Impact of coronary plaque characteristics on periprocedural myocardial injury after elective percutaneous coronary intervention -MDCT and CMR analysis-

Background

Percutaneous coronary intervention (PCI) is often complicated by periprocedural myocardial injury (PMI) manifested by elevated cardiac biomarkers. The occurrence of PMI has been shown to be associated with worse clinical outcome over short- and long-term.

Purpose

We performed multidetector computed tomography (MDCT) and cardiac magnetic resonance imaging (CMR) to evaluate the relationship between culprit plaque characteristics and PMI.

Methods

A total of 90 patients who underwent elective PCI were underwent CMR and multidetector coronary tomography before PCI. The high intensity plaque (HIP) on CMR was defined as a coronary plaque to myocardium signal intensity ratio (PMR) of >1.4. The plaque characteristics and the presence of napkin-ring sign (NRS) were analyzed on MDCT. PMI was defined as an increase in cardiac Troponin T levels to more than 5 times the upper limit of normal at 24 h after PCI. Patients were divided into 2 groups according to the presence (Group I, n=26) or absence (Group II, n=64) of PMI.

Results

Spotty calcification, positive remodeling, low attenuation plaque and NRS on MDCT were significantly more observed in Group I than in Group II. HIP on CMR was significantly more observed in Group I than in Group II. In the multivariable logistic regression analysis, the presence of NRS and HIP were significantly independent predictors of PMI (odds ratio (OR) 4.82, 95% confidence interval 1.13–20.60, P=0.034 and OR 3.66, 95% CI 1.09–12.30, P=0.036, respectively). Moreover, for prediction of PMI, NRS and HIP showed a high positive predictive value of 81%, and their absence showed a high negative predictive value of 91%.

Conclusions

MDCT and CMR may play an important role in detecting which lesions are high risks for myocardial necrosis after PCI in elective coronary stenting.

Funding Acknowledgement

Type of funding source: None

Association of coronary high-intensity plaque on T1-weighted magnetic resonance imaging and circulating malondialdehyde-modified low-density lipoprotein levels with cardiac events

Background

Although elevated oxidized low-density lipoprotein could play critical roles in vulnerable plaque, there are no studies that compared coronary high-intensity plaque (HIP) on non-contrast T1-weighted magnetic resonance imaging (T1WI_MRI) and circulating malondialdehyde-modified low-density lipoprotein (MDA-LDL) levels for the prediction of cardiac events.

Methods and results

A total of 139 patients with coronary artery stenosis (>70%) were examined with non-contrast T1WI using a 1.5-T MRI (HIP: n=63, non-HIP: n=76). Scheduled percutaneous coronary intervention (PCI) for culprit lesions was performed within 48 h after MRI. HIP was defined as a signal intensity of coronary plaque to cardiac muscle ratio (PMR) of ≥1.4. At admission, circulating levels of MDA-LDL and other lipid-related markers were measured. We evaluated the subsequent cardiac events, which were defined as major adverse cardiac events (MACE; cardiac death, myocardial infarction, and/or ischemia-driven PCI) during follow-up periods (5.6±1.3 years). Circulating MDA-LDL levels were significantly higher in patients with HIP than in those without HIP (p<0.0001). MDA-LDL levels were significantly correlated with PMR (r=0.490, p<0.0001). In multivariable logistic regression analysis, MDA-LDL levels were independently associated with the presence of HIP (OR 1.05; 95% CI, 1.02–1.08, p<0.0001). The incidence of MACE was significantly higher in patients with HIP (27%) than in those without HIP (5%; p=0.011 by the log-rank test). In the multivariable Cox proportional hazard analysis, the MDA-LDL levels (HR 1.03; 95% CI:1.01–1.05, p=0.007) and PMR (HR 2.39; 95% CI:1.19–4.65, p=0.016) were significantly associated with MACE. For MACE prediction, the C-statistic values for MDA-LDL, PMR, and PMR+MDA-LDL were 0.724, 0.791, and 0.800, respectively. Compared with MDA-LDL alone, the addition of PMR to MDA-LDL increased the net reclassification improvement by 0.78 (p=0.012).

Conclusions

MDA-LDL levels might be associated with the presence of HIP in patients with coronary artery disease. Furthermore, adding PMR to MDA-LDL levels markedly improved MACE prediction.

Funding Acknowledgement

Type of funding source: None

P3098Association with coronary high-intensity plaque on T1-weighted magnetic resonance imaging and circulating levels of malondialdehyde-modified low-density lipoprotein

Objectives

This study aimed to evaluate the association with coronary high-intensity plaque (HIP) on non-contrast T1-weighted magnetic resonance imaging (T1WI) and circulating levels of malondialdehyde-modified low-density lipoprotein (MDA-LDL).

Methods

A total of 139 patients with coronary artery stenosis (>70%) were imaged with non-contrast T1WI by using a 1.5-T magnetic resonance system (HIP: n=60, non-HIP: n=79). HIP was defined as a signal intensity of coronary plaque to cardiac muscle ratio (PMR) of ≥1.4. At admission, circulating levels of MDA-LDL and other lipid-related markers (triglyceride, HDL, LDL, Lp(a), RLP-C, and EPA/AA) were measured.

Results

Circulating levels of MDA-LDL (p=0.001) and LDL (p=0.041) were significantly higher in patients with HIP than those without, whereas the other lipid-related markers were not significantly different between both groups. In multivariable logistic regression analysis, MDA-LDL levels were independently associated with the presence of HIP (OR 1.03; 95% CI, 1.00–1.06, p=0.015) after adjusting for cofounding factors (age, sex, triglyceride, LDL, Lp(a), RLP-C, and EPA/AA). The optimal MDA-LDL threshold for predicting coronary HIP was 90.4 U/L, identified by the receiver operating characteristic curve.

Conclusion

MDA-LDL levels might be associated with the presence of HIP in patients with coronary artery disease.

Performance evaluation of the small-animal PET scanner ClairvivoPET using NEMA NU 4-2008 Standards

The aim of this study was to evaluate the performance of ClairvivoPET using NEMA NU4 standards. The ClairvivoPET incorporates a LYSO dual depth-of-interaction detector system with 151 mm axial field of view (FOV). Spatial resolution, sensitivity, counting rate capabilities, and image quality were evaluated using NEMA NU4-2008 standards. Normal mouse imaging was also performed for 10 min after intravenous injection of (18)F(-)-NaF. Data were compared with 19 other preclinical PET scanners. Spatial resolution measured using full width at half maximum on FBP-ramp reconstructed images was 2.16 mm at radial offset 5 mm of the axial centre FOV. The maximum absolute sensitivity for a point source at the FOV centre was 8.72%. Peak noise equivalent counting rate (NECR) was 415 kcps at 14.6 MBq ml(-1). The uniformity with the image-quality phantom was 4.62%. Spillover ratios in the images of air and water filled chambers were 0.19 and 0.06, respectively. Our results were comparable with the 19 other preclinical PET scanners based on NEMA NU4 standards, with excellent sensitivity because of the large FOV. The ClairvivoPET with iterative reconstruction algorithm also provided sufficient visualization of the mouse spine. The high sensitivity and resolution of the ClairvivoPET scanner provided high quality images for preclinical studies.

Wavelet-based resolution recovery using an anatomical prior provides quantitative recovery for human population phantom PET [¹¹C]raclopride data

The objective of this study was to evaluate a resolution recovery (RR) method using a variety of simulated human brain [¹¹C]raclopride positron emission tomography (PET) images. Simulated datasets of 15 numerical human phantoms were processed by a wavelet-based RR method using an anatomical prior. The anatomical prior was in the form of a hybrid segmented atlas, which combined an atlas for anatomical labelling and a PET image for functional labelling of each anatomical structure. We applied RR to both 60 min static and dynamic PET images. Recovery was quantified in 84 regions, comparing the typical 'true' value for the simulation, as obtained in normal subjects, simulated and RR PET images. The radioactivity concentration in the white matter, striatum and other cortical regions was successfully recovered for the 60 min static image of all 15 human phantoms; the dependence of the solution on accurate anatomical information was demonstrated by the difficulty of the technique to retrieve the subthalamic nuclei due to mismatch between the two atlases used for data simulation and recovery. Structural and functional synergy for resolution recovery (SFS-RR) improved quantification in the caudate and putamen, the main regions of interest, from -30.1% and -26.2% to -17.6% and -15.1%, respectively, for the 60 min static image and from -51.4% and -38.3% to -27.6% and -20.3% for the binding potential (BP(ND)) image, respectively. The proposed methodology proved effective in the RR of small structures from brain [¹¹C]raclopride PET images. The improvement is consistent across the anatomical variability of a simulated population as long as accurate anatomical segmentations are provided.

Mechanotransduction activates α₅β₁ integrin and PI3K/Akt signaling pathways in mandibular osteoblasts

It is unclear how bone cells at different sites detect mechanical loading and how site-specific mechanotransduction affects bone homeostasis. To differentiate the anabolic mechanical responses of mandibular cells from those of calvarial and long bone cells, we isolated osteoblasts from C57B6J mouse bones, cultured them for 1week, and subjected them to therapeutic low intensity pulsed ultrasound (LIPUS). While the expression of the marker proteins of osteoblasts and osteocytes such as alkaline phosphatase and FGF23, as well as Wnt1 and β-catenin, was equally upregulated, the expression of mandibular osteoblast messages related to bone remodeling and apoptosis differed from that of messages of other osteoblasts, in that the messages encoding the pro-remodeling protein RANKL and the anti-apoptotic protein Bcl-2 were markedly upregulated from the very low baseline levels. Blockage of the PI3K and α(5)β(1) integrin pathways showed that the mandibular osteoblast required mechanotransduction downstream of α(5)β(1) integrin to upregulate expression of the proteins β-catenin, p-Akt, Bcl-2, and RANKL. Mandibular osteoblasts thus must be mechanically loaded to preserve their capability to promote remodeling and to insure osteoblast survival, both of which maintain intact mandibular bone tissue. In contrast, calvarial Bcl-2 is fully expressed, together with ILK and phosphorylated mTOR, in the absence of LIPUS. The antibody blocking α(5)β(1) integrin suppressed both the baseline expression of all calvarial proteins examined and the LIPUS-induced expression of all mandibular proteins examined. These findings indicate that the cellular environment, in addition to the tridermic origin, determines site-specific bone homeostasis through the remodeling and survival of osteoblastic cells. Differentiated cells of the osteoblastic lineage at different sites transmit signals through transmembrane integrins such as α(5)β(1) integrin in mandibular osteoblasts, whose signaling may play a major role in controlling bone homeostasis.

A method to measure PET scatter fractions for daily quality control

PURPOSE

Regular monitoring of PET scanner performance is mandatory to assure quality of acquired data. While extensive performance measurements include many scanner characteristics such as resolution, count rate, uniformity, sensitivity, and scatter fraction (SF), most daily QC protocols are limited to uniformity and sensitivity measurements. These measurements may be too insensitive to detect more subtle drifts in detector gains that could lead to reduced detection of primary and increased detection of scattered events. Current methods to measure SF, such as those prescribed by the NEMA protocols (SF-NEMA), however, require specially designed phantoms and are too cumbersome to be performed on a daily basis.

METHODS

In this study, a simple and versatile method to determine SF is described. This method (SF-DAILY) does not require additional measurements, making it suitable for daily QC. The method was validated for four different scanners by comparing results with those obtained with the NEMA 1994 protocol.

RESULTS

For all scanner types and acquisition modes, excellent agreement was found between SF-NEMA and SF-DAILY.

CONCLUSIONS

The proposed method is a very practical and valuable addition to current daily QC protocols. In addition, the method can be used to accurately measure SF in phantoms with other dimensions than the NEMA phantom.

Combination of gastric atrophy, reflux symptoms and histological subtype indicates two distinct aetiologies of gastric cardia cancer

INTRODUCTION

Atrophic gastritis is a risk factor for non-cardia gastric cancer, and gastro-oesophageal reflux disease (GORD) for oesophageal adenocarcinoma. The role of atrophic gastritis and GORD in the aetiology of adenocarcinoma of the cardia remains unclear. We have investigated the association between adenocarcinoma of the different regions of the upper gastrointestinal tract and atrophic gastritis and GORD symptoms.

METHODS

138 patients with upper GI adenocarcinoma and age- and sex-matched controls were studied. Serum pepsinogen I/II was used as a marker of atrophic gastritis and categorised to five quintiles. History of GORD symptoms, smoking and H pylori infection were incorporated in logistic regression analysis. Lauren classification of gastric cancer was used to subtype gastric and oesophageal adenocarcinoma.

RESULTS

Non-cardia cancer was associated with atrophic gastritis but not with GORD symptoms; 55% of these cancers were intestinal subtype. Oesophageal adenocarcinoma was associated with GORD symptoms, but not with atrophic gastritis; 84% were intestinal subtype. Cardia cancer was positively associated with both severe gastric atrophy [OR, 95% CI: 3.92 (1.77 to 8.67)] and with frequent GORD symptoms [OR, 95% CI: 10.08 (2.29 to 44.36)] although the latter was only apparent in the non-atrophic subgroup and in the intestinal subtype. The association of cardia cancer with atrophy was stronger for the diffuse versus intestinal subtype and this was the converse of the association observed with non-cardia cancer.

CONCLUSION

These findings indicate two distinct aetiologies of cardia cancer, one arising from severe atrophic gastritis and being of intestinal or diffuse subtype similar to non-cardia cancer, and one related to GORD and intestinal in subtype, similar to oesophageal adenocarcinoma. Gastric atrophy, GORD symptoms and histological subtype may distinguish between gastric versus oesophageal origin of cardia cancer.

Expression of matrilysin (matrix metalloproteinase-7) in primary cutaneous and metastatic melanoma

BACKGROUND

Matrilysin (MMP-7), a member of the matrix metalloproteinase (MMP) family of proteins, is expressed in various types of malignant tumours. There have been no previous studies of the correlation between matrilysin expression and melanoma.

OBJECTIVES

Protein expression of matrilysin was evaluated in human cutaneous melanomas, metastatic melanomas, acquired common melanocytic naevi and Spitz naevi, and the data were corrected with the clinicopathological factors.

METHODS

We retrospectively investigated 18 primary melanomas, 15 metastatic melanomas, 10 common melanocytic naevi and five Spitz naevi samples at our clinic using immunohistochemistry (IHC). Both promatrilysin and active matrilysin were found in the melanoma tissue extracts by Western immunoblotting. In situ hybridization demonstrated that melanoma cells selectively express matrilysin mRNA.

RESULTS

Of the melanoma samples, 29 of 33 (87 x 9%) were positive for matrilysin, including 14 of 18 (77 x 8%) primary cutaneous melanomas and 15 of 15 (100%) metastatic melanomas. In contrast, matrilysin was not expressed in common naevi or Spitz naevi. The matrilysin IHC staining score in primary melanomas was associated with the presence of metastases, tumour thickness and TNM staging (P=0 x 001, 0 x 025 and 0 x 021, respectively). The 5-year overall survival was 26.3% for matrilysin-positive cases and 100% for matrilysin-negative cases among melanoma specimen.

CONCLUSIONS

We found matrilysin expression in primary melanomas and in metastatic melanomas. We further demonstrated that the matrilysin IHC staining score was associated with invasive depth of primary melanoma lesions and metastases. Our observations indicate that matrilysin may be associated with melanoma progression, and may enhance melanoma tumour cell invasion. Therefore, matrilysin may be potentially valuable as a prognostic indicator to predict the clinical behaviour of melanoma.

Absence of tyrosine kinase mutations in Japanese colorectal cancer patients

Tyrosine kinases, which are important regulators of intracellular signal-transduction pathways, have mutated forms that are often associated with oncogenesis and are attractive targets for therapeutic intervention. Recently, systematic mutational analyses of tyrosine kinases revealed that a minimum of 30% of colorectal cancer contain at least one mutation in the tyrosine kinases. To further explore these mutations, we examined all reported mutations of NTRK3, FES, KDR, EPHA3, NTRK2, JAK1, PDGFRA, EPHA7, EPHA8, ERBB4, FGFR1, MLK4 and GUCY2F genes in the 24 colorectal cancer cell lines. Unexpectedly, among 24 colorectal cancer cell lines, only two cell lines (LoVo and CaR1) harbored mutation C1408T (R470C) in MLK4 gene. The mutation rate was extremely low compared to that previously reported. Therefore, we analyzed mutations in 46 colorectal cancer samples resected from the same number of Japanese patients. Surprisingly, none of the 46 samples contained any of the mutations reported. Based on our study, we advise that a more comprehensive tyrosine kinase gene mutation assay is necessary in the future.

Elevated serum IgA anticardiolipin antibody levels in adult Henoch-Schönlein purpura

BACKGROUND

Henoch-Schönlein purpura (HSP) is a small-vessel vasculitis characterized by palpable purpura on the lower extremities and IgA-dominant immune complex deposition within the wall and lumen of dermal vessels in the lesions. This disorder is associated, to varying degrees, with joint, gastrointestinal and renal involvement. Antiphospholipid antibodies, including anticardiolipin antibodies (aCL Abs), are a heterogeneous group of circulating autoantibodies found in patients with autoimmune and infectious diseases.

OBJECTIVES

To investigate the possible role of aCL Abs in adult HSP, we measured levels of serum IgA, C-reactive protein (CRP), aCL Abs of the IgG, IgM and IgA isotypes and anti-beta(2)-glycoprotein I (beta(2)GPI)-dependent aCL Abs in adult patients with HSP. We evaluated the correlation between these biological parameters and the clinical manifestations.

METHODS

Adult patients with HSP with an initial cutaneous manifestation of palpable purpura on their lower extremities seen between 2001 and 2005 in our department were retrospectively reviewed. Patients with known connective tissue diseases were not included in the study. Histological examination of all patient skin biopsy specimens revealed leucocytoclastic vasculitis in the upper and mid-dermis. Direct immunofluorescence analysis showed prominent deposits of IgA in the capillary walls of all patients. Blood samples were taken at the time that the patient presented. Serum levels of aCL Abs and anti-beta(2)GPI-dependent aCL Abs were measured by enzyme-linked immunosorbent assay.

RESULTS

Twenty adult patients with HSP (12 men and eight women), mean age 62.2 years (range 23-81) were enrolled. IgA aCL Abs were found in 15 of the 20 patients (75%). All were negative for IgG aCL Abs, IgM aCL Abs and anti-beta(2)GPI-dependent aCL Abs. The elevation of serum IgA aCL Abs in the 15 patients showed a significant correlation with serum IgA and CRP levels (r(s) = 0.91, P = 0.0007; r(s) = 0.80, P = 0.0026, respectively). Levels of serum IgA aCL Abs were also significantly associated with arthralgia (P = 0.022) and proteinuria according to urinalysis (P = 0.013).

CONCLUSIONS

Serum levels of IgA aCL Abs are elevated in the initial active stage of adult HSP, suggesting that serum IgA aCL Abs may play some role in the onset of adult HSP. We believe that serum IgA aCL Abs might be an indicator of adult HSP activity.

Predicting the development of gastric cancer from combining Helicobacter pylori antibodies and serum pepsinogen status: a prospective endoscopic cohort study

BACKGROUND AND AIMS

Helicobacter pylori infection and gastric atrophy are both risk factors for gastric cancer. We aimed to elucidate the natural history of gastric cancer development according to H pylori infection and gastric atrophy status.

SUBJECTS AND METHODS

A total of 9293 participants in a mass health appraisal programme were candidates for inclusion in the present prospective cohort study: 6983 subjects revisited the follow up programme. Subjects were classified into four groups according to serological status at initial endoscopy. Group A (n = 3324) had "normal" pepsinogen and were negative for H pylori antibody; group B (n = 2134) had "normal" pepsinogen and were positive for H pylori antibody; group C (n = 1082) had "atrophic" pepsinogen and were positive for H pylori antibody; and group D (n = 443) had "atrophic" pepsinogen and were negative for H pylori antibody. Incidence of gastric cancer was determined by annual endoscopic examination.

RESULTS

Mean duration of follow up was 4.7 years and the average number of endoscopic examinations was 5.1. The annual incidence of gastric cancer was 0.04% (95% confidence interval (CI) 0.02-0.09), 0.06% (0.03-0.13), 0.35% (0.23-0.57), and 0.60% (0.34-1.05) in groups A, B, C, and D, respectively. Hazard ratios compared with group A were 1.1 (95% CI 0.4-3.4), 6.0 (2.4-14.5), and 8.2 (3.2-21.5) in groups B, C, and D, respectively. Age, sex, and "group" significantly served as independent valuables by multivariate analysis.

CONCLUSIONS

The combination of serum pepsinogen and anti-H pylori antibody provides a good predictive marker for the development of gastric cancer.

Genotoxicity studies on dietary diacylglycerol (DAG) oil

Dietary diacylglycerol (DAG) oil is an edible oil enriched in DAG (more than 80%). A recent investigation indicated that DAG oil or its components may have beneficial effects on the prevention and management of obesity. We evaluated the genotoxic potential of DAG oil using standard genotoxicity tests. Bacterial reverse mutation assay (Ames test), the chromosomal aberration assay in cultured Chinese hamster lung cells (CHL/IU), and a bone marrow micronucleus assay in ICR CD mice were employed in the present study. In addition we have tested the possibility that genotoxic substances may be formed during cooking, heated DAG oil (HDG) was prepared by batch frying potato slices in the oil at 180 degrees C for 8 h/day for three consecutive days. Therefore, genotoxicity tests were also performed on HDG. Results obtained did not show any genotoxic effect on either unheated DAG oil (UDG) or HDG. We conclude that there are no safety concerns on the genotoxicity of DAG oil under the conditions for normal use.

Incidence and recurrence rates of colorectal adenomas estimated by annually repeated colonoscopies on asymptomatic Japanese

BACKGROUND

Whereas high recurrence rates of colorectal adenomas after polypectomy are widely recognised, little is known of the natural incidence in those with no neoplastic lesions initially. It is also known that single colonoscopy has a significant miss rate.

AIMS

To elucidate the incidence and recurrence rates of colorectal neoplasms from a large cohort of asymptomatic Japanese patients on the basis of annually repeated colonoscopies.

METHODS

A total of 6225 subjects (4659 men and 1566 women) participating in an annual colonoscopic screening programme and completing three or more colonoscopies were analysed during the 14 year period between 1988 and 2002. Patients were divided into three groups according to the findings of the initial two colonoscopies: 4084 subjects with no neoplasm, 1818 with small adenomas <10 mm, and 323 with advanced lesions, including carcinoma in situ, severe dysplasia, or large adenomas > or =10 mm. Mean age at the second colonoscopy was 48.8 years.

RESULTS

For all types of colorectal neoplasms, the incidence rate in those with no initial neoplasm was 7.2%/year whereas recurrence rates in those with small adenomas and advanced lesions were 19.3% and 22.9%/year, respectively. For advanced colorectal lesions, the incidence rate was 0.21%/year whereas recurrence rates in those with small adenomas and advanced lesions were 0.64% and 1.88%/year, respectively. Colorectal neoplasms were in general more likely to develop in males and older subjects.

CONCLUSIONS

Although recurrence rates after polypectomy were elevated, the incidence rates in subjects with no neoplastic lesions initially were quite high.

[A case of primary antiphospholipid syndrome complicated with pulmonary hypertension]

We describe the case of 55-year old male with antiphospholipid syndrome (APS) who developed pulmonary hypertension without any thromboembolic episode. Multiple pulmonary perfusion defects suggestive of in situ thrombosis were observed. Hematological findings revealed microangiopathic hemolytic anemia and thrombocytopenia. These findings were improved by anticoagulant therapy. We monitored mean pressure of pulmonary artery (mPAP) and total pulmonary vascular resistance (TPR) before and after using vasodilator agents by Swan-Ganz catheter. mPAP and TPR showed improvement on treatment with oxygen supplementation therapy and Isosorbide administration. Previously 11 cases with APS complicated with pulmonary hypertension were reported. Majority of these patients have had recurrent venous thrombosis, particularly deep vein thrombosis often accompanied by pulmonary thromboembolism (8/11 cases, 72%). However in this case pulmonary hypertension with APS may be induced by in situ thrombosis in pulmonary micro vessels.

Formation of 1,4-disilyl-2-butenes from vinyl grignard reagent and chlorosilanes catalyzed by a titanocene complex

Symmetrical 1,4-disilyl-2-butenes 1 have been prepared by the reaction of vinyl Grignard reagent with chlorosilanes. This reaction proceeds efficiently in the presence of a catalytic amount of titanocene dichloride at 0 degrees C in THF. When dichlorodiphenylsilane was used, 1,1-diphenyl-1-silacyclo-3-pentene 2 was obtained in a good yield.

Stem cell factor and/or endothelin-3 dependent immortal melanoblast and melanocyte populations derived from mouse neural crest cells

Stem cell factor (SCF) and endothelin-3 (ET3) are both necessary for melanocyte development. In order to obtain immortal cell populations of melanoblasts that can survive without feeder cells, we first obtained an immortal cell population of neural crest cells (NCCs) from Sl/+ and +/+ mice of strain WB by incubating with a culture medium supplemented with SCF and ET3, and then we designated them as NCC-SE3 cells. NCC-SE3 cells were bipolar, polygonal, or round in shape and possessed melanosomes of stages I-III (mainly stage I). They were positive to dihydroxyphenylalanine (DOPA) reaction and expressed KIT (a receptor tyrosine kinase), tyrosinase, tyrosinase-related protein-1 (TRP1), tyrosinase-related protein-2 (TRP2), and endothelin-B receptor (ETRB) as determined by immunostaining. We next cultured NCC-SE3 cells by changing culture medium from the one supplemented with SCF + ET3 to the one supplemented with SCF or ET3. NCC-SE3 cells cultured with ET3 alone, designated as NCC-E3 cells, were bipolar in shape and had mainly stage II melanosomes and expressed the same proteins as did NCC-SE3 cells. However, NCC-SE3 cells cultured with SCF alone, designated as NCC-S4.1 cells, were polygonal in shape and had mainly stage I melanosomes. They are thought to be more immature because they were positive to KIT, TRP1, and TRP2, but not to ETR(B), tyrosinase, and DOPA reaction. When 12-O-tetradecanoylphorbol 13-acetate and cholera toxin were added to the culture medium, NCC-S4.1 cells changed shape from polygonal to bipolar and became DOPA-positive. This suggests that NCC-S4.1 cells are melanoblasts that have the potential to differentiate into melanocytes. These cell populations will be extremely useful to study factors that affect melanocyte development and melanogenesis.

Noninvasive estimation of the aorta input function for measurement of tumor blood flow with

Quantitative measurement of tumor blood flow with [15O]water can be used to evaluate the effects of tumor treatment over time. Since quantitative flow measurements require an input function, we developed the profile fitting method (PFM) to measure the input function from positron emission tomography images of the aorta. First, a [11C]CO scan was acquired and the aorta region was analyzed. The aorta diameter was determined by fitting the image data with a model that includes scanner resolution, the measured venous blood radioactivity concentration, and the spillover of counts from the background. The diameter was used in subsequent fitting of [15O]water dynamic images to estimate the aorta and background radioactivity concentrations. Phantom experiments were performed to test the model. Image quantification biases (up to 15%) were found for small objects, particularly for those in a large elliptical phantom. However, the bias in the PFM concentration estimates was much smaller (2%-6%). A simulation study showed that PFM had less bias and/or variability in flow parameter estimates than an ROI method. PFM was applied to human [11C]CO and [15O]water dynamic studies with left ventricle input functions used as the gold standard. PFM parameter estimates had higher variability than found in the simulation but with minimal bias. These studies suggest that PFM is a promising technique for the noninvasive measurement of the aorta [15O]water input function.

Crescentic glomerulonephritis with antimyeloperoxidase antibodies developing during the course of IgA nephropathy in a patient with rheumatoid arthritis

Abstract Glomerulonephritis, such as membranous nephropathy, IgA nephropathy, and p-antineutrophil cytoplasmic autoantibody (ANCA)-related crescentic glomerulonephritis, has been shown to occur in rheumatoid arthritis (RA). However, the occurrence of two types of glomerulonephritis in a patient with RA is rarely observed. Here, we describe a patient with RA who developed crescentic glomerulonephritis with antimyeloperoxidase (MPO) antibodies during the course of IgA nephropathy. This case indicates that crescentic glomerulonephritis and IgA nephropathy may occur together in association with p-ANCA in RA.

A case of unilateral dermatomal cavernous haemangiomatosis

We report a 39-year-old man with unilateral dermatomal cavernous haemangiomatosis (UDCH). Clinically, three haemangiomas were unilaterally distributed in the C6 dermatome. Histologically, these haemangiomas were distinct from routine cavernous haemangioma in that hyperplasia of smooth muscle cells on the vascular wall was observed, and electron microscopy showed that smooth muscle cells contained myofilaments and a crystal-like structure in the endothelial cells. This is distinct from Weibel-Palade bodies, which are rod-shaped cytoplasmic organelles measuring approximately 0.1 microm in diameter with a parallel linear structure. In UDCH, the haemangiomas occur only in the skin. They are clinically and histologically similar to those of blue rubber bleb naevus syndrome (BRBNS), but in BRBNS there are multiple haemangiomas in the digestive tract and other organs. UDCH is distinct from Maffucci syndrome in that enchondromata and malignant tumours are absent. To our knowledge, this is the second case of UDCH reported in the literature.

A flexible single-step detection of blotted antigen using a fusion protein between protein A and green fluorescent protein

A green fluorescent protein mutant (S147P GFP) was fused with protein A and expressed in Escherichia coli. This fusion protein (PA-GFP147) was used in immunoblotting studies as a new detection system, designated as "flexible single-step detection (FSSD)". In FSSD, the detection of blotted antigen was done in one step, and the antigen-antibody reaction can be monitored by UV-irradiation in real time. The reaction time, therefore, can be flexibly controlled by monitoring the green fluorescence.

PET evaluation of [(18)F]FCWAY, an analog of the 5-HT(1A) receptor antagonist, WAY-100635

We synthesized [(18)F]FCWAY, an analog of [carbonyl-(11)C]WAY-100635 ¿[(11)C]N-(2-(1-(4-(2-methoxyphenyl)-piperazinyl)ethyl))-N-(2-(pyridi nyl))cyclohexanecarboxamide¿, by replacing the cyclohexanecarbonyl group acid with a trans-4-fluorocyclohexanecarbonyl group (FC). Control and preblocking studies were performed in anesthetized monkeys. Plasma radioactive metabolite analysis showed the presence of [(18)F]FC and [(18)F]fluoride. Tissue time-radioactivity curves were corrected for metabolite contamination based on separate positron-emission tomography studies of these two labeled metabolites. Analysis using a two-tissue compartment model gave distribution volume (V) estimates (mL/mL) ranging from 33 in frontal cortex to 4 in cerebellum. Preblocking data showed uniform V of 2-3 mL/mL. These studies demonstrate that [(18)F]FCWAY has very similar kinetic characteristics to [(11)C]WAY-100635.

Kinetic analysis of the 5-HT2A ligand [11C]MDL 100,907

The goal of this study was to develop a suitable kinetic analysis method for quantification of 5-HT2A receptor parameters with [11C]MDL 100,907. Twelve control studies and four preblocking studies (400 nmol/kg unlabeled MDL 100,907) were performed in isoflurane-anesthetized rhesus monkeys. The plasma input function was determined from arterial blood samples with metabolite measurements by extraction in ethyl acetate. The preblocking studies showed that a two-tissue compartment model was necessary to fit the time activity curves of all brain regions including the cerebellum--in other words, the need for two compartments is not proof of specific binding. Therefore, a three-tissue compartment model was used to analyze the control studies, with three parameters fixed based on the preblocking data. Reliable fits of control data could be obtained only if no more than three parameters were allowed to vary. For routine use of [11C]MDL 100,907, several simplified methods were evaluated. A two-tissue (2T') compartment with one fixed parameter was the most reliable compartmental approach; a one-compartment model failed to fit the data adequately. The Logan graphical approach was also tested and produced comparable results to the 2T' model. However, a simulation study showed that Logan analysis produced a larger bias at higher noise levels. Thus, the 2T' model is the best choice for analysis of [11C]MDL 100,907 studies.

A new approach to gene mutation analysis using "GFP-Display"

The unique behavior of green fluorescent protein (GFP) on SDS-PAGE was applied to the detection of a single amino acid substitution in GFP-tagged polypeptides. This simple detection method using SDS/urea gels was designated GFP-display. The N-terminal 18 or 37 amino acids of K-Ras was used as a model GFP-tagged polypeptide. K-ras exon 1 was fused to a gfp cDNA at each end and expressed in Escherichia coli. Amino acid number 12 of K-Ras (wild type; Gly) was changed to Ser, Arg, Cys, Asp, Ala, or Val, and the mobility shift of the greenish fluorescent bands in the SDS/urea gel was analyzed. These mutants were easily detected by GFP-display; however, detection depended strongly on the urea concentration and electrophoresis temperature. Subsequently, GFP-display was applied to the 36 amino acids encoding human p53 exon 7. Amino acid number 248 (wild type; Arg) was changed to Gly, Trp, Gln, Pro, or Leu, and similar mobility shifts were observed. GFP-display could be coupled with an in vitro translation system. Fluorescent active GFP and GFP-Ras fusion proteins were synthesized within a few hours. GFP-display shows potential as a modern approach to gene mutation analysis at the protein level, and is a useful method for protein engineering studies.

Measurement of dopamine release with continuous infusion of [11C]raclopride: optimization and signal-to-noise considerations

PET studies with [11C]raclopride provide an indirect measure of changes in synaptic dopamine. Previously, we used the bolus-plus-infusion (B/I) method to assess dopamine response from the percentage change in binding potential (deltaBP) before and after administration of amphetamine. The goal of this work is to optimize the measurement of changes in neurotransmitter with the B/I method by choosing the optimal timing for pre- and poststimulus scanning.

METHODS

Two sources of variability in deltaBP were considered: within-subject and between-subject noise. A noise model based on a phantom study and human data was used to evaluate the within-subject noise. For between-subject noise, simulated time--activity curves were generated from measured [11C]raclopride input functions. Optimal timing to measure deltaBP was determined and applied to human data.

RESULTS

According to the simulation study, the optimal scan times for pre-and poststimulus scans were 39-50 and 58-100 min, respectively. The optimal timing resulted in a 28% noise reduction compared with the original timing. By applying the optimal timing to human studies, the statistical significance of the difference in deltaBP between patients with schizophrenia and healthy volunteers increased from P = 0.038 to 0.012.

CONCLUSION

Careful assessment of the sources of noise in receptor imaging studies can increase the sensitivity of the B/I method for the detection of biologic signals.

Measurement of changes in opioid receptor binding in vivo during trigeminal neuralgic pain using [11C] diprenorphine and positron emission tomography

The binding of [11C]diprenorphine to mu, kappa, and delta subsites in cortical and subcortical structures was measured by positron emission tomography in vivo in six patients before and after surgical relief of trigeminal neuralgia pain. The volume of distribution of [11C]diprenorphine binding was significantly increased after thermocoagulation of the relevant trigeminal division in the following areas: prefrontal, insular, perigenual, mid-cingulate and inferior parietal cortices, basal ganglia, and thalamus bilaterally. In addition to the pain relief associated with the surgical procedure, there also was an improvement in anxiety and depression scores. In the context of other studies, these changes in binding most likely resulted from the change in the pain state. The results suggest an increased occupancy by endogenous opioid peptides during trigeminal pain but cannot exclude coexistent down-regulation of binding sites.

A milk clotting assay for antibody using a fusion protein between protein A and pepsinogen C

The proteolytic activity of a fusion protein between protein A and human pepsinogen C (PA-PGC) was measured by a modified milk clotting assay on 96-well microtiter plate. The assay ranges for 30 and 120 min-incubation were approximately 0.08-1.25 ng and 0.02-0.16 ng, respectively. Although the absorbance of milk solution decreased by the precipitation of clotted casein, the white precipitate was, if anything, convenient for an easy detection of reaction-positive wells. The borderline between the wells with or without precipitate was very clear and easily detected without the plate reader. This feature was thought to be suitable for the positive-negative judgment of a dilution test in enzyme immunoassay (EIA). Rabbit IgG adsorbed on a microtiter plate was then measured using PA-PGC and this milk assay (designated as PA-PGC assay). Although PA-PGC assay needed slightly longer incubation than the conventional color assay, the sensitivity of both systems was almost identical, and the reaction-positive wells containing white precipitate were easily detected at a very low range by the over night incubation without using the plate reader. PA-PGC assay possesses the unique and useful properties, and it can be used as a convenient and easy EIA technique.

[Time constant of forward body sway induced by downward optokinetic stimulus]

Forward body sway induced by a downward optokinetic stimulus (OKS) was observed in 38 healthy subjects. The downward OKS was generated by a moving random dot pattern projected onto a half-pipe screen 2 m in diameter and was provided by a rectangular-like step function with velocities of 10, 20, 30 and 40 deg/sec. A fixation target was set by a red laser spot projected onto the screen in front of the subjects. As an additional stimulatory condition, 20 deg/sec of OKS with no fixation target was employed. The induced forward body sway was measured by a force-detecting platform as displacement of the center of gravity (COG). The gradual forward shift of COG followed by the plateau state was closely akin to a graphical representation of an equation of the first order lag time. As OKS velocities increased, the plateau level increased. Curve fitting analysis using a computer was employed to establish an approximation equation of the first order lag time. This analysis showed that the time constant of the optokinetic spinal response system was approximately 15 sec and the value of the time constant was independent of OKS velocity. Based on this long time constant, we concluded that the postural readjustment induced by OKS mainly plays a role in the low frequency range of human postural control.

Detection of blotted antigen using a fusion protein between protein A and pepsinogen C

Human pepsinogen (PG) A and C were fused with protein A and expressed in Escherichia coli. Although the fusion proteins (PA-PGA and PA-PGC) were not expressed at high levels and were almost totally recovered from the insoluble fraction, the renaturation and purification procedures were easy and simple. PA-PGA and PA-PGC possessed proteolytic activity equivalent to the gastric mucosal PGA and PGC, respectively. However, the activity of PA-PGC was about 3-fold higher than that of PA-PGA. Therefore, PA-PGC was applied to the subsequent immunoblotting studies. The proteolytic activity of PA-PGC was used for digesting the blocking reagent around the target antigen (in situ digestion method) or casein-clotting in the agarose plate containing skimmed milk (caseogram print method). Although the sensitivity of these methods was lower than that of the conventional color detection, the caseogram print method was superior in that the reaction was linear over a wide range. On the other hand, the in situ digestion method possessed a unique property on Western blotting, and it was very easy to identify the relative position of the target, which could be recognized as a clear band. For PA-PGC detection, no special chemicals are required, and so the procedure is simple, rapid, and inexpensive.

Purification of recombinant human pepsinogens and their application as immunoassay standards

Human pepsinogen (PG) A and C were cloned in Escherichia coli, but the levels of expression were low and unstable. When there were fused to maltose-binding protein (MBP), the fusion proteins (MBP-PGA and MBP-PGC) were expressed as the major products. Although these fused products were almost totally recovered from the insoluble fraction, the renaturation and purification procedures were easy and simple. MBP-PGA and the PGA segment obtained by factor Xa digestion (designated as r-PGA) possessed proteolytic activities equivalent to native PGA purified from gastric tissue (t-PGA). For PGCs (MBP-PGC, r-PGC and t-PGC) also, the specific activities were almost the same. However, the activities of PGCs were about 3- to 4-hold higher than those of PGAs. In PGA and PGC immunoassay systems, r-PGs (r-PGA and r-PGC) and the EIA kit standard PGs (gastric mucosal PGs) exhibited a good correlation. From these results, r-PGs would seem to be applicable as assay standards without compromising the sensitivity of the immunoassay systems.

Estimation of absorbed dose for 2-[F-18]fluoro-2-deoxy-D-glucose using whole-body positron emission tomography and magnetic resonance imaging

The purpose of this study was to measure the cumulated activity and absorbed dose in organs after intravenous administration of 2-[F-18]fluoro-2-deoxy-D-glucose (18F-FDG) using whole-body positron emission tomography (PET) and magnetic resonance imaging (MRI). Whole-body dynamic emission scans for 18F-FDG were performed in six normal volunteers after transmission scans. The total activity of a source organ was obtained from the activity concentration of the organ measured by whole-body PET and the volume of that organ measured by whole-body T1-weighted MRI. The cumulated activity of each source organ was calculated from the time-activity curve. Absorbed doses to the individuals were estimated by the MIRD (medical internal radiation dosimetry) method using S-values adjusted to the individuals. Another calculation of cumulated activities and absorbed doses was performed using the organ volumes from the MIRD phantom and the "Japanese reference man" to investigate the discrepancy of actual individual results against the phantom results. The cumulated activities of 18 source organs were calculated, and absorbed doses of 27 target organs estimated. Among the target organs, bladder wall, brain and kidney received the highest doses for the above three sets of organ volumes. Using measured individual organ volumes, the average absorbed doses for those organs were found to be 3.1x10(-1), 3.7x10(-2) and 2.8x10(-2) mGy/MBq, respectively. The mean effective doses in this study for individuals of average body weight (64.5 kg) and the MIRD phantom of 70 kg were the same, i.e. 2.9x10(-2) mSv/MBq, while for the Japanese reference man of 60 kg the effective dose was 2.1x10(-2) mSv/MBq. The results for measured organ volumes derived from MRI were comparable to those obtained for organ volumes from the MIRD phantom. Although this study considered 18F-FDG, combined use of whole-body PET and MRI might be quite effective for improving the accuracy of estimations of the cumulated activity and absorbed dose of positron-labelled radiopharmaceuticals.

Estimation of organ cumulated activities and absorbed doses on intakes of several 11C labelled radiopharmaceuticals from external measurement with thermoluminescent dosimeters

We have developed a method for obtaining the cumulated activities in organs from radionuclides, which are injected into the patient in nuclear medicine procedures, by external exposure measurement with thermoluminescent dosimeters (TLDs) which are attached to the patient's body surface close to source organs to obtain information on body-surface doses. As the surface dose is connected to the cumulated activities in source organs through radiation transmission in the human body which can be estimated with the aid of a mathematical phantom, the organ cumulated activities can be obtained by the inverse transform method. The accuracy of this method was investigated by using a water phantom in which several gamma-ray volume sources of known activity were placed to simulate source organs. We then estimated by external measurements the organ cumulated activities and absorbed doses in subjects to whom the radiopharmaceuticals 11C-labelled Doxepin, 11C-labelled YM09151-2 and 11C-labelled Benzotropin were administered in clinical nuclear medicine procedures. The cumulated activities in the brain obtained with TLDs for Doxepin and YM09151-2 are 63.6 +/- 6.2 and 32.1 +/- 12.0 kBq h MBq-1 respectively, which are compared with the respective values of 33.3 +/- 9.9 and 23.9 +/- 6.2 kBq h MBq-1 with direct PET (positron emission tomography) measurements. The agreement between the two methods is within a factor of two. The effective doses of Doxepin, YM09151-2 and Benzotropin are determined as 6.92 x 10(-3), 7.08 x 10(-3) and 7.65 x 10(-3) mSv MBq-1 respectively with the TLD method. This method has great advantages, in that cumulated activities in several organs can be obtained easily with a single procedure, and the measurements of body surface doses are performed simultaneously with the nuclear medicine procedure, as TLDs are too small to interfere with other medical measurements.

Mode of antifungal action of benanomicin A in Saccharomyces cerevisiae

The mechanism of fungitoxic action of an antifungal antibiotic benanomicin A was studied with intact cells and protoplasts of Saccharomyces cerevisiae as well as with its enzymic preparations. The results obtained are summarized as follows: (1) benanomicin A at relatively high concentrations (almost equal to MIC) was fungicidal and disrupted the cell permeability barrier, inducing leakage of intracellular K+ and ATP in growing cells, while the antibiotic had none of these effects in non-growing cells; (2) no biosynthesis of any of several major cellular constituents in yeast cells was inhibited markedly or selectively enough to explain its fungitoxic activity; (3) whereas benanomicin A induced lysis of metabolically active yeast protoplasts incubated in the presence of glucose, inactive yeast protoplasts incubated without glucose were refractory to the lytic action of the antibiotic; (4) osmotically shocked yeast cells became feasible to the cidal action of benanomicin A; (5) benanomicin A substantially inhibited uptake of 6-deoxy-glucose by yeast cells; (6) liposomes composed of phospholipids and cholesterol were not susceptible to benanomicin A; and (7) benanomicin A inhibited in vitro activity of H(+)-ATPase from yeast cell membranes to a greater extent than that for H(+)-ATPase from yeast mitochondria or H(+)-ATPase from yeast vacuolar membranes. Based on these and our previous data that benanomicin A preferentially binds to mannan or mannoproteins constituting the cell wall and cell membrane of yeasts, such binding of the antibiotic is suggested to deteriorate the normal structure and function of those cell membranes of yeasts which are in a growing or metabolically active state, ultimately leading to cell death.