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Biomedical subjects

Takashi Hashimoto

Publications and source records attributed to Takashi Hashimoto.

At least 109 records · Page 6Linked to original sources
PubMed2002

Molecular genetic analysis of left-right handedness in plants.

Handedness in plant growth may be most familiar to us when we think of tendrils or twining plants, which generally form consistent right- or left-handed helices as they climb. The petals of several species are sometimes arranged like fan blades that twist in the same direction. Another less conspicuous example is 'circumnutation', the oscillating growth of axial organs, which alternates between a clockwise and an anti-clockwise direction. To unravel molecular components and cellular determinants of handedness, we screened Arabidopsis thaliana seedlings for helical growth mutants with fixed handedness. Recessive spiral1 and spiral2 mutants show right-handed helical growth in roots, hypocotyls, petioles and petals; semi-dominant lefty1 and lefty2 mutants show opposite left-handed growth in these organs. lefty mutations are epistatic to spiral mutations. Arabidopsis helical growth mutants with fixed handedness may be impaired in certain aspects of cortical microtubule functions, and characterization of the mutated genes should lead us to a better understanding of how microtubules function in left-right handedness in plants.

Genes, Plant↗
PubMed2002

Microtubule basis for left-handed helical growth in Arabidopsis.

Left-right asymmetry in plants can be found in helices of stalks, stems and tendrils, and in fan-like petal arrangements. The handedness in these asymmetric structures is often fixed in given species, indicating that genetic factors control asymmetric development. Here we show that dominant negative mutations at the tubulin intradimer interface of alpha-tubulins 4 and 6 cause left-handed helical growth and clockwise twisting in elongating organs of Arabidopsis thaliana. We demonstrate that the mutant tubulins incorporate into microtubule polymers, producing right-handed obliquely oriented cortical arrays, in the root epidermal cells. The cortical microtubules in the mutants had increased sensitivity to microtubule-specific drugs. These results suggest that reduced microtubule stability can produce left-handed helical growth in plants.

Arabidopsis↗
PubMed2002

Lipoid proteinosis maps to 1q21 and is caused by mutations in the extracellular matrix protein 1 gene (ECM1).

Lipoid proteinosis (LP), also known as hyalinosis cutis et mucosae or Urbach-Wiethe disease (OMIM 247100) is a rare, autosomal recessive disorder typified by generalized thickening of skin, mucosae and certain viscera. Classical features include beaded eyelid papules and laryngeal infiltration leading to hoarseness. Histologically, there is widespread deposition of hyaline (glycoprotein) material and disruption/reduplication of basement membrane. The aetiology of LP is currently unknown. Using DNA from three affected siblings in a consanguineous Saudi Arabian family we performed genome-wide linkage and mapped the disorder to 1q21 (marker D1S498) with a two-point LOD score of 3.45 at theta = 0. A further 28 affected individuals from five other unrelated consanguineous family groups from different geographical regions also showed complete linkage and resulted in a maximum two-point LOD score of 21.85 at theta = 0. Using available markers in the interval between D1S442 and D1S305, the observed recombinants placed the gene in a 2.3 cM critical interval between D1S2344 and D1S2343 (Marshfield genetic map) corresponding to an approximately 6.5 Mb region on the UCSC physical map. Using a candidate gene approach (comparison of control versus LP gene expression in cultured fibroblasts) and subsequent direct sequencing of genomic DNA, we identified six different homozygous loss-of-function mutations in the extracellular matrix protein 1 gene (ECM1). Although the precise function of ECM1 is not known, our findings provide the first clinical indication of its relevance to skin adhesion, epidermal differentiation, wound healing, scarring, angiogenesis/angiopathy and basement membrane physiology, as well as defining the molecular basis of this inherited disorder.

Blood Vessels↗
PubMed2002

Molecular cloning, expression and characterization of tropinone reductase II, an enzyme of the SDR family in Solanum tuberosum (L.).

Calystegines are nortropane alkaloids that are found in Solanaceae containing the classical tropane alkaloids hyoscyamine and scopolamine, and in other Solanaceae such as potato, Solanum tuberosum (L.). Calystegines are assumed to derive from the classical tropane alkaloid pathway. We isolated a cDNA from S. tuberosum with high homology to the pseudotropine-forming tropinone reductase (TRII), which presents as the first putative metabolite specific to calystegines. The equivalent amino acid sequence shows typical motifs of a short-chain dehydrogenase (SDR). The recombinant TRII protein expressed in Escherichia coli catalyzes pseudotropine formation from tropinone with a Km value, a pH optimum, substrate and co-substrate preferences similar to those reported for the TRII enzymes from other Solanaceae species. The gene is expressed in roots, tubers and aerial parts of potato. The distribution of the TRII transcript in comparison with the calystegine concentrations in the tissues suggests transport of calystegines or their precursors between potato organs.

Alcohol Oxidoreductases↗
PubMed2002

The first international consensus on mucous membrane pemphigoid: definition, diagnostic criteria, pathogenic factors, medical treatment, and prognostic indicators.

OBJECTIVE: We aimed to develop consensus-based recommendations for streamlining medical communication among various health care professionals, to improve accuracy of diagnosis and treatment, and to facilitate future investigations for mucous membrane pemphigoid. PARTICIPANTS: Because of the highly specific nature of this group of diseases, the 26 invited participants included either international scholars in the field of mucous membrane pemphigoid or experts in cutaneous pharmacology representing the 3 medical disciplines ophthalmology, oral medicine, and dermatology. EVIDENCE: The first author (L.S.C.) conducted a literature search. Based on the information obtained, international experts who had contributed to the literature in the clinical care, diagnosis, and laboratory investigation for mucous membrane pemphigoid were invited to participate in a consensus meeting aimed at developing a consensus statement. CONSENSUS PROCESS: A consensus meeting was convened and conducted on May 10, 1999, in Chicago, Ill, to discuss the relevant issues. The first author drafted the statement based on the consensus developed at the meeting and the participants' written comments. The draft was submitted to all participants for 3 separate rounds of review, and disagreements were reconciled based on literature evidence. The third and final statement incorporated all relevant evidence obtained in the literature search and the consensus developed by the participants. The final statement was approved and endorsed by all 26 participants. CONCLUSIONS: Specific consensus-based recommendations were made regarding the definition, diagnostic criteria, pathogenic factors, medical treatment, and prognostic indicators for mucous membrane pemphigoid. A system of standard reporting for these patients was proposed to facilitate a uniform data collection.

Humans↗
PubMed2002

Antiepiligrin cicatricial pemphigoid of the larynx successfully treated with a combination of tetracycline and niacinamide.

A case of antiepiligrin cicatricial pemphigoid that primarily involved the larynx and required a tracheostomy was studied. The diagnosis was based on the direct immunofluorescence findings of a biopsy specimen from the glottis, immunofluorescence using normal and 1M sodium chloride-split normal human skin as substrates, and immunoprecipitation. A dramatic clinical improvement was observed after the combined administration of tetracycline hydrochloride and niacinamide. The tracheal stoma could be shut after the narrow segment was cut by means of carbon dioxide laser therapy. The patient showed no respiratory difficulty during the 2-year follow-up period. The combined therapy of tetracycline and niacinamide is thus considered to be an effective treatment for various types of cicatricial pemphigoid.

Aged↗
PubMed2002

Apoptosis in the thymus after intraperitoneal injection of rats with Trp-P-1.

3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), a contaminant in our daily diet, induces apoptosis in cultured immunocytes. In this study, Trp-P-1 (1 mg/kg) was injected intraperitoneally into male Wistar rats to investigate whether Trp-P-1 induces apoptosis in immune tissues in vivo. In the thymus, Trp-P-1 induced DNA fragmentation and morphological changes. Trp-P-1 also activated the initiator and executioner caspases, caspase-8 and -3, respectively, and activated caspase-3 in turn cleaved its intracellular substrate poly(ADP-ribose) polymerase 1 hr after injection. On the other hand, Trp-P-1 upregulated anti-apoptotic factors Bcl-2 and Bcl-XL and downregulated pro-apoptotic factor Bax in mitochondria 1 hr after injection, indicating that Trp-P-1 also stimulated anti-apoptotic signals. Trp-P-1 activated the serine-threonine protein kinase Akt, which is known to be an anti-apoptotic protein, and increased the DNA binding activities of apoptosis-associated transcription factors NF-kappaB and AP-1. In addition to the thymus, increases in the activities of these transcription factors were also observed in the spleen and in mononuclear cells from the blood. Therefore, Trp-P-1 activates both pro- and anti-apoptotic signals in vivo in the immune system, particularly in the thymus, and the former signal overcomes the latter.

Animals↗
PubMed2002

Epidemiology of X-linked adrenoleukodystrophy in Japan.

To clarify the epidemiology of X-linked adrenoleukodystrophy (ALD) in Japan, we performed a questionnaire survey. Two hundred eighty-six patients, including 154 from internal medicine, 100 from pediatrics, 21 from psychiatry, and 11 from other hospitals, were reported to have ALD between 1990 and 1999. The data on 154 patients revealed the phenotypic distribution to be as follows: childhood cerebral form (29.9%), adrenomyeloneuropathy (25.3%), adult cerebral form (21.4%), adolescent form (9.1%), olivo-ponto-cerebellar form (8.4%), presymptomatic form (4.5%), and symptomatic female patient (1.3%). The adult cerebral form and olivo-ponto-cerebellar form were more common in Japan than in North America and Europe. The incidence of X-linked ALD in Japan was estimated to be between 1 : 30,000 and 1 : 50,000 boys, similar to previous reports. About half of the patients with adrenomyeloneuropathy and the olivo-ponto-cerebellar phenotype developed cerebral involvement with a mean interval of 8.2 and 2.2 years after ALD onset, respectively. The family histories revealed that brothers and first cousins tended to show similar phenotypes, whereas nephews tended to develop symptoms earlier than uncles. These data will help in understanding the natural history of X-linked ALD.

Adolescent↗
PubMed2002

Autoantibodies to type VII collagen mediate Fcgamma-dependent neutrophil activation and induce dermal-epidermal separation in cryosections of human skin.

Epidermolysis bullosa acquisita is an autoimmune subepidermal blistering disease associated with autoantibodies to type VII collagen, the major constituent of anchoring fibrils. Previous attempts to demonstrate the blister-inducing potential of autoantibodies to this protein have failed. To address this question, we used an in vitro model involving cryosections of human skin incubated with patients' autoantibodies and leukocytes from healthy donors. We show that sera from 14 of 16 epidermolysis bullosa acquisita patients, in contrast to sera from healthy controls, induced dermal-epidermal separation in the cryosections. Recruitment and activation of neutrophils at the dermal-epidermal junction was necessary for split induction, whereas mononuclear cells were not required. Importantly, patients' autoantibodies affinity-purified against a recombinant form of the noncollagenous 1 domain of type VII collagen retained their blister-inducing capacity in a dose-dependent manner, whereas patients' IgG that was depleted of reactivity to type VII collagen lost this ability. Monoclonal antibody LH7.2 to the noncollagenous 1 domain of type VII collagen also induced subepidermal splits in the cryosections; F(ab')(2) fragments of autoantibodies to type VII collagen were not pathogenic. We demonstrate the capacity of autoantibodies to type VII collagen to trigger an Fcgamma-dependent inflammation leading to split formation in cryosections of human skin.

Animals↗
PubMed2002

BP180 ELISA using bacterial recombinant NC16a protein as a diagnostic and monitoring tool for bullous pemphigoid.

Bullous pemphigoid (BP) is an acquired autoimmune subepidermal blistering disease against hemidesmosomal cytoplasmic BP230 and transmembrane BP180 proteins. Epitope mapping studies have shown that the membrane-proximal noncollagenous (NC) 16a domain of BP180 harbors clusters of antigenic sites recognized by the vast majority of BP sera. In this study, we developed an enzyme-linked immunosorbent assay (ELISA) using bacterial recombinant NC16a protein and evaluated its clinical benefit for diagnosis and monitoring disease activity. Fifty four (84.4%) of 64 sera from BP patients were positive, while only one (1.1%) of 91 sera from collagen disease patients and five (1.5%) of 336 sera from normal control barely exceeded the cut-off value. None of 69 pemphigus vulgaris sera and none of 42 pemphigus foliaceus sera exceeded the cut-off value. Thus, the sensitivity and specificity of NC16a ELISA were 84.4 and 98.9%, respectively. The correlation between ELISA scores and disease activity along the time course was examined using seven BP patients. NC16a ELISA scores tended to fluctuate in parallel with the disease activity along the time course and reflected the disease activity much better than indirect immunofluorescence. These findings indicate that NC16a ELISA will be a valuable tool not only for the diagnosis of patients with BP but also for the monitoring of the disease activity.

Adult↗
PubMed2002

Serum and tissue PIVKA-II expression reflect the biological malignant potential of small hepatocellular carcinoma.

A sensitive method for measuring the serum level of protein-induced by vitamin K absence or antagonist II (PIVKA-II) has become so widely available that it is now used for the clinical diagnosis of small hepatocellular carcinoma (HCC). It is known that serum PIVKA-II can be a prognostic indicator for HCC, but there have been no detailed investigations concerning the tissue expression of PIVKA-II. The present study assessed the relationship between serum or tissue PIVKA-II and the biological malignant potential of HCC. The subjects were 25 patients with histologically confirmed HCC, that were solitary and 3 cm or less in diameter. Tissue PIVKA-II was detected by immunostaining using MU-3 as the primary antibody. The biological malignant potential of the tumors was evaluated on the basis of the Ki-67 labeling index of HCC cells and the tumor arterial vascularity assesed by angiography and CO(2) enhanced ultrasonography. The recurrence-free period after treatment was also evaluated. Among the 25 patients, eight were positive for tissue PIVKA-II. Serum PIVKA-II levels were significantly higher in the tissue PIVKA-II-positive patients compared with the negative patients, but serum and tissue PIVKA-II expressions were not consistently parallel. Tumor cell proliferation was closely correlated with the tissue PIVKA-II expression, while the recurrence-free period was correlated with the serum PIVKA-II level. Tumor arterial vascularity showed a strong correlation with the expression of both serum and tissue PIVKA-II. In conclusion, serum and tissue PIVKA-II expression reflect the biological malignant potential of HCC and thus may be useful indicators for the prognosis of small HCC.

Journal Article↗
PubMed2002

Expression patterns of two tobacco isoflavone reductase-like genes and their possible roles in secondary metabolism in tobacco.

Plants contain a large number of proteins homologous to isoflavone reductase, an NADPH-dependent reductase involved in the biosynthesis of isoflavonoid phytoalexins in legumes. Although some are bonafide isoflavone reductases, others may catalyze distinct reductase reactions. Two tobacco genes, TP7 and A622, encoding isoflavone reductase-like proteins, had been previously identified from their unique expression patterns, but their functions were not known. We show here that TP7 is a tobacco phenylcoumaran benzylic ether reductase involved in lignan biosynthesis, but that A622 is not. To gain insight into the possible function of A622, we analyzed in detail the expression patterns of the A622 gene by RNA and protein blots, immunohistochemistry, and its promoter expression in transgenic Nicotiana sylvestris roots. The A622 expression patterns were qualitatively similar to those of putrescine N-methyltransferase, the first enzyme in nicotine biosynthesis, suggesting that A622 may function in the metabolism of nicotine or related alkaloids.

Cyclopentanes↗
PubMed2002

Vesiculobullous systemic lupus erythematosus: a case with circulating IgG and IgA autoantibodies to type VII collagen.

We report a case of a 17-year-old Japanese boy with vesiculobullous systemic lupus erythematosus. He had a facial "butterfly" erythema and blistering eruption develop. Antinuclear, RNP, and Sm antibodies were positive. The American Rheumatism Association criteria for a diagnosis of systemic lupus erythematosus were met. A skin biopsy specimen showed papillary microabscesses of neutrophils and subepidermal blisters and deposits of IgG, IgA, IgM, and C3 by direct immunofluorescence. Indirect immunofluorescence on salt-split skin showed linear IgG, IgA, and C3 deposits on the dermal side. IgG and IgA autoantibodies in his serum reacted with the 290-kd proteins of type VII collagen from human dermal extracts and the recombinant fusion proteins from the noncollagenous domain of type VII collagen by Western immunoblot. To our knowledge, this is the first report of vesiculobullous systemic lupus erythematosus with circulating IgG and IgA autoantibodies to type VII collagen.

Adolescent↗
PubMed2002

Pemphigoid gestationis with predominant involvement of oral mucous membranes and IgA autoantibodies targeting the C-terminus of BP180.

Pemphigoid gestationis (PG) is an autoimmune pregnancy-associated subepidermal blistering disease. It usually affects skin and, rarely, mucous membranes. In the vast majority of patients with PG, the autoimmune response is directed to the membrane-proximal NC16A domain of the 180-kd bullous pemphigoid (BP) antigen (BP180) and is mediated by IgG1 and IgG3 autoantibodies. We report the case of a patient with PG associated with extensive lesions on oral mucous membranes. Immunoblotting studies demonstrated the presence of circulating IgA autoantibodies in the patient's serum that were exclusively directed to a 49 amino acid stretch on the C-terminal portion of the BP180 ectodomain located 800 amino acids downstream from NC16A. This C-terminal stretch of BP180 has previously been demonstrated to localize to the lamina lucida/lamina densa interface and to be recognized by IgG and IgA antibodies in a subgroup of patients with cicatricial pemphigoid as well as by IgG autoantibodies in some BP sera. Our patient's lesions healed without scarring within 6 weeks after delivery of a healthy child. The findings in this patient extend the clinical and immunopathologic spectrum of PG.

Adult↗
PubMed2002

Cicatricial pemphigoid with circulating IgA and IgG autoantibodies to the central portion of the BP180 ectodomain: beneficial effect of adjuvant therapy with high-dose intravenous immunoglobulin.

Cicatricial pemphigoid (CP) is an autoimmune subepidermal blistering disease characterized by deposits of IgG, IgA, or C3 at the cutaneous basement membrane zone. CP may present with considerable variation regarding age, morphology of lesions, and mucosal involvement, which may heal with or without scarring. We describe a patient with CP who presented with circulating IgA and IgG autoantibodies to the epidermal side of salt-split human skin. By immunoblot analysis, the patient's IgA reacted with the soluble ectodomain of BP180 (LAD-1). This reactivity was mainly directed to the central portion of the BP180 ectodomain, a site that, to date, has not been described as the target of IgA autoantibodies. Different immunosuppressive treatment regimens including steroids and mycophenolate mofetil did not control this patient's disease, and severe scarring of the conjunctivae occurred with impairment of vision. Addition of adjuvant intravenous immunoglobulin (1 g/kg body weight on 2 consecutive days) every 4 weeks led to a dramatic improvement of conjunctivitis and gingivitis. Clinical improvement correlated with the serum's IgA immunoblot reactivity against LAD-1. Further studies on a larger number of patients with CP should try to correlate the specificity of autoantibodies in CP with the response to certain therapeutic regimens.

Aged↗
PubMed2002

A nonfatal case and 2 fatal cases of paraneoplastic pemphigus: can a complement indirect immunofluorescent test help to identify fatal "group A" paraneoplastic pemphigus cases?

We studied 3 recent cases of paraneoplastic pemphigus (PNP) in detail. Two patients died despite concerted management efforts. One patient received no treatment after the appearance of PNP and recovered completely from both PNP and lymphoma. Multiple serum studies of these 3 patients plus 9 other proven PNP cases revealed that 8 of 9 fatal PNP cases (referred to here as "group A") had distinctive cell surface antibodies detected by complement indirect immunofluorescent (CIIF) tests on monkey esophagus sections. By contrast, none of the sera from 3 patients with PNP who experienced long-term survival (referred to here as "group B") and none of 20 pemphigus vulgaris or 10 pemphigus foliaceus control sera revealed similar beaded cell surface CIIF reaction patterns, a difference that is statistically significant (P <.0001). Cell surface CIIF reaction patterns of group A PNP antibodies resemble the pattern of pemphigus antibody reactions in indirect immunofluorescent tests on the same substrate; however, the latter tend to be thinner and more linear, whereas the cell surface CIIF pattern tends to be more beaded, suggesting possible desmosomal reactions. We believe this test is useful in identifying an aggressive group A form of PNP.

Antibodies, Antinuclear↗