CD4+ PD-1+ T cells accumulate as unique anergic cells in rheumatoid arthritis synovial fluid

OBJECTIVE: The PD-1 receptor, whose deficiency in mice causes autoimmune diseases such as arthritis, is considered to be a negative regulator of activated T cells and to play a crucial role in peripheral tolerance. To clarify the involvement of the PD-1 system in rheumatoid arthritis (RA), we investigated PD-1 expression on synovial fluid (SF) T cells from patients with RA. METHODS: FACS analysis for PD-1 was performed on SF T cells from 44 patients with RA and 6 with osteoarthritis (OA), and also on peripheral blood (PB) T cells from 12 RA patients and 7 healthy controls. Two-color analysis of cell surface PD-1 expression and the intracellular concentration of cytokine production was used to investigate CD4+ T cells from SF of patients with RA and PB from controls. RESULTS: Scarcely any PD-1 expression was detected on control PB T or OA SF T cells. In contrast, PD-1+ cells made up 20.9 +/- 8.6% (mean +/- SD) of RA SF T cells. In RA SF, PD-1 was expressed more predominantly on CD4+ T cells than on CD8+ T cells. As well as expressing CD45RO and CXCR3, CD4+ PD-1+ T cells were mostly CTLA-4 positive and CD26 negative, and were enriched in CD45RB(low) cells. Intracellular cytokine staining revealed that CD4+ PD-1+, but not CD4+ PD-1-, T cells produced interleukin 10 (IL-10), and that CD4+ PD-1+ T cells produced less IL-2 than CD4+ PD-1- T cells. CONCLUSION: PD-1+ T cells in RA SF are enriched, and phenotypic analysis suggests that these cells constitute a unique anergic T cell subset in RA SF.     

Specific increase in enzymatic activity of adenosine deaminase 1 in rheumatoid synovial fibroblasts

OBJECTIVE: Adenosine deaminase (ADA; EC 3.5.4.4) activity is elevated in the synovial fluid (SF) of patients with rheumatoid arthritis (RA). Since the antiinflammatory effect of methotrexate is reportedly associated with increased levels of extracellular adenosine, the present study was undertaken to clarify the role of 2 ADA isozymes, ADA1 and ADA2, in the pathogenesis of RA. METHODS: The activities of ADA1 and ADA2 were measured in SF from RA and osteoarthritis (OA) patients, in sera from RA patients, and in lysates prepared from mononuclear and polymorphonuclear cells from SF from RA patients, peripheral blood from RA patients, and fibroblast-like synoviocytes (FLS) from RA and OA patients. Also measured were the effects of proinflammatory cytokines on ADA1 activity and ADA messenger RNA (mRNA) expression in RA FLS, as determined using real-time polymerase chain reaction. The adenosine concentration in RA SF was measured by radioimmunoassay. RESULTS: The adenosine concentration in RA SF ranged from 0.027 microM to 0.508 microM (mean +/- SD 0.156 +/- 0.132 microM). At those concentrations, ADA1 would be expected to be functionally dominant due to its higher affinity for adenosine. ADA1 activity in RA SF (mean +/- SD 14.4 +/- 8.5 IU/liter) was significantly higher than that in OA SF (3.0 +/- 1.1 IU/liter) or RA sera (3.0 +/- 0.6 IU/liter); moreover, ADA1 activity in RA FLS lysate was the highest among the cell lysates tested. Proinflammatory cytokines did not affect ADA1 activity or ADA mRNA expression in RA FLS. CONCLUSION: Elevated ADA1 activity is an intrinsic characteristic of RA FLS, which likely contributes to the pathogenesis of RA by neutralizing the antirheumatic properties of endogenous adenosine.     

Severe abdominal pain associated with allergic reaction to nafamostat mesilate in a chronic hemodialysis patient

A 33-year-old woman was referred from an outside dialysis clinic to our hospital because of severe abdominal pain during hemodialysis. She had been on chronic hemodialysis for the past 11 years due to chronic glomerulonephritis. Nafamostat mesilate was used as an anticoagulant for hemodialysis, because it was during her menstrual period with hypermenorrhea. On admission, she had no abdominal pain or gynecological abnormalities. On the second day, she had similar abdominal pain during hemodialysis with nafamostat mesilate in our dialysis unit. The abdominal pain disappeared within 60 minutes after discontinuing the hemodialysis. We re-started dialysis using heparin instead of nafamostat mesilate and she had no symptoms. The titer of total immunoglobulin E was high. The drug lymphocyte stimulation test was positive for nafamostat mesilate and antigen specific immunoglobulin E to nafamostat mesilate was highly positive in her blood. Although an allergic reaction to nafamostat mesilate is a rare complication, it should be one of the differential diagnoses of abdominal pain occurring during hemodialysis.     

Hyperthyroidism and the management of atrial fibrillation.

Atrial fibrillation is often induced in patients with hyperthyroidism and may trigger heart failure. Its prevalence and outcome were examined to obtain up-to-date information. Persistent atrial fibrillation was observed in approximately 1.7% of new hyperthyroid patients. It occurs more frequently in males (2.86%) than in females (1.36%), even though the number of male hyperthyroid patients is only one fifth of female patients. The rate increased with age, being 8% in the patients older than 70 years old. The initial treatment is to control the heart rate with routine pharmacologic therapy and to start antithyroid therapy as quickly as possible. Attempted cardioversion should be deferred until approximately the fourth month of maintaining a euthyroid state, because more than 56% of atrial fibrillation spontaneously reverts to sinus rhythm when the thyroid hormone levels start to decline. Elective cardioversion for those whose atrial fibrillation persists is highly effective and sinus rhythm maintenance rates were 56.7% and 47.6% at the 10th and the 14th year, respectively, even though the duration of atrial fibrillation prior to cardioversion was extremely long (35.0 +/- 29.0 months).     

Thioredoxin may exert a protective effect against tissue damage caused by oxidative stress in salivary glands of patients with Sjögren's syndrome

OBJECTIVE: To demonstrate the existence of oxidative stress and the role of the antioxidant thioredoxin (TRX) in Sj?gren's syndrome (SS). METHODS: Labial biopsy specimens from patients with SS were analyzed immunohistochemically to detect 8-hydroxy-2'-deoxyguanosine (8-OHdG), 4-hydroxy-2-nonenal (4-HNE), nitrotyrosine, and TRX. Levels of TRX in saliva and plasma were quantified by ELISA. To analyze the effect of TRX on human salivary gland (HSG) cells, recombinant TRX (rTRX)-treated HSG cells were stimulated by interferon-gamma (IFN-gamma) for detecting interleukin 6 (IL-6) with ELISA and RT-PCR, or stimulated with IFN-gamma and anti-Fas antibody for analyzing Fas-induced apoptosis with PI/annexin V staining. RESULTS: Large amounts of 8-OHdG, 4-HNE, nitrotyrosine, and TRX were produced in salivary duct cells of SS patients, whether there was periductal lymphocytic infiltration or not. Strong TRX expression was detected in acinar cells from 13 of 19 SS specimens. Levels of salivary TRX were significantly higher in SS patients than in controls (p < 0.05), and were inversely related to the salivary flow rates in SS patients. Patients who showed acinar TRX expression had higher salivary TRX levels than those who did not (p < 0.05). Interferon-gamma-induced expression of IL-6 and Fas-mediated apoptosis in HSG cells were significantly suppressed by pretreating cells with rTRX. CONCLUSION: Parallel production of oxidative stress markers together with massive secretion of TRX suggests that oxidative stress induces TRX in the salivary gland. Moreover, suppression of IL-6 production and apoptosis by rTRX in HSG cells suggests TRX acts to protect the salivary glands of SS patients from tissue damage.     

Sphingosylphosphorylcholine is a novel messenger for Rho-kinase-mediated Ca2+ sensitization in the bovine cerebral artery: unimportant role for protein kinase C

Although recent investigations have suggested that a Rho-kinase-mediated Ca2+ sensitization of vascular smooth muscle contraction plays a critical role in the pathogenesis of cerebral and coronary vasospasm, the upstream of this signal transduction has not been elucidated. In addition, the involvement of protein kinase C (PKC) may also be related to cerebral vasospasm. We recently reported that sphingosylphosphorylcholine (SPC), a sphingolipid, induces Rho-kinase-mediated Ca2+ sensitization in pig coronary arteries. The purpose of this present study was to examine the possible mediation of SPC in Ca2+ sensitization of the bovine middle cerebral artery (MCA) and the relation to signal transduction pathways mediated by Rho-kinase and PKC. In intact MCA, SPC induced a concentration-dependent (EC50=3.0 micromol/L) contraction, without [Ca2+]i elevation. In membrane-permeabilized MCA, SPC induced Ca2+ sensitization even in the absence of added GTP, which is required for activation of G-proteins coupled to membrane receptors. The SPC-induced Ca2+ sensitization was blocked by a Rho-kinase inhibitor (Y-27632) and a dominant-negative Rho-kinase, but not by a pseudosubstrate peptide for conventional PKC, which abolished the Ca2+-independent contraction induced by phorbol ester. In contrast, phorbol ester-induced Ca2+ sensitization was resistant to a Rho-kinase inhibitor and a dominant-negative Rho-kinase. In primary cultured vascular smooth muscle cells, SPC induced the translocation of cytosolic Rho-kinase to the cell membrane. We propose that SPC is a novel messenger for Rho-kinase-mediated Ca2+ sensitization of cerebral arterial smooth muscle and, therefore, may play a pivotal role in the pathogenesis of abnormal contraction of the cerebral artery such as vasospasm. The SPC/Rho-kinase pathway functions independently of the PKC pathway.     

Relationship between Urological Disease and Inferior Vena Cava Reflux on Color Doppler Ultrasonography

Objectives: The possible relationship between urological disease and inferior vena cava (IVC) reflux was examined. Methods: Transabdominal color Doppler ultrasonography of the IVC was performed. The patient was placed supine and the convex probe was positioned in vertical to the upper abdominal wall. Then the extent of reflux in the IVC accompanying each heart beat was examined near the diaphragm. A total of 403 patients (202 males and 201 females aged 12–90 years) were studied. The relationship between the existence of IVC reflux or its severity and urological disease was examined. Results: The 202 males included 104 and 98 subjects without and with IVC reflux, respectively, while the 201 females included 64 and 137 subjects without and with IVC reflux, respectively. The prevalence of IVC reflux was significantly higher in females than males. Chronic prostatitis (18/21 subjects) in males and stress incontinence (22/23 subjects) in females were significantly related to the existence of IVC reflux. Conversely, urolithiasis was related to lack of IVC reflux in females. Conclusions: IVC reflux may be positively or negatively related to the occurrence of some urological diseases. Pelvic congestion secondary to IVC reflux may be one of the factors contributing to chronic prostatitis and stress incontinence.     

Determinants of intramyocellular lipid accumulation after dietary fat loading in non‐obese men

Aims/Introduction:  Accumulation of intramyocellular lipid (IMCL) is associated with insulin resistance. However, the factors affecting the change in IMCL remain to be elucidated. The aim of the present study was to determine the factors that influence the change in IMCL level after high‐fat loading.Materials and Methods:  The study subjects were 37 non‐obese men. Each subject consumed a high‐fat diet for 3 days after a normal‐fat diet for 3 days. After each diet program, IMCL levels in the tibialis anterior (TA‐IMCL) and soleus (SOL‐IMCL) were measured by proton magnetic resonance spectroscopy. Glucose infusion rate (GIR) was evaluated by euglycemic hyperinsulinemic clamp as an index of peripheral insulin sensitivity.Results:  The high‐fat diet significantly increased TA‐IMCL and SOL‐IMCL by ∼30 and ∼20%, respectively (P < 0.05), whereas it did not significantly alter GIR. The increase in SOL‐IMCL, but not in TA‐IMCL, negatively correlated with serum high molecular weight (HMW)‐adiponectin (r = −0.36, P < 0.05) and HMW‐/total‐adiponectin ratio (r = −0.46, P < 0.05). Although high‐fat diet‐related changes in SOL‐IMCL showed high inter‐individual variations, in subjects doing exercise, changes in SOL‐IMCL (r = 0.55, P < 0.05) and TA‐IMCL (r = 0.61, P < 0.05) positively correlated with daily physical activity level. In contrast, in sedentary subjects, changes in SOL‐IMCL (r = −0.50, P < 0.01) and TA‐IMCL (r = −0.48, P < 0.05) negatively correlated with daily physical activity.Conclusions:  HMW‐adiponectin and daily physical activity are determinants of IMCL accumulation by a high‐fat diet. Intriguingly, the effect of daily physical activity on the change in IMCL depends on the level of regular exercise. (J Diabetes Invest,doi: 10.1111/j.2040‐1124.2010.00091.x, 2011)     

A case of pedunculated colonic adenoma with pseudocarcinomatous invasion and squamous metaplasia occurring in the sigmoid colon

A case of pedunculated colonic adenoma with pseudocarcinomatous invasion and squamous metaplasia occurring in the sigmoid colon is reported. The patient was a 65-year-old man who visited our hospital for further evaluation of a positive fecal occult blood test. Colonoscopy revealed a pedunculated polyp with a thick swollen stalk in the sigmoid colon. EUS revealed a hyperechoic lesion in the stalk. However, endosonographically, the third and fourth layers of the colonic wall were shown to be normal. It was suspected to be a colonic adenoma with pseudocarcinomatous invasion from these endoscopic findings. Endoscopic polypectomy was performed. Histological examination of the specimen revealed tubular adenoma with moderate epithelial atypia and submucosal displacement of adenomatous glands with variable cystic changes. Squamous metaplasia and hemosiderin deposition were also seen in the mucosal and submucosal layer, respectively. This polyp was diagnosed as a colonic adenoma with pseudocarcinomatous invasion with squamous metaplasia.