Extreme low pH, not Al3+ , is a key abiotic stressor for the extremophyte Carex angustisquama (Cyperaceae) in highly acidic solfatara fields

Volcanic acidification creates extreme soil conditions, where rhizotoxicity from extremely low pH (2-3) and high Al³⁺ strongly inhibit plant growth. C. angustisquama is a dominant extremophyte in highly acidic solfatara fields, where no other vascular plants can survive. Here we investigated the key abiotic stressor determining survival of this extremophyte. Soil analyses and topographic surveys were conducted to examine the effects of low pH and Al³⁺ , two major abiotic stressors in acidic soils, on the occurrence of C. angustisquama in solfatara fields. Hydroponic culture experiments were also performed to test its growth responses to these stressors. In field surveys, the spatial distribution of soil pH was consistent with vegetation zonation within a solfatara field. In contrast, soil exchangeable Al content was overall low due to strong eluviation. Statistical analysis also supported the significant role of soil pH in determining the distribution of C. angustisquama in a solfatara field. Furthermore, hydroponic culture experiments revealed a higher tolerance of C. angustisquama to low pH than a sister species, especially in the range pH 2-3, corresponding to the pH values of the actual habitats of C. angustisquama. Conversely, no significant interspecific difference was detected in Al³⁺ tolerance, indicating that both species had high Al³⁺ tolerance. This study suggests that low pH is a critical abiotic stressor leading to formation of the extremophyte in highly acidic solfatara fields. In contrast, C. angustisquama displayed high tolerance to Al³⁺ toxicity, probably acquired prior to speciation.

Sequentially addressable dielectrophoretic array for high-throughput sorting of large-volume biological compartments

Droplet microfluidics has become a powerful tool in precision medicine, green biotechnology, and cell therapy for single-cell analysis and selection by virtue of its ability to effectively confine cells. However, there remains a fundamental trade-off between droplet volume and sorting throughput, limiting the advantages of droplet microfluidics to small droplets (<10 pl) that are incompatible with long-term maintenance and growth of most cells. We present a sequentially addressable dielectrophoretic array (SADA) sorter to overcome this problem. The SADA sorter uses an on-chip array of electrodes activated and deactivated in a sequence synchronized to the speed and position of a passing target droplet to deliver an accumulated dielectrophoretic force and gently pull it in the direction of sorting in a high-speed flow. We use it to demonstrate large-droplet sorting with ~20-fold higher throughputs than conventional techniques and apply it to long-term single-cell analysis of Saccharomyces cerevisiae based on their growth rate.

C5a Induces Tissue Factor Activity on Endothelial Cells

Tissue factor (TF) is an integral membrane glycoprotein that serves as a cofactor for blood coagulation factor VIIa. The induction of TF on the surface of endothelial cells is initiated by various stimuli including lipopolysaccharide, interleukin-1β, and tumor necrosis factor α. We have demonstrated that recombinant human C5a induces TF activity in a dose-dependent fashion in human umbilical vein endothelial cells (HUVEC). Peak activity (4.9-fold increase) was obtained 3-6 h after treatment with 10 μM C5a. TF mRNA as assessed by RT-PCR method was also significantly increased (3.75-fold) after 3 h incubation with C5a, suggesting that C5a induces TF activity on HUVEC, at least in part, by enhancing the level of TF mRNA. The increase in TF activity by C5a was inhibited by methylprednisolone. The induction of TF on endothelial cells by C5a may represent one of many potential interrelationships between the inflammatory and coagulation schemes.

Beneficial use of serum ferritin and heme oxygenase-1 as biomarkers in adult-onset Still's disease: A multicenter retrospective study

BACKGROUND

Heme oxygenase (HO)-1 is a heme-degrading enzyme highly expressed in monocyte/macrophage, serum levels of which may be promising biomarker for adult-onset Still's disease (AOSD). We here report data on the use of serum ferritin and HO-1 levels in AOSD.

METHODS

Under the Hypercytokinemia Study Group collaboration, we collected sera from a total of 145 AOSD patients. Three independent experts judged whether the patients were definite AOSD depending on the clinical information. These 91 'definite AOSD' patients were further divided into active, remission, and relapse groups. Forty-six cases of systemic vasculitis, sepsis, etc. were included as disease controls. Serum ferritin and HO-1 levels were measured using ELISA. Associations between clinical symptoms, serum ferritin, and HO-1 were explored. Multivariate regression analysis was performed to identify independent variables associated with definite AOSD diagnosis.

RESULTS

Serum ferritin and HO-1 levels were significantly higher in active and relapsed AOSD cases compared to disease controls, and were reduced by the treatment. Although a significant correlation was found between serum ferritin and HO-1 levels, a discrepancy was found in some cases such as iron-deficiency anemia. Receiver operating characteristic analysis identified optimal levels of serum ferritin (>819 ng/ml; sensitivity 76.1% and specificity 73.8%), and serum HO-1 (>30.2 ng/ml; sensitivity 84.8% and specificity 83.3%) that differentiated AOSD from controls. Interestingly, 88.9% of patients with AOSD who relapsed exceeded the cut-off value of serum HO-1 > 30.2 ng/ml, but only 50.0% exceeded serum ferritin >819 ng/ml (p = .013), suggesting that serum HO-1 levels may be a convenient indicator of AOSD disease status. Multivariate analysis identified neutrophilia, RF/ANA negativity, sore throat, and elevated serum HO-1 as independent variables associated with AOSD diagnosis.

CONCLUSION

We confirmed that serum ferritin and HO-1 serve as highly specific and sensitive biomarkers for AOSD. A future prospective study with large sample size is necessary to determine whether these biomarkers could be included in Yamaguchi's Criteria.

Highly purified eicosapentaenoic acid ameliorates cardiac injury and adipose tissue inflammation in a rat model of metabolic syndrome

INTRODUCTION

n-3 Polyunsaturated fatty acids such as eicosapentaenoic acid (EPA), which are abundant in fish oil, have been shown to delay the onset of cardiovascular events. We previously established DahlS.Z-Lepr^fa/Lepr^fa (DS/obese) rats, which are derived from a cross between Dahl salt-sensitive and Zucker rats, as a model of metabolic syndrome. This study has now explored the influence of highly purified EPA on cardiac and adipose tissue pathophysiology in this animal model.

MATERIALS AND METHODS

DS/obese rats were administered EPA (300 or 1,000 mg kg^-1 d^-1, per os) or vehicle from age 9 to 13 weeks. Homozygous lean (DahlS.Z-Lepr⁺/Lepr⁺, or DS/lean) littermates were studied as controls.

RESULTS

Whereas EPA had no effect on body weight, food intake or systolic blood pressure in DS/obese rats, it attenuated cardiac fibrosis, diastolic dysfunction, oxidative stress and inflammation in these animals. In addition, EPA did not affect insulin resistance but reduced adipocyte hypertrophy and inflammation in visceral fat of DS/obese rats. Moreover, EPA increased circulating levels of adiponectin as well as attenuated both the down-regulation of AMP-activated protein kinase phosphorylation and the up-regulation of phosphorylation of the p65 subunit of nuclear factor-kB in the heart of DS/obese rats.

CONCLUSIONS

Treatment of DS/obese rats with EPA did not affect hypertension but reduced cardiac fibrosis and diastolic dysfunction, with the latter effects being accompanied by AMP-activated protein kinase activation and inactivation of nuclear factor-kB signalling in the heart, possibly as a result of an increase in adiponectin secretion. EPA may be suitable for the treatment of cardiac injury associated with metabolic syndrome.

Prevention of steroid-induced osteonecrosis of femoral head in systemic lupus erythematosus by anti-coagulant

Although osteonecrosis of femoral head (ONF) is one of the serious complications in systemic lupus erythematosus (SLE) associated with corticosteroid therapy, there has been few trials of prevention of ONF described. We aimed to prevent ONF in steroid-treated SLE patients using anticoagulant, warfarin, conducting a multicenter prospective study. Sixty newly diagnosed SLE patients requiring 40 mg/day or more prednisolone were alternately assigned to either of two groups; a warfarin group and a control one. Warfarin (1 ∼ 5 mg/day) was started together with the beginning of steroid therapy and continued at least for three months. Patients were observed for the development of silent ONF by magnetic resonance imaging (MRI) and symptomatic ONF by plain radiography for over five years. The warfarin group consisted of 31 patients (62 hips) and the control one 29 patients (58 hips). Silent ONF developed in 13 hips (21%) and 19 hips (33%) in the warfarin group and the control group, respectively ( P = 0.13). On the other hand, warfarin tended to prevent symptomatic ONF; only three hips of 62 (4.8%) in the warfarin group and eight hips of 58 (14%) in the control group ( P = 0.08) developed silent ONF. It was also found that silent ONF developed, if it did, very early; within three months in 16 of 18 patients (89%). Among risk factors for silent ONF, steroid pulse therapy was most outstanding and it seemed to overcome the effect of warfarin. Taken together, for the time being, anticoagulant therapy, if not significantly sufficient, may be of use for the prevention of steroid-induced ONF in SLE. We consider that this study added to important evidence for the pathogenesis and prevention of ONF.

Very early development of steroid-associated osteonecrosis of femoral head in systemic lupus erythematosus: prospective study by MRI

The objective of this study was to define prospectively the early development of corticosteroid-induced osteonecrosis of femoral head (ONF) in patients with systemic lupus erythematosus (SLE) and to identify the association of initial steroid treatment with the development of early (silent) ONF. Forty-five patients who were newly diagnosed as having SLE and required 40 mg/day or more prednisolone were enrolled. To detect silent ONF, examinations using magnetic resonance imaging (MRI) were done three months after starting steroid therapy, followed by every year’s MRI and plain radiography for over five years. Clinical and laboratory data were compared between silent ONF and non-ONF groups. Of 45 patients, 15 (33%) developed silent ONF and five (11%) symptomatic ONF. It was of interest that MRI detected silent ONF very early (by three months) in 14 patients (93%). It should be noted that pulse therapy with 1000 mg/day methylprednisolone was found to be done very frequently (13 of 15, 87%) in the silent ONF group compared to non-ONF group (11 of 30, 37%) (P, 0.01) although other clinical features were not significantly different between both groups. High dose corticosteroids caused elevation of serum levels of total cholesterol, albumin, and leukocyte count in most of patients. The degree of elevation of those parameters at one or three months was more prominent in the silent ONF group. In particular, the change ratio of total cholesterol at one month was outstanding in the silent ONF group compared to non-ONF group (0.551 versus 0.374, P, 0.05). In conclusion, pathological ONF develops very early in one-third of SLE patients who received high dose corticosteroids and steroid pulse therapy could be a significant risk factor. An abrupt elevation of serum total cholesterol and/or sensitivity to steroids seem to be associated with the pathogenesis of ONF.

Attenuation of cold stress-induced exacerbation of cardiac and adipose tissue pathology and metabolic disorders in a rat model of metabolic syndrome by the glucocorticoid receptor antagonist RU486

OBJECTIVES

Chronic stress affects the central nervous system as well as endocrine, metabolic and immune systems. However, the effects of cold stress on cardiovascular and metabolic disorders in metabolic syndrome (MetS) have remained unclear. We recently characterized DahlS.Z-Lepr(fa)/Lepr(fa) (DS/obese) rats, derived from a cross between Dahl salt-sensitive and Zucker rats, as a new animal model of MetS. We have now investigated the effects of chronic cold stress and glucocorticoid receptor (GR) blockade on cardiac and adipose tissue pathology as well as on metabolic parameters in this model.

METHODS

DS/obese rats were exposed to cold stress (immersion in ice-cold water to a depth of 1-2 cm for 2 h per day) with or without subcutaneous injection of the GR antagonist RU486 (2 mg kg(-1)day(-1)) for 4 weeks beginning at 9 weeks of age. Age-matched homozygous lean (DahlS.Z-Lepr(+)/Lepr(+)) littermates served as a control.

RESULTS

Chronic cold stress exacerbated hypertension as well as left ventricular (LV) hypertrophy, fibrosis and diastolic dysfunction in DS/obese rats in a manner sensitive to RU486 treatment. Cold stress with or without RU486 did not affect body weight or fat mass. In contrast, cold stress further increased cardiac oxidative stress as well as macrophage infiltration and proinflammatory gene expression in LV and visceral fat tissue, with all of these effects being attenuated by RU486. Cold stress also further increased GR and 11β-hydroxysteroid dehydrogenase type 1 mRNA and protein abundance in LV and visceral adipose tissue, and these effects were again inhibited by RU486. In addition, RU486 ameliorated the stress-induced aggravation of dyslipidemia, glucose intolerance and insulin resistance in DS/obese rats.

CONCLUSIONS

Our results implicate GR signaling in cold stress-induced exacerbation of cardiac and adipose tissue pathology as well as of abnormal glucose and lipid metabolism in a rat model of MetS.

Expression level of P2X7 receptor is a determinant of ATP-induced death of mouse cultured neurons

Activation of P2X7 receptor (P2X7R), a purinergic receptor, expressed by neurons is well-known to induce their death, but whether or not their sensitivity to ATP depends on its expression levels remains unclear. Here, we examined the effect of the expression level of P2X7Rs on cell viability using pure neuron cultures, co-cultures with astrocytes derived from SJL- and ddY-strain mice, and mouse P2X7R-expressing HEK293T cell systems. Treatment of pure neuron cultures with 5mM ATP for 2h, followed by 3-h incubation in fresh medium, resulted in death of both types of neurons, and their death was prevented by administration of P2X7R-specific antagonists. In both SJL- and ddY-neurons, ATP-induced neuronal death was inhibited by a mitochondrial permeability transition pore inhibitor cyclosporine A, mitochondrial dysfunction being involved in their death. The ATP-induced neuronal death was greater for SJL-neurons than for ddY-ones, this being correlated with the expression level of P2X7R in them, and the same results were obtained for the HEK293T cell systems. Co-culture of neurons with astrocytes increased the ATP-induced neuronal death compared to the case of pure neuron cultures. Overall, we reveal that neuronal vulnerability to ATP depends on the expression level of P2X7R, and co-existence of astrocytes exacerbates ATP-induced neuronal death.

Genetic analyses of GII.17 norovirus strains in diarrheal disease outbreaks from December 2014 to March 2015 in Japan reveal a novel polymerase sequence and amino acid substitutions in the capsid region

A novel GII.P17-GII.17 variant norovirus emerged as a major cause of norovirus outbreaks from December 2014 to March 2015 in Japan. Named Hu/GII/JP/2014/GII.P17-GII.17, this variant has a newly identified GII.P17 type RNA-dependent RNA polymerase, while the capsid sequence displays amino acid substitutions around histo-blood group antigen (HBGA) binding sites. Several variants caused by mutations in the capsid region have previously been observed in the GII.4 genotype. Monitoring the GII.17 variant's geographical spread and evolution is important.

Positive association of free triiodothyronine with pancreatic β-cell function in people with prediabetes

AIM

To analyse the effects of thyroid hormones on β-cell function and glucose metabolism in people with prediabetes who are euthyroid.

METHODS

A total of 111 people who were euthyroid underwent 75-g oral glucose tolerance tests, of whom 52 were assigned to the normal glucose tolerance and 59 to the prediabetes groups. Homeostatic model assessment of β-cell function, insulinogenic index and areas under the curve for insulin and glucose were evaluated as indices of pancreatic β-cell function.

RESULTS

In both groups, BMI, fasting insulin, homeostasis model assessment ratio and HDL cholesterol correlated significantly with all indices of pancreatic β-cell function. Free triiodothyronine correlated positively with all insulin secretion indices in the prediabetes group. Multiple linear regression analysis showed that free triiodothyronine was an independent variable that had a positive correlation with all indices of β-cell function in the prediabetes group. By contrast, no such correlation was found in the normal glucose tolerance group.

CONCLUSIONS

Free triiodothyronine is associated with both basal and glucose-stimulated insulin secretion in people with prediabetes who are euthyroid; therefore, the regulation of insulin secretion by thyroid hormones is a potentially novel therapeutic target for the treatment of diabetes.

Flexor tenosynovitis of the hands as an initial manifestation of systemic lupus erythematosus

Abstract We describe a patient who presented with flexion contractures of the bilateral fingers due to tenosynovitis of the flexor digitorum tendons as an initial manifestation of systemic lupus erythematosus (SLE). A 17-year-old woman had abrupt onset of diffuse swelling and flexion contractures in the bilateral fingers, accompanied by polyarthritis and cervical lymphadenopathy. Magnetic resonance imaging (MRI) showed flexor tenosynovitis of the hands. A diagnosis of SLE was made by immunological and hematological tests, and treatment with oral corticosteroids resulted in a rapid and complete disappearance of the flexion contractures.

Interferon regulatory factor 5 is critical for the development of lupus in MRL/lpr mice

OBJECTIVE

Interferon regulatory factor 5 (IRF-5) is a transcription factor that mediates intracellular signals activated by engagement of Toll-like receptors (TLRs). IRF5 polymorphisms are associated with an increased or decreased risk of systemic lupus erythematosus (SLE) in various human populations, but the precise role of IRF5 in SLE development is not fully understood. This study was undertaken to examine the role of IRF5 in the development of murine lupus.

METHODS

We crossed gene-targeted IRF5-deficient (IRF5(-/-) ) mice with MRL/MpJ-lpr/lpr (MRL/lpr) mice and examined the progeny for survival, glomerulonephritis, autoantibody levels, immune system cell populations, and dendritic cell function.

RESULTS

IRF5(-/-) MRL/lpr mice survived longer than control IRF5(+/+) MRL/lpr mice and displayed only very mild glomerulonephritis. Autoantibodies to SLE-related nuclear antigens were lower in IRF5(-/-) MRL/lpr mouse serum, and numbers of activated CD4+ T cells were reduced in the spleen. Splenic DCs from IRF5(-/-) MRL/lpr mice produced lower levels of inflammatory cytokines when treated in vitro with TLR-7 or TLR-9 ligands or immune complexes. Interferon-α production in response to CpG was also decreased.

CONCLUSION

Our results show that IRF5 is a crucial driver of lupus development in mice, and indicate that IRF5 may be an attractive new target for therapeutic intervention to control disease in SLE patients.

Expression of vasa and nanos3 during primordial germ cell formation and migration in Atlantic cod (Gadus morhua L.)

Primordial germ cells (PGCs), progenitors of gametes, are specified very early in embryonic development and undergo an active migration to the site where the future gonads will form. While the developmental pattern of PGCs during embryogenesis has been documented in few model teleost fishes, there is currently no information available for any representative of Superorder Paracanthopterygii. This includes Atlantic cod (Gadus morhua), which is a historically important food fish in both fisheries and aquaculture industries. In the present study, we cloned and characterized vasa and nanos3 and used them as germ cell markers in Atlantic cod. Sequencing results showed prospective vasa and nanos3 mRNA contained the domains used to describe their respective protein family. Furthermore, phylogenetic analysis using the amino acid sequence placed Atlantic cod Vasa distinct from representatives of three other taxonomic Superorders. Atlantic cod Nanos3 was placed with other homologues from the Nanos3 subfamily. Expression of both genes was detected from the first cleavage division; both were specifically expressed in Atlantic cod PGCs from the 32-cell stage. While nanos3 expression ceased during early somitogenesis, vasa was strongly expressed throughout embryonic development. Using vasa as a marker, we described the Atlantic cod PGC migration pattern. We demonstrated that Atlantic cod PGCs migrate ventral to the trunk mesoderm. With the exception of Pacific herring (Clupea pallasii), PGCs in other described teleost fishes migrate lateral to the trunk. The results from this study are the first step toward understanding germ line formation in Atlantic cod.

[Case of microscopic polyangiitis and giant cell arteritis after influenza vaccination]

We report a case of microscopic polyangiitis (mPA) and giant cell arteritis (GCA) (polyangiitis overlap syndrome) after influenza vaccination. A 67-year-old female with chronic kidney disease, who had been observed by a physician, presented fever and headache after immunization of influenza vaccine. She was diagnosed as having with mPA and GCA based on symptoms, worsening of renal function, biopsy of temporal artery (giant cell arteritis) and skin (microscopic polyangiitis), pulmonary involvement and the presence of myeloperoxidase-specific anti-neutrophil cytoplasmic antibodies (MPO-ANCA). She was treated with prednisolone (PSL) and the symptoms were improved. However, two months later she was presented with general physical weariness. She was diagnosed as having with pneumocystis pneumonia, cytomegalovirus infection and cryptococcosis. Despite intensive treatment, she was died and autopsy was performed. The present case suggests that the influenza vaccination may cause different types of vasculitis, mPA and GCA, through the common mechanism in pathophysiology. This patient is also the first case of mPA and GCA proven by histological examination.

Functional disturbance of the stress-adaptation system in patients with scleroderma

There have been several reports indicating the association between recent stress experiences and the onset or the exacerbation of rheumatic diseases, although few such reports exist in patients with scleroderma (SSc). The present study was performed to elucidate whether there were any functional disturbances in the neuro-endocrine-immune system as a homeostatic system upon stress in SSc patients. Various serum levels of stress-related hormones and cytokines were examined before and after a mental calculation stress test, and a basal questionnaire study of sense of coherence (SOC, which is related to the ability to cope with stress), recent stress experiences, and quality of life (QOL) was performed in 17 SSc patients and in 38 healthy volunteers. Physical QOL state was impaired in patients, but there were no differences in recent stress experiences and SOC scores between patients and controls. Basal serum cortisol levels were similar in patients and controls, but increased levels of proinflammatory cytokine and noradrenalin were seen in SSc patients. Characteristically, contrary to the control group, whose cortisol levels increased significantly following the mental calculation stress test, no significant increase was observed in the patients when post-test cortisol levels were compared to pre-test levels, suggesting a defect in the normal cortisol response upon stress in SSc patients. The present results suggest that there may be impaired function of the neuro-endocrine-immune system upon stress in SSc patients.

[Influenza virus infection: clinical diagnosis and current considerations]

Point-of-care diagnosis of influenza requires sound recognition of the prevalence of the signs and symptoms of the patients, which would help to define the pattern of clinical presentation of this infection. In severely ill patients, however, clinical features of influenza could be erroneously modified by the exacerbation of co-morbid conditions, resulting in a delay of the diagnosis. Enzymatic rapid diagnostic tests, although establishing the diagnosis with positive result especially when the virus is in high circulation, has relatively poor sensitivity for the 2009 A/H1N1 virus and it varies among the different age groups. Given the likelihood of long-term circulation of the novel H1N1 virus, patients' clinical features and the performance of the rapid tests should continuously be monitored.

[A case of cutaneous Mycobacterium nonchromogenicum infection suggesting sarcoidosis association]

A 67-year-old man clinically diagnosed a year earlier with sarcoidosis based on low-grade fever, lymphadenopathy, trunk skin rash, and histopathological skin tests was admitted for newly developing subcutaneous nodules on the trunk and arms and fever of 38 degrees C. Although initially suspected of recurrent sarcoidosis, he was diagnosed with Mycobacterium chromogenicum infection isolated from skin lesion culture. Combined clarithromycin of 800 mg/day, ethambutol of 750 mg/day, and embiomycin of 0.5 g/day was started, after which fever declined and WBC count and CRP decreased to normal in a week. One month later, skin lesions had disappeared. This case is interesting considering the association of nontuberculous mycobacterial infection with sarcoidosis.

Autoantibody-producing RP105(-) B cells, from patients with systemic lupus erythematosus, showed more preferential expression of BCMA compared with BAFF-R than normal subjects

OBJECTIVE

B cells lacking RP105 produce autoantibodies in patients with SLE. Expression of B-cell activating factor (BAFF) binding receptors (BBRs) and survival of RP105(-) B cells from SLE patients were examined.

METHODS

Detection of difference of gene expression between RP105(-) and RP105(+) B cells was done by DNA microarrays. Surface expression was confirmed by flow cytometry. The contribution of BAFF, a proliferation-inducing ligand (APRIL) and monomers/trimers of sCD40L to survival of RP105(-) and RP105(+) B cells was examined.

RESULTS

Gene expression of B-cell maturation antigen (BCMA) was different among BBRs in RP105(-) and RP105(+) B cells in SLE. Preferential expression of BCMA on RP105(-) B cells was confirmed compared with RP105(+) B cells by flow cytometry, although BAFF receptor (BAFF-R) expression on RP105(-) B cells was significantly lower. Additionally, relative ratios of BCMA/BAFF-R expression on RP105(-) B cells were increased significantly in SLE patients compared with normal subjects. Stimulation by sCD40L decreased the number of surviving RP105(-) and RP105(+) B cells in vitro. RP105(+) B cells were not rescued from sCD40L-induced cell death by BAFF and/or APRIL. In contrast, either BAFF or APRIL maintained the survival of RP105(-) B cells due to avoidance of cell death. Activated RP105(-) B cells reduced BAFF-R and increased BCMA levels.

CONCLUSIONS

RP105(-) B cells from SLE patients showed more preferential expression of BCMA compared with BAFF-R than normal subjects, and were possibly regulated by BAFF/APRIL. Our results provide a new insight of BCMA and their ligands in B cells from SLE patients.

High expression of Toll-like receptor 4 on CD14+ monocytes in acute infectious diseases

Toll-like receptor 4 (TLR4) recognizes lipopolysaccharide (LPS) and other exogenous and endogenous molecules, and is thought to contribute to defense mechanisms against infections. Our objective was to elucidate the clinical significance of TLR4 in acute infectious diseases by analyzing its sequential expression on CD14+ monocytes. Peripheral blood samples were obtained from 36 patients with acute infectious diseases on admission and after treatment within certain intervals. The TLR4 expression on CD14+ monocytes was analyzed using flow cytometry and was presented as a mean fluorescence intensity (MFI). TLR4 expression during the acute phase of infection was highly enhanced compared to that of normal subjects (MFI: 22.1 vs 8.5). TLR4 expression was promptly reduced to normal levels in parallel with the disease improvement. In patients who died despite treatment, the enhancement of TLR4 expression during the acute phase was less prominent compared to those who survived (MFI: 14.6 vs 23.5) and its sequential change was also subtle. These results indicate that monocytes respond to acute infections by the induction of TLR4 expression and that a poor response may be associated with a poor prognosis.

Luminal hydrogen sulfide plays a pronociceptive role in mouse colon

OBJECTIVE

Given recent evidence that hydrogen sulfide (H(2)S), a gasotransmitter, promotes somatic pain through redox modulation of T-type Ca(2+) channels, the roles of colonic luminal H(2)S in visceral nociceptive processing in mice were examined.

METHODS

After intracolonic administration of NaHS, an H(2)S donor, visceral pain-like behaviour and referred abdominal allodynia/hyperalgesia were evaluated. Phosphorylation of extracellular signal-regulated protein kinase (ERK) in the spinal dorsal horn was determined immunohistochemically. The whole-cell recording technique was used to evaluate T-type Ca(2+) currents (T-currents) in cultured dorsal root ganglion (DRG) neurons.

RESULTS

Like capsaicin, NaHS, administered intracolonically at 0.5-5 nmol per mouse, triggered visceral nociceptive behaviour accompanied by referred allodynia/hyperalgesia in mice. Phosphorylation of ERK in the spinal dorsal horn was detected following intracolonic NaHS or capsaicin. The behavioural effects of intracolonic NaHS were abolished by a T-type channel blocker or an oxidant, but not inhibitors of L-type Ca(2+) channels or ATP-sensitive K(+) (K(ATP)) channels. Intraperitoneal NaHS at 60 micromol/kg facilitated intracolonic capsaicin-evoked visceral nociception, an effect abolished by the T-type channel blocker, although it alone produced no behavioural effect. In DRG neurons, T-currents were enhanced by NaHS.

CONCLUSIONS

These findings suggest that colonic luminal H(2)S/NaHS plays pronociceptive roles, and imply that the underlying mechanisms might involve sensitisation/activation of T-type channels probably in the primary afferents, aside from the issue of the selectivity of mibefradil.

Effect of disease activity and corticosteroids on serum levels of soluble endothelial cell protein C receptor in patients with systemic lupus erythematosus

To assess the effects of disease activity of systemic lupus erythematosus (SLE) and high-dose corticosteroids on endothelial injuries, the significance of soluble endothelial cell protein C receptor (sEPCR) and soluble thrombomodulin (sTM) was analyzed. Serum levels of sEPCR and sTM were measured by enzyme-linked immunosorbent assay (ELISA) cross-sectionally in 97 SLE patients, 49 patients with other rheumatic diseases and 22 normal subjects. The changes in these levels upon corticosteroid treatment were also analyzed in 41 patients. The levels of sEPCR and sTM were both higher in SLE and other rheumatic disease patients than in normal subjects. When low-dose corticosteroids were used, both the level of sEPCR and the ratio of positive tests for sEPCR were significantly higher in active SLE patients than in inactive patients [median 2.30 ng/ml (range 0.00-147.10 ng/ml) vs 0.00 ng/ml (0.00-58.90 ng/ml) and 53.5 vs 13.0%, respectively] (P < 0.005). Moreover, the ratio of positive tests for sEPCR was higher after corticosteroid treatment in 9 of 19 (47.3%) SLE patients compared to other rheumatic diseases (3/22; 13.6%). Although the mean level of sTM was significantly higher in active SLE patients than in inactive patients, the ratio of positive tests for sTM was not affected by disease activity or corticosteroids. In conclusion, the positive test for sEPCR is a more sensitive biomarker than that for sTM in reflecting endothelial injuries caused by active disease and often by corticosteroids in SLE.

Toll-like receptor homolog RP105 modulates the antigen-presenting cell function and regulates the development of collagen-induced arthritis

Introduction

RP105 is a Toll-like receptor homolog expressed on B cells, dendritic cells (DCs), and macrophages. We investigated the role of RP105 in the development of collagen-induced arthritis (CIA).

Methods

CIA was induced in RP105-deficient DBA/1 mice and the incidence and arthritis index were analyzed. The cytokine production by spleen cells was determined. The functions of the DCs and regulatory T cells (Tregs) from RP105-deficient or control mice were determined by adding these cells to the lymph node cell culture. Arthritis was also induced by incomplete Freund's adjuvant (IFA) plus collagen or by injecting anti-collagen antibody and lipopolysaccharide.

Results

RP105-deficient mice showed accelerated onset of arthritis and increased severity. Interferon-gamma (IFN-γ) and tumor necrosis factor-alpha production by spleen cells from RP105-deficient mice was increased in comparison with that from wild-type mice. The DCs from RP105-deficient mice induced more IFN-γ production, whereas Tregs from those mice showed less inhibitory effect against IFN-γ production. RP105-deficient mice also showed more severe arthritis induced by collagen with IFA.

Conclusions

These results indicate that RP105 regulates the antigen-presenting cell function and Treg development, which induced the attenuation of the cell-mediated immune responses and, as a result, suppressed the development of CIA.

A dose-escalation study of rituximab for treatment of systemic lupus erythematosus and Evans' syndrome: immunological analysis of B cells, T cells and cytokines

OBJECTIVE

Accumulating evidence suggests that B-cell depletion therapy by rituximab may be effective for autoimmune disorders. However, an optimal dose of rituximab and a mechanism of its action remain to be established. We performed a dose-escalation study for treatment of Japanese patients with autoimmune diseases including eight with SLE and one with Evans' syndrome.

METHODS

Rituximab was infused intravenously, weekly 4 times in a dose-escalating fashion at three different doses of 100, 250 or 375 mg/m(2) to three patients each. Immunological parameters were monitored at certain points until 12 months after the treatment.

RESULTS

Rituximab was well tolerated and safe in these patients. Seven out of eight SLE patients and one with Evans' syndrome clinically responded completely or partially to the treatment. Four patients achieved long-term remission (18-30 months) without any additional treatment. In these patients, a significant decrease in circulating B cells continued for 6 months after the treatment. The mean fluorescence intensities of CD19, CD21, CD40 and BR3 on the residual B cells as well as the percentage of CD69+ CD4+ T cells decreased significantly. Serum TNF-alpha levels decreased significantly on day 2. The Th1/Th2 balance of CD4+ T cells gradually shifted towards a Th1 type by 6 months.

CONCLUSION

In addition to B-cell depletion, modification of B-cell and T-cell phenotypes as well as cytokine profiles may be involved in the action of rituximab.

High-resolution computed tomography characterization of interstitial lung diseases in polymyositis/dermatomyositis

OBJECTIVE

Interstitial lung disease (ILD) associated with polymyositis (PM) and dermatomyositis (DM) sometimes progresses rapidly and is resistant to therapy. Clinical features that forecast the prognosis of the disease remain to be elucidated. Our aim was to assess if selected clinical features and high-resolution computed tomography (HRCT) findings can assist in predicting the clinical course of ILD in PM/DM.

METHODS

We examined HRCT findings retrospectively for ILD identified in 17 patients with PM and 16 with DM. Radiological patterns and clinical features are analyzed in comparison with clinical course.

RESULTS

Mortality rates were 12% and 44% for ILD associated with PM and DM, respectively. Most patients with DM died of rapidly progressive lung deterioration. No patient in the PM group died of respiratory failure. In the DM group, all patients with fatal ILD had ground-glass attenuation and reticular opacity as the principal radiological findings. Consolidation was recognized frequently as the principal pattern in nonfatal cases. Radiological patterns were categorized into 3 groups; A: consolidation dominant, B: ground-glass attenuation/reticular opacity dominant without chronic fibrosing process, and C: ground-glass attenuation/reticular opacity dominant with chronic fibrosing process. Occurrences of fatal disease were 0%, 83%, and 20%, in groups A, B, and C.

CONCLUSION

The prognosis of ILD associated with DM differs from that with PM. The former can be classified into 3 subgroups on the basis of radiological findings, which are closely associated with clinical course.

Increase of RP105-lacking activated B cells in the peripheral blood and salivary glands in patients with Sjögren's syndrome

OBJECTIVE

To quantify the activated B cells in the peripheral blood and salivary glands of patients with Sjögren's syndrome (SS) by analyzing the expression of RP105 molecule on the B cells.

METHODS

The expression of RP105 on the peripheral blood B cells of patients with SS (19 cases) was analyzed by flow cytometry. RP105-positive and negative B cells were sorted and cultured in vitro and the amount of immunoglobulins (IgG and IgM) produced in the supernatant was measured by enzyme-linked immunosorbent assay (ELISA). Salivary gland biopsy samples from 9 SS patients were histologically evaluated and the sequential frozen sections were separately immunostained by anti-RP105 and anti-CD20 monoclonal antibodies.

RESULTS

A significantly higher proportion of peripheral blood RP105-negative B cells was found in SS patients than in healthy individuals. RP105-negative, but not positive, B cells from SS patients were capable of producing IgG and IgM spontaneously in vitro, which was enhanced by the addition of Staphylococcus aureus Cowan I strain (SAC) or IL-6. Salivary glands from 2 of 9 SS patients were found to have lymphoid follicles whose germinal centers consisted of RP105-negative B cells. Moreover, a larger proportion of B cells extensively infiltrating the area other than lymphoid follicles was also RP105-negative.

CONCLUSION

RP105-negative B cells, a subset of highly activated and well differentiated B cells, which are increased in number in the peripheral blood and extensively infiltrate salivary glands, may be responsible for the production of class-switched immunoglobulin in SS. In addition, those cells might be associated with the inflammation and tissue damage of the salivary glands.

Reflux esophagitis and Helicobacter pylori infection in patients with scleroderma

OBJECTIVE

This study aimed to evaluate the possible effects of Helicobacter pylori (H. pylori) infection in reflux esophagitis with scleroderma.

PATIENTS AND METHODS

There were a total of 138 patients with scleroderma in our hospital between October 1998 and June 2005. Among these patients, 64 consecutive patients of scleroderma, who did not receive medication for gastrointestinal diseases, underwent endoscopy after informed consent. H. pylori was examined using an H. pylori IgG ELISA. The endoscopists graded esophageal mucosal breaks according to the Los Angeles Classification of Esophagitis.

RESULTS

Among the 64 patients, 37 patients (57.8%) were positive for H. pylori infection. Reflux esophagitis was observed in 10 of 37 H. pylori-positive patients and in 19 of 27 H. pylori-negative patients. Significantly fewer H. pylori-infected patients had reflux esophagitis than H. pylori-negative patients (p<0.01). The odds ratio for H. pylori infection and reflux esophagitis was 0.16 (95%CI; 0.052-0.47).

CONCLUSION

These findings suggest an important role for H. pylori infection in reflux esophagitis with scleroderma.