Clinical and ultrasound features of difficult-to-treat rheumatoid arthritis: A multicenter RA ultrasound cohort study

OBJECTIVE

The optimal strategy for difficult-to-treat (D2T) rheumatoid arthritis (RA) has not been identified, and the ultrasound characteristics of D2T RA have not been reported. We investigated the clinical characteristics and factors contributing to the outcome in D2T RA in a multicentre RA ultrasound observational cohort.

METHOD

We reviewed 307 Japanese patients diagnosed with RA who underwent treatment with biological and targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs). We compared the differences in patient characteristics between the D2T RA and non-D2T RA groups. We examined the factors contributing to a good response [defined as b/tsDMARD continuation and Clinical Disease Activity Index (CDAI) ≤ 10 at 12 months] in the D2T RA patient group.

RESULTS

Forty-three patients (14%) were categorized as D2T RA and the remaining 264 (86%) as non-D2T RA at baseline. The grey-scale (GS) score, disease duration, and CDAI at the initiation of treatment were significantly higher in the D2T RA group than in the non-D2T RA group. In contrast, the power Doppler (PD) score was not significantly different between the two groups. Of the 43 D2T RA patients, 20 achieved a good response. The introduction of CTLA4-Ig (n = 5) was significantly associated with a good response in analysis based on inverse probability weighting with propensity score. GS and PD scores at baseline were not significantly associated with therapeutic response at 12 months in D2T RA patients.

CONCLUSIONS

Patients with D2T RA had high clinical and ultrasound activity and poor responses to treatment with b/tsDMARDs. CTLA4-Ig was associated with a good response at 12 months in D2T RA patients.

Bilaterally Asymmetric Helical Myofibrils in Ascidian Tadpole Larvae

The locomotor system is highly bilateral at the macroscopic level. Homochirality of biological molecules is fully compatible with the bilateral body. However, whether and how single-handed cells contribute to the bilateral locomotor system is obscure. Here, exploiting the small number of cells in the swimming tadpole larva of the ascidian Ciona, we analyzed morphology of the tail at cellular and subcellular scales. Quantitative phase-contrast X-ray tomographic microscopy revealed a high-density midline structure ventral to the notochord in the tail. Muscle cell nuclei on each side of the notochord were roughly bilaterally aligned. However, fluorescence microscopy detected left-right asymmetry of myofibril inclination relative to the longitudinal axis of the tail. Zernike phase-contrast X-ray tomographic microscopy revealed the presence of left-handed helices of myofibrils in muscle cells on both sides. Therefore, the locomotor system of ascidian larvae harbors symmetry-breaking left-handed helical cells, while maintaining bilaterally symmetrical cell alignment. These results suggest that bilateral animals can override cellular homochirality to generate the bilateral locomotor systems at the supracellular scale.

Ultrasound efficacy of targeted-synthetic disease-modifying anti-rheumatic drug treatment in rheumatoid arthritis: a multicenter prospective cohort study in Japan

OBJECTIVE

This study investigated the effectiveness of treatment with Janus kinase (JAK) inhibitors in rheumatoid arthritis (RA) assessed by ultrasonography (US) activity, and the influence of patient characteristics and previous treatments.

METHOD

This prospective study assessed 60 treatment initiations among 53 Japanese patients diagnosed with RA who underwent treatment with JAK inhibitors during June 2013 to February 2020. Of the 53 patients, seven patients were enrolled in duplicate because they were treated with two different JAK inhibitors at different periods. For each case, the improvement rate on the power Doppler (PD) score was assessed at 6 month follow-up. Median improvement rate of PD score was used to classify cases as either US responders or non-responders, and patient characteristics were compared between the two groups.

RESULTS

All indicators of clinical disease activity and US activity showed a significant improvement at 3 months compared with baseline. Although the JAK inhibitor-cycler group and the interleukin-6 (IL-6) inhibitor inadequate response (IR) group tended to show a later improvement for US activity, all indicators of clinical disease activity and US activity showed a significant improvement at 6 months compared with baseline for both groups. Multivariate analysis showed that concomitant methotrexate use and an IR to the previous biologic or targeted-synthetic disease-modifying anti-rheumatic drug (b/tsDMARD) treatment were independently and significantly associated with US responders.

CONCLUSION

Use of a JAK inhibitor in combination with methotrexate and an absence of IR to any previous b/tsDMARDs demonstrated superior effectiveness for patients with RA.

Discrepancy between clinical and ultrasound remissions in rheumatoid arthritis: a multicentre ultrasound cohort study in Japan

Objectives: Using multicentre ultrasound (US) cohort data among patients with rheumatoid arthritis (RA), we aimed to identify baseline factors that permit differentiation between two patient cohorts achieving US remission and clinical remission, and to determine the factors contributing to the discrepancy.Method: We reviewed 248 Japanese patients diagnosed with RA who underwent treatment with biological disease-modifying anti-rheumatic drugs at 13 centres. We performed US assessments of the synovia of 22 joints. We assessed the percentages of patients with clinical remission and US remission, defined as total power Doppler scores of 0 at 12 months.Results: The 87 patients who achieved US remission were divided into a group that achieved both clinical and US remission (n = 53) and a group that achieved US remission only (n = 34). Baseline factors that were significantly and independently associated with clinical remission at 12 months among patients who also achieved US remission included short disease duration, the presence of concomitant methotrexate use, and low patient global assessment score (p < 0.05, p < 0.05, and p < 0.005, respectively).Conclusions: RA patients with baseline high patient global assessment scores and long disease duration at baseline were unlikely to achieve clinical remission even after achieving US remission. Objective joint assessments using US provide additional information of potential importance for the management of RA.

Fluorescence optical imaging in patients with active rheumatoid arthritis: a comparison with ultrasound and an association with biomarkers

Objectives: This study compared indocyanine green (ICG)-enhanced fluorescence optical imaging (FOI) and musculoskeletal ultrasound (MSUS), and explored the significance of the FOI findings based on the association between the FOI and MSUS findings and serum biomarkers in patients with rheumatoid arthritis (RA). The study also explored the association between the FOI findings and patients' joint destruction at the joint-area level.Method: We enrolled 50 consecutive patients with active RA from among the patients hospitalized from May 2014 to March 2016 at Nagasaki University Hospital, Japan. FOI images were acquired with the Xiralite^® fluorescence imaging system and compared with the patients' clinical examination results and MSUS findings. On the same day, the patients' clinical disease activity and levels of serum biomarkers (including vascular endothelial growth factor) were obtained.Results: Although the FOI detected synovitis with high sensitivity, the frequency of positive findings and the diagnostic performance with MSUS as the reference standard for FOI differed considerably among the phases of FOI as well as among the affected joint regions. The FOI scores were positively correlated with clinical disease activity, MSUS scores, and serum biomarkers. The severity of FOI-proven synovitis was associated with the presence of MSUS-proven bone erosion.Conclusion: FOI is effective for detecting joint inflammation in RA patients, with high accuracy. The severity of the FOI score was closely associated with the joint destruction at the joint-area level. However, the significance of positive FOI findings differed depending on not only the phase of FOI but also the affected joint regions.

Significance of anti-Ro/SSA antibodies in the response and retention of abatacept in patients with rheumatoid arthritis: a multicentre cohort study

Objective: To determine whether the positivity of baseline anti-Ro/Sjögren's syndrome antigen A (SSA) antibodies influences the response to abatacept, we compared therapeutic responses between anti-Ro/SSA antibody-negative and -positive patients with rheumatoid arthritis (RA) using a multicentre RA ultrasonography prospective cohort. Method: We reviewed Japanese patients with RA who started abatacept as the first biological disease-modifying anti-rheumatic drug between June 2013 and April 2018. We assessed 28-joint Disease Activity Score-erythrocyte sedimentation rate (DAS28-ESR) change between baseline and 6 or 12 months after treatment in RA patients treated with abatacept, and European League Against Rheumatism (EULAR) response at 6 and 12 months. The Global OMERACT-EULAR Synovitis Score (GLOESS) was calculated at baseline and at 6 and 12 months. Results: Overall, 51 patients were enrolled and divided into anti-Ro/SSA antibody-negative and -positive groups of 35 and 16, respectively. Median age at baseline was significantly higher in the anti-Ro/SSA antibody-negative group (p = 0.04). The retention rate and percentage of EULAR good responders at 12 months were significantly higher in the anti-Ro/SSA antibody-negative group (both p = 0.02). Anti-Ro/SSA antibody-negative patients exhibited larger decreases in both DAS28-ESR and DAS28-C-reactive protein at 12 months than anti-Ro/SSA antibody-positive patients (p = 0.02 and 0.04, respectively). GLOESS decreased significantly at 6 months in anti-Ro/SSA antibody-negative patients (p = 0.03). Multivariate analyses showed that anti-Ro/SSA antibody positivity was an independent factor associated with change in the DAS28-ESR at 6 months (p < 0.05). Conclusion: Anti-Ro/SSA antibody positivity predicts a poor response to abatacept and low retention rate.

FRI0098 ASSOCIATION BETWEEN THE SEROLOGIC STATUS OF ISOTYPE-SPECIFIC AUTOANTIBODIES AND THERAPEUTIC EFFICACY IN RHEUMATOID ARTHRITIS PATIENTS TREATED WITH ABATACEPT: A PROSPECTIVE ULTRASOUND COHORT STUDY IN JAPAN

Background:

The presence of anti-cyclic citrullinated protein antibodies (ACPA) and anti-carbamylated protein (anti-CarP) antibody is specific for rheumatoid arthritis (RA). Recently, it was reported that the serological status of ACPA is associated with the therapeutic response of the T-cell co-stimulation blocker abatacept (1, 2). However, it is currently unclear whether the serological status of each isotype levels of these autoantibodies before treatment introduction or the changes during treatment are associated with the therapeutic response of abatacept.

Objectives:

To evaluate longitudinal changes in the isotypes of ACPA and anti-CarP in RA patients treated with abatacept, and associations between the baseline serological status/ these changes and clinical response/ ultrasonographic response.

Methods:

This study is part of an ongoing non-randomized multicenter prospective cohort study of patients with active RA who received biological or targeted DMARD therapy at 13 participating rheumatology centers from the Kyushu region of Japan since June 2013 (3). As of the present report, we enrolled 43 consecutive Japanese patients with active RA who have introduced treatment with abatacept and had finished the first 12-month observation period. We evaluated disease activity by clinical composite measure and ultrasound score at baseline, 3, 6, 9 and 12 months. In ultrasound of bilateral hands from 22 sites, the findings obtained by gray-scale (GS) and power Doppler (PD) assessments were graded on a semi-quantitative scale from 0 to 3 and the sum of GS or PD scores was used as the total GS or PD score. The serum levels of IgG/IgM/IgA-type of ACPA and anti-CarP were measured by the ELISA method in Leiden University Medical Center. We evaluated the association between serologic status of autoantibodies and clinical /ultrasonographic therapeutic efficacy.

Results:

The median age was 72 years, and the disease duration was 54 months. Methotrexate was concomitant in 22 (51%). Sixteen (37%) patients had a history of previous use of biological DMARDs. Nineteen (44%) and 23 (54%) patients achieved SDAI remission and PD remission (total PD score =0) at 12 months, respectively. The serum levels of all isotypes of ACPA/anti-CarP significantly decreased at 12 months from baseline. The reduction of IgM-ACPA level significantly correlated with the reduction of SDAI (rs=0.33, p=0.031) and total PD score (rs=0.49, p=0.0007). Both clinical and ultrasonographic therapeutic responses were better in patients with the detectable IgM-ACPA at baseline than in patients without that (Figure): the reduction of SDAI (p=0.0078) and that of total PD score (p=0.0079) were significantly larger in the former than in the latter. All isotype of anti-CarP did not associate with therapeutic response.

Conclusion:

Treatment of abatacept induced to the reduction of the autoantibody levels. The IgM-ACPA level at baseline and the change in IgM-ACPA associated with both clinical and ultrasonographic therapeutic response in patients treated with abatacept. IgM-ACPA, compared with usual IgG-ACPA, better reflects the treatment response of abatcept in patients with RA

References:

[1]Ann Rheum Dis. 2016;75:709, 2) RMD Open. 2018;4:e000564, 3)Arthritis Care Res (Hoboken). 2018;70:1719.

Acknowledgments:

We have acknowledged for all the members of Kyushu multicenter rheumatoid arthritis ultrasound prospective observational cohort study group.

Disclosure of Interests:

Shin-ya Kawashiri Grant/research support from: This work was supported by Bristol-Myers Squibb and Ono Pharmaceutical. co., Yushiro Endo: None declared, Ayako Nishino: None declared, Toshimasa Shimizu: None declared, Yukitaka Ueki: None declared, Nobutaka Eiraku: None declared, Akitomo Okada: None declared, Naoki Matsuoka: None declared, Tamami Yoshitama: None declared, Hideki Nakamura: None declared, Mami Tamai: None declared, Tomoki Origuchi: None declared, Rene Toes: None declared, Thomas Huizinga Grant/research support from: Ablynx, Bristol-Myers Squibb, Roche, Sanofi, Consultant of: Ablynx, Bristol-Myers Squibb, Roche, Sanofi, Atsushi Kawakami: None declared

An α7-related nicotinic acetylcholine receptor mediates the ciliary arrest response in pharyngeal gill slits of Ciona

Ciliary movement is a fundamental process to support animal life, and the movement pattern may be altered in response to external stimuli under the control of nervous systems. Juvenile and adult ascidians have ciliary arrays around their pharyngeal gill slits (stigmata), and continuous beating is interrupted for seconds by mechanical stimuli on other parts of the body. Although it has been suggested that neural transmission to evoke ciliary arrest is cholinergic, its molecular basis has not yet been elucidated in detail. Here, we attempted to clarify the molecular mechanisms underlying this neurociliary transmission in the model ascidian Ciona Acetylcholinesterase histochemical staining showed strong signals on the laterodistal ciliated cells of stigmata, hereafter referred to as trapezial cells. The direct administration of acetylcholine (ACh) and other agonists of nicotinic ACh receptors (nAChRs) onto ciliated cells reliably evoked ciliary arrest that persisted for seconds in a dose-dependent manner. While the Ciona genome encodes ten nAChRs, only one of these called nAChR-A7/8-1, a relative of vertebrate α7 nAChRs, was found to be expressed by trapezial cells. Exogenously expressed nAChR-A7/8-1 on Xenopus oocytes responded to ACh and other agonists with consistent pharmacological traits to those observed in vivo Further efforts to examine signaling downstream of this receptor revealed that an inhibitor of phospholipase C (PLC) hampered ACh-induced ciliary arrest. We propose that homomeric α7-related nAChR-A7/8-1 mediates neurociliary transmission in Ciona stigmata to elicit persistent ciliary arrest by recruiting intracellular Ca2+ signaling.

Usefulness of soluble CD163 as a biomarker for macrophage activation syndrome associated with systemic lupus erythematosus

OBJECTIVE

We aimed to study the usefulness of serum soluble CD163 (sCD163) as a biomarker for macrophage activation syndrome (MAS) associated with systemic lupus erythematosus (SLE).

METHODS

Serum sCD163 levels were retrospectively measured by enzyme-linked immunosorbent assay for SLE patients associated with MAS (SLE-MAS), lupus nephritis (LN), or autoimmune hemolytic anemia (AIHA) and/or immune thrombocytopenia (ITP) and healthy controls (HCs). Posttreatment samples were also evaluated in the available SLE-MAS patients. The associations between serum sCD163 levels and clinical information were statistically analyzed.

RESULTS

The serum sCD163 levels in SLE-MAS, LN and SLE-AIHA/ITP groups were significantly higher than those in HCs (n = 17, 29, 13, and 68, respectively; p < 0.01 for all comparisons). In addition, the serum sCD163 levels in the SLE-MAS group were even higher than those in the LN and SLE-AIHA/ITP groups (p < 0.01 for both comparisons). Serum sCD163 levels were correlated with the SLE Disease Activity Index 2000 scores (r = 0.53), whereas they were not correlated with the serum ferritin levels. With the determined cut-off value, the sensitivity and specificity of serum sCD163 for the diagnosis of SLE-MAS were 59% and 86%, respectively. Retesting showed that the serum sCD163 levels decreased significantly following treatment in parallel with disease amelioration in the SLE-MAS group (p < 0.01).

CONCLUSIONS

The present study suggests the usefulness of serum sCD163 as a diagnostic and disease-activity biomarker for SLE-associated MAS. Serum sCD163 might also have a different role as a biomarker for SLE-associated MAS than serum ferritin does.

The efficacy of adjunct tacrolimus treatment in pregnancy outcomes in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) involves multiple organ systems and primarily affects women during their reproductive years. Pregnancy in a woman with SLE may lead to higher rates of disease flares. Little is known regarding which medications are safe to maintain remission and/or treat flares throughout such pregnancies. Here we retrospectively analyzed the efficacy of tacrolimus (TAC) in the pregnancy outcomes of SLE patients. We studied the 54 deliveries of 40 SLE patients over an eight-year period from 2008 to 2016. We used analyses of covariance with adjustments for the propensity score and inverse probability of treatment weights to compare the patient backgrounds between the TAC users and non-TAC users. TAC was administered to the patient in 15 of the 54 (27.8%) pregnancies, and these patients had a significantly higher dose of prednisolone, hypocomplementemia, lower estimated glomerular filtration rate, past history of lupus nephritis, and complication with antiphospholipid syndrome. In the adjusted background of the TAC deliveries, the risks of decreased fetal body weight, low birth weight infant, non-reassuring fetal status (NRFS), and preterm birth were not increased compared to the non-TAC deliveries. Thrombocytopenia and hypertension during the pregnancy were extracted as independent predictive risk factors for decreased fetal body weight and NRFS, respectively. We had anticipated that the maternal and fetal outcomes in the TAC-use deliveries would be poor before the analysis; however, the TAC-use group showed no significant difference in risks contributing to outcomes compared to the non-TAC group, suggesting that adjunct TAC treatment corrected various risk factors during the lupus pregnancies.

Evolutionary History of Voltage-Gated Sodium Channels

Every cell within living organisms actively maintains an intracellular Na⁺ concentration that is 10-12 times lower than the extracellular concentration. The cells then utilize this transmembrane Na⁺ concentration gradient as a driving force to produce electrical signals, sometimes in the form of action potentials. The protein family comprising voltage-gated sodium channels (Na_Vs) is essential for such signaling and enables cells to change their status in a regenerative manner and to rapidly communicate with one another. Na_Vs were first predicted in squid and were later identified through molecular biology in the electric eel. Since then, these proteins have been discovered in organisms ranging from bacteria to humans. Recent research has succeeded in decoding the amino acid sequences of a wide variety of Na_V family members, as well as the three-dimensional structures of some. These studies and others have uncovered several of the major steps in the functional and structural transition of Na_V proteins that has occurred along the course of the evolutionary history of organisms. Here we present an overview of the molecular evolutionary innovations that established present-day Na_V α subunits and discuss their contribution to the evolutionary changes in animal bodies.

Morphology and Physiology of the Ascidian Nervous Systems and the Effectors

Neurobiology in ascidians has made many advances. Ascidians have offered natural advantages to researchers, including fecundity, structural simplicity, invariant morphology, and fast and stereotyped developmental processes. The researchers have also accumulated on this animal a great deal of knowledge, genomic resources, and modern genetic techniques. A recent connectomic analysis has shown an ultimately resolved image of the larval nervous system, whereas recent applications of live imaging and optogenetics have clarified the functional organization of the juvenile nervous system. Progress in resources and techniques have provided convincing ways to deepen what we have wanted to know about the nervous systems of ascidians. Here, the research history and the current views regarding ascidian nervous systems are summarized.

Is there intracellular cellulose in the appendicularian tail epidermis? A tale of the adult tail of an invertebrate chordate

All tunicates produce a cellulosic extracellular matrix external to the epidermis; this is the most remarkable character of the subphylum (Tunicata = Urochordata). In Ascidiacea and Thaliacea, two of the three classes of Tunicata, cellulose is the main component of the tunic matrix that covers the whole body. In Appendicularia, however, the animals do not possess a tunic, and instead secrete a feeding apparatus called a "house" that is composed of cellulose. In the appendicularian Oikopleura dioica, we found a unique intracellular matrix in the apical cytoplasm of the adult tail epidermis that appears to form a tough shell supporting the tail. Although some experimental data suggest that this matrix may contain cellulose, the composition is still unknown. The significance of the tunicate capacity for cellulose synthesis is briefly discussed.

KCNQ1 subdomains involved in KCNE modulation revealed by an invertebrate KCNQ1 orthologue

KCNQ1 channels are voltage-gated potassium channels that are widely expressed in various non-neuronal tissues, such as the heart, pancreas, and intestine. KCNE proteins are known as the auxiliary subunits for KCNQ1 channels. The effects and functions of the different KCNE proteins on KCNQ1 modulation are various; the KCNQ1–KCNE1 ion channel complex produces a slowly activating potassium channel that is crucial for heartbeat regulation, while the KCNE3 protein makes KCNQ1 channels constitutively active, which is important for K⁺ and Cl⁻ transport in the intestine. The mechanisms by which KCNE proteins modulate KCNQ1 channels have long been studied and discussed; however, it is not well understood how different KCNE proteins exert considerably different effects on KCNQ1 channels. Here, we approached this point by taking advantage of the recently isolated Ci-KCNQ1, a KCNQ1 homologue from marine invertebrate Ciona intestinalis. We found that Ci-KCNQ1 alone could be expressed in Xenopus laevis oocytes and produced a voltage-dependent potassium current, but that Ci-KCNQ1 was not properly modulated by KCNE1 and totally unaffected by coexpression of KCNE3. By making chimeras of Ci-KCNQ1 and human KCNQ1, we determined several amino acid residues located in the pore region of human KCNQ1 involved in KCNE1 modulation. Interestingly, though, these amino acid residues of the pore region are not important for KCNE3 modulation, and we subsequently found that the S1 segment plays an important role in making KCNQ1 channels constitutively active by KCNE3. Our findings indicate that different KCNE proteins use different domains of KCNQ1 channels, and that may explain why different KCNE proteins give quite different outcomes by forming a complex with KCNQ1 channels.

Forming a tough shell via an intracellular matrix and cellular junctions in the tail epidermis of Oikopleura dioica (Chordata: Tunicata: Appendicularia)

A postanal tail is a major synapomorphy of the phylum Chordata, which is composed of three subphyla: Vertebrata, Cephalochordata, and Tunicata (Urochordata). Among tunicates, appendicularians are the only group that retains the tail in the adult, and the adult tail functions in locomotion and feeding in combination with a cellulose-based house structure. Given the phylogenetic position of tunicates, the appendicularian adult tail may possess ancestral features of the chordate tail. We assess the ultrastructural development of the tail epidermis of the appendicularian Oikopleura dioica. The epidermis of the larval tail is enclosed by the larval envelope, which is a thin sheet similar to the outer tunic layer of ascidian larvae. The epidermis of the adult tail seems to bear no tunic-like cellulosic integuments, and the tail fin is a simple folding of the epidermis. Every epidermal cell, except for the triangular cells at the edge of the tail fin, has a conspicuous matrix layer of fibrous content in the apical cytoplasm without enclosing membranes. The epidermis of the larval tail does not have a fibrous matrix layer, suggesting the production of the layer during larval development and metamorphosis. Zonulae adhaerentes firmly bind the epidermal cells of the adult tail to one another, and the dense microfilaments lining the cell borders constitute a mechanical support for the cell membranes. The intracellular matrix, cell junctions, and cytoskeletons probably make the tail epidermis a tough, flexible shell supporting the active beating of the oikopleuran adult tail.

The crystalline phase of cellulose changes under developmental control in a marine chordate

The native form of cellulose is a fibrillar composite of two crystalline phases, the triclinic I(α) and monoclinic I(β) allomorphs. Allomorph ratios are species-specific, and this gives rise to natural structural variations in cellulose crystals. However, the mechanisms contributing to crystal formation remain unknown. We show that the two crystalline phases of cellulose are tailored to distinct structures during different developmental stages of the tunicate chordate Oikopleura dioica. Larval cellulose consisting of I(α) allomorph constitutes the body cuticle fin, whereas adult cellulose consisting of I(β) allomorph frames a mucous filter-feeding device, the "house." Both structures are secreted from the epidermis in accordance with the mutually exclusive expression patterns of two distinct putative cellulose synthase genes. We discuss a possible linkage between structural variations of the crystalline phases of cellulose and the underlying evolutionary genetics of cellulose biosynthesis.

A mechanism for graded motor control encoded in the channel properties of the muscle ACh receptor

The larva of the invertebrate chordate Ciona intestinalis possesses only 36 striated muscle cells and lacks body segmentation. It can swim, however, like a vertebrate tadpole, and how its simple body achieves such sophisticated motor control remains puzzling. We found that muscle contractions in Ciona larvae are variable and can be changed by sensory stimuli, so that neuromuscular transmission can convert the variable neural inputs into graded muscle activity. We characterized the molecular nature of the nicotinic acetylcholine receptor (nAChR) at neuromuscular synapses. When heterologously expressed in Xenopus oocytes, this nAChR channel exhibited two biophysical features resembling vertebrate neuronal nAChRs rather than the muscle type: inward rectification and high Ca(2+) permeability. Both of these properties were abolished by a simple mutation at the channel pore in one of the non-α subunits, called BGDE3, so as to adopt the sequence of related subunits in vertebrates, γ and ε. In vivo exchange of native BGDE3 with this mutant severely disrupted graded motor control, producing instead sporadic all-or-none-like flexions. The graded nature of excitation-contraction (E-C) coupling in this organism is based on the traits of the nAChR channel pore, which confer fine controllability on such a coarse motor architecture.

Gene expression profile of Ci-VSP in juveniles and adult blood cells of ascidian

VSP is a transmembrane protein whose cytoplasmic region shows significant similarity to phosphatase and tensin homolog deleted on chromosome 10 (PTEN). Notably, VSP exhibits a unique ability to transduce electrical signals into phosphoinositide turnover by coupling a transmembrane voltage sensor domain to the PTEN-like phosphoinositide phosphatase domain. Moreover, VSP gene is known to be widely conserved among deuterostome genomes, though the function of VSP in vivo remains largely unknown. In the present study, the expression pattern of ascidian VSP(Ci-VSP) was examined in embryos and juveniles of a marine invertebrate chordate, Ciona intestinalis. RT-PCR showed that Ci-VSP is expressed at the larval stage and that expression persists in juveniles. Whole mount in situ hybridization showed that Ci-VSP is expressed in cells of the stomach, intestine and blood cells of 2- to 3-week-old juveniles. Moreover, double staining blood cells from 2-month-old adults with Ci-VSP and Ci-PTEN probes showed that Ci-VSP-positive cells are a distinct population, separate from cells expressing Ci-PTEN. These findings suggest that in addition to its previously suggested roles in testis or sperm, Ci-VSP plays a key role in voltage-induced signal transduction in cells of the digestive system and blood.

Plasticity of animal genome architecture unmasked by rapid evolution of a pelagic tunicate

Genomes of animals as different as sponges and humans show conservation of global architecture. Here we show that multiple genomic features including transposon diversity, developmental gene repertoire, physical gene order, and intron-exon organization are shattered in the tunicate Oikopleura, belonging to the sister group of vertebrates and retaining chordate morphology. Ancestral architecture of animal genomes can be deeply modified and may therefore be largely nonadaptive. This rapidly evolving animal lineage thus offers unique perspectives on the level of genome plasticity. It also illuminates issues as fundamental as the mechanisms of intron gain.

A glycine receptor is involved in the organization of swimming movements in an invertebrate chordate

BACKGROUND

Rhythmic motor patterns for locomotion in vertebrates are generated in spinal cord neural networks known as spinal Central Pattern Generators (CPGs). A key element in pattern generation is the role of glycinergic synaptic transmission by interneurons that cross the cord midline and inhibit contralaterally-located excitatory neurons. The glycinergic inhibitory drive permits alternating and precisely timed motor output during locomotion such as walking or swimming. To understand better the evolution of this system we examined the physiology of the neural network controlling swimming in an invertebrate chordate relative of vertebrates, the ascidian larva Ciona intestinalis.

RESULTS

A reduced preparation of the larva consisting of nerve cord and motor ganglion generates alternating swimming movements. Pharmacological and genetic manipulation of glycine receptors shows that they are implicated in the control of these locomotory movements. Morphological molecular techniques and heterologous expression experiments revealed that glycine receptors are inhibitory and are present on both motoneurones and locomotory muscle while putative glycinergic interneurons were identified in the nerve cord by labeling with an anti-glycine antibody.

CONCLUSIONS

In Ciona intestinalis, glycine receptors, glycinergic transmission and putative glycinergic interneurons, have a key role in coordinating swimming movements through a simple CPG that is present in the motor ganglion and nerve cord. Thus, the strong association between glycine receptors and vertebrate locomotory networks may now be extended to include the phylum chordata. The results suggest that the basic network for 'spinal-like' locomotion is likely to have existed in the common ancestor of extant chordates some 650 M years ago.

Ion channel clustering at the axon initial segment and node of Ranvier evolved sequentially in early chordates

In many mammalian neurons, dense clusters of ion channels at the axonal initial segment and nodes of Ranvier underlie action potential generation and rapid conduction. Axonal clustering of mammalian voltage-gated sodium and KCNQ (Kv7) potassium channels is based on linkage to the actin-spectrin cytoskeleton, which is mediated by the adaptor protein ankyrin-G. We identified key steps in the evolution of this axonal channel clustering. The anchor motif for sodium channel clustering evolved early in the chordate lineage before the divergence of the wormlike cephalochordate, amphioxus. Axons of the lamprey, a very primitive vertebrate, exhibited some invertebrate features (lack of myelin, use of giant diameter to hasten conduction), but possessed narrow initial segments bearing sodium channel clusters like in more recently evolved vertebrates. The KCNQ potassium channel anchor motif evolved after the divergence of lampreys from other vertebrates, in a common ancestor of shark and humans. Thus, clustering of voltage-gated sodium channels was a pivotal early innovation of the chordates. Sodium channel clusters at the axon initial segment serving the generation of action potentials evolved long before the node of Ranvier. KCNQ channels acquired anchors allowing their integration into pre-existing sodium channel complexes at about the same time that ancient vertebrates acquired myelin, saltatory conduction, and hinged jaws. The early chordate refinements in action potential mechanisms we have elucidated appear essential to the complex neural signaling, active behavior, and evolutionary success of vertebrates.

Clinical manifestation and treatment strategy for non hemorrhagic cerebral arterial dissection

Spontaneous dissections of cerebral and cervical artery are relatively uncommon lesions in Japan. Although reported cases of cerebral and cervical arterial dissection are gradually increasing, natural history and optimal treatment remain unclear. The purpose of this study was to clarify the clinical features, natural history, and optimal treatment for patients suffering from non-hemorrhagic cerebral arterial dissection. Fifty-four males and 14 females with cerebral or cervical arterial dissection were treated between January 1998 and December 2003 at the Stroke Center, Sendal Medical Center in Japan. Although most patients suffering from non-hemorrhagic cerebral arterial dissection recover well by conservative treatments, some cases require surgical treatment if they are complicated by enlargement of aneurysms, cerebral ischemia due to bilateral vertebral arterial dissection.

Relationship between quadriceps femoris muscle volume and muscle torque after anterior cruciate ligament repair

This study was performed to obtain evidence regarding bilateral hindrance of motor unit (MU) recruitment in the quadriceps femoris (QF) of patients with anterior cruciate ligament (ACL) reconstruction. The subjects included 70 patients who underwent ACL reconstruction and 35 healthy subjects. To identify the muscle torque per unit volume (MTPUV), the peak torque of each velocity of isokinetic performance was divided by muscle volume of the QF measured by a series of cross-sectional images obtained by magnetic resonance imaging scans. Tests revealed that the mean MTPUV of the uninjured (0.113+/-0.03 N m/cm3 at 60 degrees /s, 0.081+/-0.02 N m/cm3 at 180 degrees /s) and injured sides (0.109+/-0.03 N m/cm3 at 60 degrees /s, 0.079+/-0.023 N m/cm3 at 180 degrees /s) were significantly lower than those of the control group (0.144+/-0.05 N m/cm3 at 60 degrees /s, 0.096+/-0.04 N m/cm3 at 180 degrees /s). Previous studies suggested that MU recruitment in the QF of patients with ACL injury was hindered bilaterally. However, the design of their studies could not provide evidence of bilateral hindrance of MU recruitment in the QF. The results of the present study demonstrated that the MTPUV of both injured and uninjured sides of patients were significantly lower than those of the control group.

Phylogenetic correspondence of the body axes in bilaterians is revealed by the right-sided expression of Pitx genes in echinoderm larvae

Chordates and echinoderms are two of the three major deuterostome phyla and show conspicuous left-right (LR) asymmetry. The establishment of LR asymmetry has been explored in vertebrates, but is largely unknown in echinoderms. Here, we report the expression pattern of genes that are orthologous to the chordate left-side specific gene Pitx, cloned from the sea urchin Hemicentrotus pulcherrimus (HpPitx) and the starfish Asterina pectinifera (ApPitx). HpPitx transcripts were first detected bilaterally in one cell of the ventrolateral primary mesenchyme-cell aggregate of early prism larvae. New expression was detected asymmetrically in the right counterpart of a bilateral pair of mesodermal coelomic pouches and in the right ectoderm. In starfish bipinnaria larvae, the ApPitx signal was detected in the right coelomic pouch and in the right half of the ectoderm along the ciliary bands. These results suggest that the function of Pitx in establishing LR asymmetry was introduced in the last common ancestor of echinoderms and chordates. However, the right-side specific expression in echinoderm larvae is inverted compared to chordate embryos. This indicates that the LR axis is inversely represented between echinoderms and chordates, which supports the scenario that dorsoventral axis inversion was introduced into the chordate lineage by turning upside down.

Ion flow regulates left-right asymmetry in sea urchin development

The degree of conservation among phyla of early mechanisms that pattern the left-right (LR) axis is poorly understood. Larvae of sea urchins exhibit consistently oriented LR asymmetry. The main part of the adult rudiment is formed from the left coelomic sac of larvae, the left hydrocoel. Although this left preference is conserved among all echinoderm larvae, its mechanism is largely not understood. Using two marker genes, HpNot and HpFoxFQ-like, which are asymmetrically expressed during larval development of the sea urchin Hemicentrotus pulcherrimus, we examined in this study the possibility that the recently discovered ion flux mechanism controls asymmetry in sea urchins as it does in several vertebrate species. Several ion-transporter inhibitors were screened for the ability to alter the expression of the asymmetric marker genes. Blockers of the H(+)/K(+)-ATPase (omeprazole, lansoprazole and SCH28080), as well as a calcium ionophore (A23187), significantly altered the normal sidedness of asymmetric gene expression. Exposure to omeprazole disrupted the consistent asymmetry of adult rudiment formation in larvae. Immuno-detection revealed that H(+)/K(+)-ATPase-like antigens in sea urchin embryos were present through blastula stage and exhibited a striking asymmetry being present in a single blastomere in 32-cell embryos. These results suggest that, as in vertebrates, endogenous spatially-regulated early transport of H(+) and/or K(+), and also of Ca(2+), functions in the establishment of LR asymmetry in sea urchin development.

Endovascular GDC Treatment of an Idiopathic Carotid-Cavernous Fistula Caused by Aneurysmal Rupture of the Intra-Cavernous Carotid Artery. Case Report

SUMMARY

Aneurysmal rupture of the intra-cavernous carotid artery may cause idiopathic carotid-cavernous fistula (CCF), and the treatment choice for occluding shunting fistula in this type of CCF is an endovascular approach using detachable balloons. However, little has been reported on treating such lesions with the intra-aneurysmal embolization using Guglielmi detachable coils (GDCs).To our knowledge, ours is the first reported case of successful treatment by selective intra-fistula and intra-aneurysmal embolization with GDCs. A 74-year-old woman exhibited proptosis and chemosis of her left eye over a period of one month. Symptoms of double vision in conversion and pulsatile murmur in her left eye were also noted. Angiography revealed an intra-cavernous aneurysm of the left internal carotid artery (ICA) with a shunting fistula, which drained into the dilated cavernous sinus, superior orbital vein (SOV), superior petrosal sinus, inferior petrosal sinus, and pterygoid plexus.We thought the fistula would occlude by intra-aneurysmal embolization, but we had no confidence of tight packing of the aneurysm since the aneurismal neck was relatively wide. So, we embolized the venous side of the shunting fistula and then the dome of the aneurysm with GDCs. Immediately after the operation, her symptoms and signs were ameliorated, and complete occlusion of the CCF was observed on long-term follow-up. We suggest selective intrafistula and intra-aneurysmal embolization with GDCs as an alternative method of treatment of idiopathic CCF originating from aneurysmal rupture of the intra-cavernous carotid artery.

GABAergic synaptic transmission modulates swimming in the ascidian larva

To examine the role of the amino acid GABA in the locomotion of basal chordates, we investigated the pharmacology of swimming and the morphology of GABA-immunopositive neurones in tadpole larvae of the ascidians Ciona intestinalis and Ciona savignyi. We verified that electrical recording from the tail reflects alternating muscle activity during swimming by correlating electrical signals with tail beats using high-speed video recording. GABA reversibly reduced swimming periods to single tail twitches, while picrotoxin increased the frequency and duration of electrical activity associated with spontaneous swimming periods. Immunocytochemistry for GABA revealed extensive labelling throughout the larval central nervous system. Two strongly labelled regions on either side of the sensory vesicle were connected by an arc of labelled fibres, from which fibre tracts extended caudally into the visceral ganglion. Fibre tracts extended ventrally from a third, more medial region in the posterior sensory vesicle. Two rows of immunoreactive cell bodies in the visceral ganglion extended neurites into the nerve cord, where varicosities were seen. Thus, presumed GABAergic neurones form a network that could release GABA during swimming that is involved in modulating the time course and frequency of periods of spontaneous swimming. GABAergic and motor neurones in the visceral ganglion could interact at the level of their cell bodies and/or through the presumed GABAergic fibres that enter the nerve cord. The larval swimming network appears to possess some of the properties of spinal networks in vertebrates, while at the same time possibly showing a type of peripheral innervation resembling that in some protostomes.

Comprehensive analysis of the ascidian genome reveals novel insights into the molecular evolution of ion channel genes

Ion fluxes through membrane ion channels play crucial roles both in neuronal signaling and the homeostatic control of body electrolytes. Despite our knowledge about the respective ion channels, just how diversification of ion channel genes underlies adaptation of animals to the physical environment remains unknown. Here we systematically survey up to 160 putative ion channel genes in the genome of Ciona intestinalis and compare them with corresponding gene sets from the genomes of the nematode Chaenorhabditis elegans, the fruit fly Drosophila melanogaster, and the more closely related genomes of vertebrates. Ciona has a set of so-called "prototype" genes for ion channels regulating neuronal excitability, or for neurotransmitter receptors, suggesting that genes responsible for neuronal signaling in mammals appear to have diversified mainly via gene duplications of the more restricted members of ancestral genomes before the ascidian/vertebrate divergence. Most genes responsible for modulation of neuronal excitability and pain sensation are absent from the ascidian genome, suggesting that these genes arose after the divergence of urochordates. In contrast, the divergent genes encoding connexins, transient receptor potential-related channels and chloride channels, channels involved rather in homeostatic control, indicate gene duplication events unique to the ascidian lineage. Because several invertebrate-unique channel genes exist in Ciona genome, the crown group of extant vertebrates not only acquired novel channel genes via gene/genome duplications but also discarded some ancient genes that have persisted in invertebrates. Such genome-wide information of ion channel genes in basal chordates enables us to begin correlating the innovation and remodeling of genes with the adaptation of more recent chordates to their physical environment.

[Multi-vessel dissection; report of a case]

We report an extremely rare case of multi-vessel dissection including left carotid artery, ascending aorta and thoracoabdominal aorta independently. A 65-year-old man suffered from cerebral infarction due to left carotid artery dissection. Five days later, he complained of severe back pain and was diagnosed as acute DeBakey type IIIb aortic dissection. He had been treated medically. One month later, computed tomography (CT) scan demonstrated DeBakey type II as well as type IIIb aortic dissections. The ascending aorta was replaced on August 8, 2001. Then replacement of the descending thoracic aorta with reconstruction of the eighth and tenth intercostal arteries was performed on September 26, 2001. The left carotid artery dissection has been treated medically.

Clinical manifestations, character of aneurysms, and surgical results for unruptured cerebral aneurysms presenting with ophthalmic symptoms

OBJECTS

Cases with unruptured cerebral aneurysms presenting with visual symptoms were investigated about their site, size, symptom, operative methods and results.

MATERIAL

Between 1984 and 1999, 8 cases were treated in Sendai National Hospital. One man and 7 women, mean age 66.4 years. Ophthalmic symptoms were as follows: diplopia in 6, visual acuity deterioration in 2, impaired visual field in 2 and ptosis in 3. Aneurysm location was IC cavernous in 3, IC ophthalmic in 3, ICPC in 1 and Acom in 1. Aneurysms of more than 25 mm numbered 6 cases.

RESULTS

Operative methods and results were as follows: Direct clipping 3 cases, parent artery occlusion + EC/IC bypass 4 cases, Aneurysm trapping + EC/IC bypass 1 case. One patient who underwent direct clipping died following intraoperative complication. Of the remaining 7 cases, visual symptoms were improved in 4, remained unchanged in 2 cases, worsened in 1 case.

CONCLUSIONS

These results suggest that in cases with unruptured large or giant aneurysms presenting with ophthalmic symptoms, especially in IC cavernous or IC ophthalmic aneurysms, parent artery occlusion + EC/IC bypass is the safest operative procedure.

Gene expression profiles in Ciona intestinalis tailbud embryos

A set of 3423 expressed sequence tags derived from the Ciona intestinalis tailbud embryos was categorized into 1213 independent clusters. When compared with DNA Data Bank of Japan database, 502 clusters of them showed significant matches to reported proteins with distinct function, whereas 184 lacked sufficient information to be categorized (including reported proteins with undefined function) and 527 had no significant similarities to known proteins. Sequence similarity analyses of the 502 clusters in relation to the biosynthetic function, as well as the structure of the message population at this stage, demonstrated that 390 of them were associated with functions that many kinds of cells use, 85 with cell-cell communication and 27 with transcription factors and other gene regulatory proteins. All of the 1213 clusters were subjected to whole-mount in situ hybridization to analyze the gene expression profiles at this stage. A total of 387 clusters showed expression specific to a certain tissue or organ; 149 showed epidermis-specific expression; 34 were specific to the nervous system; 29 to endoderm; 112 to mesenchyme; 32 to notochord; and 31 to muscle. Many genes were also specifically expressed in multiple tissues. The study also highlighted characteristic gene expression profiles dependent on the tissues. In addition, several genes showed intriguing expression patterns that have not been reported previously; for example, four genes were expressed specifically in the nerve cord cells and one gene was expressed only in the posterior part of muscle cells.

This study provides molecular markers for each of the tissues and/or organs that constitutes the Ciona tailbud embryo. The sequence information will also be used for further genome scientific approach to explore molecular mechanisms involved in the formation of one of the most primitive chordate body plans.

[A case of anaplastic astrocytoma arising 8 years after initial treatment by partial resection and irradiation for central neurocytoma]

A 31-year-old female developed the anaplastic astrocytoma in the right basal ganglia and temporal lobe 8 years after partial resection and irradiation of the central neurocytoma. Probably the malignant astrocytoma was an irradiation-induced tumor. Postoperative radiation therapy for the central neurocytoma appears to have a good effect on tumor local control. But it should be carefully decided whether to use radiation therapy for residual tumor because of the risk of delayed complications of irradiation, such as the present case.

Brachyury (T) gene expression and notochord development in Oikopleura longicauda (Appendicularia, Urochordata)

Appendicularia (Larvacea) is a subgroup of Urochordata (Tunicata) comprised of holoplanktonic organisms that retain their tailed architecture throughout their life history, while other tunicates, including ascidians and doliolids, resorb the tail after metamorphosis. In order to investigate the characteristics of the appendicularian unresorbed notochord, we isolated a partial genomic clone and a full-length cDNA sequence homologous to the mouse Brachyury (T) gene from the appendicularian Oikopleura longicauda. Brachyury is known to be predominantly expressed in the notochord cells and plays an important role in their differentiation in other chordates. While phylogenetic analysis robustly supports the orthology of the isolated Brachyury gene, the exon-intron organization found in the genomic clone was distinct from that well-conserved among other T-box genes. In addition to a detailed observation of notochord development in living specimens, whole-mount double in situ hybridization was carried out using a Brachyury probe along with a muscle actin probe. The Brachyury transcripts were found in the notochord of the tailbud embryos and persisted into later stages. The present study highlights characteristics of notochord development in the appendicularian. Furthermore, these results provide basic knowledge for comprehensive understanding of the cellular- and molecular-based mechanisms needed to build the characteristic cytoarchitecture of notochord that varies among tunicate species.