Implications of FoxP3-positive and -negative CD4(+) CD25(+) T cells in Graves' ophthalmopathy

Graves' ophthalmopathy (GO) is a common manifestation of Graves' disease (GD); however, its pathogenesis is not well understood. Recently, the dysregulation of regulatory T cells (Tregs) has been thought to be closely associated with the pathogenesis and clinical symptoms of autoimmune disease. We therefore evaluated whether T cell subsets, including Tregs, are associated with GO pathogenesis and clinical symptoms. In this observational study we evaluated 35 GD patients with overt ophthalmopathy (GOs) and 28 patients without ophthalmopathy (non-GOs). Fifteen healthy euthyroid patients served as healthy controls (HCs). Peripheral blood mononuclear cells from GOs, non-GOs and HCs were analyzed for CD4, CD25, and FoxP3 expression using flow cytometry. We also evaluated their correlation with disease activity according to the clinical activity score (CAS) and magnetic resonance imaging (MRI) findings. Disease severity was evaluated using the NOSPECS score, and clinical progression of GO was followed for 24 weeks. The main outcome measures were the frequencies of FoxP3-positive and -negative CD4(+) CD25(+) T cells at study outset, namely Tregs and effector T cells (Teffs), respectively. GOs had higher frequencies of Teffs (30.8±8.4%) than non-GOs (19.4±7.1%) and HCs (22.7±7.9%). Notably, patients with improved GOs had lower frequencies of Tregs (5.8±1.1%) than patients with stable or deteriorated GOs (7.3±1.2%), although ophthalmic and radiological parameters were not significantly different at the start of the study. In conclusion, an expanded Teff population may be associated with GO pathogenesis. Additionally, decreased Tregs in peripheral blood may predict a good clinical outcome.

Implication of intracellular localization of transcriptional repressor PLZF in thyroid neoplasms

BACKGROUND

Promyelocytic leukaemia zinc finger (PLZF) is a transcriptional repressor that was originally isolated from a patient with promyelocytic leukaemia. PLZF also affects key elements for cell cycle progression, such as cyclin A, and can affect the tumourigenicity of various cancers. Thus far, the behaviour of PLZF in thyroid carcinoma remains unclear.

METHODS

We analysed the expression profile of PLZF in different types of benign and malignant thyroid lesions as well as in normal thyroid tissue. Specifically, we examined PLZF expression in normal thyroid (N; n = 4), adenomatous lesion (AL; n = 5), follicular adenoma (FA; n = 2), papillary thyroid carcinoma (PTC; n = 20), and anaplastic thyroid carcinoma (ATC; n = 3) samples. PLZF expression was estimated by western blotting and immunohistochemical (IHC) staining.

RESULTS

PLZF was expressed in all samples of thyroid lesions examined. In N, AL, and FA, PLZF was mainly localized in the nucleus. In contrast, in PTC and ATC, PLZF was mainly expressed in the cytosol with high intensity. In more detail, the cytoplasmic IHC scores in PTC with capsular invasion (CI) and lymph node (LN) metastasis were higher than those in PTC without CI and LN metastasis.

CONCLUSIONS

PLZF shows different subcellular localizations among PTC, ATC, and other thyroid lesions. Furthermore, high cytoplasmic expression of PLZF may be correlated with CI and LN metastasis in thyroid carcinoma. The present report is the first to describe the implications of intracellular PLZF expression in thyroid carcinomas.

Autoantibody against WD repeat domain 1 is a novel serological biomarker for screening of thyroid neoplasia

BACKGROUND

Thyroid nodules are common among adults, and accurate diagnosis is critical in for management decisions. Ultrasound and fine needle aspiration cytology are the most common methods to evaluate nodules, but they are not practical for screening large numbers of patients because of cost and time considerations.

OBJECTIVE

The aim of this study was to isolate an autoantibody to tumour antigen, WD repeat domain 1 (WDR1), and evaluate its diagnostic sensitivity and specificity for thyroid neoplasms.

PATIENTS AND METHODS

We investigated serological biomarkers in patients with thyroid carcinoma who had a poor prognosis. Using a serological analysis of recombinant cDNA expression cloning (SEREX) strategy, we isolated WDR1 and its specific autoantibody in the sera of patients with undifferentiated thyroid carcinoma (UTC). We examined using indirect ELISA, the titre of the anti-WDR1 antibody (AWA) in 54 study patients: 10 with UTC, 20 with papillary thyroid carcinoma (PTC), 17 with benign thyroid nodule (BTN), 7 with autoimmune thyroid disease (AITD), as well as 38 controls (N).

RESULTS

WDR1 was ubiquitously expressed in various types of thyroid tissues. However, the titre of AWA in UTC and PTC was significantly higher than that in BTN, AITD and N (P < 0·001). No significant correlation was observed between thyroid function, serum thyroglobulin and tumour diameter. The cut-off value estimated using ROC to differentiate malignancies from others was 0·95 (sensitivity 96·7%, specificity 91·9%, AUC 0·969, P < 0·001).

CONCLUSIONS

Anti-WDR1 antibody could be a novel approach for serological screening of PTC and UTC, and could be an efficient and inexpensive biomarker.

Different distribution of Cav3.2 and Cav3.1 transcripts encoding T-type Ca(2+) channels in the embryonic heart of mice

We investigated the distribution of T-type Ca(2+) channel mRNAs in the mouse embryonic heart. Cav3.2, but not Cav3.1, was expressed in the E8.5 embryonic heart along with cardiac progenitor markers (Nkx2.5, Tbx5, Isl-1) and contractile proteins (alpha and beta MHC). In the E10.5 heart, the distribution of Cav3.1 mRNA was confirmed in the AV-canal and overlapped with that of MinK or Tbx2. Cav3.2 mRNA was observed not only in the AV-canal but also in the outflow tract, along with MinK and Isl-1, indicating the expression of Cav3.2 in the secondary heart field. Thus, Cav3.2 may contribute to the development of the outflow tract from the secondary heart field in the embryonic heart, whereas Cav3.1 may be involved in the development of the cardiac conduction-system together with Cav3.2.

Addition of losartan to angiotensin-converting enzyme inhibitors improves insulin resistance in patients with chronic heart failure treated without β-blockers

BACKGROUND

Angiotensin II and insulin resistance (IR) have clinical implications in the pathophysiology of chronic heart failure (CHF). However, it is still unclear whether the combination of an angiotensin-receptor blocker and angiotensin-converting enzyme inhibitor (ACEI) improves IR in CHF patients who do not receive β-blockers. Thus, the aim of the present study was to evaluate the effects of losartan on glucose metabolism and inflammatory cytokines in CHF patients treated with ACEI but not β-blockers.

METHODS AND RESULTS

The effect of losartan treatment for 16 weeks on IR was analyzed in 16 CHF patients in a randomized crossover trial. Insulin level and homeostasis model IR index (HOMA-IR) decreased significantly (P<0.05), but fasting plasma glucose did not change significantly. Serum tumor necrosis factor (TNF)-α, interleukin (IL)-6, and monocyte chemoattractant protein (MCP)-1 levels were significantly decreased with losartan (P<0.05). Furthermore, the changes in IL-6 and MCP-1 levels were significantly correlated with the reduction in HOMA-IR (P<0.05), but the change in TNF-α levels was not significantly correlated.

CONCLUSIONS

The addition of losartan to ACEI therapy improved IR and decreased inflammatory cytokines in CHF patients who did not receive β-blockers.

Effect of losartan and benzbromarone on the level of human urate transporter 1 mRNA

Both an angiotensin II receptor blocker, losartan (CAS 124750-99-8) and a serum urate lowering agent, benzbromarone (CAS 3562-84-3) exert a uricosuric action by inhibiting urate transporter 1 (URAT1). A recent clinical trial indicated that losartan could reduce the level of serum urate in hypertensive patients treated with urate lowering agents, suggesting the different mode of action of losartan from benzbromarone. In the present study, the effect of losartan and benzbromarone on the level of URAT1 mRNA was determined in transfected HEK293 cells. Losartan caused a significant reduction of its mRNA level, whereas it was not affected by benzbromarone. These results indicate that losartan decreases the level of human URAT1 mRNA, which may underlie the uricosuric action of losartan in hypertensive patients treated with serum urate lowering agents.

Metaboli-Net: online groupware system providing counseling guidance for patients with metabolic syndrome

This study presented a newly developed online groupware system, Metaboli-Net, to yield counseling guidance on diet and exercise to patients with metabolic syndrome. A distinctive feature adopted in the system to maintain the retention rate of patients was the social network service (SNS) that enables the patients to share their dietary and relevant health information with other participants in the same group on the network. A pilot study was conducted to prove the effectiveness of the system in improving the patient's lifestyle and dietary health awareness. SNS also contributed to the participant's adherence to intervention programs.

[Calcium antagonists: current and future applications based on new evidence. The mechanisms on lowering serum uric acid level by calcium channel blockers]

In hypertensive subjects, their serum uric acid levels tend to be higher because of decreasing urinary secretion or overproduction of uric acid. Among calcium channel blockers (CCBs) , long acting nifedipine and cilnidipine reveal serum uric acid lowering action. They decrease the production of uric acid precursor in skeletal muscles under anaerobic condition induced by hypertension or insulin resistance. Hyperuricemia is considered to be a risk factor of not only gout but also renal and cardiovascular diseases, thus, it is important to use CCBs without adverse effect on uric acid metabolisms.

Uric acid-lowering treatment with benzbromarone in patients with heart failure: a double-blind placebo-controlled crossover preliminary study

BACKGROUND

Hyperuricemia is common in chronic heart failure (CHF), and it is a strong independent marker of prognosis. Upregulated xanthine oxidase (XO) activity and impaired renal excretion have been shown to account for increased serum uric acid (UA) levels in CHF. Therapeutic interventions with allopurinol to reduce UA levels by XO inhibition have been shown to be beneficial. Discussions are ongoing whether UA itself is actively involved or it is a mere marker of upregulated XO activity within CHF pathophysiology. Therefore, the aim of this study was to test the effect of lowering UA by uricosuric treatment without XO inhibition on hemodynamic and metabolic characteristics of CHF. Impaired renal excretion of UA was taken into account.

METHODS AND RESULTS

Serum UA (SUA), urinary UA (uUA) excretion, and renal clearance test for UA (Cl(UA)) were measured in 82 patients with CHF. SUA was significantly increased compared with controls of similar age (control, 5.45+/-0.70 mg/dL; New York Heart Association I, 6.48+/-1.70 mg/dL; New York Heart Association II, 7.34+/-1.94 mg/dL; New York Heart Association III, 7.61+/-2.11 mg/dL; P<0.01). Patients with CHF showed lower uUA excretion and Cl(UA). On multivariate analysis, insulin, brain natriuretic peptide (P<0.01), and creatinine levels (P=0.05) showed independent correlation with SUA. The treatment effect of the uricosuric agent benzbromarone was tested in 14 patients with CHF with hyperuricemia in a double-blind, placebo-controlled, randomized crossover study design. Benzbromarone significantly decreased SUA (P<0.01). Brain natriuretic peptide, left ventricular ejection fraction, and dimensions in echocardiographic assessment did not change after benzbromarone therapy. In contrast, fasting insulin (placebo, 18.8+/-8.9 microU/mL; benzbromarone, 11.0+/-6.2 microU/mL; P<0.05), homeostasis model assessment of insulin resistance index (placebo, 5.4+/-2.6; benzbromarone, 3.0+/-1.7; P<0.05), and tumor necrosis factor-alpha (placebo, 2.59+/-0.63 pg/mL; benzbromarone, 2.14+/-0.51 pg/mL; P<0.05) improved after benzbromarone, and the changes in tumor necrosis factor-alpha levels were correlated with reduction of SUA (P<0.05).

CONCLUSIONS

These results show that UA lowering without XO inhibition may not have an effect on hemodynamic impairment in CHF pathophysiology. To the extent that these data are correct, this finding suggests that upregulated XO activity rather than UA itself is actively involved in hemodynamic impairment in CHF. Clinical Trial Registration- clinical trials.gov. Identifier: NCT00422318.

Appropriate use of nasal continuous positive airway pressure decreases elevated C-reactive protein in patients with obstructive sleep apnea

BACKGROUND

C-reactive protein (CRP) is an important risk factor for cardiovascular disease. Furthermore, it has been reported that levels of CRP are increased in patients with obstructive sleep apnea (OSA). The aim of this study was to examine the effects of long-term therapy with nasal continuous positive airway pressure (nCPAP) on CRP levels and to investigate whether compliance with nCPAP therapy more effectively attenuated markers of systemic inflammation in patients with OSA.

METHODS AND RESULTS

Fifty-five patients (mean [+/- SEM] age, 55 +/- 2 years; 44 male patients, 11 female patients) with newly diagnosed moderate-to-severe OSA (apnea-hypopnea index > 20 events/h) were studied before and after 6 months of nCPAP treatment. There was a significant reduction in CRP levels after nCPAP therapy (before nCPAP therapy, 0.23 +/- 0.03 mg/dL; after nCPAP therapy, 0.17 +/- 0.02 mg/dL; p < 0.01). Additionally, we divided these patients into two groups based on adherence to nCPAP therapy. A group of patients using nCPAP > 4 h/d and > 5 d/wk were designated as the good compliance group. The decrease in CRP concentration was significant (before nCPAP therapy, 0.23 +/- 0.04 mg/dL; after nCPAP therapy, 0.16 +/- 0.03 mg/dL; p < 0.05) in the good compliance group but not in the poor compliance group (before nCPAP therapy, 0.24 +/- 0.05 mg/dL; after nCPAP therapy, 0.20 +/- 0.05 mg/dL; p = 0.21). Furthermore, we divided those patients into a high CRP group (>/= 0.2 mg/dL) and a normal CRP group (< 0.2 mg/dL) before nCPAP therapy. The significant decrease in CRP levels in the good compliance group was evident only in those patients with an initially elevated CRP level (before nCPAP therapy, 0.48 +/- 0.08 mg/dL; after nCPAP therapy, 0.29 +/- 0.06 mg/dL; p < 0.05).

CONCLUSION

Appropriate use of nCPAP in patients with OSA may be required to decrease elevated CRP levels, with possible implications for cardiovascular morbidity and mortality.

Pendrin is a novel autoantigen recognized by patients with autoimmune thyroid diseases

CONTEXT

Pendrin is an apical protein of thyroid follicular cells, responsible for the efflux of iodide into the follicular lumen via an iodide-chloride transport mechanism. It is unknown whether pendrin is recognized by autoantibodies.

OBJECTIVE

Our objective was to examine the prevalence of pendrin antibodies in autoimmune thyroid diseases and compare with that of thyroglobulin, thyroperoxidase, TSH receptor, and sodium iodide symporter antibodies.

DESIGN

In a prevalent case-control study, we analyzed the sera of 140 autoimmune thyroid disease cases (100 with Graves' disease and 40 with Hashimoto's thyroiditis) and 80 controls (50 healthy subjects, 10 patients with papillary thyroid cancer, 10 with systemic lupus erythematosus, and 10 with rheumatoid arthritis). Pendrin antibodies were measured by immunoblotting using extract of COS-7 cells transfected with pendrin and a rabbit polyclonal pendrin antibody.

RESULTS

Pendrin antibodies were found in 81% of the cases and 9% of controls (odds ratio = 44; P < 0.0001). Among cases, pendrin antibodies were more frequent and of higher titers in Hashimoto's thyroiditis than in Graves' disease. Pendrin antibodies correlated significantly with thyroglobulin, thyroperoxidase, and sodium iodide symporter antibodies but not with TSH receptor antibodies. Pendrin antibodies were equally effective as thyroglobulin and thyroperoxidase antibodies in diagnosis of autoimmune thyroid diseases, especially Hashimoto's thyroiditis.

CONCLUSIONS

The study identifies pendrin as a novel autoantigen recognized by patients with autoimmune thyroid diseases and proposes the use of pendrin antibodies as an accurate diagnostic tool.

[How do we set the standard value of serum uric acid levels?]

In most medical facilities in Japan, either uricase-catalase or uricase-peroxidase method has been adopted as a sensitive determination of serum uric acid concentration. However, the values obtained from the same patients at different time points are often variable with those methods. Accelerated generation of uric acid and impaired excretion in the kidney are promoted by several dietary factors, such as foods with higher content of sugars (fructose and xylitol), fat and purine bases, and by alcohol consumption, starvation and dehydration. In contrast, hyperglycemia and excess salt ingestion are conductive to accelerate urate excretion. Physicians should notice representative factors fluctuating serum uric acid levels as described above.

Age-related BM-MNC dysfunction hampers neovascularization

Although ischemia-induced neovascularization is reportedly impaired with aging, the effect of aged-bone marrow mononuclear cells (BM-MNCs) on neovascularization has not been investigated. The neovascularization capacity of BM-MNCs obtained from 8-week-old mice (young) was compared to those obtained from 18-month-old mice (old), both in vivo and in vitro. Neovascularization in ischemic limbs was significantly impaired in old mice. Whereas transplantation of young BM-MNCs significantly improved blood perfusion, tissue capillary density, and vascular endothelial growth factor (VEGF) production in transplanted ischemic limbs, no such effects were observed with old BM-MNCs. Old BM-MNCs also showed a significant impairment of in vitro VEGF production and migratory capacity in response to VEGF. The number of Dil/lectin-positive cells was significantly lower in old mice, but there was no difference in the number of AC133(+)/CD34(+) and CD34(+)/VEGF-R2(+) positive cells between young and old BM-MNCs. Transplantation of young BM-MNCs improved neovascularization and VEGF production in the ischemic limbs of old recipients, with results that were similar to those obtained in young recipients. These results indicate that the neovascularization capacity of transplanted BM-MNCs is impaired with aging. However, aging does not hamper the revitalization of neovascularization in the murine host in response to transplantation of young BM-MNCs.

Remote reperfusion lung injury is associated with AMP deaminase 3 activation and attenuated by inosine monophosphate

BACKGROUND

Remote reperfusion lung injury occurs in patients with vascular occlusion and surgical procedures. Inosine monophosphate (IMP) produced by adenosine monophosphate deaminase (AMPD) 3 is involved in the remote reperfusion injury. The purpose of the present study was to identify whether IMP administration attenuated the remote reperfusion lung injury in a skeletal muscle ischemia-reperfusion model.

METHODS AND RESULTS

A remote reperfusion lung injury was created using reperfusion after the bilateral ligation of the hind-limb. AMPD activity, myeloperoxidase (MPO) activity, IMP, AMPD3 mRNA and tumor necrosis factor (TNF)-alpha in the lungs before and after reperfusion were analyzed. Furthermore, the effects of IMP on these parameters were examined. AMPD3 mRNA, AMPD activity and IMP production in the lungs significantly increased after ischemia-reperfusion with increases in MPO activity, TNF-alpha level and decreased oxygen saturation (SpO(2)). Histological examination of the lungs demonstrated significant neutrophil infiltration and accumulation. IMP administration significantly reduced MPO activity, TNF-alpha and neutrophil infiltration, with ameliorated SpO(2).

CONCLUSIONS

Along with the activation of AMPD3, ischemia-reperfusion-induced lung inflammation is associated with increased MPO activity and TNF-alpha level. IMP significantly decreased the lung injury, MPO activity, TNF-alpha and increased SpO(2). These findings may lead to the development of a new therapeutic strategy for remote reperfusion lung injury.

Plasma levels of uridine correlate with blood pressure and indicators of myogenic purine degradation and insulin resistance in hypertensive patients

BACKGROUND

The relationship between plasma uridine levels and blood pressure (BP), and indicators of muscular purine degradation and insulin resistance (IR) has been evaluated in hypertensive (HT) patients.

METHODS AND RESULTS

In 36 HT patients and 10 normotensive subjects, seated BP was measured, and blood samples were drawn after overnight fast. In 18 of the HT patients, the semi-ischemic forearm test was performed to examine the release of hypoxanthine, ammonium and lactate. Plasma uridine levels were significantly higher than in the normotensive subjects. Fasting plasma insulin levels and homeostasis model assessment of IR correlated with plasma uridine levels in the HT patients. Plasma uridine levels showed a significant correlation with hypoxanthine, ammonia and lactate released from the semi-ischemic exercising muscles of the HT patients.

CONCLUSIONS

Taken together with the positive correlation with indicators of IR, it is suggested that plasma uridine levels in HT are responsible for purine degradation and IR in skeletal muscles.

Catabolism of adenine nucleotides favors adenosine production following exercise in patients with chronic heart failure

BACKGROUND

Adenosine 5'-triphosphate is catabolized to adenosine 5'-monophosphate (AMP), which is further degraded by 2 pathways: deamination to inosine 5'-monophosphate and ammonia by AMP deaminase, or dephosphorylation to adenosine and inorganic phosphate by 5'-nucleotidase. Because adenosine is believed to be cardioprotective and we have reported that ammonia production decreased after exercise in patients with chronic heart failure (CHF), we determined if plasma adenosine levels after exercise increases in patients with CHF.

METHODS AND RESULTS

Maximal ergometer exercise tests with expired gas analysis were performed in 51 patients with CHF (age = 61 +/- 2 years, New York Heart Association [NYHA] class I/II/III = 19/18/14) and 20 age-matched normal controls. Serial changes in both plasma ammonia and adenosine levels were determined. The ratio for delta ammonia to peak work rate became smaller (control, NYHA I/II/III: 0.59 +/- 0.13/0.41 +/- 0.06/0.37 +/- 0.10/0.22 +/- 0.11 microg/dL x watts, respectively) and the ratio for delta adenosine to peak work rate was significantly higher in class III CHF (control, NYHA I/II/III: 0.93 +/- 0.21/0.86 +/- 0.14/1.11 +/- 0.27/2.92 +/- 0.67 nmol/L x watts, respectively).

CONCLUSION

In patients with CHF after exercise, the plasma levels of adenosine increased along with the decrease in the plasma levels of ammonia. Considering the physiologic cardioprotective actions of adenosine, the enhanced adenosine production after exercise may be an important adaptive response in patients with CHF.

Status of Uric Acid Management in Hypertensive Subjects

Hyperuricemia in hypertensive subjects has been considered one of risk factors of cardiovascular diseases. We investigated the status of uric acid management in 799 hypertensive subjects (432 females and 367 males; mean age 70.9 years) managed by 43 doctors (19 cardiologists and 24 noncardiologists; 25 private practice doctors and 18 hospital doctors). The serum uric acid level was available in 85.7% of the patients. This availability was equivalent regardless of facility size, and more cardiologists than noncardiologists monitored this information. The prevalence of hyperuricemia was 17.5% and was higher in men and in patients with high triglyceridemia, left ventricular hypertrophy, renal dysfunction, proteinuria, and smokers, but was not higher in subjects with chronic heart failure, diabetes mellitus, and those with prescriptions for diuretics and beta-blockers. The average serum uric acid level was higher in men and patients with chronic heart failure, renal dysfunction, high triglyceridemia, low high-density cholesterolemia, smokers, and subjects prescribed beta-blockers. Fifty percent of hyperuricemic patients were medicated, and 48.6% of them cleared the uric acid target level (6 mg/dL). No differences were observed in the treatment rate or the achievement rate of the target between genders, concurrent diseases, and physician specialties. Although doctors, especially cardiologists, have a high concern for the serum uric acid level, they do not intervene intensively, and specific treatment for individual patterns is not routinely given. Thus, more attention to uric acid management is necessary in hypertensive subjects to prevent cardiovascular diseases.

Characteristics of cardiac myxoma with constitutional signs: a multicenter study in Japan

BACKGROUND

A relationship between constitutional signs in patients with cardiac myxoma and interleukin-6 has been noted. However, there is little information about characteristics of cardiac myxomas associated with constitutional signs.

HYPOTHESIS

The objective of this study was to clarify the characteristics of myxoma patients who had constitutional signs.

METHODS

Questionnaires were sent to cardiology or cardiovascular surgery divisions at university hospitals throughout Japan. Constitutional signs were considered present when a patient had fever, weight loss, or elevations of C-reactive protein or gammaglobulin. In addition, interleukin-6 concentrations were evaluated in some patients.

RESULTS

Data were obtained in 249 patients with primary cardiac tumors (204 myxomas, 15 other primary benign tumors, and 30 primary malignant tumors), confirmed histologically between 1993 and 1996. Fever and weight loss were observed in 15 and 6% of patients with myxoma, respectively, while C-reactive protein and gammaglobulin were increased in 39 and 21%, respectively. This amounted to a prevalence of constitutional signs in 49%. All constitutional signs disappeared after tumor resection. Age, gender, tumor site, and frequency of thrombosis did not differ between patients with and without constitutional signs. Tumors associated with constitutional signs were significantly more likely to be large, multiple, or recurrent than those unassociated with constitutional signs.

CONCLUSIONS

Constitutional signs are present in about half of patients with myxoma. Large or multicentric tumors are likely to induce constitutional signs, which are reversible upon resection. These might suggest that constitutional signs result when interleukin-6 concentrations exceed a certain threshold.

Small extra-adrenal pheochromocytoma causing severe hypertension in an elderly patient

We report the case of a 67-year-old woman with severe hypertension caused by an extra-adrenal pheochromocytoma. The tumor was detected by 131I metaiodobenzylguanidine scintigraphy and it was found to be small (2 cm ø) by enhanced CT. After the extirpation of the tumor, the blood pressure of the patient immediately normalized. It should be taken into account that a small extra-adrenal pheochromocytoma can be one of the causes of secondary hypertension in elderly patients. Since small extra-adrenal pheochromocytomas are difficult to detect, it is also important to perform suitable examinations to establish the diagnosis. Furthermore, we emphasize the importance of an accurate diagnosis in elderly patients with pheochromocytoma, for they often have less symptomatology and more severe cardiovascular complications due to refractory hypertension than younger patients.

Delayed onset of beating and decreased expression of T-type Ca2+ channel in mouse ES cell-derived cardiocytes carrying human chromosome 21

The mouse ES cell line hcgp7/#21, which carries a human chromosome 21 (hChr.21), was used as an in vitro model to examine the effects of hChr.21 on cardiomyocyte differentiation. Cardiomyocytes derived from hcgp7/#21 showed a significant delay in the onset of spontaneous beating. The number of Nkx2.5/GFP(+) cardiac progenitor cells was comparable to that in control ES cells and they also expressed comparable mRNA levels for mesodermal markers, cardiac specific transcription factors, contractile proteins, and L-type Ca(2+) channels. However, cells from hcgp7/#21 expressed significantly reduced levels of mRNA for Cav3.1 and Cav3.2, which was consistent with the decreased number of cells expressing T-type Ca(2+) channels and decreased T-type Ca(2+) channel currents. These findings suggest that the presence of human chromosome 21 suppresses expression of T-type Ca(2+) channels in cardiomyocytes during differentiation, which may be responsible for delayed onset of spontaneous beating.

Human organic cation transporter (OCT1 and OCT2) gene polymorphisms and therapeutic effects of metformin

Organic cation transporters (OCTs) are responsible for the hepatic and renal transport of metformin. In this study we analyzed variants of OCT1 and OCT2 genes in 33 patients (24 responders and nine non-responders) based on the hypothesis that polymorphisms in both genes contribute to large inter-patient variability in the clinical efficacy of metformin. The sequences of the 5'-flanking and coding regions of the two genes of interest were screened by single-strand conformation polymorphism (SSCP) analysis. To compare the causative factors between responders and non-responders, we performed stepwise discriminant functional analysis. Age, body mass index (BMI) and treatment with lipid-lowering agents were demonstrated as positive predictors, and two mutations in the OCT1 gene, -43T > G in intron 1 and 408Met > Val (1222A > G) in exon 7, were negative and positive predictors, respectively, for the efficacy of metformin; the predictive accuracy was 55.5% (P < 0.05). Subsequent study indicated that OCT1 mRNA levels tended to be lower in human livers with the 408Met (1222A) variant, though the differences did not reach the level of significance. In this study it is suggested that OCT1 and OCT2 gene polymorphisms have little contribution to the clinical efficacy of metformin.

Pharmacogenetic determinants of variability in lipid-lowering response to pravastatin therapy

Pravastatin is mainly taken up from the circulation into the liver via organic anion-transporting polypeptide 1B1 (SLCO1B1 gene product). We examined the contribution of genetic variants in the SLCO1B1 gene and other candidate genes to the variability of pravastatin efficacy in 33 hypercholesterolemic patients. In the initial phase of pravastatin treatment (8 weeks), heterozygous carriers of the SLCO1B1*15 allele had poor low-density lipoprotein cholesterol (LDL-C) reduction relative to non-carriers (percent reduction: -14.1 vs -28.9%); however, the genotype-dependent difference in the cholesterol-lowering effect disappeared after 1 year of treatment. Cholesterol 7alpha-hydroxylase (CYP7A1) and apolipoprotein E (APOE) are known to contribute to lipid metabolism. Homozygous carriers of the CYP7A1 -204C allele or heterozygotes for both CYP7A1 -204C and APOE epsilon4 alleles showed significantly poorer LDL-C reduction compared to that in other genotypic groups after 1 year of treatment (-24.3 vs -33.1%). These results suggest that the SLCO1B1*15 allele is associated with a slow response to pravastatin therapy, and the combined genotyping of CYP7A1 and APOE genes is a useful index of the lipid-lowering effect of pravastatin.

Autoperipheral blood mononuclear cell transplantation improved giant ulcers due to chronic arteriosclerosis obliterans

We report the case of a 74-year-old man with Fontaine stage IV chronic arteriosclerosis obliterans who had been suffering from inveterate giant skin ulcers on the dorsum and heel of the right foot. As conventional medical treatments had not improved these ulcers and surgical treatment was considered unfeasible, amputation of the right lower limb below the knee appeared to represent the only option. The patient was admitted to Tottori University Hospital to attempt a new angiogenic therapy using auto-mononuclear cell transplantation to avoid amputation. On admission, neither right ankle blood pressure nor transcutaneous partial pressure of oxygen at the right toe were detectable. The patient had a history of multiple cerebral infarctions, and collection of mononuclear cells from bone marrow was considered too difficult, so collection of peripheral blood mononuclear cells was selected. Transcutaneous partial pressure of oxygen and skin temperature in the treated limb started to improve from 2 weeks after implantation. Ulcer size was recognizably reduced by 1 month after treatment. Partial auto-skin implantation on the right heel was performed 2 months after treatment, and the giant skin ulcer was finally completely covered. No adverse effects were noted during follow-up lasting 1 year. These results suggest that peripheral blood mononuclear cell implantation may offer a suitable alternative rescue therapy for patients with critical limb ischemia whose general condition is not good.

Allopurinol Reduces Neointimal Hyperplasia in the Carotid Artery Ligation Model in Spontaneously Hypertensive Rats

Uric acid and oxidative stress promote cardiovascular diseases, including atherosclerosis and hypertension. Xanthine oxidase, through which uric acid is generated, is a free-radical generating enzyme. The aim of the current study was to investigate whether allopurinol, an inhibitor of xanthine oxidase activity, affects vascular remodeling and vascular smooth muscle cell (VSMC) proliferation. In the carotid artery ligation model using spontaneously hypertensive rats (SHR), treatment with allopurinol induced a reduction in the neointima/media ratio by 27% (38.5+/-34.3% in the control group and 28.1 20.8% in the allopurinol-treated group, respectively, p<0.01) without alterations in vascular circumference at 3 weeks after ligation when compared to the control. Allopurinol lowered the serum uric acid concentration (147.0+/-3.6 micromol/l in the control group and 16.1+/-3.6 micromol/l in the allopurinol-treated group, respectively p<0.01) and xanthine oxidase activity, but not the blood pressure. In an in vitro study, high concentrations of uric acid (100 and 200 micromol/l) stimulated VSMC growth, but there was no stimulation of these cells by a low concentration of uric acid (50 micromol/I) or by any of three concentrations of xanthine (50, 100 and 200 micromol/l). In addition, allopurinol (5 micromol/I) had no effect on the cell growth. In conclusion, uric acid is a potent stimulator of VSMC proliferation, and allopurinol prevented vascular remodeling in SHR at least in part by inhibiting uric acid concentration.

Status of endothelial dependent vasodilation in patients with hyperuricemia

Hyperuricemia has been associated with an increased risk for cardiovascular disease and increased mortality. However, the biologic mechanisms that link elevated serum uric acid to cardiovascular disease are uncertain. This study tested the hypothesis that elevated serum uric acid is associated with impaired endothelial function in hyperuricemic patients without any overt cardiovascular disease. Seventeen male patients with hyperuricemia (mean age 42+/-4 years) and 9 control subjects (mean age 45+/-5 years) were studied. All subjects were nonsmokers. All patients had never been treated for hyperuricemia, were on no medications, and were free of any other known diseases. Endothelial function was evaluated by flow-mediated dilation measured by ultrasound. Flow-mediated dilation was significantly impaired in patients with hyperuricemia (4.0+/-0.7%) compared with control subjects (6.4+/-0.8%) (p=0.044). Flow-mediated dilation correlated inversely with uric acid levels (r=-0.4, p=0.05). Nitrate-induced dilation was 12.3+/-1.0% in patients with hyperuricemia and 11.8+/-2.3% in control subjects (p=0.82). Impaired endothelial-dependent vasodilation is present in hyperuricemic patients even in the absence of any overt cardiovascular disease. The elevated serum uric acid, per se, may constitute a novel risk factor for endothelial dysfunction.

Proteasomal degradation of Kir6.2 channel protein and its inhibition by a Na+ channel blocker aprindine

ATP-sensitive K+ channels (K(ATP):SUR2A+Kir6.2) play a pivotal role in cardiac protection against ischemia and reperfusion injury. When expressed in COS cells, Kir6.2 was short-lived with a half-life time of 1.9 h. The half-life time of Kir6.2 was prolonged by proteasome inhibitors MG132, ALLN, proteasome inhibitor 1, and lactacystine, but not at all by a lysosomal inhibitor chloroquine. MG132 also increased the level of ubiquitinated Kir6.2 without affecting its localization in the endoplasmic reticulum and Golgi apparatus. In electrophysiological recordings, MG132 augmented nicorandil-activated K(ATP) currents in COS cells expressing SUR2A and Kir6.2 as well as the same currents in neonatal rat cardiomyocytes. Like MG132, a Na+ channel blocker aprindine prolonged the half-life time of Kir6.2 and augmented K(ATP). Finally, both aprindine and MG132 inhibited the 20S proteasome activity in vitro. These results suggest a novel activity of aprindine to enhance K(ATP) currents by inhibiting proteasomal degradation of Kir 6.2 channels, which may be beneficial in the setting of cardiac ischemia.

Transient left ventricular apical ballooning in a patient with bicuspid aortic valve created a left ventricular thrombus leading to acute renal infarction

A 44-year-old woman had tako-tsubo-like ventricular dysfunction with chest pain and ST segment elevation on the ECG. Echocardiography revealed a bicuspid aortic valve with moderate to severe aortic regurgitation. She developed mild heart failure during the clinical course, but the medication (furosemide, enalapril, and asprin) had to be stopped because of skin eruptions. Four weeks after ceasing the antiplatelet agent, she was re-admitted with acute renal infarction. Enhanced chest computed tomography revealed a filling defect in the left ventricle and echocardiography showed a high echogenic mass in the left ventricular apical wall. These findings strongly suggested that the renal infarction was caused by an embolism derived from a left ventricular thrombus that formed during the clinical course of the transient left ventricular apical ballooning. Anticoagulation therapy with urokinase and warfarin successfully lysed the thrombus. Left ventricular thrombus should be considered a complication of transient left ventricular apical ballooning, especially in patients with organic heart disease.

Effects of Angiotensin II on the Action Potential Durations of Atrial Myocytes in Hypertensive Rats

Angiotensin II (Ang II) has been reported to indirectly influence atrial electrical activity and to play a critical role in atrial arrhythmias in hypertensive patients. However, it is unclear whether Ang II has direct effects on the electrophysiological activity of the atrium affected by hypertension. We examined the effects of Ang II on the action potentials of atrial myocytes enzymatically isolated from spontaneous hypertensive rats (SHRs). The action potentials were recorded by the perforated patch-clamp technique and the atrial expression of the receptors AT1a and AT2 was measured by radioimmunoassay. Ang II significantly shortened the action potential durations (APDs) of SHRs without changes in the resting membrane potentials (RMPs). Pretreatment with selective AT1a blockers abolished the Ang II-induced reduction of atrial APDs of SHRs; however, a selective AT2 blocker did not, which was consistent with the results of the receptor assay. Pretreatment with phosphatidylinositol 3 (PI3)-kinase inhibitor, phospholipase C inhibitor, or protein kinase C (PKC) inhibitor abolished the Ang II-induced shortening of atrial APDs, but pertussis toxin and protein kinase A (PKA) inhibitor did not. To study the effects of chronic AT1a inhibition on Ang II-induced shortening of atrial APD, SHRs were treated with AT1a blocker for 4 weeks. AT1a blocker abolished the Ang II-induced reduction of atrial APDs of SHRs and also significantly lowered their blood pressure. In conclusion, Ang II shortened atrial APDs of SHRs via AT1a coupled with the Gq-mediated inositol triphosphate (IP3)-PKC pathway. Our findings indicated that Ang II caused atrial arrhythmias in hypertensive patients by shortening the effective refractory period of the atrium.

Acute Myocardial Infarction in a Patient With Essential Thrombocythemia Successful Treatment With Percutaneous Transluminal Coronary Recanalization

A 65-year-old woman with essential thrombocythemia (ET) was admitted to hospital where she was diagnosed as acute myocardial infarction (AMI). Because of abundant thrombus of right coronary arteries, percutaneous transluminal coronary recanalization by administration of urokinase was selected as the reperfusion therapy, resulting in successful revascularization with Thrombolysis in Myocardial Infarction grade III coronary flow. The maximum creatine kinase reached 507 IU/L, and left ventriculography performed at 1 month after initiation of both anticoagulant and antiplatelet therapies revealed reduced motion in the inferior wall with an ejection fraction of 57%. Despite good recovery of left ventricular function, bleeding complications, such as epistaxis or ecchymoma, which did not require blood transfusion, occurred during the clinical course. Because ET causes not only thrombus formation but also bleeding tendency, it is very important to carefully follow-up any clotting abnormality in AMI patients with ET.

Subtype Switching of T-Type Ca 2+ Channels From Cav3.2 to Cav3.1 During Differentiation of Embryonic Stem Cells to Cardiac Cell Lineage

BACKGROUND

The developmental changes of Ni(2+)-sensitivity to automaticity of Nkx2.5-positive cells derived from mouse embryonic stem cell have been identified, suggesting developmental regulation of expressing Ni(2+)-sensitive T-type Ca(2+) channel, although the mechanism of the change has not been fully studied.

METHODS AND RESULTS

Transcripts of Cav3.2, Cav3.1 and Cav1.2 genes of beating Nkx2.5-positive cells, which encode the Ni(2+)-sensitive T-type Ca(2+) channel, Ni(2+)-insensitive T-type Ca(2+) channel, and L-type Ca(2+) channel, respectively, were investigated by real-time reverse-transcriptase-polymerase chain reaction, and the current density of each channel was measured by patch-clamp techniques at the early and late stages of differentiation. The expression of the Cav3.2 transcript predominated in the early stage whereas those of Cav3.1 and Cav1.2 transcripts were upregulated in the late stage, which was consistent with the change in each current density, suggesting the expression of channel proteins is largely determined at the transcriptional level.

CONCLUSION

The results indicate that the mechanism of change of Ni(2+)-sensitivity is partly, if not completely, the subtype switch of T-type Ca(2+) channel from Cav3.2 to Cav3.1 at the transcriptional level, and that the expression of the L-type Ca(2+) channel might have an attenuating effect on Ni(2+)-sensitivity to automaticity in the late stage of differentiation.

[Alteration of education programs for anesthesia after the start of the obligatory postgraduate clinical training in Japan: survey at affiliated teaching hospitals of medical schools]

BACKGROUND

There is little information on education programs for anesthesia evaluating the present educational contents of early postgraduate clinical training period.

METHODS

A questionnaire that consisted of 40 questions graded from 1 (absolutely unnecessary) to 5 (absolutely necessary) was send to 80 medical universities in Japan to investigate the alterations of education programs for anesthesia at their affiliated teaching hospitals after the start of the obligatory early postgraduate clinical training.

RESULTS

Answers were obtained from 59 of 80 universities (74%). Educational necessities after the obligation were significantly reduced at the following items compared with pre-obligation; intravenous anesthesia technique (P<0.05), epidural (P<0.01) and spinal (P<0.05) anesthesia technique, anesthesia for cesarean section (P<0.01), and adult patients of more than ASA PS 3 (P<0.01) and pediatric patients (P<0.05). Contrarily, educational necessities increased significantly in the attending (P<0.01) and presentation (P<0.05) at the academic meetings.

CONCLUSIONS

Clinical anesthesia education after the obligation was likely to change the direction to establish the safer anesthesia in patients with low anesthetic risk(s) along with encouraging the trainees to be interested in medicine.

Neurohumoral profiles in patients with hypertrophic cardiomyopathy: differences to hypertensive left ventricular hypertrophy

BACKGROUND

Patients with hypertrophic cardiomyopathy (HCM) or hypertensive heart disease (HHD) have increased concentrations of various neurohumoral factors. Thus, the aim of the present study was to evaluate the differences in the neurohumoral profiles of HCM and HHD.

METHODS AND RESULTS

Plasma concentrations of epinephrine, norepinephrine, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), angiotensin II and endothelin-1 were measured in 40 patients with HCM, 35 with HHD, and 15 controls. Additionally, the concentrations of these neurohumoral factors in the coronary sinus and aortic root were measured in 12 HCM patients and 10 controls. Plasma concentrations of norepinephrine, ANP and BNP were significantly higher in HCM than HHD and controls. In HCM, there was no significant correlation between the left ventricular mass index and any neurohumoral factor. The plasma BNP concentration significantly correlated with left intraventricular pressure gradient in HCM. There were significant differences in the plasma concentrations of ANP and BNP between HCM with and without left ventricular diastolic dysfunction. Transcardiac production of BNP was significantly higher in patients with obstructive HCM than in those with non-obstructive HCM.

CONCLUSIONS

The significant neurohumoral differences between HCM and HHD were the plasma concentrations of norepinephrine, ANP and BNP. In HCM patients, the plasma BNP concentration may reflect the intraventricular pressure gradient and left ventricular diastolic dysfunction whereas the plasma ANP concentration reflects only the left ventricular diastolic dysfunction.

Mechanism of iodide/chloride exchange by pendrin

We performed an electrophysiological study to investigate ion transport of pendrin and thereby understand the pathogenesis of Pendred syndrome. Using pendrin-transfected COS-7 cells, we could show that pendrin transports both iodide and chloride measured as voltage-dependent inward and outward membrane currents. Chloride in the culture medium, [Cl-]o, was efficiently exchanged with cytoplasmic iodide, [I-]i, under physiological concentrations, indicating that pendrin is important for chloride uptake and iodide efflux. Although exchange of iodide in the medium, [I-]o, with cytoplasmic chloride, [Cl-]i, was observed, a significantly high concentration of iodide (10 mm) was required. In addition, either iodide or chloride was required on both sides of the cell membrane for the anion exchange activity of pendrin, indicating that iodide and chloride activate the exchange activity of pendrin while they are transported. The present study further supports that pendrin is responsible for the iodide efflux in thyroid cells where intracellular iodide concentration is high and that the general function of pendrin in other tissues is to transport chloride through exchange with other anions.