Evaluation of anti-ribosomal P protein immunoassay in Japanese patients with connective tissue diseases: comparison with an indirect immunofluorescence assay

OBJECTIVES

To investigate the prevalence of anti-ribosomal P protein (anti-P) antibodies in Japanese patients with connective tissue diseases (CTDs) using enzyme-linked immunosorbent assays (ELISAs) and western blotting (WB) and to evaluate the indirect immunofluorescence (IIF) staining patterns of anti-P-positive sera.

METHODS

Anti-P antibodies were measured by two different commercially available ELISA kits and WB in 239 outpatients, 99 with systemic sclerosis (SSc), 73 with systemic lupus erythematosus (SLE), 45 with dermatomyositis (DM), and 22 with Sjögren's syndrome (SjS). Sera positive for anti-P antibodies by WB were analysed by IIF.

RESULTS

The frequency of positive WB findings in SLE (18/73, 25%) was higher than in other diseases. ELISA kits A and B for anti-P antibodies showed 21% and 43% sensitivity, and 93% and 88% specificity, respectively, for diagnosing SLE, based on the manufacturer's cut-off values. Receiver operating characteristic (ROC) curve analysis, based on positive WB findings, determined a new cut-off threshold but revealed that both ELISA kits still had good diagnostic characteristics. In IIF assays on anti-P antibody positive sera, typical anti-P antibody cytoplasmic staining patterns (n=8) were seen less frequently than other staining patterns (n=17).

CONCLUSIONS

Routine screening for anti-P antibodies by IIF has low sensitivity. ELISAs using cut-off values established by individual facilities are suitable for detecting anti-P antibodies and provide a tool with good diagnostic characteristics, on a parity with WB.

Effects of lipopolysaccharide on the induction of mixed chimerism in cyclophosphamide-induced tolerance

Cyclophosphamide (CP)-induced tolerance is a mixed chimerism-based tolerance and is one of the strategies used to induce transplant tolerance. Toll-like receptor (TLR) agonists are reportedly able to abrogate the induction of tolerance by activating alloreactive T cells, or by inhibiting Treg cells. However, little is known about the effect of the immune response mediated by TLR on mixed chimerism-based tolerance protocols. In this study, we evaluated the influence of lipopolysaccharide (LPS), which is best known as an TLR4 agonist, on CP-induced tolerance. BALB/c (H-2(d)) mice received a conditioning regimen consisting of 10(8) donor DBA/2 (H-2(d)) spleen cells (SC) on day 0 and 200 mg/kg CP on day 2. A single dose of 20 microg LPS was injected on day -2, 0, 7, or 35. Our results showed that LPS infusion at any time point resulted in chronic rejection of donor skin grafts and the abrogation of mixed chimerism in 33-60% of recipients. We found a correlation between skin graft acceptance and higher levels of mixed chimerism. Flow cytometric analysis revealed that donor-reactive T cells were permanently eliminated, regardless of LPS infusion. In conclusion, LPS-infusion had little influence on the immune response of donor-reactive T cells, but had a significant effect on the induction and maintenance of mixed chimerism in CP-induced tolerance.

Measurement of bottom versus charm as a function of transverse momentum with electron-hadron correlations in p + p collisions at square root of s = 200 GeV

The momentum distribution of electrons from semileptonic decays of charm and bottom quarks for midrapidity |y|<0.35 in p+p collisions at square root of s=200 GeV is measured by the PHENIX experiment at the Relativistic Heavy Ion Collider over the transverse momentum range 2<pT<7 GeV/c. The ratio of the yield of electrons from bottom to that from charm is presented. The ratio is determined using partial D/D-->e(+/-)K(-/+)X (K unidentified) reconstruction. It is found that the yield of electrons from bottom becomes significant above 4 GeV/c in pT. A fixed-order-plus-next-to-leading-log perturbative quantum chromodynamics calculation agrees with the data within the theoretical and experimental uncertainties. The extracted total bottom production cross section at this energy is sigma(bb)=3.2(-1.1)(+1.2)(stat)(-1.3)(+1.4)(syst)mub.

Chronic Cardiovascular Effects of Central Vasopressin in Conscious Rats

To clarify the cardiovascular effects of central vasopressin (AVP), a chronic intracerebroventricular (ICV) infusion of AVP was performed in conscious Wistar normotensive rats. Animals were divided into 3 groups: 1) AVP 1 ng/hr (Low), 2) AVP 100 ng/hr (High), and 3) saline (control) ICV infusion. After a 6 day control period, AVP or saline was continuously infused into the lateral cerebroventricle at a rate of 1 microliter/hr using osmotic minipump for 7 days. As a result, a dose-related elevation of AVP concentration in CSF was achieved. Systolic blood pressure in both Low and High AVP infusion was slightly (7-12 mmHg) but significantly higher than that in control. ICV infusion of AVP did not alter urine volume, electrolytes excretion or osmolality, and AVP vascular antagonist injected intravenously failed to affect mean arterial pressure. Furthermore, plasma catecholamines and renin activity did not differ significantly among the groups. Thus, chronic ICV infusion of AVP induced the elevation of blood pressure, which is due to centrally mediated effect of AVP.

Gluon-spin contribution to the proton spin from the double-helicity asymmetry in inclusive pi0 production in polarized p+p collisions at [sqrt]s=200 GeV

The double helicity asymmetry in neutral pion production for pT=1 to 12 GeV/c was measured with the PHENIX experiment to access the gluon-spin contribution, DeltaG, to the proton spin. Measured asymmetries are consistent with zero, and at a theory scale of micro2=4 GeV2 a next to leading order QCD analysis gives DeltaG[0.02,0.3]=0.2, with a constraint of -0.7<DeltaG[0.02,0.3]<0.5 at Deltachi2=9 (approximately 3sigma) for the sampled gluon momentum fraction (x) range, 0.02 to 0.3. The results are obtained using predictions for the measured asymmetries generated from four representative fits to polarized deep inelastic scattering data. We also consider the dependence of the DeltaG constraint on the choice of the theoretical scale, a dominant uncertainty in these predictions.

A phase II study of S-1 for the treatment of cytokine-refractory metastatic renal cell carcinoma

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Background: S-1 is a novel oral anticancer agent, contains tegafur (FT), a prodrug of 5-fluorouracil (5-FU), with 5-chloro-2,4-dihydroxypyridine (CDHP) and potassium oxonate (Oxo) at a molar ratio of FT: CDHP: Oxo = 1:0.4:1. The purpose of this study was to evaluate the efficacy and safety of S-1 in cytokine-refractory metastatic renal cell carcinoma (mRCC), and to examine the relation between response and mRNA expression levels of 5-FU-related enzymes. Methods: Eligible patients had a histologically confirmed diagnosis of clear cell or papillary type of RCC, measurable lesions, treatment histories with cytokines, an ECOG performance status of 0 or 1 (2 was allowed in patients with bone metastasis), an age of at least 20 years, prior nephrectomy, and adequate organ functions. Any prior treatment for mRCC was discontinued more than 4 weeks before registration. S-1 was administered orally at a dose of 40 mg/m2 twice daily for 28 days, followed by 14 days of rest. The primary endpoint was the objective response rate (ORR) as confirmed by an independent reviewer. The planned sample size was 44 patients. The threshold response rate was defined as 5%, and the expected rate was set at 17.5%. If the lower limit of the 95% CI exceeded the threshold rate (6 of the 44), S-1 was evaluated to be effective. Formalin fixed paraffin embedded specimens, which had been obtained by radical nephrectomy, were used for mRNA expression assay, performed by RT-PCR method. Results: Between April 2006 and May 2007, 45 patients were enrolled, and 31 assay samples were obtained. ORR was 24.4% (11/45, 95% CI: 12.9 - 39.5%). The median PFS was 9.2 months. The median OS could not be calculated, but the survival rate at 1 year was 87.5%. The most common grade 3–4 adverse events assessed according to the CTCAE v.3.0 included anemia (6.7%), neutropenia (8.9%), anorexia (8.9%), hyperglycemia (6.7%), stomatitis (4.4%), diarrhea (4.4%), and fatigue (4.4%). On mRNA expression analysis, the expression level of 5-FU-related enzyme correlated with ORR and PFS. Conclusions: S-1 is effective and well tolerated in patients with cytokine-refractory mRCC. Measurement of the mRNA level of 5-FU-related enzyme in tumors before treatment may facilitate prediction of the response to S-1.

No significant financial relationships to disclose.

An evaluation of the efficacy of the toe brachial index measuring vascular involvement in systemic sclerosis and other connective tissue diseases

OBJECTIVE

The ankle and toe brachial indices (ABI and TBI) are calculated as the ankle and toe systolic blood pressures divided by the highest brachial systolic pressure, respectively. We sought to evaluate the efficacy of ABI and TBI as an objective, non-invasive assessment of vascular involvement in patients with systemic sclerosis (SSc) and to investigate the clinical significance of TBI in SSc.

METHODS

ABI and TBI were measured using an oscillometric method in 136 outpatients, including 77 with SSc, 29 with systemic lupus erythematosus (SLE), 16 with primary Sjögren's syndrome (SjS), and 14 with dermatomyositis (DM). We also analyzed 21 healthy controls.

RESULTS

The mean ABI and frequency of reduced ABI values (%1.0) did not differ significantly between disease groups. TBI values in patients with SSc and lSSc were significantly lower than in those with SjS and DM, respectively (p%0.01). Patients with SSc and lSSc had significantly lower TBI values than healthy controls (p%0.05). Reduced TBI values (%0.6) were significantly more common in patients with SSc, including both dSSc and lSSc, than in those with SLE (p%0.05). Similarly, the frequency of decreased TBI was higher in patients with SSc and dSSc than in those with SjS or healthy controls (p%0.05). Skin ulcers (p=0.041) or overlap with rheumatoid arthritis (p=0.018) were associated with reduced TBI values by logistic regression analysis.

CONCLUSION

The TBI value is a useful, non-invasive tool to evaluate vascular involvement in SSc.

Salivary duct carcinoma of the parotid gland: clinical and MR features in six patients

This study reports the clinical and MR features of salivary duct carcinoma (SDC) of the parotid gland, which is a rare and highly malignant tumour. We assessed retrospectively the clinical and MR features of six patients with histologically proven SDC of the parotid gland. The five men and one woman, ranging in age from 65-71 years (mean, 67 years), had undergone MRI before surgery. All patients presented with parotid masses and four patients had facial paralysis. Two had been aware of the parotid mass for more than 10 years. On MRI, all of the tumours had an ill-defined margin along either the entire circumference or part of the circumference. Four tumours showed infiltration into the subcutaneous or parapharyngeal space. Two tumours showed a wholly solid internal content, and four tumours had varying proportions of cystic content. The signal intensity of the solid portion was low to intermediate on both T(1) weighted and T(2) weighted images. Three patients showed multiple cervical lymph node swellings. Although SDC can show non-specific MRI findings, the combined findings (e.g. low-to-intermediate signal intensities on T(2) weighted images, ill-defined boundaries, infiltration into the surrounding fat space, facial nerve paralysis and associated cervical lymphoadenopathy, seem to suggest a high-grade malignancy.

Onset of pi(0) suppression studied in Cu+Cu collisions at sqrt S NN=22.4, 62.4, and 200 GeV

Neutral pion transverse momentum (p(T)) spectra at midrapidity (|y| less than or approximately 0.35) were measured in Cu+Cu collisions at sqrt[s(NN)]=22.4, 62.4, and 200 GeV. Relative to pi_(0) yields in p+p collisions scaled by the number of inelastic nucleon-nucleon collisions (N(coll) the pi_(0) yields for p(T) more than or approximately 2 GeV/c in central Cu+Cu collisions are suppressed at 62.4 and 200 GeV whereas an enhancement is observed at 22.4 GeV. A comparison with a jet-quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.

Identification of mutations in the pigment cell-specific gene located at the brown locus in mouse

The pigment cell-specific gene, located at the brown (b)-locus in mouse, encodes the protein that determines the type of melanin synthesized. This protein is known as tyrosinase-related protein, but here we tentatively term it b-locus protein to avoid confusions with the related sequence cross-hybridizing to the tyrosinase gene. In order to identify the mutation at the b-locus, we have cloned and characterized the b-locus protein gene of BALB/c mouse (b/b, c/c). The gene is about 18 kb long and organized into 8 exons and 7 introns. Sequence analysis of the b-locus protein gene reveals four base changes within the protein-coding regions: two missense mutations and two silent mutations. Two missense mutations result in the Cys to Tyr substitution at position 86 (codon 110) and the Arg to His substitution at position 302 (codon 326) of a b-locus protein molecule. Using allele-specific amplification, we confirmed that these missense mutations are actually present in the genomic DNA of two b-mutant strains examined, BALB/c and DBA/2 (b/b, C/C) mice, suggesting that these mutations are specific for the mutant mice at the b-locus. Moreover, we are able to show that the b-locus protein containing Tyr 86 is not reactive with the anti-b-locus protein monoclonal antibody, TMH-1, in transient expression assays.

Molecular bases of tyrosinase-negative oculocutaneous albinism: a single base insertion or a missense point mutation in the tyrosinase gene

We have identified two different mutations in the tyrosinase genes of Japanese patients with tyrosinase-negative oculocutaneous albinism (OCA). One is a single base insertion in the exon 2 of the tyrosinase gene that shifts the reading frame and introduces a premature termination codon (TGA) after the amino acid residue 298 (codon 316). The other is a G to A transition at residue 312, leading to a single amino acid substitution, arginine at position 59 (codon 77) to glutamine. The promoter activity of the patients' tyrosinase genes was evaluated in the cell-free transcription system prepared from pigmented melanoma cells, indicating that the patients' genes were accurately transcribed in vitro. It is therefore conceivable that the tyrosinase gene is expressed in their melanocytes. Furthermore, transient expression of the mutated genes indicates that the truncated tyrosinase or the tyrosinase containing glutamine 59 is unable to form melanin in melanocytes. We therefore propose that these mutations in the tyrosinase genes lead to a phenotype of tyrosinase-negative OCA.

High concomitance of disease marker autoantibodies in anti-DFS70/LEDGF autoantibody-positive patients with autoimmune rheumatic disease

Autoantibodies against dense fine speckles 70 (DFS70) are found in 10% of healthy individuals, but only in a tiny population of patients with autoimmune rheumatic disease. The antibody may thus be a marker of autoimmune rheumatic disease negativity. To investigate this possibility, we examined the presence of various disease-marker autoantibodies in anti-DFS70 antibody-positive patients with autoimmune rheumatic disease. Serum samples from 500 patients with various types of autoimmune rheumatic disease were examined for anti-DFS70 antibodies by indirect immunofluorescence and immunoblotting. Various disease-marker autoantibodies were measured by enzyme-linked immunosorbent assay. Twenty-two patients were positive for anti-DFS70 antibodies. Eighteen patients also had disease-marker autoantibodies including anti-double stranded DNA, anti-cardiolipin, anti-SS-A, or other antibodies. In one patient with Sjögren syndrome and two patients with dermatomyositis, no disease-marker antibodies were found; however, one patient with dermatomyositis had a concomitant anti-cytoplasmic antibody. All seven systemic lupus erythematosus patients fulfilled the classification criteria for this disease even if anti-nuclear antibody-positive findings were excluded. One patient with morphea had high-titer anti-single stranded DNA antibody. According to this and previous studies, patients with only anti-DFS70 antibody are rarely diagnosed as having autoimmune rheumatic disease. Recognizing dense fine speckle patterns in anti-nuclear antibodies tests is, thus, very important for analysis of laboratory results in rheumatology clinics.