[Impact of COVID-19 pandemic on the management of imported malaria in China]

OBJECTIVE

To examine the impact of COVID-19 pandemic on the epidemic status of imported malaria and national malaria control program in China, so as to provide insights into post-elimination malaria surveillance.

METHODS

All data pertaining to imported malaria cases were collected from Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region during the period from January 1, 2018 through December 31, 2021. The number of malaria cases, species of malaria parasites, country where malaria parasite were infected, diagnosis and treatment after returning to China, and response were compared before (from January 1, 2018 to January 22, 2020) and after the COVID-19 pandemic (from January 23, 2020 to December 31, 2021).

RESULTS

A total of 2 054 imported malaria cases were reported in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region during the period from January 1, 2018 to December 31, 2021, and there were 1 722 cases and 332 cases reported before and after the COVID-19 pandemic, respectively. All cases were reported within one day after definitive diagnosis. The annual mean number of reported malaria cases reduced by 79.30% in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region after the COVID-19 pandemic (171 cases) than before the pandemic (826 cases), and the number of monthly reported malaria cases significantly reduced in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region since February 2020. There was a significant difference in the constituent ratio of species of malaria parasites among the imported malaria cases in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region before and after the COVID-19 pandemic (χ2 = 146.70, P < 0.05), and P. falciparum malaria was predominant before the COVID-19 pandemic (72.30%), while P. ovale malaria (44.28%) was predominant after the COVID-19 pandemic, followed by P. falciparum malaria (37.65%). There was a significant difference in the constituent ratio of country where malaria parasites were infected among imported malaria cases in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region before and after the COVID-19 pandemic (χ2 = 13.83, P < 0.05), and the proportion of malaria cases that acquired Plasmodium infections in western Africa reduced after the COVID-19 pandemic that before the pandemic (44.13% vs. 37.95%; χ2 = 4.34, P < 0.05), while the proportion of malaria cases that acquired Plasmodium infections in eastern Africa increased after the COVID-19 pandemic that before the pandemic (9.58% vs. 15.36%; χ2 = 9.88, P = 0.02). The proportion of completing case investigation within 3 days was significantly lower after the COVID-19 pandemic than before the pandemic (96.69% vs. 98.32%; χ2= 3.87, P < 0.05), while the proportion of finishing foci investigation and response within 7 days was significantly higher after the COVID-19 pandemic than before the pandemic (100.00% vs. 98.43%; χ2 = 3.95, P < 0.05).

CONCLUSIONS

The number of imported malaria cases remarkably reduced in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region of China during the COVID-19 pandemic, with a decreased proportion of completing case investigations within 3 days. The sensitivity of the malaria surveillance-response system requires to be improved to prevent the risk of secondary transmission of malaria due to the sharp increase in the number of imported malaria cases following the change of the COVID-19 containment policy.

Pulmonary Artery Strain Predicts Prognosis in Pulmonary Arterial Hypertension

BACKGROUND

Current cardiac magnetic resonance (CMR) imaging in pulmonary arterial hypertension (PAH) focuses on measures of ventricular function and coupling.

OBJECTIVES

The purpose of this study was to evaluate pulmonary artery (PA) global longitudinal strain (GLS) as a prognostic marker in patients with PAH.

METHODS

The authors included 169 patients with PAH from the ASPIRE (Assessing the Spectrum of Pulmonary hypertension Identified at a REferral centre) and INITIATE (Integrated computatioNal modelIng of righT heart mechanIcs and blood flow dynAmics in congeniTal hEart disease) registries, and 82 normal controls with similar age and gender distributions. PA GLS was derived from CMR feature tracking. Right ventricular measurements including volumes, ejection fraction, and right ventricular GLS were also derived from CMR. Patients were followed up a median of 34 months with all-cause mortality as the primary endpoint. Other known risk scores were collected, including the REVEAL (Registry to Evaluate Early and Long-term Pulmonary Arterial Hypertension Disease Management) 2.0 and COMPERA (Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension) 2.0 scores.

RESULTS

Of 169 patients (mean age: 57 ± 15 years; 80% female), 45 (26.6%) died (median follow-up: 34 months). Mean PA GLS was 23% ± 6% in normal controls and 10% ± 5% in patients with PAH (P < 0.0001). Patients with PA GLS <9% had a higher risk of mortality than those with PA GLS ≥9% (P < 0.001), and this was an independent predictor of mortality in PAH on multivariable analysis after adjustment for known risk factors (HR: 2.93; P = 0.010). Finally, in patients with PAH, PA GLS provided incremental prognostic value over the REVEAL 2.0 (global chi-square; P = 0.001; C statistic comparison; P = 0.030) and COMPERA 2.0 (global chi-square; P = 0.001; C statistic comparison; P = 0.048).

CONCLUSIONS

PA GLS confers incremental prognostic utility over the established risk scores for identifying patients with PAH at higher risk of death, who may be targeted for closer monitoring and/or intensified therapy.

Real-world outcomes of Selexipag for treatment of pulmonary hypertension in an Asian population

Funding Acknowledgements

Type of funding sources: None.

Introduction

Selexipag is an oral selective prostacyclin IP receptor agonist indicated for treatment of pulmonary arterial hypertension (PAH). Data on its real-world safety and efficacy in Asians is lacking.

Purpose

We sought to evaluate the clinical characteristics, treatment regimens and outcomes of patients initiated on selexipag in a tertiary cardiac centre in Asia.

Methods

This was a retrospective study on all patients initiated on selexipag from January 2017 to December 2020. Baseline and follow up characteristics including demographics, functional status and clinical data were collected. Clinical outcomes evaluated included hospitalisation for PH related complications and all-cause mortality. Patients were risk stratified using the COMPERA 2.0 risk scores.

Results

A total of 36 PAH patients were treated with selexipag. At baseline, most patients were WHO functional class II or III (36.4% and 51.5% respectively), with a NT-proBNP of 1335 pg/ml (557 – 2918) and 6 minute walk test (6MWT) duration of 327.5 ±126.4 meters. Selexipag was initiated at 200mcg twice daily dosage for all except one patient (started at 200mcg once daily) and the maximum tolerated dose ranged from 200mcg twice daily to 1400mcg twice daily, with majority tolerating up to a dose of 600mcg twice daily (58.3%). Side effects were reported in 23 patients (63.9%), of which headache (27.8%), diarrhea (30.6%) or musculoskeletal symptoms (27.8%) were predominant. After a median follow up duration of 25.9 ± 23.1 months, selexipag was stopped in 20 patients (55.6%), of which eight patients were due to PAH progression requiring alternative therapy, and 12 patients due to side effects from selexipag. At baseline, patients were classified into low (8.3%), intermediate-low (30.6%), intermediate-high (33.3%) and high risk (27.8%) respectively. Patients who continued on selexipag at follow up showed no change (46.2%), improvement (15.4%) and deterioration (38.5%) in risk score. In the overall cohort of 36 patients, majority (75%) had at least one hospitalisation for PAH related complications and 15 patients (41.7%) demised.

Conclusion

In this real-world study, while selexipag was associated with a stable or improved PAH risk scores in majority of patients, there was a subset of patients with disease progression or intolerance to the medication. Further studies are warranted to identify patients who will benefit most from this therapy.

Clinical profile and outcomes in patients with moderate to severe aortic stenosis with or without concomitant chronic kidney disease

Introduction

Management of aortic stenosis (AS) in patients with chronic kidney disease (CKD) may often be overlooked, and this could confer poorer outcomes.

Methods

Consecutive patients (n = 727) with index echocardiographic diagnosis of moderate to severe AS (aortic valve area <1.5 cm²) were examined. They were divided into those with CKD (estimated glomerular filtration rate < 60 mL/min) and those without. Baseline clinical and echocardiographic parameters were compared, and a multivariate Cox regression model was constructed. Clinical outcomes were compared using Kaplan-Meier curves.

Results

There were 270 (37.1%) patients with concomitant CKD. The CKD group was older (78.0 ± 10.3 vs. 72.1 ± 12.9 years, P < 0.001), with a higher prevalence of hypertension, diabetes mellitus, hyperlipidaemia and ischaemic heart disease. AS severity did not differ significantly, but left ventricular (LV) mass index (119.4 ± 43.7 vs. 112.3 ± 40.6 g/m², P = 0.027) and Doppler mitral inflow E to annular tissue Doppler e' ratio (E: e' 21.5 ± 14.6 vs. 17.8 ± 12.2, P = 0.001) were higher in the CKD group. There was higher mortality (log-rank 51.5, P < 0.001) and more frequent admissions for cardiac failure (log-rank 25.9, P < 0.001) in the CKD group, with a lower incidence of aortic valve replacement (log-rank 7.12, P = 0.008). On multivariate analyses, after adjusting for aortic valve area, age, left ventricular ejection fraction and clinical comorbidities, CKD remained independently associated with mortality (hazard ratio 1.96, 95% confidence interval 1.50-2.57, P < 0.001).

Conclusion

Concomitant CKD in patients with moderate to severe AS was associated with increased mortality, more frequent admissions for cardiac failure and a lower incidence of aortic valve replacement.

Right ventricular energetic biomarkers from 4D Flow CMR are associated with exertional capacity in pulmonary arterial hypertension

BACKGROUND

Cardiovascular magnetic resonance (CMR) offers comprehensive right ventricular (RV) evaluation in pulmonary arterial hypertension (PAH). Emerging four-dimensional (4D) flow CMR allows visualization and quantification of intracardiac flow components and calculation of phasic blood kinetic energy (KE) parameters but it is unknown whether these parameters are associated with cardiopulmonary exercise test (CPET)-assessed exercise capacity, which is a surrogate measure of survival in PAH. We compared 4D flow CMR parameters in PAH with healthy controls, and investigated the association of these parameters with RV remodelling, RV functional and CPET outcomes.

METHODS

PAH patients and healthy controls from two centers were prospectively enrolled to undergo on-site cine and 4D flow CMR, and CPET within one week. RV remodelling index was calculated as the ratio of RV to left ventricular (LV) end-diastolic volumes (EDV). Phasic (peak systolic, average systolic, and peak E-wave) LV and RV blood flow KE indexed to EDV (KEIEDV) and ventricular LV and RV flow components (direct flow, retained inflow, delayed ejection flow, and residual volume) were calculated. Oxygen uptake (VO2), carbon dioxide production (VCO2) and minute ventilation (VE) were measured and recorded.

RESULTS

45 PAH patients (46 ± 11 years; 7 M) and 51 healthy subjects (46 ± 14 years; 17 M) with no significant differences in age and gender were analyzed. Compared with healthy controls, PAH had significantly lower median RV direct flow, RV delayed ejection flow, RV peak E-wave KEIEDV, peak VO2, and percentage (%) predicted peak VO2, while significantly higher median RV residual volume and VE/VCO2 slope. RV direct flow and RV residual volume were significantly associated with RV remodelling, function, peak VO2, % predicted peak VO2 and VE/VCO2 slope (all P < 0.01). Multiple linear regression analyses showed RV direct flow to be an independent marker of RV function, remodelling and exercise capacity.

CONCLUSION

In this 4D flow CMR and CPET study, RV direct flow provided incremental value over RVEF for discriminating adverse RV remodelling, impaired exercise capacity, and PAH with intermediate and high risk based on risk score. These data suggest that CMR with 4D flow CMR can provide comprehensive assessment of PAH severity, and may be used to monitor disease progression and therapeutic response.

TRIAL REGISTRATION NUMBER

https://www.

CLINICALTRIALS

gov . Unique identifier: NCT03217240.

Identification of cell senescence molecular subtypes in prediction of the prognosis and immunotherapy of hepatitis B virus-related hepatocellular carcinoma

Hepatitis B virus (HBV)-infected hepatocellular carcinoma (HCC) has a high incidence and fatality rate worldwide, being among the most prevalent cancers. The growing body of data indicating cellular senescence (CS) to be a critical factor in hepatocarcinogenesis. The predictive value of CS in HBV-related HCC and its role in the immune microenvironment are unknown. To determine the cellular senescence profile of HBV-related HCC and its role in shaping the immune microenvironment, this study employed a rigorous evaluation of multiple datasets encompassing 793 HBV-related HCC samples. Two novel distinct CS subtypes were first identified by nonnegative matrix factorization, and we found that the senescence-activated subgroup had the worst prognosis and correlated with cancer progression. C1 and C2 were identified as the senescence-suppressed and senescence-activated subgroups. The immune microenvironment indicated that C2 exhibited a relatively low immune status, higher tumor purity, and lower immune scores and estimated scores, while the C1 subgroup possessed a better prognosis. The CS score signature based on five genes (CENPA, EZH2, G6PD, HDAC1, and PRPF19) was established using univariate Cox regression and the lasso method. ICGC-LIRI and GSE14520 cohorts were used to validate the reliability of the CS scoring system. In addition, we examined the association between the risk score and hallmark pathways through gene set variation analysis and gene set enrichment analysis. The results revealed a high CS score to be associated with the activation of cell senescence-related pathways. The CS score and other clinical features were combined to generate a CS dynamic nomogram with a better predictive capacity for OS at 1, 2, and 3 years than other clinical parameters. Our study demonstrated that cellular senescence patterns play a non-negligible role in shaping the characteristics of the immune microenvironment and profoundly affecting tumor prognosis. The results of this study will help predict patient prognosis more accurately and may assist in development of personalized immunotherapy for HBV-related HCC patients.

Insights into LiMXO4F (M-X = Al-P and Mg-S) as Cathode Coatings for High-Performance Lithium-Ion Batteries

Cathode coatings have received extensive attention due to their ability to delay electrochemical performance degradation in lithium-ion batteries. However, the development of cathode coatings possessing high ionic conductivity and good interfacial stability with cathode materials has proven to be a challenge. Here, we performed first-principles computational studies on the phase stability, thermodynamic stability, and ionic transport properties of LiMXO₄F (M-X = Al-P and Mg-S) used as cathode coatings. We find that the candidate coatings are thermodynamically metastable and can be synthesized experimentally. The coating materials possess high oxidative stability, with the materials predicted to decompose above 4.2 V, suggesting that they have good electrochemical stability under a high-voltage cathode. In addition, the candidate coatings exhibit significant chemical stability when in contact with oxide cathodes. Finally, we have studied the Li-ion transport paths and migration barriers of LiMXO₄F (M-X = Al-P and Mg-S) and calculated the low migration barriers to be 0.19 and 0.09 eV, respectively. Our findings indicate that LiMXO₄F (M-X = Al-P and Mg-S) are promising cathode coatings, among which LiAlPO₄F has been experimentally confirmed. The theoretical cathode coating computational methods presented here can be extended to the solid-state battery system.

ILF3 represses repeat-derived microRNAs targeting RIG-I mediated type I interferon response

MicroRNAs (miRNAs) play important roles in regulated gene expression and miRNA biogenesis is also subject to regulation, together constituting critical regulatory circuitries in numerous physiological and pathological processes. As a dsRNA binding protein, interleukin enhancer binding factor 3 (ILF3) has been implicated as a negative regulator in miRNA biogenesis, but the mechanism and specificity have remained undefined. Here, combining small-RNA-seq and CLIP-seq, we showed that ILF3 directly represses many miRNAs or perhaps other types of small RNAs annotated in both miRBase and MirGeneDB. We demonstrated that ILF3 preferentially binds to A/U-enriched motifs, which tend to lengthen and/or stabilize the stem-loop in pri-miRNAs, thereby effectively competing with the Microprocessor to block miRNA biogenesis. Focusing on the biological function of ILF3-suppressed miR-582-3p, we discovered that this LINE-derived miRNA targets a critical interferon-inducible gene RIG-I for repression, thus establishing a novel ILF3/miR-582/RIG-I axis in the antiviral response.

Intravenous epoprostenol therapy in the treatment of pulmonary arterial hypertension: the Singapore experience

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary arterial hypertension (PAH) is a progressive disease with significant morbidity and mortality. While intravenous (IV) Epoprostenol, a prostacyclin analogue, has been shown to improve exercise tolerance, symptoms, hemodynamics and survival, there are challenges with initiation and maintenance of this IV therapy.

Purpose

We aim to describe our local experience of the use of IV Epoprostenol in the treatment of PAH patients in Singapore, highlighting various issues and challenges.

Methods

From 2016, patients at a tertiary cardiac institution diagnosed with Group 1 PAH and remaining in intermediate to high risk class with progressive symptoms (despite being on maximum tolerable doses of PhosphoDiEsterase-5 inhibitors and Endothelin-1 receptor antagonists) were assessed and counselled for initiation of Epoprostenol therapy. With a fixed set of local protocols, comprehensive assessment and support of a multi-disciplinary team including physicians, specialist nurses and pharmacists, suitable patients were started on this treatment.

Results

A total of 12 patients (11 female, mean age 42.8 +/- 11.0 years) were included. The average New York Heart Association class of the patients initiated on Epoprostenol was II-III. The pulmonary artery pressures and pulmonary vascular resistance on right heart catheterization prior to initiation was 52.5 (IQR 47.0-54.0) mmHg and 12.6 (IQR 10.0-14.2) Woods respectively. The duration from diagnosis to time of initiating Epoprostenol was 89 (IQR 62-140) months. Epoprostenol was generally well tolerated. The most common side effect experienced was diarrhea (5/12 patients) followed by headache and musculoskeletal complains (3/12 patients each). Of the 12 patients, 6 passed away after 12 (IQR 10-16) months of Epoprostenol therapy. Of the remaining 6, PAH was diagnosed 110 (IQR 104-136) months ago and Epoprostenol therapy has been continued for 17 (IQR 14-27) months. Of those who survived, right ventricle size and PA pressures on echocardiography remained relatively stable as compared to those who passed on. 2 patients had line related infections requiring a line change 1 and 2 times respectively.

Conclusion

While not without its challenges, the establishment of concrete protocols with the support of a multidisciplinary team allows for the introduction of IV Epoprostenol as an additional potential line of effective therapy for PAH patients in Singapore.

Limosilactobacillus reuteri ATCC 6475 metabolites upregulate the serotonin transporter in the intestinal epithelium

The serotonin transporter (SERT) readily takes up serotonin (5-HT), thereby regulating the availability of 5-HT within the intestine. In the absence of SERT, 5-HT remains in the interstitial space and has the potential to aberrantly activate the many 5-HT receptors distributed on the epithelium, immune cells and enteric neurons. Perturbation of SERT is common in many gastrointestinal disorders as well as mouse models of colitis. Select commensal microbes regulate intestinal SERT levels, but the mechanism of this regulation is poorly understood. Additionally, ethanol upregulates SERT in the brain and dendritic cells, but its effects in the intestine have never been examined. We report that the intestinal commensal microbe Limosilactobacillus (previously classified as Lactobacillus) reuteri ATCC PTA 6475 secretes 83.4 mM ethanol. Consistent with the activity of L. reuteri alcohol dehydrogenases, we found that L. reuteri tolerated various levels of ethanol. Application of L. reuteri conditioned media or exogenous ethanol to human colonic T84 cells was found to upregulate SERT at the level of mRNA. A 4-(4-(dimethylamino) phenyl)-1-methylpyridinium (APP+) uptake assay confirmed the functional activity of SERT. These findings were mirrored in mouse colonic organoids, where L. reuteri metabolites and ethanol were found to upregulate SERT at the apical membrane. Finally, in a trinitrobenzene sulphonic acid model of acute colitis, we observed that mice treated with L. reuteri maintained SERT at the colon membrane compared with mice receiving phosphate buffered saline vehicle control. These data suggest that L. reuteri metabolites, including ethanol, can upregulate SERT and may be beneficial for maintaining intestinal homeostasis with respect to serotonin signalling.

Comparison of Outcomes of Asymptomatic Moderate Aortic Stenosis With Preserved Left Ventricular Ejection Fraction in Patients ≥80 Years Versus 70-79 Years Versus <70 Years

Aortic stenosis (AS) is increasingly diagnosed in the aging population with more studies focused on the prognostic outcomes of severe asymptomatic AS. However, little is known about the outcomes of moderate asymptomatic AS in the elderly population. From 2001 to 2020, 738 consecutive patients with asymptomatic moderate AS with preserved left ventricular ejection fraction were studied. They were allocated according to the age group at the index echocardiography: very elderly (≥80 years), elderly (70 to 79 years) and control group (<70 years). The primary study outcomes were aortic valve replacement (AVR), congestive cardiac failure (CCF) and all-cause mortality. Overall, about one-third of the subjects were in the very elderly, elderly and control groups each. The median follow-up duration was 114.2 (interquartile range, 27.0 to 183.7) months. There was significantly higher all-cause mortality in the very elderly group (47.9%) followed by elderly (34.8%) and control group (21.9%). Similarly, there was significantly higher CCF rates in the very elderly group (5.8%) compared to elderly (5.1%) and control group (2.8%). There were significantly lower rates of AVR offered and completed in the very elderly group compared to control group. Multivariable logistic regression demonstrated that age ≥80 years remained an independent predictor of mortality after adjusting for important prognostic cofounders (Adjusted HR 2.424, 95% CI 1.728 to 3.400, p < 0.001). Cox regression showed no significant difference in mortality between patients ≥80 years with moderate AS compared to a younger age-group ≥70 years with severe AS. In conclusion, very elderly patients of ≥80 years of age with moderate AS have worse prognostic outcomes than their younger counterparts. They share similar unfavorable prognostic outcomes as those of a younger age-group ≥70 years with severe AS. Closer surveillance are warranted in this group of at-risk elderly patients.

[Epidemiological characteristics and diagnosis of imported malaria cases in Zhejiang Province from 2017 to 2020]

OBJECTIVE

To analyze the epidemiological features and diagnosis of imported malaria cases in Zhejiang Province from 2017 to 2020, so as to provide the scientific evidence for the management of imported malaria in the province.

METHODS

The data of malaria cases reported in Zhejiang Province were captured from the Information Management System for Parasitic Disease Control of China Information System for Disease Control and Prevention from 2017 to 2020, and the temporal, spatial and human distribution, and initial and definitive diagnosis of imported malaria cases were descriptively analyzed.

RESULTS

A total of 593 malaria cases were reported in Zhejiang Province from 2017 to 2020, and all were overseas imported cases, including 532 men and 61 women, with a mean age of 41 years. There were 93.93% of the malaria cases from African countries, and the malaria parasites infecting these cases included Plasmodium falciparum, P. vivax, P. ovale, P. malariae and mixed infections, with P. falciparum as the predominant species (76.73%, 455/593). All malaria cases received totally correct initial diagnoses in county- and city-level centers for disease control and prevention (CDC) and entry-exit inspection and quarantine sectors, and the proportion of malaria cases with confirmation at the day of initial diagnosis was 41.48% (207/499) in medical institutions and 66.18% (45/68) in CDC (χ² = 14.779, P < 0.001). In addition, the median interval [M (Q_R)] of malaria cases was 1 (2) d from onset to initial diagnosis and 1 (2) d from initial diagnosis to confirmation in Zhejiang Province from 2017 to 2020, and the median interval [M (Q_R)] of severe malaria cases was significantly longer than that of non-severe cases [2 (3) d vs. 1 (2) d; Z = -3.002, P < 0.05].

CONCLUSIONS

Zhejiang Province faces great challenges of malaria control, and post-elimination surveillance of malaria still requires to be reinforced. Meanwhile, the awareness of seeking medical services requires to be improved among returners from malaria-endemic regions and the diagnostic capability of malaria requires to be improved among medical professionals.

Low Relative Valve Load is Associated With Paradoxical Low-Flow Aortic Stenosis Despite Preserved Left Ventricular Ejection Fraction and Adverse Clinical Outcomes

BACKGROUND

Paradoxical low-flow (LF) severe aortic stenosis (AS) despite preserved left ventricular (LV) ejection fraction (LVEF) has been shown to be distinct from normal-flow (NF) AS, with a poorer prognosis. Relative valve load (RVL) is a novel echocardiographic haemodynamic index based on the ratio of transaortic mean pressure gradient to the global valvulo-arterial impedance (Zva) in order to estimate the contribution of the valvular afterload to the global LV load. We aimed to determine the usefulness of RVL in LF AS versus NF AS.

METHOD

A total of 450 consecutive patients with medically managed severe AS (aortic valve area <1.0 cm²) with preserved LVEF (>50%) were studied. Patients were divided into LF (stroke volume index <35 mL/m²) or NF, and high RVL or low RVL. Baseline clinical and echocardiographic profiles, as well as clinical outcomes, were compared.

RESULTS

There were 149 (33.1%) patients with LF. Despite higher global impedance in LF (Zva 6.3±2.4 vs 3.9±0.9 mmHg/mL/m²; p<0.001) compared with NF, the RVL in LF AS was significantly lower (5.4±2.7 vs 9.8±5.1 mL/m²; p<0.001). On multivariable analysis, low RVL (≤7.51) remained independently associated with poor clinical outcomes on Cox regression (hazard ratio, 1.31; 95% confidence interval, 1.03-1.68), with 53.2% sensitivity and 70.3% specificity. This was comparable to other prognostic indices in AS. Kaplan-Meier curves demonstrated that low RVL was associated with increased mortality.

CONCLUSIONS

Increased systemic arterial afterload may be important in the pathophysiology of LF AS. Low RVL was an independent predictor of poor clinical outcomes in medically managed severe AS. There may be a greater role in the attenuation of systemic arterial afterload in AS to improve outcomes.

Age- and Sex-Specific Changes in CMR Feature Tracking-Based Right Atrial and Ventricular Functional Parameters in Healthy Asians

Cardiovascular magnetic resonance (CMR) is the reference standard for non-invasive assessment of right-sided heart function. Recent advances in CMR post-processing facilitate quantification of tricuspid annular (TA) dynamics and longitudinal strains of the right ventricle (RV) and right atrium (RA). We aimed to determine age- and sex-specific changes in CMR-derived TA dynamics, and RV and RA functional parameters in healthy Asian adults. We studied 360 healthy subjects aged 21-79 years, with 30 men and 30 women in each of the six age groups. Functional parameters of RV and RA were measured on standard four-chamber cine CMR using fast feature tracking: (1) TA peak velocities (systolic velocity S', early diastolic velocity E', late diastolic velocity A') and TA plane systolic excursion (TAPSE); (2) RV global longitudinal strain (GLS) and strain rates; and (3) RA phasic longitudinal strains and strain rates. S' and TAPSE exhibited negative correlations with age. RV GLS was significantly higher in females than in males but not associated with age in both sexes. Females had similar E', lower A', and higher E'/A' ratios compared to males. Positive associations of E' and E'/A', and negative association of A' with age were observed in both sexes. Females had higher RA reservoir and conduit strains compared to males. There were significantly negative and positive associations between RA conduit and booster strains, respectively, with age. Age- and sex-specific reference ranges were established, and associations revealed, for fast CMR feature tracking parameters of right heart function in a large normal Asian population.

Implications of Coexisting Aortic Regurgitation in Patients With Aortic Stenosis

Background

Aortic regurgitation (AR) is a common comorbidity in patients with aortic stenosis (AS), but coexisting AR has often been excluded from major clinical studies on AS. The impact of coexisting AR on the natural history of AS has not been well-described.

Objectives

The authors compared clinical outcomes in medically managed patients with moderate-to-severe AS with or without coexisting AR.

Methods

Consecutive patients (N = 1,188) with index echocardiographic diagnosis of moderate-to-severe AS (aortic valve area <1.5 cm²) were studied. All patients were medically managed and were divided into those with coexisting AR (at least moderate severity) and those without. Adverse composite clinical outcomes were defined as mortality or admissions for congestive cardiac failure on subsequent follow-up. The authors compared differences in clinical profile and outcomes between the groups.

Results

There were 88 patients (7.4%) with coexisting AR and AS. These patients did not differ significantly in age, but had lower body mass index (22.9 ± 3.8 vs 25.3 ± 5.1 kg/m²), lower diastolic blood pressure (68.7 ± 10.7 vs 72.2 ± 12.3 mm Hg), larger end-diastolic volume index (68.8 ± 18.8 vs 60.4 ± 17.8 mL/m²) and larger left ventricular mass index (118.6 ± 36.4 vs 108.9 ± 33.1 g/m²). The prevalence of cardiovascular risk factors did not differ significantly. Coexisting AR was associated with increased incidence of adverse outcomes (log-rank 4.20; P = 0.040). On multivariable Cox regression, coexisting AR remained independently associated with adverse outcomes (HR: 1.36; 95% CI: 1.02-1.82) after adjusting for age, AS severity, left ventricular ejection fraction, and year of study.

Conclusions

In patients with AS, coexisting AR was associated with changes in echocardiographic profile and adverse outcomes.

Cardiovascular magnetic resonance-assessed fast global longitudinal strain parameters add diagnostic and prognostic insights in right ventricular volume and pressure loading disease conditions

BACKGROUND

Parameters of myocardial deformation may provide improved insights into right ventricular (RV) dysfunction. We quantified RV longitudinal myocardial function using a fast, semi-automated method and investigated its diagnostic and prognostic values in patients with repaired tetralogy of Fallot (rTOF) and pulmonary arterial hypertension (PAH), who respectively exemplify patients with RV volume and pressure overload conditions.

METHODS

The study enrolled 150 patients (rTOF, n = 75; PAH, n = 75) and 75 healthy controls. RV parameters of interest were fast global longitudinal strain (GLS) and strain rates during systole (GLSRs), early diastole (GLSRe) and late diastole (GLSRa), obtained by tracking the distance from the medial and lateral tricuspid valve insertions to the RV epicardial apex on cine cardiovascular magnetic resonance (CMR).

RESULTS

The RV fast GLS exhibited good agreement with strain values obtained by conventional feature tracking approach (bias - 4.9%, error limits (± 2·standard deviation) ± 4.3%) with fast GLS achieving greater reproducibility and requiring reduced analysis time. Mean RV fast GLS was reduced in PAH and rTOF groups compared to healthy controls (PAH < rTOF < healthy controls: 15.1 ± 4.9 < 19.3 ± 2.4 < 24.4 ± 3.0%, all P < 0.001 in pairwise comparisons). In rTOF patients, RV fast GLS was significantly associated with metabolic equivalents, peak oxygen consumption (PVO2) and percentage of predicted PVO2 achieved during cardiopulmonary exercise testing. Lower RV fast GLS was associated with subnormal exercise capacity in rTOF (area under the curve (AUC) = 0.822, sensitivity = 72%, specificity = 91%, cut-off = 19.3%). In PAH patients, reduced RV fast GLS was associated with RV decompensated hemodynamics (AUC = 0.717, sensitivity = 75%, specificity = 58%, cut-off = 14.6%) and higher risk of clinical worsening (AUC = 0.808, sensitivity = 79%, specificity = 70 %, cut-off = 16.0%).

CONCLUSIONS

Quantitative RV fast strain and strain rate parameters assessed from CMR identify abnormalities of RV function in rTOF and PAH and are predictive of exercise capacity, RV decompensation and clinical risks in these patients. Trial registry Clinicaltrials.gov: NCT03217240.

Clinical Updates on the Diagnosis and Management of Chronic Thromboembolic Pulmonary Hypertension

Introduction: Chronic thromboembolic pulmonary hypertension (CTEPH) is a known sequela after acute pulmonary embolism (PE). It is a debilitating disease, and potentially fatal if left untreated. This review provides a clinically relevant overview of the disease and discusses the usefulness and limitations of the various investigational and treatment options. Methods: A PubMed search on articles relevant to pulmonary embolism, pulmonary hypertension, chronic thromboembolic pulmonary hypertension, pulmonary endarterectomy, and balloon pulmonary angioplasty were performed. A total of 68 articles were found to be relevant and were reviewed. Results: CTEPH occurs as a result of non-resolution of thrombotic material, with subsequent fibrosis and scarring of the pulmonary arteries. Risk factors have been identified, but the underlying mechanisms have yet to be fully elucidated. The cardinal symptom of CTEPH is dyspnoea on exertion, but the diagnosis is often challenging due to lack of awareness. The ventilation/perfusion scan is recommended for screening for CTEPH, with other modalities (eg. dual energy computed tomography pulmonary angiography) also being utilised in expert centres. Conventional pulmonary angiography with right heart catherisation is important in the final diagnosis of CTEPH. Conclusion: Operability assessment by a multidisciplinary team is crucial for the management of CTEPH, as pulmonary endarterectomy (PEA) remains the guideline recommended treatment and has the best chance of cure. For inoperable patients or those with residual disease post-PEA, medical therapy or balloon pulmonary angioplasty are potential treatment options. Keywords: Balloon pulmonary angioplasty, Chronic thromboembolic pulmonary hypertension, Pulmonary embolism, Pulmonary endarterectomy, Pulmonary hypertension

Clinical Updates on the Diagnosis and Management of Chronic Thromboembolic Pulmonary Hypertension

INTRODUCTION

Chronic thromboembolic pulmonary hypertension (CTEPH) is a known sequela after acute pulmonary embolism (PE). It is a debilitating disease, and potentially fatal if left untreated. This review provides a clinically relevant overview of the disease and discusses the usefulness and limitations of the various investigational and treatment options.

METHODS

A PubMed search on articles relevant to PE, pulmonary hypertension, CTEPH, pulmonary endarterectomy, and balloon pulmonary angioplasty were performed. A total of 68 articles were found to be relevant and were reviewed.

RESULTS

CTEPH occurs as a result of non-resolution of thrombotic material, with subsequent fibrosis and scarring of the pulmonary arteries. Risk factors have been identified, but the underlying mechanisms have yet to be fully elucidated. The cardinal symptom of CTEPH is dyspnoea on exertion, but the diagnosis is often challenging due to lack of awareness. The ventilation/perfusion scan is recommended for screening for CTEPH, with other modalities (eg. dual energy computed tomography pulmonary angiography) also being utilised in expert centres. Conventional pulmonary angiography with right heart catheterisation is important in the final diagnosis of CTEPH.

CONCLUSION

Operability assessment by a multidisciplinary team is crucial for the management of CTEPH, as pulmonary endarterectomy (PEA) remains the guideline recommended treatment and has the best chance of cure. For inoperable patients or those with residual disease post-PEA, medical therapy or balloon pulmonary angioplasty are potential treatment options.

Elevated Right Atrial Pressure Associated with Alteration of Left Ventricular Contractility and Ventricular-Arterial Coupling in Pulmonary Artery Hypertension

Pulmonary artery hypertension (PAH) is a progressive disorder which leads to heart failure and death. Development of dilated right ventricle (RV), progressive RV dysfunction and increased right atrial (RA) pressure make the RV transition from a compensated to a decompensated phase and eventually leads to heart failure. However, the relationship between elevated RA pressure and left ventricular contractility and ventricular arterial coupling (VAC) has not been well studied. 36 patients were recruited and underwent both right heart catheterization (RHC) and cardiac magnetic resonance (CMR). Left ventricular (LV) pressure-volume loops were reconstructed from RHC and CMR. LV contractility was assessed by end-systolic elastance (E_es) using single-beat method and arterial elastance (E_a) was estimated as the ratio of end-systolic pressure and stroke volume (SV). The VAC was calculated as the ratio of E_es and E_a (i.e. E_es/E_a). The results demonstrated a nonlinear relationship between RA pressure and E_es, RA pressure and VAC. E_es increased when RA pressure increased to 7 mmHg and then decreased when RA pressure exceeded 7 mmHg. E_es were 2.79 ± 1.61 mmHg/ml, 4.27 ±1 33 mmHg/ml, 2.69 ± 0.89 mmHg/ml and 2.36± 1.10 mmHg/ml at ascending quartiles of RA pressure, respectively (quartile 1: RAP≤5 mmHg; quartile 2: 5<; RAP≤7 mmHg; quartile 3: 7<; RAP 10 mmHg and quartile 4: RAP>10 mmHg). Similarly, VAC were 1.36 ± 0.61, 1.93±0.86, 1.16 ± 0.55 and 0.95± 0.27 the four quartiles (both ANOVA P <; 0.05). We found that there was a nonlinear relationship between RA pressure and LV contractility, and between RA pressure and ventricular-arterial coupling. A cut-off value of 7 mmHg of RAP may indicate a decompensated LV hemodynamics.

Associations between Skeletal Muscle and Myocardium in Aging: A Syndrome of "Cardio-Sarcopenia"?

OBJECTIVES

The link between skeletal muscle and heart disease remains intriguing. It is unknown how skeletal muscle may be associated with aspects of myocardial structure and function, particularly in the presence of aging-related sarcopenia. We hypothesize that among aging adults with sarcopenia, alterations in myocardial structure and/or function may exist, resulting in a syndrome of "cardio-sarcopenia."

METHODS

Participants derived from a community cohort study underwent same-day bioimpedance body composition analysis that measured skeletal muscle in sites such as the trunk, upper limb, and lower limb, and echocardiography for assessment of myocardial structure and function. Sarcopenia was diagnosed using the Asian Working Group for Sarcopenia criteria.

RESULTS

We studied a total of 378 participants, of whom 88 (23.3%) had sarcopenia. Participants with sarcopenia had smaller left ventricular (LV) sizes (lower LV internal diameter end diastole (4.1 ± .7 vs 4.5 ± .6 cm; P < .0001), lower LV internal diameter end systole (2.3 ± .5 vs 2.5 ± .4 cm; P = .010), lower LV posterior wall end diastole (.7 ± .1 vs .8 ± .1 cm; P = .0036), and lower LV posterior wall end systole (1.4 ± .3 vs 1.5 ± .2 cm; P = .0031). Sarcopenic participants also had lower LV mass (106 ± 35 vs 126 ± 53; P = .0014) and lower left atrial (LA) volume (33 ± 13 vs 36 ± 13; P = .033). Adjusting for age and diabetes mellitus, skeletal muscle mass was associated with LV diameter (β = .06; 95% confidence interval [CI] = .03-.09; P < .0001), LV mass (β = 4.04; 95% CI = 1.78-6.29; P = .001), LA diameter (β = .05; 95% CI = .01-.09; P = .007), and LA volume (β = 1.26; 95% CI = .38-2.13; P = .005). A positive linear correlation was observed between LV mass and handgrip strength (r = .25; P < .0001).

CONCLUSION

Among a community sample of older adults with preserved heart function, sarcopenia is associated with reductions in LV and LA sizes. Skeletal muscle mass was independently associated with specific indices of myocardial structure. J Am Geriatr Soc 67:2568-2573, 2019.

Sleep duration and the risk of osteoporosis among middle-aged and elderly adults: a dose-response meta-analysis

It remains unclear how many hours of sleep are associated with the lowest risk of osteoporosis. This meta-analysis was performed to assess the dose-response relationship between sleep duration and risk of osteoporosis. PubMed and Web of Science were searched from inception to December 3, 2017, supplemented by manual searches of the bibliographies of retrieved articles. Data were pooled using fixed- and random-effects models. Restricted cubic spline analysis with four knots was used to model the sleep duration and osteoporosis association. Four cross-sectional studies with eight records were eligible for inclusion in the meta-analysis. A U-shaped dose-response relationship was observed between sleep duration and risk of osteoporosis, with the lowest risk observed at a sleep duration category of 8-9 h per day. Compared with 8-h sleep duration per day, the pooled odds ratio for osteoporosis were 1.03 (95% CI 1.01-1.06) for each 1-h reduction among individuals with shorter sleep duration and 1.01 (95% CI 1.00-1.02) for each 1-h increment among individuals with longer sleep duration. Our dose-response meta-analysis shows a U-shaped relationship between sleep duration and risk of osteoporosis, with the lowest osteoporosis risk at about 8 h per day of sleep duration. Both short and long sleep duration is associated with a significantly increased risk of osteoporosis in the middle-aged and elderly adults, appropriate sleep duration could help for delay or prevention of osteoporosis.

Synthesis, energy transfer and tunable emission properties of SrSb2O6:Eu(3+), Bi(3+) phosphor

Host SrSb2O6, SrSb2O6:Bi(3+), SrSb2O6:Eu(3+), and SrSb2O6:Eu(3+), Bi(3+) phosphors are synthesized by solid state reaction method in air. Host SrSb2O6 with excitation 254nm shows weak green-yellow emission in the range of 320-780nm due to Sb(5+)→O(2-) transition. SrSb2O6:Bi(3+) phosphor with excitation 365nm emits green light within the range 400-650nm owing to the (3)P1→(1)S0 transition of Bi(3+) ion. SrSb2O6:Eu(3+) phosphor with excitation 254nm exhibits a systematically varied hue from green to orange-red light by increasing Eu(3+) concentration from 0 to 7mol%, and that with excitation 394nm only shows orange-red light. The optimal Eu(3+) concentration is ~4mol% in SrSb2O6:Eu(3+) phosphor. SrSb2O6:Eu(3+), Bi(3+) phosphor with excitation 254 and 394nm emits orange-red light. Emission intensity of SrSb2O6:Eu(3+) phosphor may be enhanced >2 times by co-doping Bi(3+) ion because of the fluxing agent and energy transfer roles of Bi(3+) ion in SrSb2O6:Eu(3+), Bi(3+) phosphor. The luminous mechanism of SrSb2O6:Eu(3+), Bi(3+) phosphor is analyzed and explained by the simplified energy level diagrams of Sb2O6(2-) group, Bi(3+) and Eu(3+) ions, and energy transfer processes between them.

Eiger-induced cell death relies on Rac1-dependent endocytosis

Signaling via tumor necrosis factor receptor (TNFR) superfamily members regulates cellular life and death decisions. A subset of mammalian TNFR proteins, most notably the p75 neurotrophin receptor (p75NTR), induces cell death through a pathway that requires activation of c-Jun N-terminal kinases (JNKs). However the receptor-proximal signaling events that mediate this remain unclear. Drosophila express a single tumor necrosis factor (TNF) ligand termed Eiger (Egr) that activates JNK-dependent cell death. We have exploited this model to identify phylogenetically conserved signaling events that allow Egr to induce JNK activation and cell death in vivo. Here we report that Rac1, a small GTPase, is specifically required in Egr-mediated cell death. rac1 loss of function blocks Egr-induced cell death, whereas Rac1 overexpression enhances Egr-induced killing. We identify Vav as a GEF for Rac1 in this pathway and demonstrate that dLRRK functions as a negative regulator of Rac1 that normally acts to constrain Egr-induced death. Thus dLRRK loss of function increases Egr-induced cell death in the fly. We further show that Rac1-dependent entry of Egr into early endosomes is a crucial prerequisite for JNK activation and for cell death and show that this entry requires the activity of Rab21 and Rab7. These findings reveal novel regulatory mechanisms that allow Rac1 to contribute to Egr-induced JNK activation and cell death.

Surgical correction of persistent truncus arteriosus on a 33-year-old male with unilateral pulmonary hypertension from migration of pulmonary artery band

BACKGROUND

Persistent truncus arteriosus is a rare congenital condition with which survival into adulthood is dismal without surgery. This is the oldest patient reported to our knowledge demonstrating the feasibility of assessing operability in persistent truncus arteriosus with unilateral pulmonary stenosis, and performing full corrective surgery in adulthood.

CASE PRESENTATION

We report a Chinese male with successful correction of Type I persistent truncus arteriosus at 33 years of age. He had unilateral pulmonary hypertension from migration of pulmonary artery band from the main to the right pulmonary artery, severe truncal valve regurgitation from previous infective endocarditis, and progressive congestive heart failure. Improvement of lung perfusion was demonstrated 21 months post operation.

CONCLUSION

This case demonstrated that in patients with persistent truncus arteriosus and two pulmonary arteries, pulmonary vascular disease or underdevelopment of one lung does not preclude a full corrective surgery so long as the other vascular bed is normal. It is important to emphasize the importance of assessing patient's operability in totality.

Prevalence, Presentation, and Outcome of Heart Failure with Preserved Ejection Fraction among Patients Presenting with Undifferentiated Dyspnoea to the Emergency Room: A 10-year Analysis from a Tertiary Centre

INTRODUCTION

We assessed the local prevalence, characteristics and 10-year outcomes in a heart failure (HF) cohort from the emergency room (ER).

MATERIALS AND METHODS

Patients presenting with acute dyspnoea to ER were prospectively enrolled from December 2003 to December 2004. HF was diagnosed by physicians' adjudication based on clinical assessment and echocardiogram within 12 hours, blinded to N-terminal-pro brain natriuretic peptide (NT-proBNP) results. They were stratified into heart failure with preserved (HFPEF) and reduced ejection fraction (HFREF) by left ventricular ejection fraction (LVEF).

RESULTS

At different cutoffs of LVEF of ≥50%, ≥45%, ≥40%, and >50% plus excluding LVEF 40% to 50%, HFPEF prevalence ranged from 38% to 51%. Using LVEF ≥50% as the final cutoff point, at baseline, HFPEF (n = 35), compared to HFREF (n = 55), had lower admission NT- proBNP (1502 vs 5953 pg/mL, P <0.001), heart rate (86 ± 22 vs 98 ± 22 bpm, P = 0.014), and diastolic blood pressure (DBP) (75 ± 14 vs 84 ± 20 mmHg, P = 0.024). On echocardiogram, compared to HFREF, HFPEF had more LV concentric remodelling (20% vs 2%, P = 0.003), less eccentric hypertrophy (11% vs 53%, P <0.001) and less mitral regurgitation from functional mitral regurgitation (60% vs 95%, P = 0.027). At 10 years, compared to HFREF, HFPEF had similar primary endpoints of a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, and rehospitalisation for congestive heart failure (CHF) (HR 0.886; 95% CI, 0.561 to 1.399; P = 0.605), all-cause mortality (HR 0.663; 95% CI, 0.400 to 1.100; P = 0.112), but lower cardiovascular mortality (HR 0.307; 95% CI, 0.111 to 0.850; P = 0.023).

CONCLUSION

In the long term, HFPEF had higher non-cardiovascular mortality, but lower cardiovascular mortality compared to HFREF.

Breast Cancer Chemoprevention in Pre-Neoplastic Lesions with a Somatostatin Analog in Nine Women: A Proof of Principle Trial

Background: Atypical duct and lobular hyperplasia and lobular neoplasia of the mammary gland increases breast cancer risk. Tamoxifen and Raloxifene in post menopausal women are considered standard chemopreventive agents in these high risk women. We have previously shown insulin-like growth factor-I (IGF-I) is required to permit estrogen (E2) and progesterone action in the mammary gland, and that a novel somatostatin analog, SOM230, can prevent E2 action by reducing pituitary growth hormone (hGH), and by directly inhibiting IGF-I action in the mammary gland. It inhibits hGH and E2 induced cell proliferation and increases apoptosis in rat mammary gland. This study was designed to determine whether women at high risk for breast cancer respond to SOM230 in the same way that rats do.Methods: Women carrying a diagnosis of atypical hyperplasia and Lobular carcinoma in-situ (lesions that increase relative risk of breast cancer) were included. After the diagnosis was made on corebiopsies, women were treated for 9.5 days with SOM230 (600mcg BID). Surgical excision was performed on day 10. Sections were examined before and after SOM230 treatment for cell proliferation (Ki67) and apoptosis (TUNEL). Serum IGF-I, fasting glucose, insulin, and HbA1C were measured in anticipation of changes.Results: Of the nine patients who have so far completed the trial, three had LCIS. When comparing the core to surgical excision, SOM230 caused decreased proliferation and increased apoptosis. There was no atypical ductal hyperplasia tissue remaining in surgical specimens. However, all nine had typical ductal hyperplasia before and after treatment. SOM230 caused decreased cell proliferation and increased apoptosis in each case.All nine patients evaluated had elevations in fasting fingerstick glucose from a mean of 97.7 mg/dL (range 84 - 117) to a mean of 113.4 mg/dL (range 100 - 134) at three days into SOM230 treatment. This was accompanied by a reduction in fasting insulin, which occurred in all. The reductions in insulin and increase in capillary glucose resolved with discontinuation of the study medication in all patients and HbA1c levels measured at three months were unchanged from baseline.Discussion: The preliminary short-term data show that SOM230 can inhibit cell proliferation and increase apoptosis in preneoplastic human breast lesions, supporting in principle that SOM230 prevents IGF-I action in women, and therefore E2 action, as it does in rats. Further results from this and other clinical trials will be important in determining whether SOM230 will offer an alternative to replace antiestrogens in breast cancer chemoprevention, and/or reverse premalignant lesions of the breast without causing symptoms of estrogen deficiency.SOM230 causes reduced serum IGF-I and fasting hypoinsulinemia, which may explain the fasting hyperglycemia. It is not yet clear whether SOM230 will be effective as long term chemoprevention, or if its usefulness will be limited by the adverse effects on glucose and IGF-I.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1044.

Serial assessment of left ventricular remodeling and function by echo-tissue Doppler imaging after myocardial infarction in streptozotocin-induced diabetic swine

BACKGROUND

The aim of this study was to determine the value of Doppler tissue imaging (DTI) in detecting serial changes in left ventricular (LV) geometry and function after myocardial infarction (MI) in diabetic swine.

METHODS

Thirteen minipigs with streptozotocin-induced diabetes for 1 month and 13 controls were subjected to occlusion of the left anterior descending coronary artery. Echocardiography and DTI were performed before, 30 minutes, 90 minutes, and 4 weeks after left anterior descending coronary artery occlusion.

RESULTS

At baseline, LV end-diastolic volume and mass were greater in pigs with diabetes. After MI, LV ejection fractions and systolic mitral annular velocities were decreased and LV chambers dilated in both groups, which were exacerbated in animals with diabetes. At 30 minutes, 90 minutes, and 4 weeks after MI, strain rates were significantly lower in both infarct and noninfarct areas in the diabetic group than in controls.

CONCLUSIONS

DTI proved to be a useful tool in the serial assessment of subclinical LV dysfunction after MI in pigs with diabetes.

Evidence that SOM230 can prevent experimental mammary hyperplasia by blocking IGF-I and thus estrogen action in the mammary gland: preliminary evidence for an effect in humans

Abstract #5084

Background: Antiestrogens or aromatase inhibitors are used for breast cancer chemoprevention, however, they are poorly tolerated. We have shown that IGF-I is required to permit estrogen and progesterone action in the mammary gland. A novel somatostatin analog, SOM230, which binds to several somatostatin subtype receptors (SSTR), prevents estrogen action by reducing pituitary growth hormone, and also by a direct IGF-I action inhibitory effect on the mammary gland. Menopausal symptoms have not been observed in acromegalic patients receiving SOM230. Material and Methods: Several approaches have been undertaken. 1) We developed a model of hyperplasia in hypophysectomized and oophorectomized female rats. Hyperplasia was induced by treatment with 600 mcg hGH and follicular phase concentrations of estradiol. 2) To assess translatability to humans we cell proliferation (Ki67) and apoptosis (TUNEL) were measured in normal human breast from reduction mammoplasty and in samples of proliferative fibrocystic change (FCC). 3) We also measured expression of SSTR in atypical ductal hyperplasia and DCIS, and 4) A proof of principal trial with SOM230 has begun accrual to determine whether SOM230 acts in human breast as in rats. Results: 1) hGH and E2 caused florid hyperplasia in rat mammary glands within a week. Twenty-six percent of gland structures exhibited hyperplasia with 50% of those showing florid hyperplasia. SOM230 reduced the number of areas of florid hyperplasia to 7.5 ±0.5 from 18.9±1.3 (p&lt;0.001). This was accomplished by a reduction in cell proliferation and an increase in apoptosis. Interestingly, co-administration with tamoxifen provided no additional benefit over that of SOM230. 2) Proliferative lesions from human breast had 8.09 % of cells stain for Ki67. 3) All 5 somatostatin subtype receptor (SSTR) were present in pathology samples of atypical hyperplasias and DCIS, but SSTR3 and 5 were present in highest concentrations. SSTR 3 is the receptor most likely to mediate the effect of SOM230 with SSTR5 being the next most likely. 4) In the first patient tested we found that SOM230 increased apoptosis and reduced cell proliferation (1000 cells counted).&#x2028; &#x2028; Discussion: Our data show that SSTR are present in ADH and DCIS and normal breast tissue. Our data also show that SOM230 can prevent cell proliferation and increase apoptosis both in rats and humans. Thus, further clinical trials will be important as SOM230 may have a role in breast cancer chemoprevention.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5084.

[Left ventricular dyssynchrony evaluated by echocardiography in chronic heart failure patients with normal and wide QRS duration]

OBJECTIVE

The aim of the study is to evaluate the left ventricular (LV) dyssynchrony in chronic heart failure (HF) patients with normal and wide QRS duration.

METHODS

Time to peak velocity at peak systolic and early diastolic phase (Ts and Te) were determined in 12 segments of LV by echocardiography (GE Vivid 7) in 54 HF patients (28 with wide and 26 with normal QRS duration) and 15 normal controls to evaluate LV systolic and diastolic dyssynchrony. The risk factors related to LV dyssynchrony were also evaluated.

RESULTS

LV end systolic and diastolic volumes were significantly larger and 12 segmental mean Ts and maximal Te difference (Te-diff) were significantly higher in HF patients with wide QRS duration than HF patients with normal QRS duration. Using mean Ts >or= 182 ms as the cut-off value, systolic dyssynchrony was present in 46% HF patients with normal QRS and 71% HF patients with wide QRS. Using Te-diff >or= 79 ms as the cut-off value, diastolic dyssynchrony was seen in 58% HF patients with normal QRS and 89% HF patients with wide QRS. Combined systolic and diastolic dyssynchrony was seen in 31% HF patients with normal QRS and in 64% HF patients with wide QRS. Systolic dyssynchrony was significantly correlated to LV end systolic volume and diastolic dyssynchrony was correlated to end diastolic volume.

CONCLUSION

Percentage of LV dyssynchrony was significantly higher in HF patients with wide QRS, especially in HF patients with increased LV end systolic and diastolic volume.

Methylation patterns ofIGFBP7 in colon cancer cell lines are associated with levels of gene expression

Altered expression of insulin-like growth factor binding protein 7 (IGFBP7) has been found in colon cancer, but the exact regulatory mechanism has not been fully investigated. In order to elucidate the mechanisms underlying aberrant IGFBP7 expression in colon cancer, we used bisulphite sequencing PCR (BSP) to detect the detailed methylation profiles of the IGFBP7 5' CpG island. Exon 1 of the IGFBP7 gene was highly methylated in IGFBP7-negative cell lines but unmethylated in IGFBP7-positive lines. The methylation status of the promoter region and the intron 1 region was not so discriminating in IGFBP7-positive and -negative cell lines. Methylation-specific PCR (MSP) confirmed the hypermethylation of IGFBP7 exon 1 in IGFBP7-negative cell lines. Treatment with 5-aza-2'-deoxycytidine (5-aza-dC) induced demethylation of the CpG island in exon 1 of IGFBP7, as examined by both MSP and bisulphate genomic sequencing. Furthermore, the expression of IGFBP7 was restored, as detected by both RT-PCR and immunocytochemistry. Our study is the first to provide detailed methylation profiles of the IGFBP7 5' CpG island and shows that hypermethylation of the CpG island in exon 1 of IGFBP7 is closely related to the absence of its expression in colon cancer cells.

Assessment of left ventricular segmental function after autologous bone marrow stem cells transplantation in patients with acute myocardial infarction by tissue tracking and strain imaging

BACKGROUND

Emerging evidence suggests that stem cells can be used to improve cardiac function in patients after acute myocardial infarction. In this randomized trial, we aimed to use Doppler tissue tracking and strain imaging to assess left ventricular segmental function after intracoronary transfer of autologous bone-marrow stem cells (BMCs) for 6 months' follow up.

METHODS

Twenty patients with acute myocardial infarction and anterior descending coronary artery occlusion proven by angiography were [corrected] randomized into intracoronary injection of bone-marrow cell (treated, n = 9) or diluted serum (control, n = 11) groups. GE vivid 7 and Q-analyze software were used to perform echocardiogram in both groups 1 week, 3 months and 6 months after treatment. Three apical views of tissue Doppler imaging were acquired to measure peak systolic displacement (Ds) and peak systolic strain (epsilonpeak) from 12 segments of LV walls. Left ventricular ejection fraction (LVEF), end-diastolic volume (EDV) and end-systolic volume (ESV) were obtained by Simposon's biplane method.

RESULTS

(1) 3 months later, Ds and epsilonpeak over the infract-related region clearly increased in the BMCs group [Ds: (4.49 +/- 2.71) mm vs (7.56 +/- 2.95) mm, P < 0.01; epsilonpeak: (-13.40 +/- 6.00)% vs (-17.06 +/- 6.05)%, P < 0.01], but not in the control group [Ds: (4.74 +/- 2.67) mm vs (5.01 +/- 3.23) mm, P > 0.05; epsilonpeak: (-13.84 +/- 6.05)% vs (-15.04 +/- 6.75)%, P > 0.05]. At the same time, Ds over the normal region also increased, but the Ds enhancement was markedly higher in the BMCs group than that in the control group [(3.21 +/- 3.17) mm vs (0.76 +/- 1.94) mm, P < 0.01]. Parameters remained steady from the 3rd to 6th month in either group (P > 0.05). (2) LVEF in treated and control groups were almost the same at baseline (1st week after PCI) [(53.37 +/- 8.92)% vs (53.51 +/- 5.84)%, P > 0.05]. But 6 months later, LVEF in the BMCs group were clearly higher than that in the control group [(59.33 +/- 12.91)% vs (50.30 +/- 8.30)%, P < 0.05]. (3) There were no evident difference in EDV or ESV between two groups at baseline [EDV: (113.74 +/- 23.24) ml vs (129.94 +/- 32.72) ml, P > 0.05; ESV: (57.12 +/- 18.66) ml vs (62.09 +/- 17.68) ml, P > 0.05]. Three months later, EDV and ESV in the control group were markedly greater than those in the BMCs group [EDV: (154.89 +/- 46.34) ml vs (104.85 +/- 33.21) ml, P < 0.05; ESV: (82.91 +/- 35.79) ml vs (49.54 +/- 23.32) ml, P < 0.05]. But EDV and ESV did not change much from 3rd to 6th month in either group (P > 0.05).

CONCLUSIONS

Emergency transplantation of autologous BMCs in patients with acute myocardial infarction helps to improve global and regional contractility and attenuate post-infarction left ventricular remodeling. Tissue tracking and strain imaging provide quick, simple and noninvasive methods for quantifying left ventricular segmental function in humans.

Mapping various information sources to a semantic network

Giessen Data Dictionary Server (GDDS) provides context sensitive information services to disparate clinical applications by automatically navigating a semantic network that stores medical knowledge. Mapping multiple information sources to single clinical application becomes a challenge due to different organization of semi-structured information sources. Linking huge unstructured information sources such as medical literature is even more challenging because we need to develop a mechanism to organize unstructured information and take into account the scalability issue. In this paper, we have successfully mapped two drug information sources by developing an independent subnet for each source and linking them at proper nodes. For medical literature, we have demonstrated that the semantic network of the Unified Medical Language Systems and human assigned topics to each document can be used to organize the large amount of medical literature into the framework of the GDDS service.

Self assembly of the transmembrane domain promotes signal transduction through the erythropoietin receptor

Hematopoietic cytokine receptors, such as the erythropoietin receptor (EpoR), are single membrane-spanning proteins. Signal transduction through EpoR is crucial for the formation of mature erythrocytes. Structural evidence shows that in the unliganded form EpoR exists as a preformed homodimer in an open scissor-like conformation precluding the activation of signaling. In contrast to the extracellular domain of the growth hormone receptor (GHR), the structure of the agonist-bound EpoR extracellular region shows only minimal contacts between the membrane-proximal regions. This evidence suggests that the domains facilitating receptor dimerization may differ between cytokine receptors. We show that the EpoR transmembrane domain (TM) has a strong potential to self interact in a bacterial reporter system. Abolishing self assembly of the EpoR TM by a double point mutation (Leu 240-Leu 241 mutated to Gly-Pro) impairs signal transduction by EpoR in hematopoietic cells and the formation of erythroid colonies upon reconstitution in erythroid progenitor cells from EpoR(-/-) mice. Interestingly, inhibiting TM self assembly in the constitutively active mutant EpoR R129C abrogates formation of disulfide-linked receptor homodimers and consequently results in the loss of ligand-independent signal transduction. Thus, efficient signal transduction through EpoR and possibly other preformed receptor oligomers may be determined by the dynamics of TM self assembly.

brakeless is required for photoreceptor growth-cone targeting in Drosophila

The R1-R6 subclass of photoreceptor neurons (R cells) in the Drosophila compound eye form specific connections with targets in the optic ganglia. In this paper, we report the identification of a gene, brakeless (bks), that is essential for R1-R6 growth cone targeting. In brakeless mutants, R1-R6 growth cones frequently fail to terminate migration in their normal target, the lamina, and instead project through it and terminate in the second optic ganglion, the medulla. Genetic mosaic analysis and transgene rescue experiments indicate that bks functions in R cells and not within the lamina target region. bks encodes a nuclear protein. We propose that it participates in a gene expression pathway regulating one or more growth cone components controlling R1-R6 targeting.