells, SW620 and CaCo2 stimulated with interleukin-1 beta (IL-1 beta) or lipopolysaccharide (LPS), but did not suppress this response when cells were stimulated with tumour necrosis factor (TNF)-alpha. These results suggest that enprostil affects a point in the pathway between the IL-1 receptor or LPS receptor and nuclear factor-kappa B(NF-kappa B), without affecting the pathway between the TNF receptor and NF-kappa B, with the latter factor being required for the IL-8 gene transcription. The therapeutic effect of exogenous enprostil on DSS colitis may involve the inhibition of IL-8 production in colonic epithelial cells stimulated by IL-1 beta or LPS.

Colitis, Ulcerative↗
PubMed2000

Neurobiological basis of behavioral and psychological symptoms in dementia of the Alzheimer type.

Recent dementia studies indicate that behavioral and psychological symptoms of dementia (BPSD) are not merely an epiphenomenon of cognitive impairment, but could be attributed to specific biological brain dysfunction. We describe findings from different research modalities related with BPSD (psychopathological, neuropsychological, neurochemical, and psychophysiological strategies), and attempt to reconcile them into the more integrated form. Characteristics of delusions in dementia patients should be studied in more detail from a psychopathological aspect, aiming for the integration of psychopathology and neurobiology. Imperfect integration of memory function and cognitive function, assigned to the limbic systems and association areas, respectively, may result in BPSD. More intimate collaboration of psychopathological and neurobiological study would be fruitful to promote the research in psychological basis of BPSD. Neurochemical studies indicated that density of extracellular tangles and/or PHF-tau protein have relationships with delusion or misidentification. These changes in neurochemical parameters should be the key to understanding the pathogenesis of BPSD. More importantly, neurochemical and psychological study could be linked by the research in psychophysiology. Computer-assisted electroencephalogram analysis suggests that the right posterior hemisphere shows significant age-associated change earlier than the left in the elderly. Cerebral metabolic rate by positron emission tomography study indicates that paralimbic, left medial temporal, and left medial occipital area are involved in pathogenesis of BPSD in some dementia patients.

Aged↗
PubMed2000

Compound heterozygosity for a point mutation and a deletion located at splice acceptor sites in the LAMB3 gene leads to generalized atrophic benign epidermolysis bullosa.

An autosomal recessive disorder, generalized atrophic benign epidermolysis bullosa, is a rare form of nonlethal type junctional epidermolysis bullosa. It is associated not only with skin fragility but also with other unique clinical features including widespread atrophic skin changes, alopecia, reduced axillary and pubic hair, dysplastic teeth, and dystrophic nails. The majority of generalized atrophic benign epidermolysis bullosa cases are caused by mutations in the COL17A1 gene coding for type XVII collagen (or the 180 kDa bullous pemphigoid antigen). Another candidate gene for mutations in some forms of generalized atrophic benign epidermolysis bullosa is LAMB3 encoding the beta3 chain of laminin 5. This report documents compound heterozygosity for novel mutations in LAMB3 of a Japanese patient showing typical clinical features of generalized atrophic benign epidermolysis bullosa. One is an A-to-G transversion at the splice acceptor site of intron 14, which is designated as a 1977-2A-->G mutation; the other is a deletion of 94 bp located at the junction of intron 18 and exon 19, which is a 2702-29del94 mutation. Reverse transcriptase polymerase chain reaction analysis suggested skipping of exon 19 in LAMB3 mRNA produced from the allele with 2702-29del94 and impaired stability of the aberrant mRNA transcribed from the second allele with the 1977-2A-->G mutation.

Atrophy↗
PubMed2000

The extracellular domain of BPAG2 has a loop structure in the carboxy terminal flexible tail in vivo.

The 180 kDa bullous pemphigoid antigen is a hemidesmosome-associated transmembranous protein with a molecule length estimated to be 190-230 nm, which is much longer than the transverse length of the lamina lucida and lamina densa. The purpose of this study was to clarify the precise in vivo structure of the 180 kDa bullous pemphigoid antigen in normal human skin. We used three monoclonal antibodies directed to (i) the intracellular globular head of the 180 kDa bullous pemphigoid antigen, (ii) the mid-portion of the flexible tail of the antigen, corresponding approximately to amino acids 1000-1320, and (iii) the carboxyl terminal end, corresponding approximately to amino acids 1320-1500 of the antigen. Using low temperature postembedding immunoelectron microscopy, we quantitated the distribution of immunogold labeling of these monoclonal antibodies in normal human skin. The results showed that the monoclonal antibodies (i) bound to the intracellular portion of the hemidesmosome at a mean distance of 20 nm from the plasma membrane, (ii) bound to the lamina densa beneath the hemidesmosome at a mean distance of 65 nm from the plasma membrane, and (iii) bound to the lamina densa-lamina lucida interface at a mean distance of 39 nm from the plasma membrane. Considering the reported size of the 180 kDa bullous pemphigoid antigen, our results indicate that the extracellular domain of the antigen has at least one loop structure in the lamina densa in vivo. This unique structure of the antigen is thought to contribute to dermo- epidermal adhesion by intertwining with other basement membrane components.

Amino Acid Sequence↗
PubMed2000

Use of domain-swapped molecules for conformational epitope mapping of desmoglein 3 in pemphigus vulgaris.

Pemphigus vulgaris is an autoimmune blistering disease caused by autoantibodies against desmoglein 3, a member of the desmosomal cadherin family. These autoantibodies recognize conformation-dependent epitopes on desmoglein 3. In this study we attempted to map the conformational epitopes of desmoglein 3 in pemphigus vulgaris using recombinant desmoglein 3 produced by the baculovirus expression system. We developed a series of domain-swapped molecules between desmoglein 3 and desmoglein 1, which have similar structures but distinct epitopes. These were developed by substituting deleted segmental regions of desmoglein 3 by the corresponding desmoglein 1. Thus domain-swapped molecules containing desmoglein 3 residues 1-403, 1-161, 163-566, and 405-566 were constructed and used as competitors for competition enzyme-linked immunosorbent assay against the entire extracellular domain of desmoglein 3 with 25 pemphigus vulgaris sera. Considering more than 50% absorption as significant, residues 1-403 and 1-161 showed significant absorption in 24 out of 25 (96%) and 18 out of 25 (72%) pemphigus vulgaris sera, respectively, whereas only one serum and no sera showed significant absorption by residues 163-566 and 405-566, respectively. Furthermore, no apparent change in their major epitopes was seen during the time course in four pemphigus vulgaris cases tested. These findings indicate that the domain-swapping approach is useful for conformational epitope mapping in pemphigus and that amino-terminal residues 1-161, which are considered to include a region essential for cell-cell adhesion in cadherins, contain the critical residues of the conformational epitope of desmoglein 3 recognized by the autoantibodies in pemphigus vulgaris sera.

Autoantigens↗
PubMed2000

Detection of antigen-specific B cells in patients with pemphigus vulgaris by enzyme-linked immunospot assay: requirement of T cell collaboration for autoantibody production.

Patients with pemphigus vulgaris have circulating IgG autoantibodies against desmoglein 3, which inhibit cell-cell adhesion of keratinocytes and cause blister formation in the skin and mucous membrane. To examine cellular mechanisms underlying the autoantibody production in pemphigus vulgaris patients, we have successfully developed an enzyme-linked immunospot assay which was able to detect desmoglein 3-specific autoimmune B cells quantitatively. Circulating B cells producing anti-desmoglein 3 antibodies were detected exclusively in three patients with severe disease (1.3-2.3/105 peripheral blood mononuclear cells), but not in 10 patients with mild disease or in remission or in seven healthy individuals. When this enzyme-linked immunospot assay was combined with in vitro stimulation of peripheral blood mononuclear cells with pokeweed mitogen and recombinant-desmoglein 3, we could detect circulating desmoglein 3-specific memory B cells in nine of 14 patients (6.3-84. 0/105 peripheral blood mononuclear cells), but in none of 10 healthy individuals. We further analyzed the role of CD4 + T cells in promoting anti-desmoglein 3 antibody production. The in vitro anti-desmoglein 3 antibody production was abolished when CD4 + cells were depleted or when anti-HLA-DR or anti-HLA-DQ monoclonal antibody was added to the cultures. Our results demonstrated the quantitative detection of circulating "activated" and "memory" desmoglein 3-specific B cells and suggested the important part of HLA class II-restricted CD4 + T cells in the autoantibody production in pemphigus vulgaris. In addition, the enzyme-linked immunospot assay in combination with in vitro stimulation of B cells could be broadly applied to study mechanisms for autoantibody production in various autoimmune diseases.

Adult↗