Association of propionate with coronary artery disease in a large cross-sectional study

Background

Microbiome has been linked to the pathogenesis of coronary artery disease (CAD) but data providing direct evidence for an association of short-chain fatty acids (SCFA) like propionate with CAD are lacking.

Purpose

To study the association of propionate in blood samples with the presence of CAD

Methods

This was a cross-sectional study enrolling patients admitted to invasive coronary angiography in a university hospital in Germany. Patients were prospectively recruited between from March 2017 to January 2020. Patients with known or suspected CAD and risk factors for cardiovascular diseases were screened for eligibility to participate in the trial. Main exclusion criteria were inflammatory/rheumatic disease, active cancer disease and acute infection. Blood sampling was performed after overnight fasting and before invasive procedures. Measurement of propionate was performed though liquid chromatography.

Results

The study included 691 patients (median n [IQR] age, 69 [60–78] years; 406 men [59%]). A total of 368 had invasively confirmed CAD with at least one coronary artery stenosis ≥50% and 323 had non CAD and 194 had invasively excluded CAD. 129 additional patients without suspicion for CAD and without diabetes/smoking were also recruited in the no CAD group. CAD patients had significant lower levels of propionate (median) 6.08 μM (IQR, 4.31–7.65) compared to the no CAD groups 6.92 μM (4.89–9.25, <0.05). Linear regression multivariate analysis adjusted for age, gender, body mass index, hypertension, smoking, diabetes and hyperlipidemia revealed an odds ratio of 0.92 (CI 0.89–0,96, p<0.001) for propionate as predictor of CAD.

Conclusions

The study provides large-scale data for a protective role of propionate in the development of CAD, independent of the presence of other known cardiovascular risk factors.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Internal Grant, Medical School of Brandenburg

Reduced antioxiadant high-density lipoprotein function in patients with acute coronary syndrome

Background

High-density lipoprotein (HDL) function rather than concentration plays an important role in the pathogenesis of cardiovascular diseases associated with oxidative stress and inflammation such as coronary artery disease (CAD). In the last years, inflammation has been identified to have a pivotal role in the pathogenesis of acute coronary syndrome (ACS).

Purpose

The aim of the present study is to determine whether reduced antioxidant function of HDL is associated with ACS.

Methods

197 patients with ACS were prospectively recruited and blood samples were taken in the first 48h after enrollment. Patients with chronic coronary syndrome CCS (n=727) and with invasively excluded CAD (no CAD, n=498) from another cohort from our group served as control patients. A validated cell-free biochemical assay was used to determine reduced HDL antioxidant function as assessed by increased HDL-lipid peroxide content (HDLox) normalized by HDL-C levels and the mean value of a pooled serum control from healthy participants (nHDLox; no units).

Results

Patients with ACS had significantly increased HDLox blood levels compared to patients with CCS and to patients without CAD (p<0.001, Figure 1A). Prior intake of statins did not influenc the differences of HDLox among the groups (Figure 1B). In the regression analysis increased HDLox was a strong risk factor for the presence of ACS compared to CCS (odds ratio 4.09 (2.98–5.62), p<0.001, Figure 2).

Conclusions

HDL peroxidation is associated with the presence of ACS independent of the presence of other traditional risk factors.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): BIOX

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

ICD exchange in the elderly

Background

ICD therapy in elderly patients is controversially discussed, since survival benefits might be attenuated by non-arrhythmic causes of death.

Purpose

This study aimed to investigate the outcome of septua- and octogenarians after ICD generator exchange (GE).

Methods

506 patients undergoing elective GE were analysed to determine the incidence of ICD shocks and survival after GE. For further analysis, patients were divided according to age (70 – 79 or ≥80 years) and previous ICD therapy: patients that did not experience a shock and patients that received at least one shock from prior ICDs.

Results

The effect of the ICD on all-cause mortality and arrhythmic death was determined for two groups (patients with 70 – 79 and ≥80 years). Comparing septua- with octogenarians, similar left ventricular ejection fraction (35.6±11.2% vs. 32.4±8.9%) and baseline prevalence of NYHA class 3 or 4 heart failure (17.1% vs. 14.7%) was found. Older patients were more likely to die of non-arrhythmic death (22% per year vs. 8% per year, p<0.001). We also investigated the necessity of ICD therapy dependent on whether ICD therapy occurred during the previous battery live. Septuagenarians and octogenarians with previous shocks had a higher incidence of further ICD therapy in the following battery life period (41% vs. 19%, p<0.001, and 22% vs. 17%, p<0.001).

Conclusion

Decision making for ICD generator exchange among elderly patients should be considered carefully for an individual patient during clinical practice.

Funding Acknowledgement

Type of funding sources: None.

Investigations regarding the role of NOS1AP in the heart using a conditional overexpression mouse model

Background

35.3% of deaths in 2019 in Germany are caused by cardiovascular diseases (Destatis). 95% of these people were 60 years and older. To increase survival rate in elderly patients we investigate the relevance of altered expression of neuronal nitric oxide synthase 1 (NOS1) adaptor protein (NOS1AP) acting as an L-type calcium channel (CaV1.2) modulator via directing NOS1 to CaV1.2 on cardiac electrophysiology. Genome-wide association studies have linked genetic polymorphisms in NOS1AP to variations in QT interval duration (QTc). The QT interval reflects ventricular de- and repolarization. It may predispose individuals to ventricular tachycardia and sudden cardiac death (SCD) if prolonged, shortened or otherwise unregularly. In addition, about 20% of families with a clinically proven diagnosis of long QT syndrome (LQTS) host no mutation in any of the 16 associated genes.

Methods and results

Transgenic mice with conditional overexpression of NOS1AP in cardiac myocytes were used as model organism. We confirmed the interaction of NOS1AP with NOS1 and CaV1.2. Electrocardiography in NOS1AP overexpressing mice showed atrial and ventricular tachycardia both spontaneously and upon programmed stimulation associated with a significant decrease in QTc. Heart rates in NOS1AP overexpressing mice were similar to non-induced animals. Survival was significantly reduced (only 60% after 12 weeks vs. 100% in non-induced mice). Induced QTc alterations and accompanied deaths subsided upon re-administration of doxycycline.

Whole-cell patch-clamp measurements in isolated adult ventricular myocytes were performed and action potential duration at 90% of repolarization (APD90) was significantly reduced in induced transgenic NOS1AP overexpressing mice compared to control littermates.

In addition, we investigated the functional effect of the human SNP rs16847548 (T/C) located within the NOS1AP promoter. The SNP was found to decrease the transcriptional activity of NOS1AP in vitro and therefore, potentially leading to a decrease in NOS1AP expression in humans.

Conclusion

Myocardial overexpression of NOS1AP leads to short QT syndrome with increased susceptibility to atrial and ventricular arrhythmias and cardiac death. In accordance, APD90 is significantly shortened in overexpressing animals. The human SNP rs16847548, which is located in the promoter region of NOS1AP, results in a reduced NOS1AP promoter activity in vitro, hereby providing an explanation for the frequently published elongation of QT intervals. In summary, not only mutations in ion channels themselves but also genetic alterations in the expression of ion channel modulators such as NOS1AP, have an impact on QTc and arrhythmogenesis and represent a promising therapeutic target for LQTS patients.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Gesundheitscampus Brandenburg (MWFK)

High-density lipoprotein lipid peroxidation in association with presence of coronary artery disease and atrial fibrillation in a large cross-sectional study

Background

The function of high-density lipoprotein (HDL) cholesterol may play a more important role in the prevention of cardiovascular disease compared to the concentration of the HDL. Cardiovascular diseases such as coronary artery disease (CAD) and atrial fibrillation (AF) have been linked to impaired HDL function.

Purpose

The aim of the present study is to assess a biochemical measure of the antioxidant function of HDL and its association with presence of CAD and AF.

Methods

Patients admitted for elective cardiac catheterization were recruited in this cross-sectional study. Out of 1231 participants that were included in the analyses, 727 patients had confirmed CAD (CAD group), 369 patients had no CAD (no CAD group) and 129 persons were included as a control group. HDL function was measured in sera by determination of HDL-lipid peroxidation content (HDLox) assessed by a validated fluorometric cell-free biochemical assay and was normalized for the levels of HDL cholesterol (normalized HDLox/HDL-C ratio or nHDLox; no units). Results are expressed as median with interquartile range. Associations of nHDLox with presence of CAD and AF were assessed by univariate and multivariate analyses.

Results

Participants in the CAD group had higher levels of nHDLox (0.80, 0.61–1.03) compared to the no CAD (0.70, 0.55–0.93) and control (0.66, 0.55–1.03, no units, p<0.001) group. Out of 1206 participants, 233 (19%) had AF and 973 (81%) had no AF. Patients with AF have also higher nHDLox (0.82, 0.60–10.03) compared to persons without AF (0.73, 0.58–0.98, p=0.03). In univariate analysis nHDLox was associated with CAD (p<0.001). In multivariate analysis adjusted for age, gender, CAD, BMI and hypertension, nHDLox was a strong independent predictor of atrial fibrillation (p=0.015) but was not an independent predictor of CAD (p>0.05)

Conclusions

Reduced antioxidant function of HDL (increased HDLox measured by a biochemical assay), a metric of HDL function, is increased in patients with atherosclerosis and manifested CAD and is also associated with the presence of atrial fibrillation independent of the presence of CAD.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Medical School of Brandenburg-MHB Fontane

Effective treatment of electrical storm by a wearable cardioverter defibrillator in a patient with severely impaired left ventricular function after myocardial infarction: a case report

Background

The implantation of cardioverter defibrillators (ICDs) is an established therapy in the prevention of sudden cardiac death in patients with systolic dysfunction after myocardial infarction. To avoid immediate implantation of an ICD, wearable cardioverter defibrillator vests (WCD) can be used to protect patients against malignant rhythm disorders, while at the same time drug-based heart failure therapy has to be initiated. This drug therapy can improve left ventricular ejection fraction and primary prophylactic cardioverter defibrillator implantation may not be necessary. However, the recent Vest Prevention of Early Sudden Death Trial (VEST) questioned the regular use of the WCD in this setting.

Case presentation

A 47-year-old Caucasian man with severely impaired left ventricular function early after myocardial infarction was prescribed a WCD as primary prophylaxis to prevent sudden cardiac death. Seven days after the patient was supplied with a WCD, the patient suffered from an electrical storm with recurrent ventricular tachycardia (VT), which was successfully terminated 17 times by the WCD. On coronary angiography, the formerly infarct-related right coronary artery had TIMI (Thrombolysis in Myocardial Ischemia Trial) III flow, and a remaining stenosis in the left anterior descending artery (LAD) was stented, which did not stop recurrent VT. In the electrophysiology (EP) study, a focus was mapped in the left inferior ventricle, which was ablated. This stopped the VT. A second radio-frequency (RF) ablation in the same area was necessary after 14 days. Finally, a permanent cardioverter defibrillator was implanted.

Conclusion

We report the case of a patient who survived recurrent episodes of VT early after myocardial infarction by effective defibrillation with a WCD. The WCD is a useful device to bridge time until a final decision for implantation of a defibrillator.

AKI Epidemiology and Outcomes: A Retrospective Cohort Study from the Prenephrology Era

BACKGROUND

Acute kidney injury substantially worsens the prognosis of hospitalized patients. The Brandenburg Medical School was founded in 2014, and a nephrology section was opened in summer 2017. The aim of the study was to analyze AKI epidemiology and outcomes in one of two university hospitals belonging to the medical school. The period of interest dated from January to December 2015.

METHODS

The investigation was designed as a single-center, retrospective cohort study at the Brandenburg Hospital of the Brandenburg Medical School. All in-hospital patients treated between January and the end of December 2015 were included. AKI was defined as specified in the 2012 published KDIGO criteria (criteria 1 and 2). Four parameters were evaluated in particular: AKI incidence, in-hospital mortality, frequency of renal replacement therapy, and renal recovery during the stay at the hospital.

RESULTS

A total number of 5,300 patients were included in the analysis. AKI was diagnosed in 490 subjects (10.1%). The in-hospital mortality was 26%. The following conditions/parameters significantly differed between survivors (s) and nonsurviving (ns) subjects: duration of in-hospital treatment (s > ns), AKI onset (outpatient vs. in-hospital) (outpatient in s > ns), dialysis due to AKI (s < ns), vasopressor administration (s < ns), and invasive ventilation (s < ns). 5.6% received dialysis therapy, and renal recovery occurred in 31% of all surviving AKI subjects.

CONCLUSION

Both, the AKI incidence and the frequency of dialysis were lower than reported in the literature. However, fewer subjects recovered from AKI. These discrepant findings possibly result from the lack of prehospitalization creatinine values, the lack of follow-up data, and a generally lower awareness for the need to perform renal replacement therapy in AKI.

Oxidation of HDL in patients with coronary artery disease

 

The function of high-density lipoprotein (HDL) cholesterol may play a more important role in the prevention of cardiovascular disease compared to the concentration of the HDL. The aim of the present study is to assess a novel cell-free test to quantify oxidation of HDL and its association to coronary artery disease (CAD).

We performed a prospective trial by including patients undergoing elective cardiac catheterization and healthy controls. A total of 895 subjects were included. In 483 patients CAD was confirmed (CAD group) and in 241 patients CAD was ruled-out (no CAD). Control patients (n=171) had no known CAD, had no diabetes and were not smokers. HDL function was measured in serum samples by determining its HDL-lipid peroxidation by a novel fluorometric cell-free biochemical assay. HDL lipid peroxide content (HDLox) is adjusted for the HDL cholesterol and has no units.

Patients with confirmed CAD had higher levels of HDLox (0.92±0.58, no units) compared to patients with no CAD (0.8±0.46, no units) and controls (0.78±0.41, no units, p=0.003). HDL-Cholesterol was lower in the CAD group (50.7±17.7mg/dl) compared to no CAD (58.4±17.6mg/dl) and healthy subjects (59.1±15.9mg/dl, p&lt;0.001). HDLox was a strong predictor of coronary artery disease status (odds ratio for coronary disease 1.69; 95% confidence interval [CI], 1.24 to 2.38; P=0.001).

Oxidation of HDL, a metric of HDL function, measured by a cell-free biochemical assay, is increased in patients with CAD and is a predictor of the disease.

Logistic Regression analysis

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Medical School of Brandenburg

The impact of aerobic and isometric exercise on different measures of dysfunctional high-density lipoprotein in patients with hypertension

BACKGROUND

Exercise training increases high-density lipoprotein (HDL) cholesterol, but its effect on HDL function is unclear. In hypertensives, exercise improves endothelial dysfunction, which is related to HDL function. In the present study, we assess for the first time the effects of different exercise modalities on two cell-free assays of HDL function.

DESIGN

The study was conducted as a prospective randomized controlled trial in 75 hypertensive patients.

METHODS

Patients were randomized in three groups: (a) handgrip isometric training five times weekly; (b) placebo-handgrip; and (c) aerobic exercise training at least three times per week. HDL function was assessed in serum samples at baseline and after 12 weeks of training by two independent assays that determine the proinflammatory phenotype (haptoglobin content) of a specific amount of HDL (Haptoglobin-HDL [HPHDL]) and oxidized HDL (HDLox) as a measure of reduced antioxidant function of HDL. HDL function measures were normalized by the measures of a pooled control of sera from healthy participants and by HDL-C levels (normalized ratio, no units).

RESULTS

Aerobic exercise led to significant reduction of the HDLox from 0.99 ± 0.27 to 0.90 ± 0.29 (no units, p = 0.03). The HPHDL did not change in any training group. Changes of HDLox correlated with reduction of the systolic blood pressure only after aerobic exercise (R = 0.64, p = 0.03).

CONCLUSIONS

Aerobic but not isometric exercise improves the antioxidant function of HDL in patients with hypertension. This improvement correlates positively with reductions of blood pressure.

Description of a novel RyR2 mutation in a juvenile patient with symptomatic catecholaminergic polymorphic ventricular tachycardia in sleep and during exercise: a case report

Background

Catecholaminergic polymorphic ventricular tachycardia is an inherited disease presenting with arrhythmic events during physical exercise or emotional stress. If untreated, catecholaminergic polymorphic ventricular tachycardia is a highly lethal condition: About 80% of affected individuals experience recurrent syncope, and 30% experience cardiac arrest. Catecholaminergic polymorphic ventricular tachycardia is caused by mutations in genes encoding ryanodine receptor type 2 (RyR2) and cardiac calsequestrin (CASQ2). In cases of sympathoadrenergic activation, both mutations result in a spontaneous Ca²⁺ release in cardiac cells, facilitating ventricular arrhythmias.

Case presentation

We present a case of a 17-year-old Caucasian boy who survived sudden cardiac death caused by ventricular fibrillation while performing running exercise in a fitness center. The diagnostic workup included blood tests, coronary angiography, electrophysiological testing, and cardiac magnetic resonance imaging, but all results were normal. Because the patient’s medical history included recurrent syncope during physical and emotional stress, we strongly suspected catecholaminergic polymorphic ventricular tachycardia as the underlying disease. Genetic screening was performed and confirmed the diagnosis, revealing a new heterozygous point mutation in the gene for RyR2, c.12520T>A (p.F4174 l, exon 90, RyR2 gene). The patient was discharged from our hospital after undergoing implantation of an implantable cardioverter defibrillator for secondary prevention. Shortly after implantation, the implantable cardioverter defibrillator terminated a sustaining ventricular tachycardia episode by antitachycardic pacing. This episode occurred early in the morning while the patient was asleep.

Conclusions

We present a case of catecholaminergic polymorphic ventricular tachycardia associated with a novel single point mutation in the RyR2 gene, which, to the best of our knowledge, has not been described in the literature so far. Our patient experienced arrhythmic events under both resting conditions and physical activity, an uncommon finding in patients with catecholaminergic polymorphic ventricular tachycardia. This novel mutation may cause arrhythmias independent of sympathoadrenergic stimulation, but further evidence is needed to prove causality.

Autophagy activation in circulating proangiogenic cells aggravates AKI in type I diabetes mellitus

Acute kidney injury (AKI) occurs frequently in hospitals worldwide, but the therapeutic options are limited. Diabetes mellitus (DM) affects more and more people around the globe. The disease worsens the prognosis of AKI even further. In recent years, cell-based therapies have increasingly been applied in experimental AKI. The aim of the study was to utilize two established autophagy inducers for pharmacological preconditioning of so-called proangiogenic cells (PACs) in PAC treatment of diabetic AKI. Insulin-dependent DM was induced in male C57/Bl6N mice by intraperitoneal injections of streptozotocine. Six weeks later, animals underwent bilateral renal ischemia for 45 min, followed by intravenous injections of either native or zVAD (benzyloxycarbonyl-Val-Ala-Asp-fluoro-methylketone)- or Z-Leu-Leu-Leu-al (MG132)-pretreated syngeneic murine PACs. Mice were analyzed 48 h (short term) and 6 wk (long term) later, respectively. DM worsened postischemic AKI, and PAC preconditioning with zVAD and MG132 resulted in a further decline of excretory kidney function. Injection of native PACs reduced fibrosis in nondiabetic mice, but cell preconditioning promoted interstitial matrix accumulation significantly. Both substances aggravated endothelial-to-mesenchymal transition (EndoMT) under diabetic conditions; these effects occurred either exclusively in the short (zVAD) or in the short and long term (MG132). Preconditioned cells stimulated the autophagocytic flux in intrarenal endothelial cells, and all experimental groups displayed increased endothelial abundances of senescence-associated β-galactosidase, a marker of premature cell senescence. Pharmacological autophagy activation may not serve as an effective strategy for improving PAC competence in diabetic AKI in general. On the contrary, several outcome parameters (excretory function, fibrosis, EndoMT) may even be worsened.

Untersuchung der Streuung von Positronen an Elektronen in der Wilsonschen Nebelkammer

In einer "langsamen", mit Methan gefüllten Wilson-Kammer, die hier beschrieben wird, wird die Streuung von Positronen aus Cu64 an Elektronen untersucht. Aus 5000 Aufnahmen mit 2900 m ausgewerteter Positronenbahnlänge wird die Häufigkeit von Stößen mit verschiedener Energieübertragung im Energiebereich 100-400 ekV bestimmt und mit der Theorie von Möller-Bhabha verglichen. Innerhalb der experimentellen Unsicherheit besteht Übereinstimmung zwischen den beobachteten und den berechneten Absolutwerten. Ein Dreierstoß zwischen einem Positron und zwei Elektronen wurde beobachtet.

Pharmacological pre- and post-conditioning with the sphingosine-1-phosphate receptor modulator FTY720 after myocardial ischaemia-reperfusion

BACKGROUND AND PURPOSE

Our recent experiments demonstrated that the Sphingosine-1-phosphate (S1P) receptor agonist FTY720 (2-amino-2-[2-(4-octylphenyl)ethyl]-1,3-propanediol hydrochloride) improves recovery of function after myocardial ischaemia-reperfusion ex vivo. Therefore, we tested the hypothesis that pharmacological post-conditioning with FTY720 reduces infarct size after myocardial ischaemia-reperfusion in vivo.

EXPERIMENTAL APPROACH

Myocardial ischaemia was induced in Wistar rats by ligation of the left coronary artery for 45 min. FTY720 (0.5 mg kg(-1)) was applied i.p. either once, before reperfusion, or twice, 24 h before myocardial ischaemia and before reperfusion. After 24 h reperfusion, we determined infarct size by triphenyltetrazolium chloride staining and granulocyte infiltration by immunohistochemistry. Tumour necrosis factor-alpha (TNF)-alpha concentration was determined by elisa. S1P receptor expression was studied by Western blot. Calcium transients were evaluated in Indo-1-loaded cardiomyocytes.

KEY RESULTS

In both groups, FTY720 significantly reduced lymphocyte count in peripheral blood. FTY720 treatment attenuated granulocyte infiltration and TNF-alpha protein expression in reperfused myocardium. However, both treatment regimens were not able to reduce infarct size. FTY720 increased mortality due to induction of fatal ventricular tachyarrhythmias when administered once before reperfusion, but protected against reperfusion arrhythmias when given 24 h prior to ischaemia. Pretreatment selectively down-regulated S1P(1) receptor expression within the myocardium. S1P receptor agonists did not induce calcium deregulation in cardiomyocytes.

CONCLUSIONS AND IMPLICATIONS

FTY720 applied during reperfusion did not reduce infarct size but increased mortality during myocardial ischaemia-reperfusion due to induction of arrhythmias. Pretreatment with FTY720 before ischaemia abrogated the deleterious pro-arrhythmic effects without reducing infarct size.

Electrical conductivity images of active and fossil fault zones

We compare recent magnetotelluric investigations of four large fault systems: (i) the actively deforming, ocean-continent interplate San Andreas Fault (SAF); (ii) the actively deforming, continent-continent interplate Dead Sea Transform (DST); (iii) the currently inactive, trench-linked intraplate West Fault (WF) in northern Chile; and (iv) the Waterberg Fault/Omaruru Lineament (WF/OL) in Namibia, a fossilized intraplate shear zone formed during early Proterozoic continental collision. These fault zones show both similarities and marked differences in their electrical subsurface structure. The central segment of the SAF is characterized by a zone of high conductivity extending to a depth of several kilometres and attributed to fluids within a highly fractured damage zone. The WF exhibits a less pronounced but similar fault-zone conductor (FZC) that can be explained by meteoric waters entering the fault zone. The DST appears different as it shows a distinct lack of a FZC and seems to act primarily as an impermeable barrier to cross-fault fluid transport. Differences in the electrical structure of these faults within the upper crust may be linked to the degree of deformation localization within the fault zone. At the DST, with no observable fault-zone conductor, strain may have been localized for a considerable time span along a narrow, metre-scale damage zone with a sustained strength difference between the shear plane and the surrounding host rock. In the case of the SAF, a positive correlation of conductance and fault activity is observed, with more active fault segments associated with wider, deeper and more conductive fault-zone anomalies. Fault-zone conductors, however, do not uniquely identify specific architectural or hydrological units of a fault. A more comprehensive whole-fault picture for the brittle crust can be developed in combination with seismicity and structural information. Giving a window into lower-crustal shear zones, the fossil WF/OL in Namibia is imaged as a subvertical, 14 km-deep, 10 km-wide zone of high and anisotropic conductivity. The present level of exhumation suggests that the WF/OL penetrated the entire crust as a relatively narrow shear zone. Contrary to the fluid-driven conductivity anomalies of active faults, the anomaly here is attributed to graphitic enrichment along former shear planes. Once created, graphite is stable over very long time spans and thus fault/shear zones may remain conductive long after activity ceases.

Myokardinfarkt nach Influenza-Schutzimpfung

Influenza is a common disease in the population. Influenza vaccination is performed routinely and is usually well tolerated. Minor local or systemic side effects like fever and myalgia are described. Rarely there are more severe adverse events. Systemic vasculitis has been reported in some cases. In this case we report on a female patient with secondary vasculitis and myocardial infarction after influenza vaccination. The patient received cortisol and recovered. The literature about influenza vaccination, its side effects and recommendations about vaccination in patients with coronary artery disease is reviewed.

Remodeling of the hypertrophied human myocardium by cardiac bHLH transcription factors

The basic helix-loop-helix transcription factors eHAND and dHAND are involved in developmental cardiac growth and differentiation. We investigated HAND gene expression in the normal and in the hypertrophied right and left ventricle of patients with tetralogy of Fallot (ToF) and hypertrophic obstructive cardiomyopathy (HOCM). HAND mRNA was constitutively expressed in the hypertrophied heart and increased in the hypertrophic tissue of both patient groups. HAND genes had a complementary left-right cardiac asymmetry of expression with dHAND predominantly in the right and eHAND in the left ventricle. The two cardiac bHLH factors have the ability to form heterodimers with the ubiquitous bHLH protein E12, subsequently recognizing E-boxes in the promoter region of target genes like ALC-1. We found a highly significant positive correlation between HAND and ALC-1 mRNA. The total ALC-1 protein level in ToF was smaller than in HOCM, although ALC-1 mRNA as well as HAND mRNA levels were significantly higher. ToF patients expressed around four times more ALC-1 mRNA for similar amounts of ALC-1 than HOCM patients. Suggesting disturbed ALC-1 translation in ToF, we found ALC-1 antisense mRNA expression in the hypertrophied, but not in the normal, ventricles. The higher the antisense/sense ALC-1 mRNA ratio, the lower ALC-1 protein was expressed.

Expression of atrial myosin light chains but not alpha-myosin heavy chains is correlated in vivo with increased ventricular function in patients with hypertrophic obstructive cardiomyopathy

The adult rodent heart adapts to increased work load by reexpression of its fetal genes, for example, beta-myosin heavy chain (MHC), in order to improve contractile function. However, the human ventricle regulates contractility by expression of atrial essential myosin light chain (ALC-1) rather than beta-MHC. We evaluated the impact of both mechanisms in patients with hypertrophic cardiomyopathy. MHC isoform expression was quantified at the mRNA and protein levels by reverse transcriptase polymerase chain reaction and immunoblotting, respectively. Although alpha-MHC mRNA was detected in control and hypertrophied human ventricular tissue, alpha-MHC protein was not observed. Similarly, we investigated the expression of ALC-1 by two-dimensional polyacrylamide gel electrophoresis and the clinical and hemodynamic parameters of the patients with hypertrophic cardiomyopathy. We found a significant positive correlation between ALC-1 protein expression and dP/dtmax in the hypertrophied human ventricle in vivo. Correlations between dP/dtmax and expression of protein for the ryanodine receptor and L-type Ca2+ channel were excluded. Our data suggest that reexpression of ALC-1 improves the contractile state of the adult human heart. We propose that two evolutionarily divergent compensatory mechanisms for increased work demand exist in the mammalian heart: MHC regulation in rodents and essential MLC regulation, of cardiac contractility, in humans.

Regulation of Limulus skeletal muscle contraction

Skeletal muscle contraction of Limulus polyphemus, the horseshoe crab, seemed to be regulated in a dual manner, namely Ca2+ binding to the troponin complex as well phosphorylation of the myosin light chains (MLC) by a Ca2+/calmodulin-dependent myosin light chain kinase. We investigated muscle contraction in Limulus skinned fibers in the presence of Ca2+ and of Ca2+/calmodulin to find out which of the two mechanisms prevails in Limulus skeletal muscle contraction. Although skinned fibers revealed high basal MLC mono- and biphosphorylation levels (0.48 mol phosphate/mol 31 kDa MLC; 0.52 mol phosphate/mol 21 kDa MLC), the muscle fibers were fully relaxed at pCa 8. Upon C2+ or Ca2+/calmodulin activation, the fibers developed force (357+/-78.7 mN/mm2; 338+/-69.7 mN/mm2, respectively) while the MLC phosphorylation remained essentially unchanged. We conclude that Ca2+ activation is the dominant regulatory mechanism in Limulus skeletal muscle contraction.

Protein Data Bank (PDB): database of three-dimensional structural information of biological macromolecules

The Protein Data Bank (PDB) at Brookhaven National Laboratory, is a database containing experimentally determined three-dimensional structures of proteins, nucleic acids and other biological macromolecules, with approximately 8000 entries. Data are easily submitted via PDB's WWW-based tool AutoDep, in either mmCIF or PDB format, and are most conveniently examined via PDB's WWW-based tool 3DB Browser.

Information management for complex systems: a case study in genomics

Genome mapping and sequencing projects push the frontiers of molecular biology and genetics toward information science. I will try to demonstrate that the information management characteristics of genome research may apply to other large-scale systematic studies of complex systems such as the brain.

Myosin light chain-actin interaction regulates cardiac contractility

The amino-terminal domain of the essential myosin light chain (MLC-1) binds to the carboxy terminus of the actin molecule. We studied the functional role of this interaction by two approaches: first, incubation of intact and chemically skinned human heart fibers with synthetic peptide corresponding to the sequences 5 through 14 (P5-14), 5 through 8 (P5-8), and 5 through 10 (P5-10) of the human ventricular MLC-1 (VLC-1) to saturate actin-binding sites, and second, incubation of skinned human heart fibers with a monoclonal antibody (MabVLC-1) raised against the actin-interacting N-terminal domain of human VLC-1 using P5-14 as antigen to deteriorate VLC-1 binding to actin. P5-14 increased isometric tension generation of skinned human heart fibers at both submaximal and maximal Ca2+ activation, the maximal effective peptide dosage being in the nanomolar range. A scrambled peptide of P5-14 with random sequence had no effects up to 10(-8) mol/L, ie, where P5-14 was maximally effective. P5-8 and P5-10 increased isometric force to the same extent as P5-14, but micromolar concentrations were required. Amplitude of isometric twitch contraction, rate of tension development, rate of relaxation, and shortening velocity at near-zero load of electrically driven intact human atrial fibers increased significantly on incubation with P5-14. These alterations were not associated with modulation of intracellular Ca2+ transients as monitored by fura 2 fluorescence measurements. Incubation of skinned human heart fibers with MabVLC-1 increased isometric tension at both submaximal and maximal Ca2+ activation levels, having a maximal effective concentration in the femtomolar range.

X-HUSAR, an X-based graphical interface for the analysis of genomic sequences

Management and analysis of nucleotide and protein sequence and structure data constitute a traditional area of bioinformatics. Since the analytical programs are frequently developed by researchers, rather than software engineers, they tend to suffer from idiosyncratic and non-ergonomic man-machine interfaces. We report on HUSAR, our 140+ collection of third-party, as well as in-house developed or adapted, sequence manipulation and analysis tools, well integrated into the UNIX operating system environment and accessible via consistent menu-aware interface. Most of the HUSAR programs can be completely specified by UNIX command-line options; they can thus be run in batches or combined into pipes. Adding such a program into the HUSAR environment is almost a 'plug-and-play' exercise. HUSAR has been recently complemented with a graphical client interface, X-HUSAR, to support users on UNIX platforms with X11 windowing systems. The whole X-HUSAR interface is based on a single generic program, COMLIGEN, and a number of specific configuration files. COMLIGEN interprets those files and renders appropriate windows, menus, and other interactive elements, which help the end user in selecting application programs and specifying their options. Efforts of extending both HUSAR and X-HUSAR are roughly linear to the size of the collection.

Characterizing heterogeneous molecular biology database systems

Molecular biology data are distributed among multiple databases. Although containing related data, these databases are often isolated and are characterized by various degrees of heterogeneity: they usually represent different views (schemas) of the scientific domain and are implemented using different data management systems. Currently, several systems support managing data in heterogeneous molecular biology databases. Lack of clear criteria for characterizing such systems precludes comprehensive evaluations of these systems or determining their relationships in terms of shared goals and facilities. In this paper, we propose criteria that would facilitate characterizing, evaluating, and comparing heterogeneous molecular biology database systems.

Prototype implementation of the integrated genomic database

We aim to develop an open software system to handle human genome data. The system, called Integrated Genomic Database (IGD), will integrate information from many genomic databases and experimental resources into a comprehensive target-end database (IGD TED). Users will access front-end client systems (IGD FRED) to download data of interest to their computers and merge them with their own local data. FREDs will provide persistent storage of, and instant access to, retrieved data; a friendly graphical interface; tools for querying, browsing, analyzing, and editing local data; interface to external analysis; and tools for communicating with the outside world. The TED will be accessible over the network (online and offline) as a read-only resource for multiple clients. It collects data from major databases for nucleotide and protein sequences and structures, genome maps, experimental reagents, phenotypes, and bibliographic data, and sets of raw data produced at genome centers and laboratories. Beside character-based access via Gopher, WAIS, FTP, and several query language interfaces to the TED, we will develop a specialized front-end client, IGD FRED, with its own database manager, based on the ACEDB program. The FRED will support graphical display methods for sequence feature maps, chromosomal genetic and physical maps, and experimental objects like clone grids, etc. FRED will also provide an interface to important analysis software packages and tools for submitting data to external databases in their own format.

Presence of antibody reactive with synthetic peptide derived from L2 open reading frame of human papillomavirus types 6b and 11 in human sera

Nine oligopeptides corresponding to segments of different open reading frame (ORF) proteins of human papillomavirus (HPV) 6b and HPV-16 were prepared and tested for reactivity with human sera in enzyme-immunoassay (ELISA). Of these only heptadecapeptide derived from L2 ORF of HPV-6b, and encoded also by L2 ORF of HPV 11, was reactive with some human sera. Over 400 human sera of different origin were tested for the presence of antibody to this antigen. While less than 15% of sera from healthy subjects or cervical carcinoma patients were found antibody positive, sera from the majority of condylomata accuminata (CA) patients were reactive. The antibody titres varied from 1:10 (initial serum dilution) to 1:80; in this respect there was no marked difference between sera from CA patients and the other subjects. The prevalence of antibody was higher among promiscuous than nonpromiscuous women. This is in line with the assumption that sexual intercourse is the most important route of HPV 6 and 11 transmission.