Non-cardiac comorbid health outcomes and prevalence after myocardial infarction: an umbrella review

OBJECTIVE

There exists limited comprehensive evidence on the potential association between non-cardiac comorbidities and myocardial infarction (MI). Thus, we conducted an umbrella review of existing meta-analyses to provide a broad understanding of non-cardiac health outcomes associated with MI.

MATERIALS AND METHODS

The primary focus on the prevalence of related health outcomes in patients with MI was systemically searched. Each original meta-analysis that was included had its methodological quality evaluated by a Measurement Tool Assessment Systematic Reviews 2 (AMSTAR2). To evaluate the certainty in the evidence for each outcome, we employed GRADE and the Joanna Briggs Institute Prevalence Critical Appraisal Tool. The protocol was registered in PROSPERO (CRD42023458642).

RESULTS

We identified seven meta-analyses comprising 126 studies with 336,581 participants from 22 countries and five continents. The pooled prevalence of comorbidities in patients with MI was 39% anxiety [95% confidence interval (CI), 30-48; GRADE, very low certainty], 29% depression (95% CI, 23-36; very low certainty), 39% frailty (95% CI, 24-55; very low certainty), and 23% failure of returning to work (95% CI, 16-29; very low certainty). The diagnosis of MI was associated with an increased risk of cognitive impairment (odds ratio, 1.45; 95% CI, 1.10-1.92; moderate certainty). Among frail patients, MI was associated with an increased risk of major bleeding (relative risk, 1.93; 95% CI, 1.08-3.45; low certainty) and mortality (relative risk, 2.29; 95% CI, 1.48-3.53; moderate certainty). However, we did not find any evidence of cancer risk associated with the development of MI.

CONCLUSIONS

Our umbrella meta-analysis provided comprehensive evidence of the association between MI and several non-cardiac health conditions. The robustness of our study is attributed to the integration of evidence across several studies, thus, these insights offer valuable treatment options for policymakers and physicians to develop personalized health strategies.

Effectiveness of low-intensity atorvastatin 5 mg and ezetimibe 10 mg combination therapy compared with moderate-intensity atorvastatin 10 mg monotherapy: A randomized, double-blinded, multi-center, phase III study

BACKGROUND

We compared the efficacy and safety of low-intensity atorvastatin and ezetimibe combination therapy with moderate-intensity atorvastatin monotherapy in patients requiring cholesterol-lowering therapy.

METHODS

At 19 centers in Korea, 290 patients were randomized to 4 groups: atorvastatin 5 mg and ezetimibe 10 mg (A5E), ezetimibe 10 mg (E), atorvastatin 5 mg (A5), and atorvastatin 10 mg (A10). Clinical and laboratory examinations were performed at baseline, and at 4-week and 8-week follow-ups. The primary endpoint was percentage change from baseline in low-density lipoprotein (LDL) cholesterol levels at the 8-week follow-up. Secondary endpoints included percentage changes from baseline in additional lipid parameters.

RESULTS

Baseline characteristics were similar among the study groups. At the 8-week follow-up, percentage changes in LDL cholesterol levels were significantly greater in the A5E group (49.2%) than in the E (18.7%), A5 (27.9%), and A10 (36.4%) groups. Similar findings were observed regarding the percentage changes in total cholesterol, non-high-density lipoprotein cholesterol, and apolipoprotein B levels. Triglyceride levels were also significantly decreased in the A5E group than in the E group, whereas high-density lipoprotein levels substantially increased in the A5E group than in the E group. In patients with low- and intermediate-cardiovascular risk, 93.3% achieved the target LDL cholesterol levels in the A5E group, 40.0% in the E group, 66.7% in the A5 group, and 92.9% in the A10 group. In addition, 31.4% of patients in the A5E group, 8.1% in E, 9.7% in A5, and 7.3% in the A10 group reached the target levels of both LDL cholesterol < 70 mg/dL and reduction of LDL ≥ 50% from baseline.

CONCLUSIONS

The addition of ezetimibe to low-intensity atorvastatin had a greater effect on lowering LDL cholesterol than moderate-intensity atorvastatin alone, offering an effective treatment option for cholesterol management, especially in patients with low and intermediate risks.

Innate immunity and protective effects of orally administered betaine against viral and bacterial diseases in the olive flounder Paralichthys olivaceus (Temminck & Schlegel)

Sustainable methods that increase farmed fish yield while controlling infections are required to prevent economic losses in aquaculture farms. In this study, we evaluated the effects of betaine-supplemented (0%, 0.1%, 0.5%, and 1.0%) feed on the growth and immunity of the olive flounder Paralichthys olivaceus. Feed conversion ratios, post-infection cumulative mortality rates and innate immune responses were monitored. Weight gain was significantly higher with 0.5% and 1.0% than with 0% and 0.1% betaine-supplemented feed. Lysozyme activity was highest with 1.0% betaine. Respiratory burst activity was highest with 0.5% and 1.0% betaine. Serum bactericidal activity against Edwardsiella tarda was highest with 1.0% betaine (40% increase in survival rates compared with those in the control). Furthermore, serum virucidal activity against the viral haemorrhagic septicaemia virus (VHSV) was higher with 1.0% betaine than with other concentrations. With 0.5% and 1.0% betaine, the survival rates against VHSV were higher than those in the control until day 11, after which they declined. Our study suggests that betaine is a promising agent for promoting the growth of and enhancing immunity against E. tarda in olive flounders. Our findings may further contribute to developing necessary alternatives to conventional antibiotics in fish farming.

Optical coherence tomography in coronary atherosclerosis assessment and intervention

Since optical coherence tomography (OCT) was first performed in humans two decades ago, this imaging modality has been widely adopted in research on coronary atherosclerosis and adopted clinically for the optimization of percutaneous coronary intervention. In the past 10 years, substantial advances have been made in the understanding of in vivo vascular biology using OCT. Identification by OCT of culprit plaque pathology could potentially lead to a major shift in the management of patients with acute coronary syndromes. Detection by OCT of healed coronary plaque has been important in our understanding of the mechanisms involved in plaque destabilization and healing with the rapid progression of atherosclerosis. Accurate detection by OCT of sequelae from percutaneous coronary interventions that might be missed by angiography could improve clinical outcomes. In addition, OCT has become an essential diagnostic modality for myocardial infarction with non-obstructive coronary arteries. Insight into neoatherosclerosis from OCT could improve our understanding of the mechanisms of very late stent thrombosis. The appropriate use of OCT depends on accurate interpretation and understanding of the clinical significance of OCT findings. In this Review, we summarize the state of the art in cardiac OCT and facilitate the uniform use of this modality in coronary atherosclerosis. Contributions have been made by clinicians and investigators worldwide with extensive experience in OCT, with the aim that this document will serve as a standard reference for future research and clinical application.

Effects of Fixed-dose Combination of Low-intensity Rosuvastatin and Ezetimibe Versus Moderate-intensity Rosuvastatin Monotherapy on Lipid Profiles in Patients With Hypercholesterolemia: A Randomized, Double-blind, Multicenter, Phase III Study

PURPOSE

We investigated whether the combination therapy of low-intensity rosuvastatin and ezetimibe is an useful alternative to moderate-intensity rosuvastatin monotherapy in patients requiring cholesterol-lowering therapy.

METHODS

This was a multicenter randomized, double-blind study to investigate the safety and efficacy of a fixed-dose combination of rosuvastatin 2.5 mg and ezetimibe 10 mg (R2.5+E10) compared to those of ezetimibe 10 mg monotherapy (E10), rosuvastatin 2.5 mg (R2.5), and rosuvastatin 5 mg monotherapy (R5) in patients with hypercholesterolemia. A total of 348 patients at 15 centers in Korea were screened, and 279 patients were randomized to different groups in the study. Clinical and laboratory examinations were performed at baseline and 4 and 8 weeks after intervention. The primary endpoint was the percentage change of low-density lipoprotein (LDL) cholesterol levels at the 8-week follow-up.

FINDINGS

Baseline characteristics were similar among the four groups. There were significant changes in lipid profiles at the 8-week follow-up. A greater decrease in the LDL cholesterol levels (primary endpoint) were found in the R2.5+E10 group (-45.7±18.6%) than in the E10 group (-16.7±14.7%, p<0.0001), R2.5 group (-32.6±15.1%, p<0.0001), and R5 group (-38.9±13.9%, p=0.0003). Similar outcomes were observed regarding the decrease in total cholesterol, non-high-density lipoprotein (HDL) cholesterol, and apolipoprotein B protein. In addition, changes in the triglyceride and HDL levels in the R2.5+E10 group were significantly different compared with those in the E10 group; however, the changes were similar to those in the other treatment groups. In patients with low and moderate risk, all patients achieved the target LDL cholesterol levels in the R2.5+E10 group (100%) compared to 13.0% in the E10 group, 47.6% in the R2.5 group, and 65.2% in the R5 group. Adverse effects were rare and similar in the four groups.

IMPLICATIONS

Fixed-dose combination of low-intensity rosuvastatin and ezetimibe was more effective in lowering LDL cholesterol and achieving LDL cholesterol goals than moderate-intensity rosuvastatin monotherapy. These findings suggest that the combination therapy of low-intensity rosuvastatin and ezetimibe is an useful alternative to moderate-intensity rosuvastatin monotherapy for cholesterol management, particularly in patients with low and moderate risk. ClinicalTrials.gov identifier: NCT04652349.

Retroductal Delivery of Epidermal Growth Factor Protects Salivary Progenitors after Irradiation

Salivary gland hypofunction after irradiation is associated with a deficit of epithelial stem/progenitors in salivary glands. Although epidermal growth factor (EGF) is known to stimulate the proliferation of epithelial cells, the therapeutic effect of EGF on salivary epithelial stem/progenitors remains undetermined. In this study, we administered EGF to submandibular glands (SMGs) via a retrograde route through the SMG excretory duct before fractionated irradiation and examined whether EGF could protect salivary epithelial progenitor cells from radiation and alleviate radiation-induced salivary hypofunction. EGF-treated mice exhibited greater body and gland weights at 12 wk after irradiation than untreated mice. The retroductal delivery of EGF improved salivary secretory function and increased salivary amylase activity in a dose-dependent manner. Histological examinations highlighted the amelioration of the loss of keratine-14⁺ (KRT14⁺) basal ductal and/or MIST1⁺ acinar cells, as well as induction of fibrosis, following irradiation in EGF-treated mice. An additional in vitro experiment using a salivary gland organoid irradiation model indicated that the radioprotective effects of EGF promoted the growth and inhibited the apoptotic cell death of salivary epithelial cells. Our results suggest that retroductal delivery of EGF may be a promising therapeutic option for preventing radiation-induced salivary gland hypofunction.

Efficacy and Safety of Omega-3 Fatty Acids in Patients Treated with Statins for Residual Hypertriglyceridemia: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

BACKGROUND

Cardiovascular risk remains increased despite optimal low density lipoprotein cholesterol (LDL-C) level induced by intensive statin therapy. Therefore, recent guidelines recommend non-high density lipoprotein cholesterol (non-HDL-C) as a secondary target for preventing cardiovascular events. The aim of this study was to assess the efficacy and tolerability of omega-3 fatty acids (OM3-FAs) in combination with atorvastatin compared to atorvastatin alone in patients with mixed dyslipidemia.

METHODS

This randomized, double-blind, placebo-controlled, parallel-group, and phase III multicenter study included adults with fasting triglyceride (TG) levels ≥200 and <500 mg/dL and LDL-C levels <110 mg/dL. Eligible subjects were randomized to ATOMEGA (OM3-FAs 4,000 mg plus atorvastatin calcium 20 mg) or atorvastatin 20 mg plus placebo groups. The primary efficacy endpoints were the percent changes in TG and non-HDL-C levels from baseline at the end of treatment.

RESULTS

After 8 weeks of treatment, the percent changes from baseline in TG (-29.8% vs. 3.6%, P<0.001) and non-HDL-C (-10.1% vs. 4.9%, P<0.001) levels were significantly greater in the ATOMEGA group (n=97) than in the atorvastatin group (n=103). Moreover, the proportion of total subjects reaching TG target of <200 mg/dL in the ATOMEGA group was significantly higher than that in the atorvastatin group (62.9% vs. 22.3%, P<0.001). The incidence of adverse events did not differ between the two groups.

CONCLUSION

The addition of OM3-FAs to atorvastatin improved TG and non-HDL-C levels to a significant extent compared to atorvastatin alone in subjects with residual hypertriglyceridemia.

Three-year clinical outcome of biodegradable hybrid polymer Orsiro sirolimus-eluting stent and the durable biocompatible polymer Resolute Integrity zotarolimus-eluting stent: A randomized controlled trial

AIMS

We compared long-term clinical outcomes between patients treated with Orsiro sirolimus-eluting stent (O-SES) and those treated with durable biocompatible polymer Resolute Integrity zotarolimus-eluting stent (R-ZES).

METHODS AND RESULTS

The ORIENT trial was a randomized controlled noninferiority trial to compare angiographic outcomes between O-SES and R-ZES. We performed a post hoc analysis of 3-year clinical outcomes and included 372 patients who were prospectively enrolled and randomly assigned to O-SES (n = 250) and R-ZES (n = 122) groups in a 2:1 ratio. The primary endpoint was target lesion failure defined as a composite of cardiac death, nonfatal myocardial infarction, and target lesion revascularization. At 3 years, target lesion failure occurred in 4.7% and 7.8% of O-SES and R-ZES groups, respectively (hazard ratio, 0.58; 95% confidence intervals, 0.24-1.41; p = .232 by log-rank test). Secondary endpoints including cardiac death, myocardial infarction, and target lesion revascularization showed no significant differences between the groups. Stent thrombosis occurred in two patients in R-ZES group (0.0% vs. 1.6%, p = .040).

CONCLUSION

This study confirms long-term safety and efficacy of the two stents. We found a trend for lower target lesion failure with O-SES compared to R-ZES, although statistically insignificant.

Slow Heart Rate Recovery Is Associated with Increased Exercise-induced Arterial Stiffness in Normotensive Patients without Overt Atherosclerosis

BACKGROUND

This study evaluated whether blunted autonomic activity as measured by heart rate recovery (HRR) was associated with increased arterial stiffness, especially increased exercise-induced arterial stiffness, in normotensive patients without overt atherosclerosis.

METHODS

One hundred fifty-four normotensive patients without overt atherosclerosis who had undergone a treadmill exercise test were consecutively enrolled. HRR was measured at one minute after exercise. Brachial-ankle pulse wave velocity (baPWV) at rest was measured, and carotid arterial stiffness indices at rest (CSI at rest) and after exercise (CSI after exercise) were assessed.

RESULTS

Patients with slow HRR were older and tended to be male, and they had diabetes, higher resting and peak systolic blood pressures, higher resting heart rate, lower peak heart rate, lower metabolic equivalents, increased baPWV, and increased CSIs at rest and after exercise. HRR was inversely associated with baPWV and CSI after exercise when established cardiovascular risk factors were adjusted as confounding factors, and HRR was associated with CSI after exercise when resting systolic blood pressure and metabolic equivalent of tasks on cardiovascular risk factors were added as confounding factors.

CONCLUSIONS

Sympathovagal imbalance demonstrated by slow HRR was associated with increased arterial stiffness and, above all, was closely associated with exercise-induced arterial stiffness in normotensive patients without overt atherosclerosis. This phenomenon might have been observed because blunt carotid arterial vasomotion following exercise results from autonomic dysfunction as well as vascular endothelial dysfunction.

Characteristics of Earlier Versus Delayed Presentation of Very Late Drug-Eluting Stent Thrombosis: An Optical Coherence Tomographic Study

Background

The pathophysiology underlying very late drug‐eluting stent (DES) thrombosis is not sufficiently understood. Using optical coherence tomography, we investigated characteristics of very late stent thrombosis (VLST) according to different onset times.

Methods and Results

A total of 98 patients from 10 South Korean hospitals who underwent optical coherence tomography for evaluation of very late DES thrombosis were retrospectively included in analyses. VLST occurred at a median of 55.1 months after DES implantation. All patients were divided into 2 equal groups of earlier versus delayed presentation of VLST, according to median onset time. In total, 27 patients were treated with next‐generation DES and 71 with first‐generation DES. Based on optical coherence tomography findings at thrombotic sites, main VLST mechanisms were as follows, in descending order: neoatherosclerosis (34.7%), stent malapposition (33.7%), and uncovered struts without stent malapposition or evagination (24.5%). Compared with patients with earlier VLST, patients with delayed VLST had lower frequency of uncovered struts without stent malapposition or evagination (34.7% versus 14.3%, respectively; P=0.019). Conversely, the frequency of neoatherosclerosis was higher in patients with delayed versus earlier VLST (44.9% versus 24.5%, respectively; P=0.034). The frequency of stent malapposition was not different between patients with earlier and delayed VLST (34.7% versus 32.7%, respectively; P=0.831). The frequency of stent malapposition, evagination, and uncovered struts was still half of delayed VLST.

Conclusions

The pathological mechanisms of very late DES thrombosis changed over time. Delayed neointimal healing remained a substantial substrate for VLST, even long after DES implantation.

Roles of High-Density Lipoprotein Cholesterol in Patients With Acute Myocardial Infarction

Many observational studies showed hogh-density lipoprotein cholesterol (HDL-C) is a strong inverse predictor of cardiovascular (CV) outcome. However, recent large clinical trials evaluating therapies to raise HDL-C level in those already on statin therapy have been discouraging. This complexity is not well-known.A total of 28,357 acute myocardial infarction (AMI) patients were enrolled in the Korea Acute Myocardial Infarction Registry (KAMIR), which was a prospective, multicenter, nationwide, web-based database of AMI in Korea. From this registry, we evaluated 3574 patients with AMI who have follow-up HDL-C level to investigate its association with clinical outcomes. The primary endpoint was the relationship between follow-up change in HDL-C and a 12-month composite of major adverse cardiac events (MACEs).Patients with initial HDL-C ≥ 40 mg/dL showed significantly lower rates of 12-month MACEs, especially cardiac and all-cause mortalities (P < 0.001). When patients were stratified into 4 groups according to the change of HDL-C, patients with decreasing HDL-C showed significantly higher rates of 12-month MACEs as comparable with patients with increasing HLD-C. A multivariate analysis indicated that HDL-C level was a significant predictor of CV events (hazard ratio, 1.38; 95% confidence interval, 1.12-1.71) after correcting for confounding variables.The follow-up change in HDL-C level was significantly related with CV outcomes in patients with AMI.

Comparison of alfuzosin 10 mg with or without propiverine 10 mg, 20 mg in men with lower urinary tract symptom and an overactive bladder: randomised, single-blind, prospective study

PURPOSE

The efficacy and safety of treatment with alfuzosin 10 mg plus propiverine 10 or 20 mg in men with lower urinary tract symptoms (LUTS) and an overactive bladder were investigated.

MATERIALS AND METHODS

In this parallel-arm, prospective, multicentre, single-blind study, men who were ≥ 40 years old, had an International Prostate Symptom Score (IPSS) of ≥ 8, an Overactive Bladder Symptom Score (OABSS) of ≥ 3 and an OABSS urgency item score of ≥ 2 were randomised in a 1 : 1 :1 ratio to receive alfuzosin 10 mg alone (Group A) or with propiverine 10 mg (Group B) or 20 mg (Group C) for 8 weeks. Four and 8 weeks after commencing treatment, OABSS was measured along with IPSS, maximal urinary flow rate (Qmax ) and postvoid residual volume (PVR). Adverse events were recorded.

RESULTS

A total of 135 men, including 43 in Group A, 48 in Group B and 44 in Group C, completed the study. Relative to baseline, all groups demonstrated significant reductions in OABSS and the IPSS after eight treatment weeks (p < 0.005). The improvement of OABSS in Group C was significantly greater than Group A and B (Group A: 0.70 ± 1.94; Group B: 2.50 ± 2.98; Group C: 4.30 ± 3.40; p < 0.005). An observed improvement of Qmax and PVR in the three groups did not achieve statistical significance. Overall adverse event rates were higher in Group C but not significant compared with others.

CONCLUSION

In patients with LUTS and overactive bladder, combined therapy with alfuzosin 10 mg plus propiverine 20 mg was significantly more effective than alfuzosin monotherapy and propiverine 10 mg combined therapy in terms of improving OABSS while not significantly affecting Qmax or PVR.

Angiographic and clinical comparison of novel Orsiro Hybrid sirolimus-eluting stents and Resolute Integrity zotarolimus-eluting stents in all-comers with coronary artery disease (ORIENT trial): study protocol for a randomized controlled trial

Background

The Orsiro Hybrid sirolimus-eluting stent is a newly developed third-generation drug-eluting stent, featuring a unique dual-polymer mix. An active bioabsorbable polymer delivers the anti-proliferative drug, sirolimus, via controlled release, while a passive biocompatible polymeric coating shields the metallic strut from surrounding tissue, preventing interaction. To date, the Orsiro Hybrid sirolimus-eluting stent has excelled in terms of late lumen loss at 9 months in a first-in-man single-arm trial. However, the efficacy and safety data for Orsiro Hybrid sirolimus-eluting stents in a broader population of all-comers are limited. The present study offers an angiographic and clinical comparison of the Orsiro Hybrid sirolimus-eluting stent and the Resolute Integrity zotarolimus-eluting stent in the treatment of patients with coronary artery disease.

Methods/design

The ORIENT trial is a multicenter, randomized, open-label, parallel-arm study designed to demonstrate the non-inferiority of the Orsiro Hybrid sirolimus-eluting stent relative to the Resolute Integrity zotarolimus-eluting stent. A total of 375 patients with a spectrum of coronary artery disease will undergo prospective, random assignment to a Orsiro Hybrid sirolimus-eluting stent or Resolute Integrity zotarolimus-eluting stent (2:1 ratio), for a primary endpoint of in-stent late lumen loss at 9 months by quantitative coronary angiography. Secondary 12-month clinical endpoints are death, target lesion revascularization, target vessel revascularization, myocardial infarction, stent thrombosis and target lesion failure (a composite of cardiac death, target lesion revascularization and target vessel-related myocardial infarction).

Discussion

The ORIENT trial is the first study to date comparing the Orsiro Hybrid sirolimus-eluting stent with the Resolute Integrity zotarolimus-eluting stent for efficacy and safety in a population of all-comers with coronary artery disease.

Trial registration

Clinicaltrials.gov NCT01826552

Preliminary study for gait phases detection to develop a rehabilitation equipment for hemiplegic patients

Preliminary experiment for analyzing weight shift during gait phases for hemiplegic patients was carried out to develop rehabilitation equipment. A gait phase detection system using pressure sensors was developed and the experiment was carried out for eight hemiplegic patients and normal adult. The weight shift during gait phases for a normal adult showed symmetrical for left and right footing phase, but that for the hemiplegic patients showed asymmetrical footing phase. However, it gave sufficient information to discriminate between left and right footing phases.

Comparison of efficacy for erectile function and lower urinary tract symptoms of tadalafil 20 mg on-demand and 5 mg once daily in patients with erectile dysfunction

Aim:  To compare the improvement in erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) as well as safety of tadalafil dosed at 20 mg on-demand and 5 mg once daily among ED patients. Materials and methods:  A total of 194 ED patients visited between March 2010 and June 2011 were recruited. Out of 194 individuals, 168 (86.6%) met inclusion criteria after completing the two-week screening period (V0). The Patients were randomly allocated into two groups: (i) 20 mg of tadalafil as needed (Group 1: n = 84, 50.0%) and (ii) 5 mg of tadalafil once daily (Group 2: n = 84, 50.0%). Blood pressure (BP), heart rate (HR) and the five-item version of the International Index of Erectile Function (IIEF-5) were assessed immediately before initiation of treatment (V1) and after four (V2) and twelve weeks of treatment (V3). In men with an IPSS of ≥ 8 at V1, IPSS, maximal flow rate (Qmax) and post-void residual volume (PVR) were also assessed. Results:  Of the 168 patients, 134 (79.8%; Group 1: n = 68, 81.0%; Group 2: n = 66, 78.6%) patients completed the trial. IIEF-5 improved in both groups, and the mean change was larger in Group 2 at V3 (4.9 ± 4.2 vs. 6.5 ± 4.5; p = 0.032) Similarly, though IPSS (with ≥ 8, n = 88, 65.7%; Group 1: n = 44, 64.7%; Group 2: n = 44, 66.7%) improved in both groups, the mean change was larger in Group 2 at V3 (-2.8 ± 4.3 vs. -4.8 ± 4.1; p = 0.026). Qmax and PVR did not differ significantly in either group. Conclusions:  Once daily tadalafil was more efficacious in treating both ED and LUTS than on-demand dosing. However, no differences were observed between the two dosing schedules with regard to the improvement in LUTS when stratified by improvement in ED. The side effects were insignificant for both dosing schedules.

Contrast-enhanced MR cholangiography: comparison of Gd-EOB-DTPA and Mn-DPDP in healthy volunteers

OBJECTIVE

The purpose of this study was to compare the biliary enhancement dynamics of gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic-acid (Gd-EOB-DTPA) and mangafodipir trisodium (Mn-DPDP) for contrast-enhanced MR cholangiography (MRC) in healthy subjects.

METHODS

15 healthy volunteers underwent MRI at 1.5 T with volumetric interpolated breath-hold examination sequence. Each volunteer was scanned once for each contrast agent. The signal-to-noise ratio (SNR) of the liver parenchyma and common hepatic duct (CHD) and the contrast-to-noise ratio (CNR) of CHD to liver parenchyma were evaluated and compared before and at several time points (5, 15, 30, 45, 60, 90, and 120 min) after injection of each agent.

RESULTS

SNR was significantly higher for Gd-EOB-DTPA than for Mn-DPDP in liver parenchyma after 5 min and in CHD after 15 min (p<0.05). CNR of CHD to liver parenchyma using Gd-EOB-DTPA showed an initial decrease at 5 min post-injection followed by a steep increase to a peak at 15 min post-injection. CNR using Mn-DPDP showed a steady increase to a peak at 15 min post-injection without an initial decrease. At 15 min, the value of CNR was significantly higher for Gd-EOB-DTPA than for Mn-DPDP (p<0.05).

CONCLUSION

For both contrast agents, CNR reached a peak at 15 min after contrast injection. At this time point, CNR of Gd-EOB-DTPA was significantly higher than that of Mn-DPDP. Therefore, Gd-EOB-DTPA may provide better contrast-enhanced MRC than Mn-DPDP at 15 min after contrast administration.

De novo autoimmune hepatitis in Korean children after liver transplantation: a single institution's experience

INTRODUCTION

De novo autoimmune hepatitis (AIH) after orthotopic liver transplantation (OLT) has been described as a new type of late graft dysfunction in children who have not undergone transplantation for previous autoimmune liver disease. The purpose of this study was to evaluate the clinical aspects of de novo AIH among children following OLT.

PATIENTS AND METHODS

Between January 1994 and May 2007, 149 children underwent OLT, including 1 with recurrent AIH who was excluded from this study, whereas 4 others developed de novo AIH (2.7%; n = 4/148). We analyzed the demographics, laboratory characteristics, and response to treatment of the 4 children with de novo AIH following OLT.

RESULTS

The 4 patients were all girls with a median interval after OLT to presentation of 6.5 years (range, 0.7-8.8 years). The median age when de novo AIH developed was 12.4 years (range, 8.7-17.3 years). All cases were detected by abnormal liver function tests, namely, increased aspartate aminotransferase (AST; median, 322 IU/L; range, 181-919 IU/L). One patient showed elevated immunoglobulin G. Three patients displayed positive antinuclear antibodies. All were seronegative for smooth muscle antibody and liver-kidney microsomal type 1 antibody. One patient showed anti-mitochondrial antibody. All patients were treated with steroids with or without azathioprine. The liver function tests in these 4 patients, improved by at least 50% during the first month of treatment, responding to steroid treatment with or without azathioprine.

CONCLUSION

In preadolescent or adolescent female patients with unexplained graft dysfunction after OLT, it is important to recognize de novo AIH rapidly and to develop an adequate diagnostic strategy, including evaluation of serum autoantibodies, immunoglobulin G, and liver biopsy.

Treadmill exercise stress echocardiography in patients with no history of coronary artery disease: a single-center experience in korean population

Background and Objectives

Treadmill exercise stress echocardiography (TSE) has superior diagnostic accuracy than exercise electrocardiography (ECG). The objectives of the study are 1) to define the diagnostic accuracy and safety of TSE in patients without a history of coronary artery disease (CAD), 2) to identify the clinical characteristics that predict positive TSE results and 3) to assess the differential predictive value between TSE and concomitant exercise ECG in a Korean population.

Subjects and Methods

A total of 1,287 patients among 1,500 consecutive patients with no prior history of CAD and who were referred for TSE during a 4-year 3-month period were enrolled.

Results

Of the 1,287 patients, 95 (7.4%) showed positive TSE results (newly developed regional wall motion abnormality). Among the 154 patients with coronary angiography, 94 patients (61%) showed significant CAD (30 of 77 patients with negative TSE results and 64 of 77 patients with positive TSE results). The TSE positive population had more cardiovascular risk factors and showed a higher Duke treadmill score and wall motion score index than the TSE negative group. TSE showed relatively good sensitivity (68%), specificity (78%) and positive and negative predictive values (83% and 61%, respectively), and TSE also had higher diagnostic accuracy than concomitant exercise ECG (72% vs. 64%, respectively).

Conclusion

TSE is safe and offers greater diagnostic power for CAD than exercise ECG in Korean population without a history of CAD. Its prognostic value in this population needs to be confirmed in a larger prospective study.

Combined Assessments of Biochemical Markers and ST-Segment Resolution Provide Additional Prognostic Information for Patients With ST-Segment Elevation Myocardial Infarction

Background and Objectives

The prognostic value of biochemical markers and the resolution of ST-segment elevation on electrocardiogram are well established. However, how a combination of these two tools affects the evaluation of risk stratification has not yet been evaluated.

Subjects and Methods

Between January 2006 and June 2008, 178 consecutive patients treated with primary percutaneous coronary interventions after ST-segment elevation myocardial infarctions (STEMI) were analyzed at two coronary care units. Patients were divided into the following three groups according to ST-segment resolution: complete (≥70% depression of the elevated ST-segment, n=63), partial (30% to 70%, n=90), and incomplete (<30%, n=25). Demographic data, including history, electrocardiography, biochemical markers, initial ejection fraction, and angiographic findings were also evaluated.

Results

There were 7 deaths, 3 repeated myocardial infarctions, and 17 readmissions for worsening heart failure during six months of follow-up. In a multivariate analysis to predict clinical outcomes, ejection fraction {hazard ratio (HR): 0.83 (0.76-0.91), p<0.01}, high-sensitivity C-reactive protein {HR: 1.15 (1.05-1.26), p<0.05}, and the degree of ST-segment resolution {HR: 0.96 (0.93-0.09), p<0.05} were independently associated with clinical outcomes. According to the Cox-proportional hazards model, the addition of ST-segment resolution markedly improved the prognostic utility of the model containing biochemical markers and ejection fraction.

Conclusion

Assessment of biomarkers upon admission and ST-segment resolution are strong predictors of clinical outcomes. The combination of these data provides additive information about prognosis at an early point in the disease progression and further improves risk stratification for STEMI.

Optical coherence tomography findings of very late stent thrombosis after drug-eluting stent implantation

Previous optical coherence tomography (OCT) studies in patients with drug-eluting stents (DESs)-related very late stent thrombosis (VLST) were scarce. Therefore, we investigated OCT findings of VLST after implantation of DESs. Using OCT, we analyzed the status of stent struts and neointimal characteristics in 18 patients who developed VLST after DES implantation. These results were compared to those in 57 patients with neointimal hyperplasia causing >40% diameter stenosis. Lipid-laden neointima was defined as a region with marked signal attenuation and a diffuse border. Four (22.2%) of 18 patients with VLST had ruptured and lipid-laden neointima inside DESs without uncovered or malapposed stent struts. In the remaining 14 patients who developed VLST without neointimal rupture, uncovered and malapposed struts were observed in nine and seven patients, respectively, and lipid-laden neointima in four patients. Lipid-laden neointima was more frequently observed in four patients with neointimal rupture than in 14 patients without neointimal rupture (100% vs. 28.6%, respectively, P = 0.023). Of 57 patients with neointimal hyperplasia, eight (14.0%) had lipid-laden neointima. Time to OCT study after DES implantation was significantly longer in the eight patients with lipid-laden neointima than in 49 patients without lipid-laden neointima (45.5 ± 17.7 months vs. 11.7 ± 7.2 months, respectively, P < 0.001). Lipid-laden neointima was detected in some patients with neointimal hyperplasia > 1 year after DES implantation. In addition to uncovered or malapposed struts, rupture of lipid-laden neointima inside DESs was identified in some patients with DES-related VLST.

The epidemiological and clinical characteristics of patients admitted for coronary angiography to evaluate ischemic heart disease

BACKGROUND

Most of the known risk factors associated with ischemic heart disease are based on studies from Western countries; there is only limited information on Korean populations. This study was designed to analyze age related differences in epidemiologic and clinical characteristics in patients who were admitted for coronary angiography for the evaluation of ischemic heart disease.

METHODS

As part of the multicenter KCAR (Korean Coronary Artery disease Registry) Study, the clinical data of 6,549 patients, who were evaluated at the cardiac catheterization laboratory by coronary angiography, at seven university hospitals in Korea from March 1999 to December 2005, were registered into the KCAR database and analyzed. All patients were divided into three groups according to age: age < or = 40, age 41-70 and age > or = 71. All demographic and coronary angiographic features were analyzed for the different groups.

RESULTS

The demographic data showed that compared to the older patients young patients < or = 40 had a higher prevalence of males and smokers, but a lower prevalence of hypertension, diabetes and prior history of stroke and myocardial infarction. For the lipid profiles, the younger patients had much higher levels of total cholesterol, triglycerides and LDL-cholesterol than the older groups; however, there was no difference in the HDL-cholesterol levels among the three age groups. The most common component of the metabolic syndrome was obesity (79%) in the younger patients and hypertension (92%) in the older patients. The most common reason for presentation was ST-segment elevated myocardial infarction in the younger patients and unstable angina in the older patients.

CONCLUSIONS

Ischemic heart disease in younger adults < or = 40 had different demographic characteristics and clinical presentation than older patients.

A diagnosis system for the spinal column nerve damaged patients

Visible evidence of spinal column damage is only apparent in 14% of the patients who receive spinal damage. We use a humidity sensor array. The humidity sensor (HDP-05) is arranged and attached to pre-assigned regions along the spinal column nerve of the actual patient. Applying pressure to the urinary bladder causes the patient to sweat. It is possible to determine which spinal column autonomic nerve is damaged in a region by humidity value. But also have some problem is that sometimes the damaged region has same value as a normal region. If will find a better attachment method and a more sensitive sensor could be found the results will be better and more precise.

Overexpression of SERTAD3, a putative oncogene located within the 19q13 amplicon, induces E2F activity and promotes tumor growth

The amplified region of chromosome 19q13.1-13.2 has been associated with several cancers. The well-characterized oncogene AKT2 is located in this amplicon. Two members of the same gene family (SERTAD1 and SERTAD3) are also located within this region. We report herein the genomic structure and potential functions of SERTAD3. SERTAD3 has two transcript variants with short mRNA half-lives, and one of the variants is tightly regulated throughout G1 and S phases of the cell cycle. Overexpression of SERTAD3 induces cell transformation in vitro and tumor formation in mice, whereas inhibition of SERTAD3 by small interfering RNA (siRNA) results in a reduction in cell growth rate. Furthermore, luciferase assays based on E2F-1 binding indicate that SERTAD3 increases the activity of E2F, which is reduced by inhibition of SERTAD3 by siRNA. Together, our data support that SERTAD3 contributes to oncogenesis, at least in part, via an E2F-dependent mechanism.

Phosphodiesterase: overview of protein structures, potential therapeutic applications and recent progress in drug development

Phosphodiesterases (PDEs) are essential regulators of cyclic nucleotide signaling with diverse physiological functions. Because of their great market potential and therapeutic importance, PDE inhibitors became recognized as important therapeutic agents in the treatment of various diseases. Currently, there are seven PDE inhibitors on the market, and the pharmacological and safety evaluations of many drug candidates are in progress. Three-dimensional (3D) structures of catalytic domains of PDE 1, -3, -4, -5 and -9 in the presence of their inhibitors are now available, and can be utilized for rational drug design. Recent advances in molecular pharmacology of PDE isoenzymes resulted in identification of new potential applications of PDE inhibitors in various therapeutic areas, including dementia, depression and schizophrenia. This review will describe the latest advances in PDE research on 3D structural studies, the potential of therapeutic applications and the development of drug candidates.

Folding and stability of sweet protein single-chain monellin. An insight to protein engineering

Engineered single-chain monellin (SCM) proteins were constructed by recombinant technology without disrupting the topology and sweet activity of native protein. Data from 8-anilinonaphthalene-1-sulfonic acid fluorescence, size-exclusion chromatography, and heteronuclear NMR strongly suggest the presence of a folding intermediate at 1.5 m GdnHCl for SCM protein. The structural feature of the folding intermediate from NMR data reveals that the secondary structures became mostly unstable, and protein experiences a dynamic equilibrium between native and unfolded state. All backbone amide protons exchange within 10 min, which imply that no stable hydrogen bonds exist in the secondary structural regions in the folding intermediate. From equilibrium unfolding and mutagenesis studies, the unfolding transition midpoints of mutant proteins gradually shifted toward lower denaturant concentration, indicating stability reductions of mutant proteins. Our results suggest that stability and folding pathways of SCM proteins could be regulated by a combined study of spectroscopy and mutagenesis, and these studies will provide useful information for understanding the folding kinetics of novel engineered proteins.

Detection of hepatocellular carcinoma: combined T2-weighted and dynamic gadolinium-enhanced MRI versus combined CT during arterial portography and CT hepatic arteriography

PURPOSE

The purpose of this study was to compare the preoperative detectability of hepatocellular carcinomas (HCCs) using combined T2-weighted and dynamic gadolinium-enhanced MRI and combined CT during arterial portography (CTAP) and CT hepatic arteriography (CTHA).

METHOD

Thirty-three patients with 43 HCCs underwent T2-weighted and dynamic gadolinium-enhanced MRI and combined CTAP and CTHA. The diagnosis was established by pathologic examination following surgical resection in 26 patients and by biopsy in 7 patients. The MR protocol included fast SE with two TEs (including T2-weighted imaging) and precontrast and gadolinium-enhanced T1-weighted fast multiplanar spoiled gradient-recalled echo images with dynamic study. The MR images of all sequences and the paired CTAP and CTHA images were independently reviewed by three radiologists. Image review was conducted on a segment-by-segment basis. Diagnostic accuracy was evaluated with receiver operating characteristic analysis.

RESULTS

The accuracies (Az values) of MRI of all sequences and combined CTAP and CTHA for all observers were 0.960 and 0.959, respectively. The mean sensitivities of MRI and CT were 90 and 94%, respectively. The differences were not statistically significant. The mean specificity of MRI (99%) was significantly higher than that of combined CTAP and CTHA (92%).

CONCLUSION

Combined T2-weighted and dynamic gadolinium-enhanced MRI is as accurate as combined CTAP and CTHA for preoperative detection of HCCs.

Solution structure, backbone dynamics, and stability of a double mutant single-chain monellin. structural origin of sweetness

Single-chain monellin (SCM), which is an engineered 94-residue polypeptide, has been characterized as being as sweet as native two-chain monellin. Data from gel-filtration high performance liquid chromatography and NMR has proven that SCM exists as a monomer in aqueous solution. In order to determine the structural origin of the taste of sweetness, we engineered several mutant SCM proteins by mutating Glu(2), Asp(7), and Arg(39) residues, which are responsible for sweetness. In this study, we present the solution structure, backbone dynamics, and stability of mutant SCM proteins using circular dichroism, fluorescence, and NMR spectroscopy. Based on the NMR data, a stable alpha-helix and five-stranded antiparallel beta-sheet were identified for double mutant SCM. Strands beta1 and beta2 are connected by a small bulge, and the disruption of the first beta-strand were observed with SCM(DR) comprising residues of Ile(38)-Cys(41). The dynamical and folding characteristics from circular dichroism, fluorescence, and backbone dynamics studies revealed that both wild type and mutant proteins showed distinct dynamical as well as stability differences, suggesting the important role of mutated residues in the sweet taste of SCM. Our results will provide an insight into the structural origin of sweet taste as well as the mutational effect in the stability of the engineered sweet protein SCM.

Non-combustible waste vitrification with plasma torch melter

Non-combustible radioactive wastes generated from Nuclear Power Plants (NPPs) are composed of concrete, glass, asbestos, metal, sand, soil, spent filters, etc. The melting tests for concrete, glass, sand, and spent filters were carried out using a 60 kW plasma torch system. The surrogate wastes were prepared for the tests. Non-radioactive Co and Cs were added to the surrogates in order to simulate the radioactive waste. Several kinds of surrogate prepared by their own mixture or by single waste were melted with the plasma torch system to produce glassy waste forms. The characteristics of glassy waste forms were examined for the volume reduction factor (VRF) and the leach rate. The VRFs were estimated through the density measurement of the surrogates and the glassy waste forms, and were turned out to be 1.2-2.4. The EPA (Environmental Protection Agency) Toxicity Characteristic Leaching Procedure (TCLP) was used to determine the leach resistance for As, Ba, Hg, Pb, Cd, Cr, Se, Co, and Cs. The leaching index was calculated using the total content of each element in both the waste forms and the leachant. The TCLP tests resulted in that the leach rates for all elements except Co and Cs were lower than those of the Universal Treatment Standard (UTS) limits. There were no UTS limits for Co and Cs, and their leach rate & index from the experiments were resulted in around 10 times higher than those of other elements.

Experimental and modeling evaluation of upward and downward velocities in the coaxial flotation column

This study was conducted to show the influence of upward velocity in the inner column and downward velocity in the outer column of the coaxial cylinder-type flotation column on the solids removal efficiency, solids concentration in the treated water, and so on. The SIMPLE (Semi-Implicit Method for Pressure Linked Equation) solution was applied to the coaxial flotation column to simulate the velocity vectors of the elements of water flowing in the column. The effects of solids loading and residence time in the agglomerate separation zone on the solids removal efficiency were also tested. In the pilot scale coaxial DAF column experiments with solids concentration of 1,000-2,000 mg of SS per liter and solids loading less than 350 kg/m2/day, approximately 90% of the solids removal efficiencies were obtained using the upward velocity of up to 110 cm/min in the contact zone of the inner column and the downward velocity of up to 30 cm/min in the outer column. In the simulation, similar results were observed as in the experiments. The solids loading in the excess of 350 kg/m2/day caused the instability of the sludge float layer and aggravated the quality of the treated water.

Expression and purification of an active, full-length hepatitis C viral NS4A

The nonstructural protein 3 (NS3) of the hepatitis C virus (HCV) is a bifunctional protein with protease and helicase activities. Nonstructural protein 4A (NS4A) is preceded by NS3 and augments the proteolytic activity of NS3 through protein-protein interaction. The central domain of NS4A has been shown to be sufficient for the enhancement of the NS3 protease activity. However, investigations on the roles of the N-terminal and the C-terminal regions of NS4A have been hampered by the difficulty of purification of full-length NS4A, a polypeptide that contains highly hydrophobic amino acid residues. Here we report a procedure by which one can produce and purify an active, full-length NS4A using maltose-binding protein fusion method. The full-length NS4A fused to the maltose binding protein is soluble and maintains its NS3 protease-enhancing activity.

RBT1, a novel transcriptional co-activator, binds the second subunit of replication protein A

Replication Protein A (RPA) is required for DNA recombination, repair and replication in all eukaryotes. RPA participation in these pathways is mediated by single-stranded DNA binding and protein interactions. We herein identify a novel protein, Replication Protein Binding Trans-Activator (RBT1), in a yeast two-hybrid assay employing the second subunit of human RPA (RPA32) as bait. RBT1-RPA32 binding was confirmed by glutathione S:-transferase pull-down and co-immunoprecipitation. Fluorescence microscopy indicates that green fluorescence protein-tagged RBT1 is localized to the nucleus in vivo. RBT1 mRNA expression, determined by semi-quantitative RT-PCR, is significantly higher in cancer cell lines MCF-7, ZR-75, SaOS-2 and H661, compared to the cell lines normal non-immortalized human mammary epithelial cells and normal non-immortalized human bronchial epithelial cells. Further, yeast and mammalian one-hybrid analysis shows that RBT1 is a strong transcriptional co-activator. Interestingly, mammalian transactivation data is indicative of significant variance between cell lines; the GAL4-RBT1 fusion protein has significantly higher transcriptional activity in human cancer cells compared to human normal primary non-immortalized epithelial cells. We propose that RBT1 is a novel transcriptional co-activator that interacts with RPA, and has significantly higher activity in transformed cells.

Needle-tract implantation in hepatocellular carcinoma: frequency and CT findings after biopsy with a 19.5-gauge automated biopsy gun

BACKGROUND

Needle-tract implantation is an important complication of cutting biopsy of hepatocellular carcinoma (HCC). This study was performed to evaluate the frequency of needle-tract implantation after ultrasound (US)-guided percutaneous biopsy of HCC and to describe triple-phase helical computed tomographic (CT) findings of implanted nodules.

METHODS

Between April 1994 and December 1997, 205 patients underwent US-guided percutaneous biopsy for HCC. Review of medical records and the pathology database disclosed seven patients who were found to have needle-tract implantation of HCC. Among these patients, five underwent triple-phase helical CT examination. We analyzed the frequency of needle-tract implantation and triple-phase helical CT findings of implanted nodules, with particular attention to the morphology and enhancement pattern.

RESULTS

Seven of 205 patients (3.4%) had tumor implantation along the needle tract at histologic examination after surgical resection. Eight implanted nodules in five patients were found on triple-phase helical CT images (one nodule in three patients, two nodules in one patient, and three nodules in one patient). All implanted nodules has well-circumscribed margins and were ovoid or lobulated in contour. On triple-phase helical CT, six (75%) implanted nodules were isodense compared with abdominal wall muscle on all triple-phase CTs, and two (25%) nodules were hyperdense on hepatic arterial and portal venous phases and isodense on equilibrium phase.

CONCLUSIONS

The frequency of needle-tract implantation of HCC after percutaneous needle biopsy was higher than reported previously, and careful attention should be paid during interpretation of CT images in patients with a history of previous percutaneous biopsy.

Dysplastic nodules in liver cirrhosis: evaluation of hemodynamics with CT during arterial portography and CT hepatic arteriography

PURPOSE

To evaluate the portal and arterial blood supplies to dysplastic nodules in the cirrhotic liver with computed tomography (CT) during arterial portography (CTAP) and CT hepatic arteriography (CTHA).

MATERIALS AND METHODS

Nineteen histopathologically proved low-grade dysplastic nodules and 13 high-grade dysplastic nodules in 17 patients with liver cirrhosis were evaluated with CTAP and CTHA for the presence of portal and arterial blood supplies to the nodules. The nodules ranged from 0.4 to 4.5 cm in diameter (mean, 1.6 cm).

RESULTS

The portal supply was present in 14 of the 19 (74%) low-grade dysplastic nodules and in seven of the 13 (54%) high-grade dysplastic nodules. The hepatic arterial supply was increased in four of the 19 (21%) low-grade dysplastic nodules, present in nine (47%), and absent in six (32%). The arterial supply was increased in four of the 13 (31%) high-grade dysplastic nodules, present in four (31%), and absent in five (38%).

CONCLUSION

The portal and arterial supplies to the low- and high-grade dysplastic nodules were variable and inconsistent. Therefore, it is difficult to detect and characterize the dysplastic nodules on the radiologic images on the basis of the blood supply.

Functional MR imaging of working memory in the human brain

OBJECTIVE

In order to investigate the functional brain anatomy associated with verbal and visual working memory, functional magnetic resonance imaging was performed.

MATERIALS AND METHODS

In ten normal right handed subjects, functional MR images were obtained using a 1.5-T MR scanner and the EPI BOLD technique. An item recognition task was used for stimulation, and during the activation period of the verbal working memory task, consonant letters were used. During the activation period of the visual working memory task, symbols or diagrams were employed instead of letters. For the post-processing of images, the SPM program was used, with the threshold of significance set at p <.001. We assessed activated brain areas during the two stimulation tasks and compared the activated regions between the two tasks.

RESULTS

The prefrontal cortex and secondary visual cortex were activated bilaterally by both verbal and visual working memory tasks, and the patterns of activated signals were similar in both tasks. The superior parietal cortex was also activated by both tasks, with lateralization to the left in the verbal task, and bilaterally without lateralization in the visual task. The inferior frontal cortex, inferior parietal cortex and temporal gyrus were activated exclusively by the verbal working memory task, predominantly in the left hemisphere.

CONCLUSION

The prefrontal cortex is activated by two stimulation tasks, and this is related to the function of the central executive. The language areas activated by the verbal working memory task may be a function of the phonological loop. Bilateral prefrontal and superior parietal cortices activated by the visual working memory task may be related to the visual maintenance of objects, representing visual working memory.

Salivary gland tumors: evaluation with two-phase helical CT

PURPOSE

To evaluate two-phase helical computed tomography (CT) in the characterization of salivary gland tumors.

MATERIALS AND METHODS

Sixty-four patients with major salivary gland tumors underwent two-phase helical CT. The histopathologic diagnosis was obtained by means of surgical resection or biopsy in all patients. After the injection of 90 mL of contrast material at a rate of 3 mL/sec, helical CT scans were obtained at early and delayed phases with scanning delays of 30 and 120 seconds, respectively. The attenuation change and enhancement patterns in the tumors were assessed. The attenuation change in the tumor also was assessed quantitatively as the ratio of the CT number (in Hounsfield units) at delayed phase scanning to that at early phase scanning.

RESULTS

There were 35 pleomorphic adenomas, nine Warthin tumors, and 20 malignant tumors. Two-phase helical CT showed increase in attenuation in 30 (86%) pleomorphic adenomas, decrease in eight (89%) Warthin tumors, and increase in 11 (55%) and no change in eight (40%) malignant tumors at delayed phase scanning. A multinodular enhancement pattern was found in only 12 (34%) pleomorphic adenomas. The ratio of CT numbers was significantly different between Warthin tumors and pleomorphic adenomas and between Warthin tumors and malignant tumors.

CONCLUSION

The analysis of enhancement patterns by using two-phase helical CT will be helpful in the differential diagnosis of salivary gland tumors.

Infantile fibromatosis in childhood: findings on MR imaging and pathologic correlation

AIM

The objective of this study was to analyse the MR imaging findings of infantile fibromatosis of childhood and to correlate them with histopathological features.

MATERIALS AND METHODS

Seven patients with histologically proven infantile fibromatosis were included in this study. The findings on MR images were retrospectively evaluated and then correlated with the pathological features. Findings on MR imaging evaluated included signal intensity, extent of hyperintense area on T2-weighted images, margins of the lesion, the degree and pattern of enhancement and the presence of fatty tissue. Pathological features evaluated included cellularity, collagenization, and myxoid change. A five point scale was used for the evaluation of the extent of hyperintense area on MR imaging, and each of pathological features.

RESULTS

On T1-weighted images, the lesions were iso-intense in two patients; iso- and hypointense in three; and iso-, hypo- and hyperintense in two. On T2-weighted images, iso-, hypo- and hyperintense areas were mixed in all patients, the hyperintense area being the largest portion of the lesion. The margins of the lesions were infiltrative in four patients (57%), smooth in two (29%) and mixed in one (14%). Enhancement was marked in five patients (72%) and diffuse in five (71%). Regardless of the hyperintense signal intensity on T2-weighted images, the grades of each pathologic feature were variable.

CONCLUSION

Infantile fibromatosis on MR imaging causes an enhancing mass, that is largely hyperintense on T2-weighted images. Areas of high signal intensity on T2-weighted images corresponded to variable grades of cellularity, collagenization, or myxoid change.

Primary mucinous cystadenocarcinoma of the appendix: CT findings

OBJECTIVE

The preoperative diagnosis of a primary appendiceal tumor can be difficult because of its rarity and the paucity of material in the radiology literature. The purpose of this study was to describe CT findings in six patients with primary mucinous cystadenocarcinoma of the appendix.

CONCLUSION

When CT reveals a cystic mass with enhancing wall nodularity in the expected area of the appendix, especially in older patients, the possibility of primary mucinous cystadenocarcinoma should be considered.

Variations in meniscofemoral ligaments at anatomical study and MR imaging

PURPOSE

To demonstrate variations in the meniscofemoral ligaments (ligaments of Wrisberg and Humphrey) at anatomical study and magnetic resonance (MR) imaging.

DESIGN

Twenty-eight cadaveric knees were partially dissected for the examination of the meniscofemoral ligaments. One hundred knee MR examinations were reviewed by two experienced musculoskeletal radiologists. Proximal variations in the meniscofemoral ligaments at MR imaging were classified into three types according to the attachment site: type I, medial femoral condyle; type II, proximal half of the posterior cruciate ligament (PCL); type III, distal half of the PCL. Distal variations were classified into vertical or oblique types according to the orientation of the intermediate signal at the interface of the ligament and lateral meniscus.

RESULTS

At anatomical study, six cases showed variations in the proximal insertion site of the meniscofemoral ligaments. At MR imaging 93 cases had one or more meniscofemoral ligaments, giving a total of 107 ligaments: 90 ligaments of Wrisberg and 17 ligaments of Humphrey. Forty-one ligaments of Wrisberg were type I, 28 type II, 19 type III, and with two indeterminate type, while 6 ligaments of Humphrey were type I and the remaining 11 were indeterminate. Seven cases showed no meniscofemoral ligament. Of the 107 meniscofemoral ligaments, the distal insertion orientation was of vertical type in 10 ligaments, oblique type in 70 and unidentified in 27.

CONCLUSION

An understanding of the high incidence of meniscofemoral ligament variations may help in the interpretation of knee MR studies.

Solution structure of a sweet protein single-chain monellin determined by nuclear magnetic resonance and dynamical simulated annealing calculations

Single-chain monellin (SCM), which is an engineered 94-residue polypeptide, has proven to be as sweet as native two-chain monellin. SCM is more stable than the native monellin for both heat and acidic environments. Data from gel filtration HPLC and NMR indicate that the SCM exists as a monomer in aqueous solution. The solution structure of SCM has been determined by nuclear magnetic resonance (NMR) spectroscopy and dynamical simulated annealing calculations. A stable alpha-helix spanning residues Phe11-Ile26 and an antiparallel beta-sheet formed by residues 2-5, 36-38, 41-47, 54-64, 69-75, and 83-88 have been identified. The sheet was well defined by backbone-backbone NOEs, and the corresponding beta-strands were further confirmed by hydrogen bond networks based on amide hydrogen exchange data. Strands beta2 and beta3 are connected by a small bulge comprising residues Ile38-Cys41. A total of 993 distance and 56 dihedral angle restraints were used for simulated annealing calculations. The final simulated annealing structures (<SA>k) converged well with a root-mean-square deviation (rmsd) between backbone atoms of 0.49 A for secondary structural regions and 0.70 A for backbone atoms excluding two loop regions. The average restraint energy-minimized (REM) structure exhibited root-mean-square deviations of 1.19 A for backbone atoms and 0.85 A for backbone atoms excluding two loop regions with respect to 20 <SA>k structures. The solution structure of SCM revealed that the long alpha-helix was folded into the concave side of a six-stranded antiparallel beta-sheet. The side chains of Tyr63 and Asp66 which are common to all sweet peptides showed an opposite orientation relative to H1 helix, and they were all solvent-exposed. Residues at the proposed dimeric interface in the X-ray structure were observed to be mostly solvent-exposed and demonstrated high degrees of flexibility.