Randomized controlled trial of daily teriparatide, weekly high-dose teriparatide, or bisphosphonate in patients with postmenopausal osteoporosis: The TERABIT study

PURPOSE

The effects of daily teriparatide (20 μg) (D-PTH), weekly high-dose teriparatide (56.5 μg) (W-PTH), or bisphosphonates (BPs) on areal bone mineral density (aBMD), bone turnover markers (BTMs), volumetric BMD (vBMD), microarchitecture, and estimated strength were investigated in postmenopausal osteoporosis patients.

METHODS

The study participants were 131 women with a history of fragility fractures. They were randomized to receive D-PTH, W-PTH, or BPs (alendronate or risedronate) for 18 months. Dual-energy X-ray absorptiometry (DXA), BTMs, and high-resolution peripheral quantitative CT (HR-pQCT) parameters were evaluated at baseline and after 6 and 18 months of treatment. The primary endpoint was the change (%) in cortical thickness (Ct.Th) after 18 months' treatment compared with baseline.

RESULTS

DXA showed that D-PTH, W-PTH, and BPs increased lumbar spine aBMD (+12.0%, +8.5%, and +6.8%) and total hip aBMD (+3.0%, +2.1%, and +3.0%), but D-PTH and W-PTH decreased 1/3 radius aBMD (-4.1%, -3.0%, -1.4%) after 18 months. On HR-pQCT, D-PTH increased trabecular vBMD (Tb.vBMD) at the distal radius and tibia after 18 months (+6.4%, +3.7%) compared with the BPs group, decreased cortical volumetric tissue mineral density (Ct.vTMD) (-1.8%, -0.9%) compared with the other groups, increased Ct.Th (+1.3%, +3.9%), and increased failure load (FL) (+4.7%, +4.4%). W-PTH increased Tb.vBMD (+5.3%, +1.9%), maintained Ct.vTMD (-0.7%, +0.2%) compared with D-PTH, increased Ct.Th (+0.6%, +3.6%), and increased FL (+4.9%, +4.5%). The BPs increased Tb.vBMD only in the radius (+2.0%, +0.2%), maintained Ct.vTMD (-0.6%, +0.3%), increased Ct.Th (+0.5%, +3.4%), and increased FL (+3.9%, +2.8%).

CONCLUSIONS

D-PTH and W-PTH comparably increased Ct.Th, the primary endpoint. D-PTH had a strong effect on trabecular bone. Although D-PTH decreased Ct.vTMD, it increased Ct.Th and total bone strength. W-PTH had a moderate effect on trabecular bone, maintained Ct.vTMD, and increased Ct.Th and total bone strength to the same extent as D-PTH.

Bone microstructure in healthy men measured by HR-pQCT: Age-related changes and their relationships with DXA parameters and biochemical markers

OBJECTIVE

The primary purpose of this cross-sectional study was to investigate the characteristics of age-related changes in bone microstructure on high-resolution peripheral quantitative computed tomography (HR-pQCT), areal bone mineral density (aBMD) on dual-energy X-ray absorptiometry (DXA), and bone-related biochemical markers in men. The secondary purpose of this study was to examine how bone microstructure is related to aBMD and biochemical markers.

METHODS

The subjects were 128 healthy Japanese men (20-97 years old). Bone microstructure was measured in the distal radius and tibia using second-generation HR-pQCT; aBMD in the proximal femur and lumbar spine was measured with DXA; and tartrate-resistant acid phosphatase-5b (TRACP-5b), type I procollagen-N-propeptide (P1NP), 25(OH) vitamin D, and pentosidine concentrations were measured by blood tests.

RESULTS

In trabecular bone, the trabecular volumetric BMD (Tb.vBMD) and trabecular number (Tb.N) were lower with age (r = -0.23, -0.35) (r = -0.36,-0.33), and trabecular separation (Tb.Sp) and the star volume of marrow space (V*ms) were higher with age (r = 0.29, 0.41) (r = 0.34, 0.38) in both the radius and tibia. In cortical bone, cortical volumetric BMD (Ct.vBMD) was lower with age (r = -0.25, -0.52), and cortical porosity (Ct.Po) was higher with age (r = 0.67, 0.62) in both the radius and tibia. In the tibia, cortical thickness (Ct.Th) and cortical area (Ct.Ar) were lower with age (r = -0.40) (r = -0.43), whereas, in the radius, they were maintained, and periosteal perimeter (Ct.Pm) was higher with age (r = 0.35). aBMD in the proximal femur and P1NP were lower, and pentosidine was higher with increased age, whereas aBMD in the lumbar spine, TRACP-5b, and 25(OH) vitamin D had no relationships with age. DXA and HR-pQCT showed strong correlations particularly with femoral aBMD and tibial Tb.vBMD and Ct.Ar (r = 0.61) (r = 0.61), whereas no DXA parameters were related with Ct.Po. In correlations between biochemical markers and HR-pQCT, TRACP-5b and total P1NP were negatively correlated with Ct.vBMD (r = -0.31) (r = -0.35), but almost no other correlations were seen.

CONCLUSIONS

Age-related changes of the bone microstructure in men were characterized by decreases in trabecular and cortical vBMD associated with decreased trabecular number, cavitation of the trabecular structure, and increased cortical porosity. Femoral aBMD was strongly related to bone microstructure in the tibia, whereas both lumbar aBMD and femoral aBMD were not related to Ct.Po, and biochemical markers showed almost no relationships with bone microstructure.

Differences in bone mineral density and morphometry measurements by fixed versus relative offset methods in high-resolution peripheral quantitative computed tomography

INTRODUCTION

High-resolution peripheral quantitative computed tomography (HR-pQCT), which enables in vivo analysis of bone morphometry, is widely used in osteoporosis research. The scan position is usually determined by the fixed offset method; however, there are concerns that the scan position can become relatively proximal if limb length is short. The present study compared bone mineral density and morphometry measured using the fixed and relative offset methods, in which the scan position is determined based on the lengths of the forearm and lower leg, and investigated factors responsible for measurement differences between the two methods.

METHODS

A total of 150 healthy Japanese subjects, comprising 75 men and 75 women, with a mean age of 45.1 years, were enrolled in this study. The distal radius and tibia were scanned using the fixed and relative offset methods; the fixed offset method involved scanning the radius and tibia at 9 mm and 22 mm, respectively, proximal to their distal articular surfaces. By contrast, the relative offset method entailed scanning the radius at 4% of the forearm length and the tibia at 7.3% of the lower leg length, proximal to their respective distal articular surfaces. The percent overlap between the scan positions of the two methods was measured using the scout views. Measurement values obtained with the two methods were compared. The correlation between the differences in the values among the two methods and forearm length, lower leg length, and body height was examined.

RESULTS

The subjects had a mean height of 164.3 ± 14.3 cm, mean forearm length of 252.9 ± 17.3 mm, and mean lower leg length of 346.7 ± 22.3 mm. The mean percent overlap was 85.0 ± 9.1% (59.2-99.6%) for the radius and 79.8 ± 12.5% (48.3-99.8%) for the tibia. Fixed offset scanning yielded higher total volumetric bone mineral density (Tt.vBMD) and cortical vBMD (Ct.vBMD) and greater cortical thickness (Ct.Th) (all p < 0.001). The differences between the two methods in terms of Tt.vBMD, Ct.vBMD and Ct.Th were significantly greater with shorter forearm length, lower leg length, and body height (radius: 0.51 < |r| < 0.63, tibia: 0.61 < |r| < 0.95).

CONCLUSION

Measurements of bone mineral density and morphometry obtained using the fixed offset method differed from those obtained using the relative offset method, which takes body size into account. Shorter body height, forearm length, and lower leg length were found to correlate with greater measurement differences. In populations with smaller stature, use of the fixed offset method results in relatively proximal images; thus, caution should be exercised when comparing groups of different height.

Deterioration of bone microstructure by aging and menopause in Japanese healthy women: analysis by HR-pQCT

INTRODUCTION

Second-generation high-resolution peripheral quantitative computed tomography (HR-pQCT) has provide higher quality of bone images with a voxel size of 61 µm, enabling direct measurements of trabecular thickness. In addition to the standard parameters, the non-metric trabecular parameters such as trabecular morphology (plate to rod-like structures), connectivity, and anisotropy can also be analyzed. The purpose of this study is to investigate deterioration of bone microstructure in healthy Japanese women by measuring standard and non-metric parameters using HR-pQCT.

MATERIALS AND METHODS

Study participants were 61 healthy Japanese women (31-70 years). The distal radius and tibia were scanned using second-generation HR-pQCT, and microstructures of trabecular and cortical bone were measured. Non-metric trabecular parameters included structure model index (SMI), trabecular bone pattern factor (TBPf), connectivity density (Conn.D), number of nodes (N.Nd/TV), degree of anisotropy (DA), and star volume of marrow space (V*ms). Estimated bone strength was evaluated by micro finite element analysis. Associations between bone microstructure, estimated bone strength, age, and menopause were analyzed.

RESULTS

Trabecular number declined with age, and trabecular separation increased. SMI and TBPf increased, Conn.D and N.Nd/TV declined, and V*ms increased. Cortical BMD and thickness declined with age, and porosity increased. Stiffness and failure load decreased with age. Cortical thickness and estimated bone strength were affected by menopause. Cortical thickness was most associated with estimated bone strength.

CONCLUSIONS

Trabecular and cortical bone microstructure were deteriorated markedly with age. Cortical thickness decreased after menopause and was most related to bone strength. Non-metric parameters give additional information about osteoporotic changes of trabecular bone.

ATP triggers a robust intracellular [Ca2+ ]-mediated signalling pathway in human synovial fibroblasts

NEW FINDINGS

What is the central question of this study? What are the main [Ca²⁺ ]_i signalling pathways activated by ATP in human synovial fibroblasts? What is the main finding and its importance? In human synovial fibroblasts ATP acts through a linked G-protein (G_q ) and phospholipase C signalling mechanism to produce IP₃ , which then markedly enhances release of Ca²⁺ from the endoplasmic reticulum. These results provide new information for the detection of early pathophysiology of arthritis.

ABSTRACT

In human articular joints, synovial fibroblasts (HSFs) have essential physiological functions that include synthesis and secretion of components of the extracellular matrix and essential articular joint lubricants, as well as release of paracrine substances such as ATP. Although the molecular and cellular processes that lead to a rheumatoid arthritis (RA) phenotype are not fully understood, HSF cells exhibit significant changes during this disease progression. The effects of ATP on HSFs were studied by monitoring changes in intracellular Ca²⁺ ([Ca²⁺ ]_i ), and measuring electrophysiological properties. ATP application to HSF cell populations that had been enzymatically released from 2-D cell culture revealed that ATP (10-100 μm), or its analogues UTP or ADP, consistently produced a large transient increase in [Ca²⁺ ]_i . These changes (i) were initiated by activation of the P₂ Y purinergic receptor family, (ii) required G_q -mediated signal transduction, (iii) did not involve a transmembrane Ca²⁺ influx, but instead (iv) arose almost entirely from activation of endoplasmic reticulum (ER)-localized inositol 1,4,5-trisphosphate (IP₃ ) receptors that triggered Ca²⁺ release from the ER. Corresponding single cell electrophysiological studies revealed that these ATP effects (i) were insensitive to [Ca²⁺ ]_o removal, (ii) involved an IP₃ -mediated intracellular Ca²⁺ release process, and (iii) strongly turned on Ca²⁺ -activated K⁺ current(s) that significantly hyperpolarized these cells. Application of histamine produced very similar effects in these HSF cells. Since ATP is a known paracrine agonist and histamine is released early in the inflammatory response, these findings may contribute to identification of early steps/defects in the initiation and progression of RA.

Evaluation of factors associated with relapse in telaprevir-based triple therapy for chronic hepatitis C

BACKGROUND AND RATIONALE

Most patients with chronic hepatitis C show virological response to telaprevir-based triple therapy, and achieve an end-of-treatment response (ETR). However, some patients showing ETR develop virological relapse. This study was carried out to evaluate factors associated with relapse after triple therapy.

MATERIALS AND METHODS

A prospective, multicentric study was conducted in chronic hepatitis C patients who received telaprevir-based triple therapy. We evaluated independent variables such as age, with or without cirrhosis, prior treatment response to interferon (IFN) therapy, IL28B genotype, core amino acid (aa) 70 mutation, drug adherence, white blood cell counts, hemoglobin level, and serum low-density lipoprotein (LDL) cholesterol level. The characteristics of the patients who relapsed after achieving ETR were compared with those who did not.

RESULTS

Among 168 patients, 157 patients achieved ETR (93.5%) and 11 discontinued. Of these 157 patients, relapse occurred in 21 patients (13.4%). Nineteen patients (90.5%) of 21 relapsed patients had the IL28B non-TT genotype (P = 1.79 × 10 -9 ). Multivariate analysis identified core amino acid 70 [P = 0.018, crude odds ratio (OR): 6.927] and the IL28B genotype (P = 3.758 × 10 -5 , crude OR: 39.311) as significantly independent factors that influenced the relapse-related variables. Among the 49 patients with the IL28B non-TT, 18 patients had core aa70 mutation and 31 patients had core aa70 wild-type. In addition, 66.7% (12/18) of those with core aa70 mutation and 22.6% (7/31) of those with core aa70 wild-type developed relapse (P = 0.005).

DISCUSSION

Core aa70 mutation and the IL28B non-TT genotype were identified as independent factors that influenced relapse after achievement of ETR for telaprevir-based triple therapy.

An open-label randomized controlled study of pegylated interferon/ribavirin combination therapy for chronic hepatitis C with versus without fluvastatin

Pegylated interferon (PEG-IFN)/ribavirin combination therapy is the standard-of-care (SOC) treatment for chronic hepatitis C patients infected with hepatitis C virus (HCV) genotype 1b and high viral load. The addition of fluvastatin to SOC treatment has been suggested to be effective for better outcome in retrospective pilot analyses. We investigated whether the combination of fluvastatin with PEG-IFN/ribavirin could actually improve sustained viral response (SVR) in patients with HCV genotype 1b and high viral load. A randomized, open-labeled, controlled study was conducted between July 2008 and December 2009 in 101 chronic hepatitis C patients allocated to PEG-IFN/ribavirin combination therapy with or without fluvastatin. SVR rates were calculated in groups, stratifying host and viral factors. We also analyzed predictive factors for SVR among patients on fluvastatin with multivariate regression analysis. Rapid and early virological, and end of treatment response rates in the fluvastatin group were not significantly different from those in the non-fluvastatin group. Notwithstanding, SVR rate was significantly higher in the fluvastatin group than in the non-fluvastatin group (63.0%vs 41.7%, P = 0.0422). Comparison of the two groups stratifying demographic data and HCV characteristics showed significantly higher SVR rates to more than 80% in males, more than two mutations in the interferon sensitivity determining region (ISDR), and a history of relapse among the fluvastatin group than the non-fluvastatin group. Being male and major genotype IL28B single nucleotide polymorphisms (SNPs) were independent predictive factors for SVR among patients on fluvastatin with multivariate analysis. Fluvastatin-combined with PEG-IFN/ribavirin therapy significantly improves SVR rates in patients with HCV genotype 1b and high viral load. Male and major genotype IL28B SNPs were independent predictors for SVR among patients on fluvastatin combination therapy.

BRAF mutation is a powerful prognostic factor in advanced and recurrent colorectal cancer

Background:

Activating mutation of KRAS and BRAF are focused on as potential prognostic and predictive biomarkers in patients with colorectal cancer (CRC) treated with anti-EGFR therapies. This study investigated the clinicopathological features and prognostic impact of KRAS/BRAF mutation in advanced and recurrent CRC patients.

Method:

Patients with advanced and recurrent CRC treated with systemic chemotherapy (n=229) were analysed for KRAS/BRAF genotypes by cycleave PCR. Prognostic factors associated with survival were identified by univariate and multivariate analyses using the Cox proportional hazards model.

Results:

KRAS and BRAF mutations were present in 34.5% and 6.5% of patients, respectively. BRAF mutated tumours were more likely to develop on the right of the colon, and to be of the poorly differentiated adenocarcinoma or mucinous carcinoma, and peritoneal metastasis. The median overall survival (OS) for BRAF mutation-positive and KRAS 13 mutation-positive patients was 11.0 and 27.7 months, respectively, which was significantly worse than that for patients with wild-type (wt) KRAS and BRAF (40.6 months) (BRAF; HR=4.25, P<0.001, KRAS13; HR=2.03, P=0.024). After adjustment for significant features by multivariate Cox regression analysis, BRAF mutation was associated with poor OS (HR=4.23, P=0.019).

Conclusion:

Presence of mutated BRAF is one of the most powerful prognostic factors for advanced and recurrent CRC. The KRAS13 mutation showed a trend towards poor OS in patients with advanced and recurrent CRC.

Progression-free survival and time to progression as surrogate markers of overall survival in patients with advanced gastric cancer: Literature-based analysis of 36 randomized trials

103

Background: We evaluated the potential of progression-free survival (PFS) and time to progression (TTP) to act as surrogates of overall survival (OS) in clinical trial settings by a comprehensive literature-based analysis.

Methods: Randomized trials of systemic chemotherapy for advanced gastric cancer were identified by comprehensive electronic and manual search. Correlations between PFS/TTP and OS were evaluated.

Results: Thirty-six trials with a total of 83 treatment arms and 10,484 patients were selected for analysis. The nonparametric Spearman rank correlation coefficient (p) between median PFS/TTP and OS was 0.70 (95% CI, 0.59 to 0.82) and the correlation coefficient between hazard ratios in PFS/TTP and OS was 0.80 (95% CI, 0.68 to 0.92). Correlation tended to be higher in non-Asian (p = 0.80; 0.61-0.98) than Asian trials (p = 0.67; 0.39-0.94), higher in trials reporting PFS (p = 0.85; 0.72-0.97) than in those reporting TTP (p = 0.60; 0.24-0.97), and higher in trials in patients with measurable lesions only (p = 0.91; 0.77-1.00) than in those including non-measurable lesions (p = 0.71; 0.50-0.93), albeit that none of these differences was significant.

Conclusions: Our results indicate that improvements in PFS/TTP in advanced gastric cancer strongly correlate with improvements in OS. PFS/TTP may be an appropriate surrogate for OS in clinical trials for advanced gastric cancer.

No significant financial relationships to disclose.

Evaluation of BRAF mutation as a powerful prognostic factor in advanced and recurrent colorectal cancer

413

Background: Alterations in the RAS/RAF/ERK signaling pathways frequently occur in colorectal cancer (CRC). KRAS mutations preclude responsiveness to EGFR-targeted therapies for CRC patients. However, prognostic significance of KRAS mutation is still controversial. The aim of this study is to investigate clinicopathological features of KRAS mutation in codon 12 and 13 as well as of BRAF mutation, and to validate prognostic impact of KRAS/BRAF mutation in advanced and recurrent CRC.

Methods: The population consisted of 230 unselected patients who had undergone first-line chemotherapy for advanced and recurrent CRC between November 2002 and June 2010. Cycleave PCR was performed to detect a point mutation at codon 12, 13 or 61 in KRAS, and the V600E mutation in BRAF. Prognostic factors associated with survival were identified using univariate and multivariate logistic and/or Cox proportional hazards analyses.

Results: KRAS mutations were present in 34.8% (n= 80) of patients, including 23.5% (n = 54) in codon 12, 11.3% (n = 26) in codon 13, and 0% in codon 61. 6.5% (n = 15) of patients had BRAF mutation. None of the CRC patients carried both KRAS and BRAF mutations. The primary tumor lesions were located on the right side of the colon in 60% of the BRAF mutant patients (p=0.0371). Furthermore, BRAF mutant was significantly associated with the pathological subtypes of poorly differentiated adenocarcinoma/mucinous carcinoma (p<0.0001) and peritoneal metastasis (p=0.0059). The median overall survival for BRAF mutant and KRAS 13 mutant patients was 11.0 and 27.7 months, respectively, which was significantly worse than that for KRAS wild-type (wt)/BRAF wt (40.6 months) (BRAF; HR=3.89, 95% CI 1.83-8.24, p<0.001, KRAS13; HR=2.03, 95% CI 1.10-3.74, p=0.024). After adjustment for significant features by multivariate Cox regression analysis, BRAF mutation was associated with poor overall survival (HR, 3.70, 95% CI, 1.48-9.28; p=0.005), together with performance status 2.

Conclusions: This retrospective analysis shows that clinicopathological features of CRC patients with BRAF mutations seem to be distinct from those with wild type BRAF. BRAF mutation is one of the most powerful prognostic factors in advanced and recurrent CRC.

No significant financial relationships to disclose.

Amphotericin B-induced nephrotoxicity: characterization of blood and urinary biochemistry and renal morphology in mice

This study was conducted to characterize blood and urinary biochemistry, and renal morphology, after single or 1-week repeated dosing of mice with the polyene macrolide antibiotic, amphotericin B (AMB). AMB was intravenously administered to mice at 2 or 4 mg/kg for the single-dose experiment or once daily at 1 or 2 mg/kg for 1 week for the repeated-dose experiment. The most prominent histopathological findings included necrosis of the tubular epithelial cells in the thick ascending limb of Henle's loop in the renal outer medulla at a single dose of 2 or 4 mg/kg, and the severity of the lesion was dose-dependent. Blood chemistry and urinalysis revealed several changes suggestive of renal dysfunction such as reduction of plasma filtration ability (increases in plasma creatinine and blood urea nitrogen, a decrease in creatinine clearance) and polyuria accompanied with dehydration (decrease in renal water reabsorption, increases in plasma total protein and albumin) at a dose of 4 mg/kg in the single-dose experiment. Among the parameters analyzed, urinary lactate dehydrogenase was the most sensitive and reliable parameter for the prediction of AMB-induced nephrotoxicity in mice. These data provided comprehensive information on the nephrotoxicity of AMB and indicate useful markers for the sensitive detection of AMB-induced renal injury in mice.

Polarization control in three-dimensional resonant coherent excitation

We present an experimental demonstration of an ingenious technique to control the alignment of the atomic internal state in the x-ray region using a periodic crystal field. The alignment directions of Ar16+ and Fe24+ ions were readily controlled by selecting the array of atomic planes using three-dimensional resonant coherent excitation, and were probed via the anisotropy of the deexcitation x-ray emission. We applied this method to a double resonance experiment, and succeeded in controlling the population of the specific magnetic substate in a Lambda-type three-level configuration.

Methyl Methacrylate Activates the Gsta1 Promoter

Residual monomers in resin-based biomaterials cause cytotoxicity. We previously showed that methyl methacrylate (MMA) induced mRNA expression of the glutathione S-transferase alpha 1 gene ( Gsta1) located downstream of the cis-acting anti-oxidant responsive element (ARE). Herein, we tested the hypothesis that MMA activated the Gsta1 promoter through the ARE. HepG2 cells were transfected with a luciferase reporter vector containing the ARE and the Gsta1 promoter (−990 to +46 bp) and cultured for 12 hrs with MMA (initial concentration, 10 mM). Analysis of the expressed luciferase activity indicated that MMA activated the promoter 2.6-fold. MMA (from 1 to 30 mM) dose-dependently increased the promoter activity, which reached a plateau between 6 and 12 hrs. In HepG2 cells transfected with a reporter vector containing 2 AREs and a TATA-like promoter, 10 mM MMA increased the reporter expression 2.8-fold. These results suggest that MMA increases Gsta1 transcription through ARE-mediated promoter activation.

Skeletal and Cardiac Muscle Defects in a Murine Model of Emery-Dreifuss Muscular Dystrophy

Previous histological findings, physiological data, and behavioral observations on the A-type lamin knockout mouse (Lmna(-/-)) suggest that important aspects of this model resemble the human Emery-Dreifuss muscular dystrophy (EDMD) phenotype. The main goal of our experiments was to study skeletal and cardiac muscle function in this murine model to obtain the semiquantitative data needed for more detailed comparisons with human EDMD defects. Measurements of the mechanical properties of preparations from two different skeletal muscle groups, the soleus and the diaphragm, were made in vitro. In addition, records of the electrocardiogram, and measurements of heart rate variability were obtained; and phasic contractions (unloaded shortening) of enzymatically isolated ventricular myocytes were monitored. Soleus muscles from Lmna(-/-) mice produced less force and work than control preparations. In contrast, force and work production in strips of diaphragm were not changed significantly. Lead II electrocardiograms from conscious, restrained Lmna(-/-) mice revealed slightly decreased heart rates, with significant prolongations of PQ, QRS, and 'QT' intervals compared with those from control recordings. These ECG changes resemble some aspects of the ECG records from humans with EDMD; however, the cardiac phenotype in this Lmna(-/-) mouse model appears to be less well-defined/developed. Ventricular myocytes isolated from Lmna(-/-) mice exhibited impaired contractile responses, particularly when superfused with the beta-adrenergic agonist, isoproterenol (1 microM). This deficit was more pronounced in myocytes isolated from the left ventricle(s) than in myocytes from the right ventricle(s). In summary, tissues from the Lmna(-/-) mouse exhibit a number of skeletal and cardiac muscle deficiencies, some of which are similar to those which have been reported in studies of human EDMD.

Dressed atoms in flight through a periodic crystal field: X-VUV double resonance

We report the Autler-Townes doublet demonstrating a novel type of coherent interaction of atoms not with photons but with a periodic crystal field when the atom is in flight through a crystal at high velocity. It was observed by the nonoptical X-VUV (vacuum-ultraviolet) double resonance of three-dimensional resonant coherent excitation with good coherence. The states strongly coupled in the VUV region were probed by the excitation in the x-ray region. The characteristic spectra are well interpreted by an analogy of the dressed atom concept often adopted for the atom-photon interaction.

Anisotropic x-ray emission from heliumlike Fe24+ ions aligned by resonant coherent excitation with a periodic crystal potential

We have measured deexcitation x rays emitted from the resonant coherently excited 2(1)P(1) state of heliumlike Fe24+ ions of 423 MeV/amu, planar channeling through a Si crystal. Large anisotropy in the angular distribution of deexcitation x-ray emission is observed: the x-ray emission in the direction parallel to the channeling plane is favored by a factor of 2 compared to the perpendicular direction. This anisotropy originates from the direction of the periodic crystal field, which populates specific m states in resonant coherent excitation and aligns the excited states.

Three-dimensional resonant coherent excitation of nonchanneling ions in a crystal

We have observed resonant coherent excitation (RCE) of H-like Ar(17+) ions traveling through a 1 microm-thick Si crystal at an energy of 391 MeV/u in the nonchanneling condition. A three-dimensional periodic array of atomic planes induces RCE of the nonchanneling ions. The high energy heavy ions together with the thin crystal allow us to observe this new RCE through the measurements of the charge-state distribution of the emerging ions. The observed resonances are much narrower than those of planar-channeling ions due to the absence of the large Stark shift caused by the planar potential.

Volumetric coronary angiography using the 256-detector row computed tomography scanner: comparison in vivo and in vitro with porcine models

PURPOSE

To investigate the feasibility of volumetric cine imaging in human cardiac studies by comparing in vivo and in vitro coronary angiography using a 256-detector row computed tomography (CT) without ECG gating.

MATERIAL AND METHODS

The left and right coronary arteries of two domestic pigs were scanned in vivo and in vitro in cine mode using the 256-detector row CT. The device scanned approximately 100 mm in the cranio-caudal direction with one rotation, with a slice thickness of 0.5 mm.

RESULTS

The coronary arteries could be observed to the third-degree branches in vitro, but could be visualized clearly only to the proximal portion (first-degree or second-degree branches) in vivo.

CONCLUSION

Application of cardiac volumetric cine imaging with 256-detector row CT may be a promising means of obtaining diagnostic information and has potential for adoption to human studies.

Voltage-sensitive dye mapping in Langendorff-perfused rat hearts

An imaging system suitable for recordings from Langendorff-perfused rat hearts using the voltage-sensitive dye 4-[beta-[2-(di-n-butylamino)-6-naphthyl]vinyl]pyridinium (di-4-ANEPPS) has been developed. Conduction velocity was measured under hyper- and hypokalemic conditions, as well as at physiological and reduced temperature. Elevation of extracellular [K(+)] to 9 mM from 5.9 mM caused a slowing of conduction velocity from 0.66 +/- 0.08 to 0.43 +/- 0.07 mm/ms (35%), and reduction of the temperature to 32 degrees C from 37 degrees C caused a slowing from 0.64 +/- 0.07 to 0.46 +/- 0.05 mm/ms (28%). Ventricular activation patterns in sinus rhythm showed areas of early activation (breakthrough) in both the right and left ventricle, with breakthrough at a site near the apex of the right ventricle usually occurring first. The effects of mechanically immobilizing the preparation to reduce motion artifact were also characterized. Activation patterns in epicardially paced rhythm were insensitive to this procedure over the range of applied force tested. In sinus rhythm, however, a relatively large immobilizing force caused prolonged PQ intervals as well as altered ventricular activation patterns. The time-dependent effects of the dye on the rat heart were characterized and include 1) a transient vasodilation at the onset of dye perfusion and 2) a long-lasting prolongation of the PQ interval of the electrocardiogram, frequently resulting in brief episodes of atrioventricular block.

Possibility of venous return through bone marrow in the free fibular osteocutaneous flap

The authors report a case of a free fibular graft that was successful as a result of venous return delivered through the bone marrow. A 26-year-old man underwent reconstruction of the left tibia and a soft-tissue defect of the lower leg. A free vascularized fibular bone and skin flap was elevated. The fibular vessels were anastomosed to the dorsalis pedis vessels. The elevated fibular bone was fixed to the tibia. The next day, reanastomosis was necessary because of venous thrombosis. However, the fibular vein rethrombosed, but blood flow was ascertained by Doppler flowmetry, with darker blood flow being recognized from the edge of the flap. Four days after surgery, the skin color gradually improved, and the flap had almost completely taken. On retrospective evaluation, the authors concluded that this flap succeeded because venous return was routed through the bone marrow in the free fibular graft.

Activation of p44/p42 mitogen-activated protein kinase limits triiodothyronine-stimulated alkaline phosphatase activity in osteoblasts

It has been shown that thyroid hormone stimulates the activity of alkaline phosphatase, a marker of mature osteoblast phenotype, in osteoblasts. In the present study, we investigated whether p44/p42 mitogen-activated protein (MAP) kinase is involved in the thyroid hormone-stimulated alkaline phosphatase activity in osteoblast-like MC3T3-E1 cells. Triiodothyronine (T(3)) markedly induced the phosphorylation of p44/p42 MAP kinase. PD98059 and U0126, inhibitors of the upstream kinase that activates p44/p42 MAP kinase, significantly enhanced the T(3)-induced alkaline phosphatase activity in a dose-dependent manner. The phosphorylation of p44/p42 MAP kinase induced by T(3) was reduced by U0126. These results strongly suggest that p44/p42 MAP kinase takes part in the thyroid hormone-stimulated alkaline phosphatase activity in osteoblasts and that p44/p42 MAP kinase plays an inhibitory role in the thyroid hormone-effect.

Effects of carvedilol on left ventricular function, mass, and scintigraphic findings in isolated left ventricular non-compaction

A four month old infant with isolated left ventricular non-compaction was treated with carvedilol. Haemodynamic studies and various types of imaging-including echocardiography, radiographic angiography, magnetic resonance imaging, and single photon emission computed tomography with (201)Tl, (123)I-beta-methyliodophenylpentadecanoic acid (BMIPP), and (123)I-metaiodobenzylguanidine (MIBG)-were performed before and 14 months after treatment. Left ventricular ejection fraction increased from 30% to 57%, and left ventricular end diastolic volume, end systolic volume, and end diastolic pressure showed striking reductions during treatment. Left ventricular mass decreased to about two thirds of the baseline value after treatment. Per cent wall thickening increased after carvedilol in the segments corresponding to non-compacted myocardium. A mismatch between (201)Tl and BMIPP uptake in the area of non-compaction observed before carvedilol disappeared after treatment. Impaired sympathetic neuronal function shown by MIBG recovered after treatment. Thus carvedilol had beneficial effects on left ventricular function, hypertrophy, and both metabolic and adrenergic abnormalities in isolated left ventricular non-compaction.

Effects of carvedilol on left ventricular function, mass, and scintigraphic findings in isolated left ventricular non-compaction

A four month old infant with isolated left ventricular non-compaction was treated with carvedilol. Haemodynamic studies and various types of imaging—including echocardiography, radiographic angiography, magnetic resonance imaging, and single photon emission computed tomography with 201Tl,123I-β-methyliodophenylpentadecanoic acid (BMIPP), and 123I-metaiodobenzylguanidine (MIBG)—were performed before and 14 months after treatment. Left ventricular ejection fraction increased from 30% to 57%, and left ventricular end diastolic volume, end systolic volume, and end diastolic pressure showed striking reductions during treatment. Left ventricular mass decreased to about two thirds of the baseline value after treatment. Per cent wall thickening increased after carvedilol in the segments corresponding to non-compacted myocardium. A mismatch between201Tl and BMIPP uptake in the area of non-compaction observed before carvedilol disappeared after treatment. Impaired sympathetic neuronal function shown by MIBG recovered after treatment. Thus carvedilol had beneficial effects on left ventricular function, hypertrophy, and both metabolic and adrenergic abnormalities in isolated left ventricular non-compaction.

The role of C5a in the development of thrombotic glomerulonephritis in rats

Thrombus formation is the important pathologic finding observed in glomerulonephritis induced by antiglomerular basement membrane (GBM) antibodies. Although strong deposition of C3 and membrane attack complex (MAC) is observed in this disease, the role of complement has not been fully elucidated. The aim of this work was to investigate the role of complement, especially an anaphylatoxin C5a, in a rat model of thrombotic glomerulonephritis. Rats were first pretreated with subclinical dose of lipopolysaccharide (LPS). Thrombotic glomerulonephritis was then induced by intravenous injection with rabbit antirat GBM (RbAGBM) (Group I). For the evaluation of the role of complement, the soluble complement receptor type 1 (sCR1) (Group II) or the C5a receptor antagonist peptide (C5aR-AP) (Group III) was intravenously administered 30 min before RbAGBM injection. For exploring the role of neutrophils, rats were pretreated with cyclophosphamide before induction of disease (Group IV). All rats were sacrificed at 6 h, and histological examination was performed. Rats in Group I developed severe glomerular thrombosis. Leucocyte accumulation and strong binding of C3 and MAC were observed in the glomeruli. In rats treated with sCR1 (Group II) and C5aR-AP (Group III), both leucocyte accumulation and thrombus formation in the glomeruli were significantly inhibited. C3 and MAC were negative in the glomeruli in Group II rats, while they were strongly observed in Group III. In neutrophil depleted rats (Group IV), there was also deposition of C3 and MAC in the glomeruli but thrombus formation was not observed. These findings indicated that glomerular thrombosis is dependent on the leucocytes, and mediated in part by the anaphylatoxin C5a but not MAC in the present model.

Multiphotoreceptor and multioscillator system in avian circadian organization

Photoperiodism and circadian rhythms have been studied intensively in birds because Aves are typical seasonal breeders and diurnal animals. Light is the most important environmental factor involved in entrainment of circadian rhythms and photoperiodism. The eyes and the extraocular photoreceptors, such as the pineal organ and hypothalamus, are reported to have an important function not only for photoreception but also for circadian organization in nonmammalian vertebrates, including birds. In this report, we review the roles of the eyes, pineal organ, and deep brain as the components of the multiphotoreceptor and multioscillator system in avian circadian organization.

Comparison of three-dimensional contrast-enhanced magnetic resonance angiography and axial radiographic angiography for diagnosing congenital stenoses in small pulmonary arteries

Accuracy of 3-dimensional contrast-enhanced magnetic resonance angiography (MRA) in diagnosing morphology of the branch pulmonary artery (PA) was evaluated in 73 patients (aged 7.2 +/- 6.4 years [mean +/- SD]) with various congenital heart diseases. The presence or absence of localized stenosis of branch PAs, PA diameter, and Nakata's PA index were determined on MRA and axial radiographic angiography, and the results were compared. Sensitivity, specificity, and overall accuracy in detecting branch PA stenoses were 92.7%, 96.2%, and 95.2%, respectively. Correlations between axial radiographic angiography and MRA were excellent in measuring PA diameter (r = 0.956, SEE = 1.49 mm, n = 139) as well as PA index (r = 0.839, SEE = 48.9, n = 37); both p < 0.0001. Bland-Altman plots showed a mean difference +/- SD for PA diameter of 0.17 +/- 1.51 mm and for PA index of 8.5 +/- 50.1. When the main right and left PAs were taken as the first generation, the most distal branches visible on MRA were the 4.7 +/- 0.7 generation with breath-holding (n = 23) and the 3.7 +/- 0.5 without breath-holding (n = 50), respectively (p < 0.0001). Both intra- and interobserver variabilities of MRA measurements were few (9.5 +/- 11.6% and 13.5 +/- 15.0%, respectively, n = 139). In conclusion, 3-dimensional contrast-enhanced MRA enables us to document branch PA morphology clearly in infants and adult patients with congenital cardiovascular defects.

[A study of recovery factor about drug addiction recovery center "DARC"]

This study examines the effectiveness of the 'DARC' (Drug Addiction Rehabilitation Center) and its program in treating patients with drug dependence. DARC is the only rehabilitation facility group managed by recovered drug users in Japan. It uses the 'Twelve Step Program' as part of its recovery regime. Through structured questionnaires, the changes of participants' and ex-participants' everyday behavior, their acceptance of spirituality, attitude toward drugs, self-esteem, their coping skills and loneliness were examined. The results revealed: a.. Negative partial correlation between loneliness and everyday behavior. b.. Negative partial correlation between loneliness and positive/effective coping skills. c.. Positive partial correlation between acceptance of 'spirituality' and attitude toward drugs. d.. Positive partial correlation between acceptance of 'spirituality' and positive/effective coping skills. These results suggest that the acceptance of 'spirituality' and decreasing loneliness are important factors in the recovery from drug dependence.

Voltage-sensitive dye mapping of activation and conduction in adult mouse hearts

A custom-made apparatus based on a charge-coupled-device camera has been used to monitor changes in fluorescence from Langendorff-perfused adult mouse hearts stained with a voltage-sensitive dye, di-4-ANEPPS. With this approach it is possible to monitor activation of the ventricles at high temporal (375 micros/frame) and spatial resolution (72 x 78 pixels, 100 x 100 microm/pixel). In sinus rhythm, activation occurred with a complicated breakthrough pattern on both ventricles, and a total activation time of 3.51+/-0.16 ms (32 degrees C). A stimulus applied near the apex of the left ventricle resulted in a single activation wave front with a total activation time of 8.18+/-0.25 ms. Pacing from a site near the middle of the left ventricular epicardial surface revealed anisotropic conduction, indicating that conduction occurs preferentially in the direction of the predominant fiber orientation. The total activation time in this configuration was 5.44+/-0.24 ms. The difference in total activation time between sinus rhythm and epicardial stimulation suggests an important role for transmural conduction (the Purkinje system) in the mouse heart. These findings provide much of the necessary background needed for studying conduction abnormalities in genetically altered mice and suggest that the comparison of sinus rhythm and epicardial pacing can be used to reveal transmural conduction abnormalities.

Location of haemagglutinin in bacterial cells of Fusobacterium necrophorum subsp. necrophorum

The location of haemagglutinin (HA) of Fusobacterium necrophorum subsp. necrophorum VPI 2891 strain was investigated by immunofluorescence, confocal laser scan microscopy and immunoelectron microscopy. The immunofluorescence study demonstrated the fluorescence specific for the HA on the bacterial cells and confocal laser scan microscopy indicated similar fluorescence around the cross section of the bacterial cell. The immunoelectron microscopic study also revealed that the protein A-gold conjugates were located around the bacterial surfaces. These findings suggest that HA is one of the components of the cell surfaces of F. necrophorum subsp, necrophorum.

Magnetic resonance angiography and blood flow quantification

A variety of magnetic resonance (MR) techniques are available for flow imaging and quantification, each exploiting a different property of flowing blood to achieve contrast with stationary tissue, and each with its own strengths and limitations dependent on the flow conditions. These same techniques have been used to perform MR angiography of peripheral as well as the coronary arteries. This article provides an overview of MR angiographic and blood flow quantification techniques and their clinical application. Future technical advances in MR in concert with continuing developments in computer software and hardware are likely to make MR a major vascular technique in the coming decade.

Chimeras of Kir6.1 and Kir6.2 reveal structural elements involved in spontaneous opening and unitary conductance of the ATP-sensitive K+ channels

The ATP-sensitive K+ (KATP) channels, e.g. in heart and pancreatic beta-cells, open spontaneously in the absence of intracellular ATP (ATPi). Their unitary conductance is approximately 80 pS with 150 mM extracellular K+. These features are shared by the K+ channels composed of various sulfonylurea receptors (SURs) and Kir6.2, whereas SUR/Kir6.1 channels have a smaller conductance (approximately 35 pS) and do not open spontaneously in the absence of ATPi. To identify the structural elements in Kir6.0 subunits which determine these properties, we analyzed the properties of functional K+ channels composed of SUR2A, the cardiac type SUR, and various chimeras of Kir6.1 and Kir6.2 heterologously expressed in HEK (human embryonic kidney) 293T cells. The analyses indicate that the extracellular linker domain between the two putative membrane-spanning regions is responsible for the difference in the single channel conductance between SUR2A/Kir6.1 and SUR2A/Kir6.2 channels. The cytosolic N-terminal domain of Kir6.2 was mandatory for spontaneous channel opening in the absence of ATPi, although a part of C-terminus was also involved. These results implicate specific regions of Kir6.0 in the spontaneous opening and the single channel conductance.

Intravascular ultrasound imaging before and after balloon angioplasty for pulmonary artery stenosis

Previous reports regarding intravascular ultrasound (IVUS) imaging of the pulmonary arteries in children and its application to balloon pulmonary angioplasty are limited. This study was designed to compare findings of IVUS imaging and those of angiography of the pulmonary artery before and after the balloon angioplasty procedure. Thirty patients had significant pulmonary artery stenosis and underwent balloon angioplasty. In all, of 34 branch pulmonary arteries were dilated. All patients underwent both angiography and IVUS imaging at the time of balloon angioplasty. The mean age at balloon angioplasty was 5.7 +/- 4.0 yr. One echo-dense layer on IVUS was detected in 9% of the 34 stenotic vessels, and a two- or three-layered vascular wall pattern in 91%. The thickness of intima-medial layer (inner and middle layers) was greater than normal in 91% of stenotic vessels. After balloon angioplasty, intimal flaps and aneurysm were observed at 29 and 28 locations, respectively. Of these locations, the intimal flaps were detected by angiography in 44% and by IVUS in 100%; the aneurysm was detected by angiography in 61% and by IVUS in 93%. Media rupture was observed at 26 locations, and the change was detected only by IVUS. The present study suggests that intimal and medial changes in the pulmonary artery can be detected more precisely by IVUS than by angiography.

Intracellular nucleotide-mediated gating of SUR/Kir6.0 complex potassium channels expressed in a mammalian cell line and its modification by pinacidil

1. We have examined the properties of intracellular nucleotide-mediated gating of K+ channel constructs composed of the sulphonylurea receptor 2B and the inwardly rectifying K+ channel subunits Kir6.1 and Kir6.2 (SUR2B/Kir6.1 and SUR2B/Kir6.2 complex K+ channels) heterologously expressed in human embryonic kidney (HEK) 293T cells. In the cell-attached form, both types of K+ channel were activated by pinacidil. 2. In inside-out (IO) patches, the SUR2B/Kir6.2 channels opened spontaneously and were inhibited by intracellular ATP (ATPi). Pinacidil attenuated the ATPi-mediated channel inhibition in a concentration-dependent manner. In contrast, the SUR2B/Kir6.1 channels required intracellular nucleoside di- or tri-, but not mono-, phosphates for opening. The potency of adenine, guanine or uracil nucleotides to activate SUR2B/Kir6.1 channels was enhanced by pinacidil. 3. In the presence of pinacidil, adenine and guanine, but not uracil, nucleotides exhibited bell-shaped concentration-dependent activating effects on SUR2B/Kir6.1 channels. This was due to channel inhibition caused by adenine and guanine nucleotides, which was unaffected by pinacidil. 4. From power density spectrum analysis of SUR2B/Kir6.1 currents, channel activation could be described by the product of two gates, a nucleotide-independent fast channel gate and a nucleotide-dependent slow gate, which controlled the number of functional channels. Pinacidil specifically increased the potency of nucleotide action on the slow gate. 5. We conclude that Kir6.0 subunits play a crucial role in the nucleotide-mediated gating of SUR/Kir6.0 complex K+ channels and may determine the molecular mode of pinacidil action.

Sympathetic denervation and reinnervation after arterial switch operation for complete transposition

BACKGROUND

Sympathetic cardiopulmonary nerves arise from the cervical sympathetic trunks and the stellate ganglia and subsequently course along the origin of the great arteries and the coronary arteries to innervate the ventricles. Therefore, the sympathetic nerves may be obligatorily interrupted by the arterial switch operation (ASO) for complete transposition of the great arteries.

METHODS AND RESULTS

To demonstrate and characterize the possible sympathetic denervation, 51 patients after ASO, 4.8 years old (range, 1 month to 10.1 years), underwent [123I]metaiodobenzylguanidine (MIBG) imaging of the sympathetic nerve terminal. MIBG uptake to the heart was graded by quantitative analysis using the heart-to-mediastinum (H/M) ratio of MIBG uptake. A quantitative criterion for absent uptake of MIBG was set to 1.48 in the H/M ratio. Four patients < 1 month after ASO showed complete absence of MIBG uptake, which had been observed preoperatively. In contrast, 47 patients late after ASO (range, 15 months to 10.1 years) showed various degrees of uptake of MIBG. Patients operated on at < or =55 days of age showed positive MIBG uptake much more frequently than those operated on at later ages. Heart rate and rate-pressure product at peak exercise on a treadmill exercise test were significantly greater in patients with positive uptake than in those with absent uptake of MIBG.

CONCLUSIONS

Cardiac sympathetic nerves were denervated early after and reinnervated late after ASO. Neonatal ASO may be favorable to facilitate sympathetic reinnervation, which may affect exercise tolerance late after surgery.

The effects of nucleotides and potassium channel openers on the SUR2A/Kir6.2 complex K+ channel expressed in a mammalian cell line, HEK293T cells

The effects of potassium channel opening drugs and intracellular nucleotides on the ATP-sensitive K+ (KATP) channel composed of SUR2A and Kir6.2 in HEK293T cells were examined using the patch-clamp technique. The SUR2A/Kir6.2 channel was activated effectively by pinacidil, marginally by nicorandil but not by diazoxide. The pinacidil-activated channel currents were inhibited by glibenclamide with a Ki value of 160 nM. Upon formation of inside-out (I-O) patches, spontaneous openings of the channels appeared, which were inhibited by intracellular ATP (ATPi) equipotently in the presence and in the absence of intracellular Mg2+ (Mg2+i). The channel activity ran-down gradually in I-O patches. The run-down channels could be reactivated by ATPi only in the presence of Mg2+i. Uridine 5'-diphosphate (UDP) antagonized the ATPi-mediated inhibition of the channel activity before run-down. After run-down, UDP activated the channel without antagonizing ATPi-mediated channel inhibition. Thus, the SUR2A/Kir6.2 reproduced the major properties of the native cardiac KATP channel well in terms of nucleotide regulation and pharmacology, and therefore can be a useful tool with which to elucidate the molecular mechanisms characterizing the KATP channel.

Electrophysiological characterization of an alternatively processed ERG K+ channel in mouse and human hearts

Mutants of HERG, the human form of ERG (the ether-a-go-go-related K+ channel gene), are responsible for some forms of the long-QT syndrome, an abnormality of cardiac repolarization. HERG was cloned from brain and has properties similar but not identical to the rapidly activating component of the native cardiac K+ channel current (Ikr). We identified in the mouse an alternatively processed form of ERG (MERG B) that is expressed abundantly in heart but only in trace amounts in brain. MERG B has a unique 36-amino acid NH2-terminal domain that is strongly basic and considerably shorter than the 376-amino acid NH2-terminal domain of HERG. When expressed in Xenopus oocytes, the kinetics of activation and deactivation of the MERG B current were best fit by a biexponential function, with the fast components dominant over the slow components. The fast component of activation had a mean tau value of 163 +/- 16 ms at -20 mV and 8 +/- 4 ms at +20 mV (n = 4). The fast component of deactivation had a mean tau value of 145 +/- 29 ms at -20 mV and 12 +/- 4 ms at -90 mV (n = 4). The MERG B current was blocked by the selective IKr blocker, dofetilide, with an IC50 of 54 nmol/L. In addition, we isolated HERG B, the human homologue of MERG B, which has electrophysiological characteristics qualitatively similar to those of MERG B. We have identified ERG B, an alternatively processed isoform of the ERG gene, expressed selectively in heart and with electrophysiological characteristics similar to those of native cardiac IKr.

Small left coronary arteries after arterial switch operation for complete transposition

BACKGROUND

Myocardial perfusion is not completely normal and ventricular function is depressed in some patients after the arterial switch operation. The basic mechanism has not yet been defined totally.

METHODS

The diameters of the right, left main trunk, anterior descending, and circumflex coronary arteries were measured by computer-assisted densitometry at 8 to 86 months (mean, 47.5 months) after the arterial switch operation in 86 patients.

RESULTS

The Z scores, compared with control, were +2.0 +/- 0.3, -1.8 +/- 0.3, and -1.5 +/- 0.3 for the right, left anterior descending, and circumflex coronary arteries, respectively. The Z score for the total cross-sectional area of the three vessels was -1.5 +/- 0.3. These parameters did not correlate with left ventricular ejection fraction.

CONCLUSIONS

At the midterm follow-up after the arterial switch operation for complete transposition of the great arteries, the left coronary arteries are small. A careful follow-up study is mandatory to clarify the clinical significance of this finding.

Sulphonylurea receptor 2B and Kir6.1 form a sulphonylurea-sensitive but ATP-insensitive K+ channel

1. We analysed the K+ channel composed of the sulphonylurea receptor 2B (SUR2B) and an inwardly rectifying K+ channel subunit Kir6.1 coexpressed in a mammalian cell line, HEK293T, with the patch clamp technique. 2. In the cell-attached configuration, K+ channel openers (pinacidil and nicorandil) activated approximately 33 pS K+ channels (approximately 145 mM external K+), which were inhibited by the sulphonylurea glibenclamide. 3. Although SUR2B forms an ATP-sensitive K+ channel with Kir6.2, whose amino acid sequence is approximately 70% homologous with that of Kir6.1, the K+ channel composed of SUR2B and Kir6.1 surprisingly did not spontaneously open on patch excision in the absence of intracellular ATP. 4. In inside-out patches, uridine diphosphate and guanosine diphosphate induced channel activity, which was inhibited by glibenclamide but not ATP. Intracellular ATP on its own activated the channels. K+ channel openers and intracellular nucleotides synergistically activated the channel. 5. Therefore, the K+ channel composed of SUR2B and Kir6.1 is not a classical ATP-sensitive K+ channel but closely resembles the nucleotide diphosphate-dependent K+ channel in vascular smooth muscle cells.

Giant hepatic angiomyolipoma associated with disseminated intravascular coagulation

We report a case of giant hepatic angiomyolipoma in a 68-year-old woman who had an increase in the fibrinolytic activity concomitant with disseminated intravascular coagulation (DIC). The presence of the tumor was confirmed by ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) of the abdomen and the selective arteriography of the liver via the superior mesenteric artery. Following treatment with heparin and gabexate mesilate, abnormal hemostatic values were corrected. Furthermore, the surgical removal of the huge hepatic angiomyolipoma completely normalized the alternations of the clotting system. These findings suggest that giant hepatic angiomyolipoma was profoundly associated with DIC.