The long-term cardiac events after coronary bifurcation stenting with second-generation drug-eluting stents in elderly patients are comparable to those of younger patients

Background

Elderly patients undergoing percutaneous coronary intervention (PCI) generally have a high risk of adverse clinical outcomes. We investigated the long-term clinical impact of PCI on coronary bifurcation disease in elderly patients in Korea and Italy.

Methods

From the BIFURCAT (comBined Insights from the Unified RAIN and COBIS bifurcAtion regisTries) data, we evaluated 5,537 patients who underwent PCI for coronary bifurcation disease. The primary outcome was major adverse cardiac events (MACEs), defined as the composite of target vessel myocardial infarction, target lesion revascularisation, and stent thrombosis. Kaplan–Meier estimates and Cox proportional hazard models were used to compare elderly patients (aged ≥75 years) and younger patients (aged <75 years).

Results

A total of 1,415 patients (26%) were aged ≥75 years. Elderly patients were more frequently female, had higher rates of hypertension and chronic kidney disease (CKD), and presented more frequently with left main (LM) disease. After a median follow-up of 2.1 years, MACEs were comparable between elderly and younger patients. In multivariable analysis, old age was not an independent predictor of MACEs (p=0.977). In elderly patients, CKD and LM disease were independent predictors of MACEs, whereas in younger patients, hypertension, diabetes, CKD, reduced left ventricular ejection fraction, LM disease, and two-stent strategy usage were independent predictors.

Conclusions

Elderly patients who underwent coronary bifurcation PCI with second-generation drug-eluting stents demonstrated similar clinical outcomes to those of younger patients. Both CKD and LM disease were independent predictors of MACEs, regardless of age after coronary bifurcation PCI.

Funding Acknowledgement

Type of funding sources: None.

The differential effects of antihypertensive drugs on central blood pressure: nebivolol versus telmisartan (ATD-CBP)

Background

Central blood pressure and central pulse pressure have a better correlation with the risk of cardiovascular disease compared to those of peripheral measurement. In a previous study, a second-generation beta-blocker showed poor CBP-lowering effects. However, the effect on CBP by third-generation beta-blockers is not fully elucidated. Thus, this randomised study investigated whether nebivolol-based hypertension treatment may confer advantages over telmisartan, an angiotensin II receptor-blocker, in reducing CBP.

Methods

This was a prospective, randomised, multicentre, open-label, controlled trial that evaluated 98 hypertensive patients. Patients received either nebivolol- (N=49) or telmisartan-based (N=49) treatment for hypertension for 12 weeks with a target BP of ≤140/80. The primary outcome was the difference in change from baseline central systolic BP (cSBP) after 12 weeks.

Results

There were no significant differences between the two groups in baseline central and peripheral SBP. The mean change in cSBP from baseline (ΔcSBP) was −17.2±3 mmHg for nebivolol group (P<0.001) and −29.9±3 mmHg for telmisartan group (P<0.001). The difference in ΔcSBP between the two groups was significant (12.7mmHg, 95% confidence interval [CI], 4.13 to 21.2; P=0.004). Peripheral SBP (pSBP) decreased less in nebivolol group compared to telmisartan group (−18.0±3 in nebivolol group vs. −26.3±3 in telmisartan group, P=0.032). After adjusting for reduction in pSBP, reduction in cSBP was higher in telmisartan group compared to nebivolol group, as shown by the ratio of changes in cSBP and pSBP (ΔcSBP/ΔpSBP; 0.67 for nebivolol group vs. 1.11 for telmisartan group, P=0.080), albeit without statistical significance.

Conclusions

Nebivolol-based hypertension treatment may have less potent CBP-lowering effects compared to telmisartan. However, larger-scale studies are warranted to further elaborate our findings.

Funding Acknowledgement

Type of funding sources: None.

Effect of an early invasive strategy based on time of symptom onset in patients with non-ST elevation myocardial infarction

Background

A limitation of the current guidelines of the timing of invasive coronary angiography (ICA) for patients with non-ST-segment elevation (NSTE) acute coronary syndrome is based on randomization time. So far, no study has reported the clinical outcomes of invasive strategy timing based on the time of symptom onset. Herein, we aimed to investigate the effect of invasive strategy timing from the time of symptom onset on the 3-year clinical outcomes of patients with NSTE myocardial infarction (MI).

Methods and results

Among 13,104 patients from the Korea Acute Myocardial Infarction Registry-National Institutes of Health, we evaluated 5,856 patients with NSTEMI. The patients were categorized according to symptom-to-catheter (StC) time (<48 h and ≥48 h). The primary outcome was 3-year all-cause mortality, and the secondary outcome was a 3-year composite of all-cause mortality, recurrent MI, and hospitalization for heart failure. Overall, 3,919 (66.9%) patients were classified into the StC time <48 h group. This group had lower all-cause mortality than the StC time ≥48 h group (7.3% vs. 13.4%, p<0.001). The continuous association of StC time and risk of primary and secondary endpoints showed shorter StC time (reference: 48 h), and lower adjusted hazard ratio reduction was observed. In multivariable analysis, independent predictors of delayed ICA were older age, non-specific symptoms, no use of emergency medical services, no ST-segment deviation, chronic kidney disease, and Global Registry of Acute Coronary Events score >140.

Conclusion

Early invasive strategy based on the StC time improves all-cause mortality in patients with NSTEMI.

Funding Acknowledgement

Type of funding sources: None.

Maximally tolerated guideline-directed medical therapy and barriers to optimization in patients with heart failure with reduced ejection fraction: the COAPT trial

Background

The COAPT trial of MitraClip therapy employed a central screening eligibility committee (CSEC) of heart failure (HF) experts to ensure the use of maximally tolerated guideline-directed medical therapy (GDMT) and systematically document intolerances in all potential patients prior to approval for randomization.

Purpose

To describe the percentage of GDMT classes, doses tolerated, predictors of intolerance, and specific intolerances limiting GDMT among patients approved for randomization by the CSEC.

Methods

We analyzed baseline use, dose, and intolerances of i) angiotensin-converting enzyme inhibitors (ACEI), angiotensin II receptor blockers (ARB) or angiotensin receptor neprilysin inhibitor (ARNI); ii) beta-blockers (BB); and iii) mineralocorticoid receptor antagonists (MRA) in the CSEC-approved COAPT population with HF with reduced ejection fraction (HFrEF; LVEF ≤40%). We analyzed variables associated with GDMT tolerance.

Results

In COAPT, 464 patients had HFrEF and complete screening medication information. Any dose of all 3, 2 or 1 GDMT classes were tolerated in 39%, 39% and 20% of patients respectively; only 2% of patients (n=9) could not tolerate any GDMT (Figure 1). BB were prescribed in the most (93%) patients followed by ACEI/ARB/ARNI (69%) and MRA (55%). Intolerances limiting each GDMT class differed, but hypotension and kidney dysfunction were most common (Figure 2). No patients tolerated goal doses of all 3 GDMT classes. For BB, only 32% tolerated ≥50% of the goal dose; while for ACEI/ARB/ARNI, no patients achieved goal doses, and only 1% tolerated ≥50% of the goal dose. For MRA, 86% of patients tolerated 25mg/day or less. Patients intolerant of BB were less likely to tolerate an ACEI/ARB/ARNI (OR 0.39, 95% CI 0.20–0.76; p=0.004) but not a MRA (p=0.21) compared with patients tolerating a low dose BB. Patients intolerant of MRA were less likely to tolerate ACEI/ARB/ARNI therapy (OR 0.37, 95% CI 0.25–0.57; p<0.0001) but not a BB (p=0.31) compared with patients tolerating MRA. Patients tolerating low dose ACEI/ARB/ARNI had a higher baseline mean eGFR (52±21 versus 40±21 ml/min/m2; p<0.0001) compared with patients intolerant of ACEI/ARB/ARNI. Likewise, patients tolerating MRA had a higher baseline mean eGFR (52±21 versus 42±21 ml/min/m2; p<0.0001) compared with patients intolerant of MRA.

Conclusion

In a contemporary trial in which HF specialists ensured GDMT optimization, many patients had medical intolerances prohibiting use of one or more GDMT classes, and few patients tolerated target doses. These findings indicate medical intolerances are the primary cause of low GDMT prescription rates in patients with moderate to severe HFrEF. Yet, use of GDMT in this very ill population was much better than “real world” registries of HFrEF suggesting that mandating careful CSEC review prior to study enrollment is important for clinical trials having the objective of randomizing a maximally treated patient cohort.

Funding Acknowledgement

Type of funding sources: None.

Cerebrovascular events after transcatheter mitral valve repair or guideline-directed medical therapy in patients with mitral regurgitation and heart failure in the COAPT trial

Background

Our knowledge regarding the risk of cerebrovascular events (CVE) in patients with heart failure (HF) and severe secondary mitral regurgitation (SMR) treated by transcatheter mitral valve repair (TMVr) is limited.

Purpose

To examine the incidence, predictors, timing, and prognostic impact of CVE in patients with heart failure and SMR treated with TMVr vs guideline-directed medical therapy (GDMT) alone.

Methods

In the COAPT trial, 614 patients with HF with moderate-to-severe or severe SMR were randomized to TMVr with the MitraClip + GDMT vs GDMT alone. After 2 years, patients who were randomized to GDMT alone could crossover and undergo TMVr. CVE (defined as stroke or TIA) were adjudicated by an independent clinical events committee.

Results

A total of 43 CVE occurred in 42 patients within 3-year follow-up (34 strokes and 9 TIAs; 1 patient had both). CVE occurred in 10.0% (n=20) of patients randomized to TMVR and 11.3% (n=22) of patients randomized to GDMT alone (p=0.53) (Figure). Of the 22 CVE in the GDMT alone group, 3 occurred after the patient had crossed over to TMVr. The incidence rates in the TMVr and GDMT groups were similar within the first 3 months (incidence rate ratio [IRR] 0.78, 95% CI 0.17–3.48, p=0.74) and between 3 months and 3 years (IRR 0.83, 95% CI 0.43–1.60, p=0.58) after randomization. After multivariable adjustment, baseline estimated glomerular filtration rate (eGFR) was associated with CVE in the overall population (HR per 5 ml/min increase in eGFR 0.91, 95% CI 0.84–0.99, p=0.03). Peripheral vascular disease was associated with CVE in patients treated by GDMT (HR=3.21, 95% CI [1.35, 7.67]) but not TMVr (HR 0.53 95% CI 0.12–2.24; p-interaction=0.04). In contrast, baseline chronic oral anticoagulation use was associated with a reduced risk of CVE in patients in the TMVr group (HR 0.18, 95% CI 0.05–0.63) but not in the GDMT alone group (HR 1.66, 95% CI 0.70–3.94; p-interaction=0.004). In a time-adjusted multivariable analysis, CVE was associated with a higher risk of death (HR 2.51, 95% CI 1.54–4.08; p=0.0002), a risk that was marked in the first 30 days after the event (HR 14.21, 95% CI 7.30–27.97, p<0.0001), and declined thereafter (HR 1.37, 95% CI 0.72–2.59, p=0.34).

Conclusions

In patients with HF and severe SMR, CVE at 3 years was not infrequent, increased linearly over time, was similar after treatment with the MitraClip and GDMT alone, and was associated with a marked increase in all-cause death. Whether anticoagulation is especially effective at preventing CVE in patients treated by TMVr, as suggested by this report, warrants further study.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Abbott Figure 1

A simple and efficient method of generating HCMV pp65-specific T cells using overlapping peptides

The methods for expansion of human cytomegalovirus (HCMV)-specific T lymphocytes are limited due to the complex culture process, long culture duration, and human leukocyte antigen (HLA) restriction. Here, we report that in vitro stimulation with pp65 kDa phosphoprotein (pp65)-derived overlapping synthetic peptides rapidly generates large numbers of HCMV-specific cytotoxic T lymphocytes from peripheral blood mononuclear cells (PBMCs) regardless of HLA type. Treatment of PBMCs from healthy volunteers expressing HLA-A*02:01 or HLA-A*24:02 with 138 pp65 overlapping peptides (OLP) resulted in an expansion of HCMV pp65 NLVPMVATV (NLV) pentamer-specific CD8+ T lymphocytes that expressed interferon (IFN)-γ, but the pp65 NLV peptide did not generate HCMV-specific CD8+ T lymphocytes in PBMCs obtained from an HLA-A*24:02 donor due to HLA restriction. The OLP-induced T lymphocytes specific for HCMV derived from PBMCs of HLA-A*02:01- and HLA-A*24:02-expressing donors showed effective cytolytic responses against target cells loaded with OLP or the NLV epitope, but pp65 NLV peptide-induced T lymphocytes did not. Phenotypic analyses demonstrated that OLP increased the frequency of CD3+ CD8+ cells, but not CD3+ CD4+, CD14+, or CD56+ cells, in donor PBMCs. Thus, this study provides evidence that in vitro stimulation with OLP efficiently generates sufficient numbers of HCMV pp65-specific cytotoxic T lymphocytes for adoptive cell therapy. Keywords: human cytomegalovirus; cytotoxic T lymphocyte; overlapping peptides; pp65; cytotoxicity.

Visceral obesity, but not central obesity, is associated with cardiac remodeling in subjects with suspected metabolic syndrome

BACKGROUND AND AIMS

Metabolic syndrome (MetS) is a cluster of multiple risk factors including central obesity that may lead to cardiac damage and cardiovascular events. We investigated whether visceral obesity induces cardiac structural and functional remodeling independently from central obesity and other risk factors in subjects with suspected MetS.

METHODS AND RESULTS

We studied 229 participants with suspected MetS. Visceral fat area (VFA) was measured by bioelectrical impedance analysis. Left ventricular (LV) mass index, early diastolic velocity of mitral annulus (e'), and LV global longitudinal strain (GLS) were measured by echocardiography. Subjects were categorized into high and low VFA group (VFA_h and VFA_l). MetS was more prevalent in the VFA_h than in the VFA_l (p = 0.004). The VFA_h had a higher waist circumference (WC) than the VFA_l (p < 0.001). LV mass index was higher, but e' and GLS were lower in the VFA_h than in VFA_l (all p < 0.05). VFA was well correlated with blood pressure, fasting blood glucose, triglyceride, high-sensitivity C-reactive protein and adiponectin (all p < 0.05). VFA was correlated to LV mass index, e', and GLS (all p < 0.05) and was independently associated with GLS after adjustment for other risk factors, including WC (p = 0.005).

CONCLUSIONS

Visceral obesity assessed by VFA was well correlated with parameters of MetS. Visceral obesity, but not central obesity measured by WC, was independently associated with structural and functional cardiac remodeling in subjects with suspected MetS. It suggests that visceral obesity should be considered as an important risk factor for cardiac damage in dysmetabolic subjects.

TRIAL REGISTRATION

NCT02077530 (date of registration: November 1, 2013).

Ligand-activated peroxisome proliferator-activated receptor-δ and -γ inhibit lipopolysaccharide-primed release of high mobility group box 1 through upregulation of SIRT1

Peroxisome proliferator-activated receptors (PPARs) inhibit lipopolysaccharide (LPS)-primed release of high mobility group box 1 (HMGB1), a late proinflammatory mediator, but the underlying molecular mechanism is not completely understood. In this study, we demonstrated that the inhibition of HMGB1 release by PPAR-δ and -γ is associated with the deacetylase activity of SIRT1. Ligand-activated PPAR-δ and -γ inhibited LPS-primed release of HMGB1, concomitant with elevation in SIRT1 expression and promoter activity. These effects were significantly reduced in the presence of small interfering (si)RNAs against PPAR, indicating that PPAR-δ and -γ are involved in both HMGB1 release and SIRT1 expression. In addition, modulation of SIRT1 expression and activity by siRNA or chemicals correspondingly influenced the effects of PPARs on HMGB1 release, suggesting a mechanism in which SIRT1 modulates HMGB1 release. Furthermore, we showed for the first time that HMGB1 acetylated in response to LPS or p300/CBP-associated factor (PCAF) is an effective substrate for SIRT1, and that deacetylation of HMGB1 is responsible for blockade of HMGB1 release in macrophages. Finally, acetylation of HMGB1 was elevated in mouse embryonic fibroblasts from SIRT1-knockout mice, whereas this increase was completely reversed by ectopic expression of SIRT1. These results indicate that PPAR-mediated upregulation of SIRT1 modulates the status of HMGB1 acetylation, which, in turn, has a critical role in the cellular response to inflammation through deacetylation-mediated regulation of HMGB1 release.

RAF kinase inhibitor-independent constitutive activation of Yes-associated protein 1 promotes tumor progression in thyroid cancer

The transcription coactivator Yes-associated protein 1 (YAP1) is regulated by the Hippo tumor suppressor pathway. However, the role of YAP1 in thyroid cancer, which is frequently associated with the BRAF^V600E mutation, remains unknown. This study aimed to investigate the role of YAP1 in thyroid cancer. YAP1 was overexpressed in papillary (PTC) and anaplastic thyroid cancer, and nuclear YAP1 was more frequently detected in BRAF^V600E (+) PTC. In the thyroid cancer cell lines TPC-1 and HTH7, which do not have the BRAF^V600E mutation, YAP1 was cytosolic and inactive at high cell densities. In contrast, YAP1 was retained in the nucleus and its target genes were expressed in the thyroid cancer cells 8505C and K1, which harbor the BRAF^V600E mutation, regardless of cell density. Furthermore, the nuclear activation of YAP1 in 8505C was not inhibited by RAF or MEK inhibitor. In vitro experiments, YAP1 silencing or overexpression affected migratory capacities of 8505C and TPC-1 cells. YAP1 knockdown resulted in marked decrease of tumor volume, invasion and distant metastasis in orthotopic tumor xenograft mouse models using the 8505C thyroid cancer cell line. Taken together, YAP1 is involved in the tumor progression of thyroid cancer and YAP1-mediated effects might not be affected by the currently used RAF kinase inhibitors.

Synthesis of sea urchin-like carbon nanotubes on nano-diamond powder

Carbon nanotubes (CNTs) have unique atomic structure and properties, such as a high aspect ratio and high mechanical, electrical and thermal properties. On the other hand, the agglomeration and entanglement of CNTs restrict their applications. Sea urchin-like multiwalled carbon nanotubes, which have a small aspect ratio, can minimize the problem of dispersion. The high hardness, thermal conductivity and chemical inertness of the nano-diamond powder make it suitable for a wide range of applications in the mechanical and electronic fields. CNTs were synthesized on nano-diamond powder by thermal CVD to fabricate a filler with suitable mechanical properties and chemical stability. This paper reports the growth of CNTs with a sea urchin-like structure on the surface of the nano-diamond powder. Nano-diamond powders were dispersed in an attritional milling system using zirconia beads in ethanol. After the milling process, 3-aminopropyltrimethoxysilane (APS) was added as a linker. Silanization was performed between the nano-diamond particles and the metal catalyst. Iron chloride was used as a catalyst for the fabrication of the CNTs. After drying, catalyst-attached nano-diamond powders could be achieved. The growth of the carbon nanotubes was carried out by CVD. The CNT morphology was examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The mean diameter and length of the CNTs were 201 nm and 3.25 microm, respectively.

Nano-tribological properties of topographically undulated nanocrystalline diamond patterns

Surface roughness-controlled nanocrystalline diamond film was fabricated as an undulated line and space pattern on a silicon oxide surface. To simulate a MEMS (Micro-/Electro-Mechanical System) and NEMS (Nano-/Electro-Mechanical System) patterned surface, 800 nm and 1 microm wide lines with a 200 nm wide space pattern were prepared on the substrate using E-beam lithography and an ESAND (Electrostatic Self-assembly of NanoDiamond) seeding layer lift-off process. Through this process, an undulated pattern of a nanocrystalline CVD diamond successfully formed by a conventional micro crystalline diamond growth system. The roughness of the deposited surface was controlled by regulating the size of the seeding nanodiamond particles. Crushing of the nanodiamond aggregates and dispersion of the nanodiamond solution was performed in an attrition milling system. An AFM (Atomic Force Microscopy) probe was used for the wear test and surface profiling of nanocrystalline diamond coatings. 2-D friction coefficient mapping by LFM (Lateral Force Microscopy) scanning showed a low friction coefficient (< 0.1) on the line-patterned diamond surface, and a higher friction coefficient (< 0.3) on a narrow area adjacent to the undulated pattern edges. With prolonged LFM scanning, the high coefficient of friction was reduced to less than 0.1. The bonding status of the nanocrystalline diamond was analyzed with Raman spectroscopy.

Constraining carbon sources and growth rates of freshwater microbialites in Pavilion Lake using (14)C analysis

This study determined the natural abundance isotopic compositions ((13)C, (14)C) of the primary carbon pools and microbial communities associated with modern freshwater microbialites located in Pavilion Lake, British Columbia, Canada. The Delta(14)C of dissolved inorganic carbon (DIC) was constant throughout the water column and consistent with a primarily atmospheric source. Observed depletions in DIC (14)C values compared with atmospheric CO(2) indicated effects due either to DIC residence time and/or inputs of (14)C-depleted groundwater. Mass balance comparisons of local and regional groundwater indicate that groundwater DIC could contribute a maximum of 9-13% of the DIC. (14)C analysis of microbial phospholipid fatty acids from microbialite communities had Delta(14)C values comparable with lake water DIC, demonstrating that lake water DIC was their primary carbon source. Microbialite carbonate was also primarily derived from DIC. However, some depletion in microbialite carbonate (14)C relative to lake water DIC occurred, due either to residence time or mixing with a (14)C-depleted carbon source. A detrital branch covered with microbialite growth was used to estimate a microbialite growth rate of 0.05 mm year(-1) for the past 1000 years, faster than previous estimates for this system. These results demonstrate that the microbialites are actively growing and that the primary carbon source for both microbial communities and recent carbonate is DIC originating from the atmosphere. While these data cannot conclusively differentiate between abiotic and biotic formation mechanisms, the evidence for minor inputs of groundwater-derived DIC is consistent with the previously hypothesized biological origin of the Pavilion Lake microbialites.

PAUF functions in the metastasis of human pancreatic cancer cells and upregulates CXCR4 expression

Pancreatic cancer is characterized by early metastatic spread, but the process of tumor cell dissemination is largely unknown. In this study we show that the soluble protein pancreatic adenocarcinoma upregulated factor (PAUF) has an important role in the metastasis and progression of the disease. Variations in the level of PAUF, either by overexpression or knockdown, resulted in altered migration, invasion and proliferation capacity of pancreatic cancer cells. Moreover, depletion of PAUF in metastatic cells dramatically abrogated the spread of the cells to distant organs in an orthotopic xenograft mouse model. PAUF elicited the activation of the extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and AKT intracellular signaling cascades and consequently their downstream transcription factors in an autocrine manner. Genome-wide expression analysis revealed that C-X-C chemokine receptor type 4 (CXCR4) expression was induced by PAUF overexpression but was repressed by PAUF knockdown. The PAUF-mediated increase in cancer cell motility was attenuated by the CXCR4 inhibitor, AMD3100, or by anti-CXCR4 antibody. Furthermore, immunohistochemical analysis of pancreatic tumor tissues clearly showed a significant positive correlation between PAUF and CXCR4 expression. Collectively, these findings indicate that PAUF enhances the metastatic potential of pancreatic cancer cells, at least in part, by upregulating CXCR4 expression.

Effect of reinforcement particle size on the tribological properties of nano-diamond filled polytetrafluoroethylene based coating

The tribological properties of PTFE composite coatings reinforced by nano-diamonds were investigated. Mechanical particle size reduction and dispersion of nano-diamond aggregates were performed by milling with ceramic beads in an organic solvent. Particle size was controlled by the milling time. Pastes comprising a PTFE solution mixed with nano-diamond having various sizes were coated on the aluminum substrate. Ball-on-plate type wear test was performed to investigate the friction and wear behavior. The results indicated that the addition of nano-diamonds effectively improved tribological performance of the PTFE coating. The reduction in nano-diamond sizes were not always improved the wear resistance of PTFE coating. This unexpected behavior was explained by observation on the worn surfaces and wear debris.

Ultra thin CVD diamond film deposition by electrostatic self-assembly seeding process with nano-diamond particles

Ultra thin and smooth nano crystalline diamond films were fabricated with electrostatic self-assembly seeding of explosively synthesized nano-diamond particles. Hard aggregates of nano-diamond particles were crushed by high revolution attrition milling at 1000 RPM to regulate the particle size. Through this process, cationic nano-diamond particles were coated with anionic PSS (poly sodium 4-styrene sulfonate) electrolytes. Anionic Si(100) substrate was coated with cationic PDDA (poly diallyldimethyl ammonium chloride) solution. Si(100)/PDDA/PSS/ND (nano-diamond) layer-by-layer structure was formed as a seeding layer by the simple dipping and rinsing of positively charged substrate into anionic PSS/nano-diamond solution. Throughout the seeding process, neither mechanical damage nor chemical attack was observed on the substrate. Every stage of this preparation was carried out at room temperature and pressure. The effect of attrition milling was determined by changing the milling time from 1 hr to 5 hrs. Through the attritional milling and monolayer formation of the nano-diamond, nucleation density was increased up to 3 x 10(11)/cm2. Typical hot filament chemical vapor deposition system was used to coat the diamond film on the ESA (electrostatic self-assembly) seeded Si(100) substrate. Although typical diamond deposition conditions (90 torr/1% CH4 in H2/800 degrees C) were maintained, ultra thin (< 100 nm) and continuous nano crystalline diamond films were deposited. Regardless of metallic or ceramic substrate, ESND (ESA Seeding of nano-diamond) process is applicable if the substrate has any charge. This simple nano technology based process ensures high thickness uniformity of diamond coating without visible edge effect.

Sero-epidemiology of hepatitis A virus infection among healthcare workers in Korean hospitals

Hepatitis A virus (HAV) has been increasingly reported in Korea as has an outbreak in Korean healthcare workers (HCWs). This 2008 study evaluated the sero-epidemiology of HAV infections among 3696 HCWs in four Korean hospitals. HCWs were tested for immunoglobulin G anti-HAV antibodies using commercially available kits. Data including demographic characteristics, occupation, workplace and serological status for other hepatitis viruses were collected. Statistical analyses were conducted to identify variables related to HAV seropositivity. Among the 3696 participants, 2742 (74%) were women and the majority (96%) were aged 20-39 years (median: 28; range: 19-68). Eighteen percent were physicians, 46% nurses, 10% nurses' aides, 11% paramedical technicians and 15% administrative staff. Seropositivity for HAV significantly increased with age (P<0.001): 1.8% for < or =24 years, 14.7% for 25-29 years, 41.8% for 30-34 years, 75.5% for 35-39 years, and 93.7% for > or =40 years. Among those aged 20-39 years, age-specific HAV seroprevalence was significantly lower in physicians than in the other occupational groups (P<0.001). In Korea, mass vaccination to HCWs aged < or =29 years or screening for seropositivity and vaccinating non-immune subjects aged 30-39 years should be considered, especially in physicians.

B-type natriuretic peptide concentrations to guide treatment of patent ductus arteriosus

OBJECTIVE

To determine whether b-type natriuretic peptide (BNP) concentrations can guide treatment of patent ductus arteriosus (PDA) to reduce the number of indomethacin doses without increasing morbidity.

DESIGN

Prospective, randomised, controlled trial.

SETTING

Single-centre referral neonatal intensive care unit.

PATIENTS

Infants with echocardiographic diagnosis of PDA. Infants with congenital heart disease or renal insufficiency were excluded.

INTERVENTIONS

BNP measurement and echocardiography were performed in all subjects before and after indomethacin treatment. The investigational group had BNP concentrations measured 12 and 24 h after the first dose (before the 2nd and 3rd doses of indomethacin). Indomethacin dosing was withheld in the BNP-guided group if the 12 or 24 h BNP concentrations were found to be <100 pg/ml.

MAIN OUTCOME MEASURES

Number of doses of indomethacin given during the primary course of treatment (three doses every 12 h).

RESULTS

Sixty patients were randomly assigned to control (n = 30) and BNP-guided (n = 30) treatment groups. There was no difference between the groups with respect to gestational age (26(+3) vs 25(+5) weeks, respectively), Apgar scores, delivery method, gender or indomethacin prophylaxis. Median baseline and 48 h BNP concentrations did not differ between the groups (0 h: 500 vs 542 pg/ml; 48 h: 85 vs 126 pg/ml; control and BNP-guided groups, respectively). During primary indomethacin treatment, the BNP-guided group received fewer doses of indomethacin than controls (70 vs 88 doses, p<0.05). The rate of PDA ligation, intestinal perforation and chronic lung disease did not differ between groups.

CONCLUSIONS

BNP-guided treatment reduced the number of primary indomethacin doses. There was no increase in PDA persistence or associated morbidity.

Traumatic ascending aortopulmonary window following pulmonary artery stent dilatation: therapy with aortic endovascular stent graft

Endovascular stent grafts have become an established therapy in adults for descending thoracic aortic disease. We report a case of a 13-year-old boy with a hemodynamically significant traumatic aortopulmonary window following angioplasty of pulmonary artery stent. Endovascular stent graft implantation into the ascending aorta was performed to seal off the communication, with dramatic hemodynamic improvement.

N-acetylphytosphingosine-induced apoptosis of Jurkat cells is mediated by the conformational change in Bak

N-acetylphytosphingosine (NAPS), a sphingolipid derivative, is one of the well-known signal molecules that mediates various cellular functions, including cell growth, differentiation, and apoptosis. In this study, we demonstrated that NAPS induces apoptosis of Jurkat cells by activating Bak, but not Bax, which are both members of a proapoptotic subfamily of the Bcl-2 proteins. NAPS activated caspase-8 in a FADD-independent manner, but the lack of caspase-8 did not suppress the activation of caspase-3 and -9 and cell death, indicating that caspase-8 activation does not play an important role in NAPS-induced cell death. The overexpression of Bcl-xL, an anti-apoptotic protein, completely inhibited the activation of the caspases and apoptosis, assuming that NAPS-induced apoptosis was initiated by the mitochondria. The expression levels of pro- and anti-apoptotic Bcl-2 family members were not changed by the NAPS treatment. However, Bad was translocated from the cytosol into the mitochondria, where it bound to Bcl-xL, and Bak was dissociated from Bcl-xL and conformationally changed. Taken together, these findings indicate that NAPS induced apoptosis of Jurkat cells in a mitochondria-dependent manner that was controlled by the translocation of Bad and the conformational change in Bak.

Multiple predictors of coronary restenosis after drug-eluting stent implantation in patients with diabetes

OBJECTIVES

To identify parameters influencing the likelihood of restenosis after implantation of drug-eluting stents (DES) in patients with diabetes.

METHODS

Stented patients (n = 840) with DES were retrospectively reviewed for inclusion in the study from the Multicenter PCI Database Registry. From this database, 211 (25.1%) of 840 patients with six-month angiographic follow up had diabetes. Predictors of coronary restenosis were identified with univariate and multivariate logistic regression analyses.

RESULTS

Restenosis occurred in 92 of 629 (14.6%) patients without diabetes and in 44 (20.9%) of 211 patients with diabetes (p < 0.001). Multivariate parameters for predicting restenosis in the diabetic group were current smoking (odds ratio (OR) 1.923, 95% confidence interval (CI) 1.055 to 4.725, p = 0.036), higher C reactive protein concentration (OR 1.031, 95% CI 1.011 to 1.075, p = 0.043), use of the paclitaxel-eluting stent (OR 2.638, 95% CI 1.338 to 5.200, p = 0.005), longer stent length (OR 1.065, 95% CI 1.021 to 1.119, p = 0.033), smaller reference diameter before DES implantation (OR 0.501, 95% CI 0.110 to 0.965, p = 0.040), smaller reference diameter (OR 0.455, 95% CI 0.120 to 0.814, p = 0.026) and minimum lumen diameter (OR 0.447, 95% CI 0.068 to 0.876, p = 0.039) after DES implantation.

CONCLUSION

Even with the introduction of DES, diabetes remains a significant predictor of coronary restenosis, especially in cases of a small baseline vessel size, small vessel size after percutaneous coronary intervention, longer stent length, use of the paclitaxel-eluting stent, current smoking and high C reactive protein concentration.

Risk-stratified approach to hybrid transcatheter-surgical palliation of hypoplastic left heart syndrome

We prospectively employed a risk-stratified approach to first-stage palliation of hypoplastic left heart syndrome. High-risk features included severe tricuspid insufficiency, severe right ventricular dysfunction, a severely restrictive or intact atrial septum, an ascending aortic diameter < or = 2 mm, late presentation, weight < 2 kg, or significant extracardiac issues, Infants without high-risk features underwent a Norwood procedure (with Sano modification), whereas infants with high-risk features underwent a hybrid procedure consisting of bilateral pulmonary artery banding, ductal stenting, and atrial septostomy or a Norwood/Sano. Operative survival for 10 infants without high-risk features undergoing a Norwood/Sano procedure was 90%. Operative survival for 5 infants with high-risk features undergoing hybrid palliation was 100%, compared to 29% in 7 infants with high-risk features undergoing the Norwood/Sano procedure. Although only short-term data are available, this hybrid palliative procedure may have a role for infants with hypoplastic left heart syndrome and high-risk features.

Aminophylline for the prevention of apnea during prostaglandin E1 infusion

BACKGROUND

Apnea is associated with prostaglandin E1 infusion (PGE1) used in the palliation of ductal-dependent congenital heart lesions.

HYPOTHESIS

Aminophylline is a central respiratory stimulant and will decrease the incidence of PGE1-associated apnea and the need for intubation for apnea in infants with ductal-dependent congenital heart disease.

METHODS

Informed consent was obtained for all patients. In a prospective, double-blinded, placebo-controlled study, newborn infants with ductal-dependent congenital heart disease were randomized to receive either aminophylline or placebo during initiation and maintenance of PGE1, which was started at 0.01 microg/kg/min and increased to 0.03 microg/kg/min. Aminophylline was given as a bolus dose of 6 mg/kg before or during initiation of PGE1, and continued at 2 mg/kg dose every 8 hours for 72 hours. Serum aminophylline levels were checked at 18 and 36 hours. The primary study endpoint was intubation for apnea, with a secondary endpoint of apnea, as defined as acute cessation of breathing with associated hypoxia and bradycardia.

RESULTS

The study evaluated 42 infants. The 2 groups were similar for gestational age, weight, hematocrit, and use of sedation. In the aminophylline group, serum levels were 7.6 +/- 1.2 microg/mL. No significant side effects of aminophylline were seen. Infants receiving aminophylline (n = 21) were less likely to have apnea (2 vs 11) or be intubated for apnea (0 vs 6). Length of postoperative stay and survival to discharge were similar between the 2 groups.

CONCLUSIONS

Aminophylline was effective for the prevention of apnea and intubation for apnea associated with PGE1 in infants with ductal-dependent congenital heart disease.

Oral lichenoid reaction to imatinib (STI 571, Gleevec)

Imatinib or STI 571 is a phenylaminopyrimidine derivative and a member of a new class of drugs known as signal transduction inhibitors. These compounds specifically inhibit the proliferation of v-abl- and bcr-abl-expressing cells and have recently been approved as treatment for chronic myeloid leukaemia (CML). Results have been promising, and imatinib may well be the best single agent for the treatment of CML in the near future. Here we report an erosive oral lichenoid eruption confined to the buccal mucosa and dorsum of the tongue which appeared 12 weeks after commencement of imatinib in a 72-year-old woman with CML. The histology was consistent with a lichenoid drug eruption. The lesions resolved upon withdrawal of the drug. To our knowledge, this is the first reported lichenoid reaction to imatinib, and in the setting of CML it must be differentiated from idiopathic lichen planus, paraneoplastic pemphigus and graft-versus-host disease.

Anti-septicaemic effect of polysaccharide from Panax ginseng by macrophage activation

The aim of the present research was conducted to elucidate anti-septicaemic effect of a polysaccharide (PS) isolated from Panax ginseng C.A. Meyer (Araliaceae) by nitric oxide production from stimulated macrophage. In vitro assays for the activity measurement of PS, NO production test with Greiss reagent, phagocytic activity test using zymosan and cytokines production test using ELISA kit were also conducted. In vivo anti-septicaemic activity was assessed by using C57BL/6J mice. This was done with Staphylococcus aureus infection test. PS used at 0.025 mg/kg concentration showed a potent anti-septicaemic activity (80%, survival). However, it did not directly inhibit S. aureus in a minimum inhibitory concentration (MIC) test, conducted in vitro (data not shown). Nitric oxide production via macrophage activation showed the highest value of 5.5 nmol/ml at 1 microg/ml PS. In in vitro phagocytic activity test, PS at 10 microg/ml concentration showed a potent phagocytic activity for zymosan with 167% of the control. Production of TNF-alpha by macrophage activation at 10 microg/ml of PS was 96% lysis of L929. Also production of IL-1 and IL-6 by stimulation of macrophage with 100 microg/ml PS dose increased to 235 pg/ml and 0.47 ng/ml, respectively. The low mortality of PS treated (0.025 mg/kg) infected mice was concurrent with decreased bacterial content in the blood. Nitric oxide production in S. aureus infected mice whose macrophage was stimulated by PS (0.025 mg/kg) increased approximately 4 times than the untreated S. aureus infected group at 24 and 48 h incubation. In the PS treated (0.025 mg/kg) group, the intracellular concentration of S. aureus in macrophages decreased approximately by 50%, compared with the untreated group. Combine treatment with PS (0.025 mg/kg body weight) and vancomycin (10 mg/kg B.W.) resulted in 100% survival of the animals, whereas only 67% or 50% of the animals survived, respectively, when treated with PS or vancomycin alone. These results suggest that PS from Panax ginseng possess a potent anti-septicaemic activity by stimulating macrophage and a potentiality as an immunomodulator against sepsis occurred by Staphylococcus aureus.

Grb2 dominantly associates with dynamin II in human hepatocellular carcinoma HepG2 cells

The two SH3 domains and one SH2 domain containing adaptor protein Grb2 is an essential element of the Ras signaling pathway in multiple systems. The SH2 domain of Grb2 recognizes and interacts with phosphotyrosine residues on activated tyrosine kinases, whereas the SH3 domains bind to several proline-rich domain-containing proteins such as Sos1. To define the difference in Grb2-associated proteins in hepatocarcinoma cells, we performed coprecipitation analysis using recombinant GST-Grb2 fusion proteins and found that several protein components (p170, p125, p100, and p80) differently associated with GST-Grb2 proteins in human Chang liver and hepatocarcinoma HepG2 cells. Sos1 and p80 proteins dominantly bind to Grb2 fusion proteins in Chang liver, whereas p100 remarkably associate with Grb2 in HepG2 cells. Also GST-Grb2 SH2 proteins exclusively bound to the p46(Shc), p52(Shc), and p66(Shc) are important adaptors of the Ras pathway in HepG2 cells. The p100 protein has been identified as dynamin II. We observed that the N-SH3 and C-SH3 domains of Grb2 fusion proteins coprecipitated with dynamin II besides Sos1. These results suggest that dynamin II may be a functional molecule involved in Grb2-mediated signaling pathway on Ras activation for tumor progression and differentiation of hepatocarcinoma cells.

ATM--a key determinant of multiple cellular responses to irradiation

Ataxia-telangiectasia is a rare clinical disorder manifesting a variety of different abnormalities, including progressive neurodegeneration, increased cancer incidence, immune deficiency, sterility, and extreme radiosensitivity. Recent studies have demonstrated that the defective gene product in this disease, ATM, is a protein kinase. The identification of several different substrates for this kinase is beginning to explain the wide array of different physiologic abnormalities that occur when this gene product is dysfunctional. Since the ATM protein is a critical signaling molecule in the cellular response to ionizing irradiation, the identification of these substrates also results in elucidation of the steps involved in a number of different cellular signaling pathways initiated by irradiation. Such insights also result in the identification of potential new targets for enhancing the efficacy of radiation therapy.

Expression profiling of cardiac genes in human hypertrophic cardiomyopathy: insight into the pathogenesis of phenotypes

OBJECTIVES

The goal of this study was to identify genes upregulated in the heart in human patients with hypertrophic cardiomyopathy (HCM).

BACKGROUND

Hypertrophic cardiomyopathy is a genetic disease caused by mutations in contractile sarcomeric proteins. The molecular basis of diverse clinical and pathologic phenotypes in HCM remains unknown.

METHODS

We performed polymerase chain reaction-select complementary DNA subtraction between normal hearts and hearts with HCM and screened subtracted libraries by Southern blotting. We sequenced the differentially expressed clones and performed Northern blotting to detect increased expression levels.

RESULTS

We screened 288 independent clones, and 76 clones had less than twofold increase in the signal intensity and were considered upregulated. Sequence analysis identified 36 genes including those encoding the markers of pressure overload-induced ("secondary") cardiac hypertrophy, cytoskeletal proteins, protein synthesis, redox system, ion channels and those with unknown function. Northern blotting confirmed increased expression of skeletal muscle alpha-actin (ACTA1), myosin light chain 2a (MLC2a), GTP-binding protein Gs-alpha subunit (GNAS1), NADH ubiquinone oxidoreductase (NDUFB10), voltage-dependent anion channel 1 (VDAC1), four-and-a-half LIM domain protein 1 (FHL1) (also known as SLIM1), sarcosin (SARCOSIN) and heat shock 70kD protein 8 (HSPA8) by less than twofold. Expression levels of ACTA1, MLC2a and GNAS1 were increased in six additional and FHL1 in four additional hearts with HCM.

CONCLUSIONS

A diverse array of genes is upregulated in the heart in human patients with HCM, which could account for the diversity of clinical and pathologic phenotypes. Markers of secondary hypertrophy are also upregulated, suggesting commonality of pathways involved in HCM and the acquired forms of cardiac hypertrophy. Elucidation of the role of differentially expressed genes in HCM could provide for new therapeutic targets.

Angiotensin II blockade reverses myocardial fibrosis in a transgenic mouse model of human hypertrophic cardiomyopathy

BACKGROUND

-Hypertrophic cardiomyopathy (HCM), the most common cause of sudden cardiac death in the young, is characterized by cardiac hypertrophy, myocyte disarray, and interstitial fibrosis. We propose that hypertrophy and fibrosis are secondary to the activation of trophic and mitotic factors and, thus, potentially reversible. We determined whether the blockade of angiotensin II, a known cardiotrophic factor, could reverse or attenuate interstitial fibrosis in a transgenic mouse model of human HCM.

METHODS AND RESULTS

We randomized 24 adult cardiac troponin T (cTnT-Q(92)) mice, which exhibit myocyte disarray and interstitial fibrosis, to treatment with losartan or placebo and included 12 nontransgenic mice as controls. The mean dose of losartan and the mean duration of therapy were 14.2+/-5.3 mg. kg(-1). d(-1) and 42+/-9.6 days, respectively. Mean age, number of males and females, and heart/body weight ratio were similar in the groups. Collagen volume fraction and extent of myocyte disarray were increased in the cTnT-Q(92) mice (placebo group) compared with nontransgenic mice (9.9+/-6.8% versus 4.5+/-2.2%, P=0.01, and 27.6+/-10.6% versus 3.9+/-2.3%, P<0.001, respectively). Treatment with losartan reduced collagen volume fraction by 49% to 4.9+/-2.9%. The expression of collagen 1alpha (I) and transforming growth factor-beta1, a mediator of angiotensin II profibrotic effect, were also reduced by 50%. Losartan had no effect on myocyte disarray.

CONCLUSIONS

Treatment with losartan reversed interstitial fibrosis and the expression of collagen 1alpha (I) and transforming growth factor-beta1 in the hearts of cTnT-Q(92) mice. These findings suggest that losartan has the potential to reverse or attenuate interstitial fibrosis, a major predictor of sudden cardiac death, in human patients with HCM.

Variants of trophic factors and expression of cardiac hypertrophy in patients with hypertrophic cardiomyopathy

Patients with hypertrophic cardiomyopathy (HCM) exhibit variable expression of left ventricular hypertrophy (LVH), a major determinant of mortality and morbidity, which is partly due to the diversity of causal mutations, genetic background (modifier genes), and probably environmental factors. We determined association of functional variants of tumor necrosis factor (TNF)- alpha, interleukin-6 (IL6), insulin-like growth factor-2 (IGF2), transforming growth factor- beta 1 (TGFB1), and aldosterone synthase (CYP11B2) genes, all previously implicated in cardiac hypertrophy, with the severity of LVH in patients with HCM. Two-dimensional echocardiography was performed and demographic variables were recorded in 142 genetically independent patients. Indices of LVH including interventricular septal thickness (IVST), left ventricular mass index (LVMI), and LVH score were measured/calculated. TNF-alpha-308G/A, IL6-174G/C, IGF2 820G/A, TGFB1-509C/T, and CYP11B2-344T/C genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Genotypes were identified by the presence of specific electrophoretic patterns and their distributions were according to the Hardy-Weinberg equilibrium. Demographic variables were not significantly different among the genotypes. Subjects with the AA genotype of TNF-alpha (n=8) were approximately 13 years younger at the time of clinical diagnosis. Despite a younger age, they had a greater mean LVMI than those with the GG (n=94) or GA (n=33) genotypes (191.8+/-59.5 v 139.1+/-47.3 v 132.1+/-34.3, respectively, P=0.004). TNF-alpha-308G/A genotypes accounted for 6.0% of variability of LVMI (P=0.002). Mean IVST, LVEDD, and LVH score were not significantly different. Variants of IL6, IGF2, TGFB1, and CYP11B2 were not associated with indices of LVH. The uncommon allele of TNF-alpha-308G/A polymorphism, known to produce more TNF- alpha, was associated with greater LVMI and clinical diagnosis at a younger age in patients with HCM. Functional variants of other trophic factors, previously implicated in cardiac hypertrophy, were not associated with the indices of LVH. These results suggest that TNF-alpha is a modifier gene for HCM.

The many substrates and functions of ATM

As its name suggests, the ATM--'ataxia-telangiectasia, mutated'--gene is responsible for the rare disorder ataxia-telangiectasia. Patients show various abnormalities, mainly in their responses to DNA damage, but also in other cellular processes. Although it is hard to understand how a single gene product is involved in so many physiological processes, a clear picture is starting to emerge.

Coronary flow reserve is reflective of myocardial perfusion status in acute anterior myocardial infarction

Our objective was to determine whether coronary vasodilatory reserve (CVR) correlates with the perfusion state of infarct zone in early recovery phase of acute anterior myocardial infarction (AMI). We studied 14 patients (11 males; mean age, 46 years) who had AMI and 6 control subjects who had chest pain but normal coronary angiograms. All patients underwent successful percutaneous revascularization of left anterior descending (LAD) coronary artery. Coronary flow velocity was measured using intracoronary (IC) Doppler at baseline and following IC injection of 18 microg of adenosine. Myocardial perfusion was evaluated by myocardial contrast echocardiography (MCE). CVR was higher in patients without a perfusion defect on MCE than in those with (2.48 +/- 0.21 vs. 1.66 +/- 0.13, P = 0.001). Subjects with a perfusion defect had a lower CVR than controls (1.66 +/- 0.13 vs.2.40 +/- 0.18, P < 0.05). CVR was > 2.0 in all subjects without a perfusion defect. There was a strong correlation between the magnitude of myocardial opacification in the LAD territory and CVR (r = 0.80, P < 0.01). Increase in peak diastolic flow velocity after adenosine infusion, but not systolic flow velocity, correlated with myocardial opacification index (r = 0.63, P = 0.016). CVR of infarct-related artery correlated closely with the perfusion status of the myocardium in infarct zone and those with a CVR > 2.0 had normal myocardial perfusion. These data suggest that CVR may be used to determine the perfusion state of the myocardium in the infarct zone, which is a known predictor of myocardial viability. Cathet. Cardiovasc. Intervent. 51:281-286, 2000.

Enhancement of adenoviral transduction with polycationic liposomes in vivo

Although the high transfection efficiency with adenovirus in vitro is well documented, it is still not clear whether adenoviral vectors are effective in vivo in solid tumor models. In our preliminary experiment, transduction of tumor tissue was limited to just around the injection site after intratumoral injection of the adenoviral vector. To improve the transduction efficiency in vivo, we tried a combination of adenoviral vector and liposome in our animal model. Adenovirus carrying human placental alkaline phosphatase (AdALP) and Lipofectamine or 1,3-di-oleoyloxy-2-(6-carboxyspermyl)-propylamide were used as a marker gene and the cationic liposome, respectively. A >15-fold increase in the transfection efficiency was observed in CT26 tumor cell lines with the combination of AdALP adenovirus carrying murine granulocyte-macrophage colony-stimulating factor (AdmGM-CSF), and liposome compared with adenovirus alone, showing the feasibility of the combination treatment. In the animal model, with the combination of liposome and AdALP, deeper and wider distribution of the marker gene in the tumor mass was shown. We conclude that the limitations of direct application of adenoviral vectors in a solid tumor model could be overcome by the use of cationic liposomes. This approach will facilitate the more effective delivery of adenoviral vectors in a clinical trial setting.

Tissue Doppler imaging consistently detects myocardial contraction and relaxation abnormalities, irrespective of cardiac hypertrophy, in a transgenic rabbit model of human hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is diagnosed clinically by the presence of left ventricular hypertrophy (LVH). However, LVH is absent in a significant number of genotype-positive patients. Because myocyte dysfunction and disarray are the primary abnormalities in HCM, we reasoned that tissue Doppler imaging could identify contraction and relaxation abnormalities, irrespective of hypertrophy, in a transgenic rabbit model of human HCM.

METHODS AND RESULTS

M-mode, 2D, Doppler echocardiography and tissue Doppler imaging were performed in nontransgenic (n=24), wild-type beta-myosin heavy chain-arginine(403) (n=14), and mutant beta-myosin heavy chain-glutamic acid(403) (n=24) transgenic rabbits. Mean septal thicknesses were 2.0+/-0.3, 2.0+/-0.25, and 2.75+/-0.3 mm in the 3 groups, respectively (P:=0.001). LVH was absent in 9 of the 24 mutant rabbits. Left ventricular dimensions, systolic function, heart rate, mitral inflow velocities, and time intervals were similar in the groups. However, the difference between atrial reversal and transmitral A wave duration was increased in the mutant rabbits (P:<0.001). More importantly, systolic and early diastolic tissue Doppler velocities were significantly lower in all mutant rabbits (7.45+/-2.2 versus 10.8+/-2.3 cm/s in nontransgenic and 9. 0+/-0.76 cm/s in wild-type; P:<0.001), including the 9 without LVH. A systolic velocity <8.5 cm/s had an 86% sensitivity and 100% specificity in identifying the mutant transgenic rabbits.

CONCLUSIONS

Myocardial contraction and relaxation were reduced in the mutant beta-myosin heavy chain-glutamic acid(403) transgenic rabbit model of human HCM, irrespective of the presence or absence of LVH. In addition, tissue Doppler imaging is more sensitive than conventional echocardiography for HCM screening.

Analysis of ku80-mutant mice and cells with deficient levels of p53

Absence of Ku80 results in increased sensitivity to ionizing radiation, defective lymphocyte development, early onset of an age-related phenotype, and premature replicative senescence. Here we investigate the role of p53 on the phenotype of ku80-mutant mice and cells. Reducing levels of p53 increased the cancer incidence for ku80(-/-) mice. About 20% of ku80(-/-) p53(+/-) mice developed a broad spectrum of cancer by 40 weeks and all ku80(-/-) p53(-/-) mice developed pro-B-cell lymphoma by 16 weeks. Reducing levels of p53 rescued populations of ku80(-/-) cells from replicative senescence by enabling spontaneous immortalization. The double-mutant cells are impaired for the G(1)/S checkpoint due to the p53 mutation and are hypersensitive to gamma-radiation and reactive oxygen species due to the Ku80 mutation. These data show that replicative senescence is caused by a p53-dependent cell cycle response to damaged DNA in ku80(-/-) cells and that p53 is essential for preventing very early onset of pro-B-cell lymphoma in ku80(-/-) mice.

Anti-leukaemic and anti-mutagenic effects of di(2-ethylhexyl)phthalate isolated from Aloe vera Linne

Extracts of Aloe vera Linne have been found to exhibit cytotoxicity against human tumour cell lines. This study examines the anti-tumour effects of di(2-ethylhexyl)phthalate (DEHP) isolated from Aloe vera Linne, in human and animal cell lines. Its anti-mutagenic effects were examined using Salmonella typhimurium TA98 and TA100 strains. Growth inhibition was specifically exerted by DEHP against three leukaemic cell lines at concentrations below 100 microg mL(-1). At 100 microg mL(-1) DEHP, K562, HL60 and U937 leukaemic cell lines showed growth inhibition of 95, 97 and 95%, respectively. DEHP exhibited an inhibitory activity of 74, 83 and 81%, respectively, in K562, HL60 and U937 cell lines at a concentration of 10 microg mL(-1). At a concentration of 1 microg mL(-1), DEHP exerted an inhibitory activity of 50, 51 and 52%, respectively, in K562, HL60 and U937. In a normal cell line, MDBK, DEHP exerted 30% growth inhibition at a concentration of 100 microg mL(-1), and showed no inhibitory activity at concentrations below 50 microg mL(-1). It was found that DEHP exerted anti-mutagenic activity in the Salmonella mutation assay. The number of mutant colonies of Salmonella typhimurium strain TA98 upon exposure to AF-2 (0.2 microg/plate) decreased in a concentration-dependent manner in the presence of different DEHP concentrations (decreasing to 90.4, 83.9, 75.4, 69.6 and 46.9%, respectively, for DEHP concentrations of 100, 50, 10, 5 and 1 microg/plate). In the case of Salmonella typhimurium strain TA100, DEHP reduced AF-2-induced mutagenicity at 1, 5, 10, 50 and 100 microg/plate to 57.4, 77.5, 80.0, 89.0 and 91.5%, respectively. The isolated compound from Aloe vera Linne, DEHP, was considered to be the active principle responsible for anti-leukaemic and anti-mutagenic effects in-vitro.

ATM phosphorylates p95/nbs1 in an S-phase checkpoint pathway

The rare diseases ataxia-telangiectasia (AT), caused by mutations in the ATM gene, and Nijmegen breakage syndrome (NBS), with mutations in the p95/nbs1 gene, share a variety of phenotypic abnormalities such as chromosomal instability, radiation sensitivity and defects in cell-cycle checkpoints in response to ionizing radiation. The ATM gene encodes a protein kinase that is activated by ionizing radiation or radiomimetic drugs, whereas p95/nbs1 is part of a protein complex that is involved in responses to DNA double-strand breaks. Here, because of the similarities between AT and NBS, we evaluated the functional interactions between ATM and p95/nbs1. Activation of the ATM kinase by ionizing radiation and induction of ATM-dependent responses in NBS cells indicated that p95/nbs1 may not be required for signalling to ATM after ionizing radiation. However, p95/nbs1 was phosphorylated on serine 343 in an ATM-dependent manner in vitro and in vivo after ionizing radiation. A p95/nbs1 construct mutated at the ATM phosphorylation site abrogated an S-phase checkpoint induced by ionizing radiation in normal cells and failed to compensate for this functional deficiency in NBS cells. These observations link ATM and p95/nbs1 in a common signalling pathway and provide an explanation for phenotypic similarities in these two diseases.

Assessment of coronary flow reserve with transthoracic Doppler echocardiography: comparison with intracoronary Doppler method

To evaluate the feasibility and usefulness of transthoracic Doppler echocardiography (TTDE) as a non-invasive method in recording distal anterior descending (LAD) coronary flow velocity, we compared coronary flow reserve (CFR) measured by TTDE with measurements by intracoronary Doppler wire (ICDW). Twenty-one patients without LAD stenosis were studied. ICDW performed at baseline and after intracoronary injection of 18 microg adenosine. TTDE was performed at baseline and after intravenous adenosine (140 microg/kgmin for 2 min). Adequate Doppler recordings of coronary flow velocities during systole were obtained in 14 of 21 study patients (67%) and during diastole in 17 (81%) patients. Baseline and hyperemic peak diastolic flow velocities measured by TTDE were significantly smaller than those obtained by ICDW (p<0.05). However, diminishing trends of diastolic and systolic velocity ratio after hyperemia were similarly observed in both methods. CFR obtained by TTDE (3.0+/-0.5), was higher than the value calculated by ICDW (2.5+/-0.4). There were significant correlations between the values obtained by the two methods (r=0.72, p<0.01). It is concluded that TTDE is a feasible method in measuring coronary flow velocity and appears to be a promising non-invasive method in evaluating CFR.

Ionizing radiation activates the ATM kinase throughout the cell cycle

The ATM protein kinase is a critical intermediate in a number of cellular responses to ionizing irradiation (IR) and possibly other stresses. ATM dysfunction results in abnormal checkpoint responses in multiple phases of the cell cycle, including G1, S and G2. Though downstream targets of the ATM kinase are still being elucidated, it has been demonstrated that ATM acts upstream of p53 in a signal transduction pathway initiated by IR and can phosphorylate p53 at serine 15. The cell cycle stage-specificity of ATM activation and p53Ser15 phosphorylation was investigated in normal lymphoblastoid cell line (GM536). Ionizing radiation was found to enhance the kinase activity of ATM in all phases of the cell cycle. This enhanced activity was apparent immediately after treatment of cells with IR, but was not accompanied by a change in the abundance of the ATM protein. Since IR activates the ATM kinase in all phases of the cell cycle, DNA replication-dependent strand breaks are not required for this activation. Further, since p53 protein is not directly required for IR-induced S and G2-phase checkpoints, the ATM kinase likely has different functional targets in different phases of the cell cycle. These observations indicate that the ATM kinase is necessary primarily for the immediate response to DNA damage incurred in all phases of the cell cycle.

A variant of p22(phox), involved in generation of reactive oxygen species in the vessel wall, is associated with progression of coronary atherosclerosis

A series of pro-oxidant and antioxidant enzymes, such as the NADPH oxidase system, maintain the redox state in the vessel wall. A major component of NADPH oxidase is p22(phox), which is implicated in atherosclerosis. We prospectively studied the association of the histidine (H)(72)-->tyrosine (Y) mutation in p22(phox) with the severity and progression/regression of coronary artery disease (CAD), plasma lipid levels, clinical events, and response to treatment with fluvastatin in a well-characterized population. Genotypes were determined by polymerase chain reaction and restriction digestion with RsaI enzyme in 368 subjects in the Lipoprotein and Coronary Atherosclerosis Study (LCAS). Fasting plasma lipids and quantitative coronary angiograms were obtained at baseline and 2.5 years after randomization to fluvastatin or placebo. Subjects with CC genotype (n=157) were identified by the presence of 396-bp and 113-bp products on gel electrophoresis. Those with TT (n=39) were identified by the presence of 316-bp, 113-bp, and 80-bp products, and those with CT (n=172) by the presence of 396-bp, 316-bp, 113-bp, and 80-bp products. Baseline and final plasma levels of lipids and the baseline severity of CAD were not significantly different among the genotypes. In the placebo group, subjects with the mutation had a 3- to 5-fold greater loss in mean minimum lumen diameter (MLD) (TT: -0.15+/-0.15; CT: -0.17+/-0.26; and CC: -0.03+/-0.22 mm; P=0. 006) and lesion-specific MLD (TT: -0.15+/-0.06; CT: -0.18+/-0.03; and CC: -0.06+/-0.03 mm; P=0.038) than those without. Progression was also more (TT: 8/17 [47%]; CT: 35/73 [48%]; and CC: 17/62 [27%]) and regression less (TT: 0/17 [0%]; CT: 1/73 [1%]; and CC: 11/72 [18%]) common in those with the mutation (P=0.002). The C(242)T mutation in p22(phox), involved in maintaining the redox state in the vessel wall, is associated with progression of coronary atherosclerosis in the LCAS population.

Decreased left ventricular ejection fraction in transgenic mice expressing mutant cardiac troponin T-Q(92), responsible for human hypertrophic cardiomyopathy

The causality of mutant sarcomeric proteins in hypertrophic cardiomyopathy (HCM) is well established. The current emphasis is to elucidate the pathogenesis of HCM in transgenic animal models. We determined the left ventricular ejection fraction (LVEF) in transgenic mice expressing mutant cardiac troponin T (cTnT)-Q(92), known to cause HCM in humans. Transgenes were constructed by placing wild-type (R(92)) or mutant (Q(92)) full-length human cTnT cDNAs 3' into a 5.5-kb murine [alpha -myosin heavy chain (MyHC)] promoter injected into fertilized zygotes. Three wild-type and six mutant lines were produced. Transgene mRNA and proteins, detected using transgene-specific probes were expressed at high levels in all wild-type and three mutant lines. The total cTnT mRNA pool was increased by up to five-fold in transgenic mice, but the total cTnT protein remained unchanged. The mean values of LVEF, determined by(178)Ta radionuclide angiography, were 57.8+/-6% (n=4) in non-transgenic littermate (NLM), 53.3+/-10 (n=6) in wild-type and 39. 4+/-6 (n=5) in mutant transgenic mice (P=0.009). The heart/body weight ratios and the number of cells stained with terminal deoxynucleotidyl transferase (TdT)-mediated nick end-labeling were similar among the groups. Three mutant mice had myocyte disarray and excess interstitial collagen and two had normal myocardial structure despite having reduced LVEF. Thus, in vivo expression of the mutant cTnT-Q(92)protein, responsible for human HCM, impaired global cardiac systolic function in transgenic mice, which also occurred in the absence of myocyte disarray and increased interstitial collagen.