Detection, epitope-mapping and function of anti-Fas autoantibody in patients with silicosis

Dysregulation of apoptosis through the Fas-Fas ligand pathway is associated with the onset of autoimmune disease. Since autoantibodies directed against unknown antigens are present in the sera of these patients, sera samples were examined for the presence of autoantibodies directed against the Fas molecule. Using Western blotting and a ProteinChip analysis, autoantibodies against Fas were detected in patients with silicosis, systemic lupus erythematosus (SLE) and systemic sclerosis (SSc), and weakly detected in healthy individuals. Using epitope mapping employing 12-amino-acid polypeptides with the SPOTs system, a minimum of four epitopes and a maximum of 10 epitopes were found. Several amino acid residues involved in binding FasL, such as C66, R87, L90, E93 and H126, were presented within the epitopes. Serum containing a large amount of anti-Fas autoantibody from silicosis patients inhibited the growth of a Fas-expressing human cell line, but did not inhibit the growth of a low Fas-expresser nor a Fas-expresser in which the Fas gene had been silenced by small interference RNA. All epitopes in the intracellular region of Fas were located in the death domain. The possible roles of anti-Fas autoantibody detected in healthy volunteers and patients with silicosis or autoimmune diseases are discussed here.     

A case of advanced gastric cancer with obstructive jaundice that responded to TS-1/CPT-11 combination therapy after percutaneous transhepatic cholangio drainage

TS-1/CPT-11 combination therapy was carried out in a case of advanced gastric cancer with liver and lymph node metastases and obstructive jaundice after percutaneous transhepatic cholangio drainage (PTCD). Regression of the primary carcinoma and reduction in size of metastases were observed. Grade 1 fatigue and grade 2 neutropenia were noted as adverse reactions to the treatment. TS-1/CPT-11 combination therapy was useful in this case of advanced gastric cancer with liver and lymph node metastases.     

SHP2 mediates gp130-dependent cardiomyocyte hypertrophy via negative regulation of skeletal alpha-actin gene

Morphological and biochemical phenotypes of cardiomyocyte hypertrophy are determined by neurohumoral factors. Stimulation of G protein-coupled receptor (GPCR) results in uniform cell enlargement in all directions with an increase in skeletal α-actin (α-SKA) gene expression, while stimulation of gp130 receptor by interleukin-6 (IL-6)-related cytokines induces longitudinal elongation with no increase in α-SKA gene expression. Thus, α-SKA is a discriminating marker for hypertrophic phenotypes; however, regulatory mechanisms of α-SKA gene expression remain unknown. Here, we clarified the role of SH2-containing protein tyrosine phosphatase 2 (SHP2) in α-SKA gene expression. In neonatal rat cardiomyocytes, endothelin-1 (ET-1), a GPCR agonist, but not leukemia inhibitory factor (LIF), an IL-6-related cytokine, induced RhoA activation and promotes α-SKA gene expression via RhoA. In contrast, LIF, but not ET-1, induced activation of SHP2 in cardiomyocytes, suggesting that SHP2 might negatively regulate α-SKA gene expression downstream of gp130. Therefore, we examined the effect of adenovirus-mediated overexpression of wild-type SHP2 (SHP2^WT), dominant-negative SHP2 (SHP2^C/S), or β-galactosidase (β-gal), on α-SKA gene expression. LIF did not upregulate α-SKA mRNA in cardiomyocytes overexpressing either β-gal or SHP2^WT. In cardiomyocytes overexpressing SHP2^C/S, LIF induced upregulation of α-SKA mRNA, which was abrogated by concomitant overexpression of either C3-toxin or dominant-negative RhoA. RhoA was activated after LIF stimulation in the cardiomyocytes overexpressing SHP2^C/S, but not in myocytes overexpressing β-gal. Furthermore, SHP2 mediates LIF-induced longitudinal elongation of cardiomyocytes via ERK5 activation. Collectively, these findings indicate that SHP2 negatively regulates α-SKA expression via RhoA inactivation and suggest that SHP2 implicates ERK5 in cardiomyocyte elongation downstream of gp130.     

Comparison of Perfusion-Metabolism Mismatch in 99mTc-MIBI and 123I-BMIPP Scintigraphy With Cardiac Magnetic Resonance in Patients With Dilated Cardiomyopathy

BackgroundCardiac magnetic resonance (CMR) imaging is an established method of detecting myocardial fibrosis related to prognosis in patients with dilated cardiomyopathy (DCM). Recent studies have found that ^99mTc–methoxy-isobutyl-isonitrile (MIBI) and ¹²³I–15-(p-iodophenyl)-3(R,S)-methylpentadecanoic acid (BMIPP) dual single-photon-emission computerized tomography (MIBI-BMIPP dual SPECT) can detect perfusion-metabolism mismatches. We compared MIBI-BMIPP dual SPECT with CMR findings and assessed their prognostic abilities to determine the significance of abnormal metabolism in patients with DCM.Methods and ResultsFifty inpatients with DCM (age 58 ± 12 y; 14 female) were assessed with the use of MIBI-BMIPP dual SPECT and CMR. Perfusion-metabolism mismatches were identified mainly at the left ventricular free wall, whereas late gadolinium enhancement (LGE) was evident mostly at the septal wall. During a median follow-up of 33 months, 9 patients developed cardiac events including death, heart failure, and fatal arrhythmia. Event-free survival rates were significantly lower for patients with LGE plus a mismatch than with other abnormalities (P = .001). Among clinical and imaging variables, LGE plus a mismatch was significantly associated with cardiac events (hazard ratio 7.9, 95% confidence interval 1.8–35.6; P = .007).ConclusionsCoexisting LGE and a perfusion-metabolism mismatch accurately predict future cardiac events in patients with DCM.     

Comparison of the effects of acetylsalicylic acid, ticlopidine and cilostazol on primary hemostasis using a quantitative bleeding time test apparatus

We examined and compared the effects of aspirin (ASA), ticlopidine (TP) and cilostazol (CS) on bleeding time (BT) in 10 healthy adult male subjects using a newly developed quantitative bleeding time (QBT) test apparatus capable of simultaneously measuring total blood loss (Tv), maximum bleeding rate (Rmax), and bleeding pattern in addition to BT. All 3 drugs inhibited platelet aggregation response to ADP, collagen, epinephrine and arachidonic acid (p < 0.05), but not to ristocetin. Following oral administration of ASA (330 mg/day) or TP (300 mg/day) for 3 days, BT was significantly prolonged (mean BT increased from 359.3 to 646.0 s, p < 0.001, and from 323.3 to 528. 7 s, p < 0.01, respectively) and Tv was significantly increased (from 14.5 to 30.2 microl, p < 0.05, and from 12.5 to 19.2 microl, p < 0.01, respectively). Aspirin also increased Rmax (from 0.118 to 0. 159 microl/s, p < 0.05). The prolonged bleeding patterns after administration of ASA and TP were both type III, which has been reported to be less likely to lead to bleeding accidents. In contrast, none of these QBT parameters were altered by CS administration.