Biomedical subjects

Takashi Hashimoto

Publications and source records attributed to Takashi Hashimoto.

At least 73 records · Page 4Linked to original sources

PubMed2004

A case of anti-p200 pemphigoid with autoantibodies against both a novel 200-kD dermal antigen and the 290-kD epidermolysis bullosa acquisita antigen.

BACKGROUND: Anti-p200 pemphigoid with autoantibodies against the 200-kD dermal antigen has recently been identified. OBJECTIVES: Our patient showed small and tense blisters on her face and trunk. METHODS: Immunoblotting (IB), using extracts of normal human epidermis and dermal skin, and immunoelectron microscopy (IEM), using normal human skin, were performed using the patient's serum. RESULTS: IB analysis showed that the patient's serum did not react with 180-kD bullous pemphigoid (BP180) or BP230 antigens; however, IgG autoantibodies in the patient's serum reacted with a 200-kD dermal antigen as well as the 290-kD epidermolysis bullosa acquisita (EBA) antigen. IEM showed that IgG antibodies in the patient's serum bound to the lamina lucida, as well as both the lamina densa and sublamina densa. After the treatment with prednisolone, the 290-kD protein reactivity decreased rapidly; however, the 200-kD protein band was still observed. CONCLUSION: We describe a rare case with immunoreactive autoantibodies against both a novel dermal 200-kD autoantigen and the 290-kD EBA antigen.

Adult↗

PubMed2004

Tea catechin suppresses adipocyte differentiation accompanied by down-regulation of PPARgamma2 and C/EBPalpha in 3T3-L1 cells.

Obesity is a serious health problem, and its prevention is promoted through life style including diet and exercise. In this study, we investigated the suppressive effects of tea catechin on the differentiation of 3T3-L1 preadipocytes to adipocytes. (-)-Catechin 3-gallate (CG), (-)-epigallocatechin (EGC), (-)-epicatechin 3-gallate, and (-)-epigallocatechin 3-gallate at 5 muM suppressed intracellular lipid accumulation. The suppressive effects of CG and EGC were stronger than the others, and CG and EGC also suppressed the activity of glycerol-3-phosphate dehydrogenase as a differentiation marker. These catechins inhibited the expression of peroxisome proliferator-activated receptor (PPAR) gamma2 and CCAAT/enhancer-binding protein (C/EBP) alpha, both of which act as key transcription factors at an early stage of differentiation, followed by the expression of glucose transporter (GLUT) 4 at a later stage. In addition, the catechins did not affect the phosphorylation status of the insulin signal pathway. Thus, catechin suppressed adipocyte differentiation accompanied by the down-regulation of PPARgamma2, C/EBPalpha, and GLUT4. These results suggest that tea catechin prevents obesity through the suppression of adipocyte differentiation.

3T3 Cells↗

PubMed2004

3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole induces apoptosis and necrosis with activation of different caspases in rat splenocytes.

A dietary carcinogen, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) at 20 microM activates caspase-3-like proteases as an apoptotic marker in rat splenocytes. The present study demonstrated 100 microM Trp-P-1 induced necrosis with activation of caspase-3-like proteases. The activation in necrosis and apoptosis resulted from the activation of caspase-9 and caspase-8, respectively. Thus, Trp-P-1 induces apoptosis and necrosis with the activation of different caspases.

Animals↗

PubMed2004

Liver transplantation-associated hypercalcemia followed by acute renal dysfunction.

A 34-year-old woman with liver insufficiency due to glycogen storage disease III underwent a living spousal liver transplantation. Soon after the successful operation, moderate hypercalcemia along with hyperbilirubinemia emerged without clarified reasons. The hypercalcemia persisted for over a month despite calcitonin treatment and the serum calcium level surged to 13.2 mg/dl with albumin correction. Renal dysfunction was indicated by an acute increase in serum creatinine (approximately 0.8 to approximately 2.8 mg/ml), which was assumed to be hypercalcemia-induced and was effectively treated with bisphosphonate, pamidronate (30 mg, i.v.). Recent topics related to transplantation-associated hypercalcemia are discussed.

Acute Kidney Injury↗

PubMed2004

Morphological changes of roof of subacromial bursa in patients with rotator cuff tear.

OBJECTIVE: To investigate the morphological changes of the roof of the subacromial bursa (SAB) and its involvement extent after rotator cuff tear. METHODS: In the experimental group, the roof of SAB was obtained from 30 cases of rotator cuff tear both at the tear site and a site 2.5-3.0 cm distal to the tear site during rotator cuff repair. In the control group, the roof of SAB was obtained from the exposed site of recurrently dislocated shoulder or fractured humeral shaft of 8 cases. The specimens were stained with hematoxylin and eosin and observed under a transmission electron microscope. The cell number was quantitated through counting the blue-stained nucleus in SAB with a computer image analysis system. RESULTS: The number of cells increased significantly in the roof of SAB in the experimental group compared with that of the control group. However, no difference of the bursal reaction was found among the type of rotator cuff tear, the bursa thickness and the presence of fluid in the bursa. The great majority of cells were type B cells observed under the transmission electron microscope. CONCLUSIONS: The increase in cell number in the roof of SAB in the experimental group is a reactive increase rather than an inflammatory process and the involvement of SAB is not limited in extent. The change of the roof of SAB is a secondary reaction to the rotator cuff tear.

Adult↗

PubMed2004

[Diffusion-weighted magnetic resonance imaging findings at early stage of acute Wernicke encephalopathy].

We describe a patient with acute Wernicke encephalopathy (WE) in whom diffusion-weighted magnetic resonance imaging (DWI) were helpful for early diagnosis. A 66-year-old alcoholic man was admitted to our department because of recurrent mild drowsiness. Thiamine concentrations in blood were at the lower limit of normal. DWI demonstrated an abnormal signal intensity in the dorsal part of the midbrain, and high-dose thiamine therapy was started. These lesions disappeared on DWI after one month of follow-up, in association with clinical improvement. These findings suggest that DWI is useful for detecting WE at the early stage when high-dose thiamine treatment can improve the prognosis of WE.

Acute Disease↗

PubMed2003

Overexpression of peroxisome proliferator-activated receptor-alpha (PPARalpha)-regulated genes in liver in the absence of peroxisome proliferation in mice deficient in both L- and D-forms of enoyl-CoA hydratase/dehydrogenase enzymes of peroxisomal beta-oxidation system.

Peroxisomal beta-oxidation system consists of peroxisome proliferator-activated receptor alpha (PPARalpha)-inducible pathway capable of catalyzing straight-chain acyl-CoAs and a second noninducible pathway catalyzing the oxidation of 2-methyl-branched fatty acyl-CoAs. Disruption of the inducible beta-oxidation pathway in mice at the level of fatty acyl-CoA oxidase (AOX), the first and rate-limiting enzyme, results in spontaneous peroxisome proliferation and sustained activation of PPARalpha, leading to the development of liver tumors, whereas disruptions at the level of the second enzyme of this classical pathway or of the noninducible system had no such discernible effects. We now show that mice with complete inactivation of peroxisomal beta-oxidation at the level of the second enzyme, enoyl-CoA hydratase/L-3-hydroxyacyl-CoA dehydrogenase (L-PBE) of the inducible pathway and D-3-hydroxyacyl-CoA dehydratase/D-3-hydroxyacyl-CoA dehydrogenase (D-PBE) of the noninducible pathway (L-PBE-/-D-PBE-/-), exhibit severe growth retardation and postnatal mortality with none surviving beyond weaning. L-PBE-/-D-PBE-/- mice that survived exceptionally beyond the age of 3 weeks exhibited overexpression of PPARalpha-regulated genes in liver, despite the absence of morphological evidence of hepatic peroxisome proliferation. These studies establish that peroxisome proliferation in rodent liver is highly correlatable with the induction mostly of the L- and D-PBE genes. We conclude that disruption of peroxisomal fatty acid beta-oxidation at the level of second enzyme in mice leads to the induction of many of the PPARalpha target genes independently of peroxisome proliferation in hepatocytes, raising the possibility that intermediate metabolites of very long-chain fatty acids and peroxisomal beta-oxidation act as ligands for PPARalpha.

Animals↗

PubMed2003

Induction of apoptosis by caffeine is mediated by the p53, Bax, and caspase 3 pathways.

Caffeine is a key component of many popular drinks, especially tea and coffee. Previous reports have shown that caffeine may contribute to the chemopreventive effect of tea in animals. Here, we report that treatment with low concentrations of caffeine induced apoptosis in JB6 Cl41 cells. JB6 Cl41 cells were starved in 0.1% fetal bovine serum/MEM for 72 h and then treated with 50-450 microM caffeine for 24 h. Cells showed the typical DNA laddering pattern and other characteristics of apoptosis. The IC(50) of caffeine on JB6 Cl41 cells was 2.7 mM. Induction of apoptosis by caffeine appeared to be p53-dependent because cells lacking p53 (p53(-/-)) showed no signs of apoptosis after treatment with caffeine. Immunoprecipitation assays and Western blot analysis showed that caffeine induced phosphorylation of p53 at Ser(15) in JB6 Cl41 cells. The same low concentration of caffeine that was effective for inducing phosphorylation of p53 was also shown to increase p53 activation. Expression of Bax, another p53 target, distinctly increased in a time- and dose-dependent manner. Cleaved caspase 3 was also increased in a time- and dose-dependent manner. These data show that a low concentration of caffeine can induce p53-dependent apoptosis in JB6 cells through the Bax and caspase 3 pathways.

Animals↗

PubMed2003

Alkaloids in plants and root cultures of Atropa belladonna overexpressing putrescine N-methyltransferase.

Putrescine N-methyltransferase (PMT) is the first alkaloid-specific enzyme for nicotine and tropane alkaloid formation. The pmt gene from Nicotiana tabacum was fused to the CaMV 35S promoter and integrated into the Atropa belladonna genome. Transgenic plants and derived root cultures were analysed for gene expression and for levels of alkaloids and their precursors. Scopolamine, hyoscyamine, tropine, pseudotropine, tropinone, and calystegines were found unaltered or somewhat decreased in pmt-overexpressing lines compared to controls. When root cultures were treated with 5% sucrose, calystegine levels were elevated in control roots, but were not affected in pmt-overexpressing roots. 1 microM auxin reduced calystegine levels in control roots, while in pmt-overexpressing roots all alkaloids remained unaltered. Expression level of pmt alone is apparently not limiting for tropane alkaloid formation in A. belladonna.

Atropa belladonna↗

PubMed2003

Plucking during telogen induces apoptosis in the lower part of hair follicles.

Highly synchronized anagen development is achieved by depilation, which contrasts with spontaneous anagen development. The precise mechanism responsible for plucking-induced synchronization has not been explained. Plucking appears to mechanically injure or wound the follicle. We hypothesized that the injured hair follicle cells are removed by apoptosis, with an associated induction of synchronized anagen development. Female C57 BL/6 mice in which all the hair follicles of the back skin were in telogen were induced to enter anagen by depilation. Skin specimens from the back at 0 to 72 h after plucking were examined, and TUNEL staining and electrophoresis of isolated DNA were applied to substantiate the presence of apoptosis. Simultaneously, cell proliferation was also examined by bromodeoxyuridine (BrdU) incorporation. All methods of analysis revealed that plucking induced apoptosis of hair follicle cells in the dermal remnant, and there was a subsequent associated proliferative response that resulted in a highly synchronized anagen phase. From 12 to 36 h after plucking, hair follicle cells with weakly BrdU-positive nuclei were detected around the holes in the lower part of the follicle, which were induced by plucking. At 48 and 72 h, many cells with BrdU-positive nuclei were seen in the entire follicle, mainly in the bulb, as well as in the epidermis. Cell proliferation and apoptosis appeared to occur simultaneously after plucking. These findings mirror the events noted during the development of other organs in which the coordination of cell proliferation and apoptosis is essential for orderly restructuring events.

Animals↗

PubMed2003

Recent advances in the study of the pathophysiology of pemphigus.

Recent rapid advances in the basic research into pemphigus have provided many insights into its pathophysiology. In particular, a recently developed enzyme-linked immunosorbent assay (ELISA) for desmogleins 1 and 3 (Dsg1 and Dsg3), antigens for pemphigus foliaceus (PF) and pemphigus vulgaris (PV), respectively, has led to great progress in the diagnosis and classification of pemphigus, as well as in understanding its pathomechanisms. Studies with the anti-Dsg1 and anti-Dsg3 antibodies have indicated that there are two types of PV, the mucosal dominant type and the mucocutaneous type. The same ELISA has identified the antigens in pemphigus herpetiformis. The autoantigens detected by this ELISA correlate well with the clinical features in pemphigus patients in showing the shift between PV and PF. In addition, the Dsg compensation theory proposed by Stanley and Amagai can reasonably explain the different depths of skin lesions and the different occurrences of skin and oral mucosal lesions between PV and PF. Furthermore, a complicated profile of autoantigens in paraneoplastic pemphigus (PNP) has been indicated in various biochemical studies, and IgG anti-Dsg1 and anti-Dsg3 antibodies have been detected in serum from all the PNP patients by the above ELISA. On the other hand, serum from subcorneal pustular dermatosis type IgA pemphigus patients have been shown to react with Dsc1, another type of desmosomal cadherin, by a novel cDNA transfection method. In addition, IgA anti-Dsg1 and anti-Dsg3 antibodies have been detected in a few patients with IgA pemphigus by an ELISA for IgA antibodies. Various autoimmune bullous diseases, including several types of pemphigus, are the only diseases in which the pathogenic role of circulating autoantibodies has been confirmed using the newborn mouse animal model. Therefore, studies of the pathophysiology of pemphigus are extremely important as a paradigm for research into various types of autoimmune diseases in other fields.

Animals↗

PubMed2003

Thyrotropin-releasing hormone in the dorsal vagal complex stimulates hepatic blood flow in rats.

Central administration of thyrotropin-releasing hormone (TRH) enhances hepatic blood flow in animal models. TRH nerve fibers and receptors are localized in the dorsal vagal complex (DVC), and retrograde tracing techniques have shown that hepatic vagal nerves arise mainly from the left DVC. However, nothing is known about the central sites of action for TRH to elicit the stimulation of hepatic blood flow. The effect of microinjection of a TRH analogue into the DVC on hepatic blood flow was investigated in urethane-anesthetized rats. After measuring basal flow, a stable TRH analogue (RX-77368) was microinjected into the DVC and hepatic blood flow response was observed for 120 minutes by laser Doppler flowmetry. Either left or right cervical vagotomy or hepatic branch vagotomy was performed 2 hours before the peptide. Microinjection of RX-77368 (0.5-5 ng) into the left DVC dose-dependently increased hepatic blood flow. The stimulation of hepatic blood flow by RX-77368 microinjection into the left DVC was eliminated by left cervical and hepatic branch vagotomy but not by right cervical vagotomy. By contrast, microinjection of RX-77368 into the right DVC did not significantly alter hepatic blood flow. These results suggest that TRH acts in the left DVC to stimulate hepatic blood flow through the left cervical and hepatic vagus, indicating that neuropeptides may act in the specific brain nuclei to regulate hepatic function.

Animals↗

PubMed2003

Dynamics and regulation of plant interphase microtubules: a comparative view.

Microtubule and actin cytoskeletons are fundamental to a variety of cellular activities within eukaryotic organisms. Extensive information on the dynamics and functions of microtubules, as well as on their regulatory proteins, have been revealed in fungi and animals, and corresponding pictures are now slowly emerging in plants. During interphase, plant cells contain highly dynamic cortical microtubules that organize into ordered arrays, which are apparently regulated by distinct groups of microtubule regulators. Comparison with fungal and animal microtubules highlights both conserved and unique mechanisms for the regulation of the microtubule cytoskeleton in plants.

Adenosine Triphosphatases↗

PubMed2003

Conformational epitope mapping and IgG subclass distribution of desmoglein 3 in paraneoplastic pemphigus.

BACKGROUND: Pemphigus vulgaris (PV) shows autoimmune reaction against desmoglein 3 (Dsg3), whereas paraneoplastic pemphigus (PNP) shows autoimmune reaction against Dsg3 as well as numerous members of the plakin family. It has been demonstrated that in PV, dominant epitopes reside in N-terminal adhesive regions of Dsg3 and that the dominant IgG subclass against Dsg3 is IgG4. OBJECTIVE: We attempted to map conformational epitopes and analyze IgG subclass distribution against Dsg3 in PNP. METHOD: Epitopes on Dsg3 for circulating IgG autoantibodies from PNP (n = 22) were studied with competition enzyme-linked immunosorbent assay (ELISA) using domain-swapped molecules between Dsg3 and Dsg1 and were compared with those for IgG autoantibodies from PV (n = 22). IgG subclass distribution was analyzed with PNP serum by Dsg3 ELISA (n = 17). RESULTS: Epitopes on Dsg3 in PNP were distributed more broadly through the extracellular domain of Dsg3 than were those in PV, although the N-terminal extracellular domains of Dsg3 were more frequently recognized than the C-terminal extracellular domains. IgG subclass in PNP was IgG1 and IgG2 dominant. CONCLUSION: Autoimmune response against Dsg3 in PNP is more diversified than that in PV, a finding that suggests PNP and PV have different pathophysiologic mechanisms for triggering production of anti-Dsg3 IgG.

Autoantibodies↗

PubMed2003

Comparative study of autoantigen profile between Colombian and Brazilian types of endemic pemphigus foliaceus by various biochemical and molecular biological techniques.

BACKGROUND: Besides Brazilian endemic pemphigus foliaceus (EPF), we have described another focus of EPF in Colombia. Our previous study suggested that Colombian EPF seemed to react various plakin family proteins, such as envoplakin, periplakin and BP230. OBJECTIVE: To further characterize the Colombian EPF and study the difference from Brazilian EPF, we examined the antigen profile of the two types of EPF. METHODS AND RESULTS: Immunoblotting using normal human epidermal extracts revealed that 38% Colombian EPF sera and 25% Brazilian EPF sera showed IgG antibodies reactive with desmoglein (Dsg) 1, pemphigus foliaceus antigen. The sera of both types of EPF showed protein bands co-migrating with plakin family proteins, particularly periplakin. Immunoblotting analyses using recombinant proteins of various domains of envoplakin, periplakin and BP230 revealed that a considerable number of Colombian EPF sera reacted with recombinant proteins of periplakin, while only few Brazilian sera reacted with some of the recombinant proteins of any plakins. Enzyme-linked immunosorbent assay (ELISA) for Dsg1 and Dsg3 showed that Dsg1 was reacted by almost all sera of both types of EPF. However, unexpectedly, while none of Colombian EPF sera reacted with Dsg3, about half of Brazilian EPF sera reacted with Dsg3. CONCLUSION: These results suggested that the Colombian EPF is basically similar to Brazilian EPF in terms that major antigen is Dsg1, but there were some different antigen profiles between the two types of EPF.

Autoantibodies↗

PubMed2003

Cicatricial pemphigoid sera specifically react with the most C-terminal portion of BP180.

BACKGROUND: cicatricial pemphigoid and bullous pemphigoid are characterized by circulating autoantibodies to the hemidesmosomal protein, BP180. Different clinical features between cicatricial pemphigoid and bullous pemphigoid appear to correlate with distinct target epitopes on BP180. Previous studies demonstrated that the majority of bullous pemphigoid sera react with immunodominant membrane-proximal non-collagenous domain (NC16a) on the extracellular portion of BP180, whereas cicatricial pemphigoid antibodies are directed to the C-terminal domains of BP180. However, the fine sites within the C-terminal domain of BP180 recognized by autoantibodies in patients with cicatricial pemphigoid and bullous pemphigoid have not yet been clearly elucidated. OBJECTIVES: the aim of the present study was to analyze the fine specificity of the reactivity within the C-terminal domain of BP180 for the autoantibodies in sera from patients with cicatricial pemphigoid, and to compare the reactivity with that of bullous pemphigoid sera. METHODS AND RESULTS: we generated three recombinant proteins with 101 amino acids, which together cover the C-terminal domain of BP180. We confirmed that cicatricial pemphigoid sera mainly react with most C-terminal portion, whereas bullous pemphigoid sera react with more N-terminal domains. CONCLUSION: this study implicated that autoantibodies of sera from patients with cicatricial pemphigoid and bullous pemphigoid reacted differently within C-terminal domain of BP180.

Autoantigens↗

PubMed2003

Immunofluorescence studies using skin sections of recessive dystrophic epidermolysis bullosa patients indicated that the antigen of anti-p200 pemphigoid is not a fragment of type VII collagen.

BACKGROUND: There are a large number of autoimmune bullous diseases, which have distinct autoantibodies. Several reports on cases with IgG autoantibodies against a novel 200 kDa dermal protein have been published, for which we suggested the term, anti-p200 pemphigoid. However, the nature of this 200 kDa antigen has not been well characterized. OBJECTIVE: In this study, we examined the relationship between the 200 kDa protein and type VII collagen. METHODS: We collected sera from 12 cases of anti-p200 pemphigoid and skin sections from six cases of recessive dystrophic epidermolysis bullosa (RDEB). The reactivity of these sera was examined by indirect immunofluorescence using sections of the disease skin. RESULTS: we have shown that all the 12 anti-p200 pemphigoid sera could react with basement membrane zone of five cases of RDEB, while epidermolysis bullosa acquisita (EBA) sera were negative in these skins. In addition, in a case of RDEB, EBA sera reacted with intracytoplasmic deposition of type VII collagen, while no anti-p200 pemphigoid sera showed this reactivity. CONCLUSION: These results strongly suggested that the 200 kDa antigen is not a fragment of type VII collagen, but a specific autoantigen.

Autoantigens↗

PubMed2003

Usefulness of immunoblotting using purified laminin 5 in the diagnosis of anti-laminin 5 cicatricial pemphigoid.

BACKGROUND: Anti-laminin 5 cicatricial pemphigoid (CP) is a mucosal-dominant subepithelial blistering disease characterized by IgG anti-basement membrane zone autoantibodies, that bind to dermal side of 1 M NaCl split skin and immunoprecipitate laminin 5. Laminin 5 is an epidermis-specific extracellular matrix consisting of alpha3, beta3 and gamma2 subunits. Recent studies have suggested that autoantibodies of anti-laminin 5 CP recognize the G domains of alpha3 subunit. OBJECTIVE: We examined the reactivity of anti-laminin 5 CP by immunoblotting using purified laminin 5 and recombinant proteins of alpha3 subunit. METHOD: We first examined the reactivity of anti-laminin 5 CP by immunoblotting using purified laminin 5. To further investigate the epitopes in the G domains of alpha3 subunit, we produced recombinant proteins of G1-2, G1-3, G2-3, G3-5 domains, that covered entire G domain, and examined the reactivity of anti-laminin 5 CP sera with these recombinant proteins by immunoblotting. RESULTS: By immunoblotting using purified laminin 5, 7 of 21 anti-laminin 5 CP sera reacted with alpha3 subunit, while 8 sera reacted with beta3 subunit and one serum reacted with gamma2 subunit. Two sera reacted with both alpha3 and beta3 subunits, while seven sera did not show positive reactivity. This result indicates that the reactivity of anti-laminin 5 CP sera is much more heterogeneous, although the previous studies suggested that most sera reacted with alpha3 subunit. However, in the studies using recombinant proteins of G domains of alpha3 subunit, none of the CP sera, including the sera reactive with alpha3 subunit in purified laminin 5, reacted with any recombinant proteins. The reason for this negative reactivity with the recombinant proteins is not clear. CONCLUSION: The immunoblotting using purified laminin 5 should be useful technique for the diagnosis of anti-laminin 5 CP, although the sensitivity was less than conventional immunoprecipitation analysis.

Base Sequence↗