Association of air pollutants, weather variables, and myocardial infarction incidence in Berlin. A study of the Berlin Brandenburg Myocardial Infarction Registry (B2HIR) based on 17873 cases

Background

Harmful health effects of air pollutants have long been assumed. Respective associations with respiratory diseases have frequently been reported. Recently, studies also pointed at possible links between air pollution and cardiovascular disease. Currently, nitric oxide (NOx) and particulate matter are of concern in Germany.

Purpose

To investigate the association of NOx, particulate matter (PM10), and weather variables with the incidence of myocardial infarction (MI) in Berlin.

Methods

The Berlin Brandenburg myocardial infarction registry (B2HIR) is documenting symptom onset, patient characteristics, comorbidity, procedural data, and outcome of patients with acute MI (onset ≤24h before admission) in Berlin and Brandenburg. From 2008 to 2014 (study period) the stable number of enrolling cardiology departments enabled epidemiologic analyses. Daily (aggregate and variable-specific) MI incidence was assessed for the study period. The government of Berlin provides detailed regional air pollution data (BLUME network). Daily and local NOx and PM10 concentrations were assessed and grouped according to regions (downtown, main roads, suburbs). Preceding days (single and 3 day average) values were also assorted to every single day. Ambient temperature, precipitation, and sunshine duration were assessed from the Berlin-Tempelhof weather station. Bivariate correlations and Poisson regression were calculated to examine associations between air pollutants, weather parameters, and MI incidence.

Results

17873 MI cases were included over 7 years. Bivariate correlations and the Poisson regression model revealed a highly significant independent association of the overall MI incidence with same day NOx concentrations (mean values across all measuring stations) and with average PM10 concentration over three preceding days. Based on regression coefficient and interquartile range of pollutant concentrations, MI incidence variation with same day NOx was 3.2% (p<0.001) and variation with three preceding days PM10 was 4.8% (p<0.001). Daily peak ambient temperature was inversely related to MI incidence (p<0.001), whereas for sunshine duration and precipitations no independent association could be identified. Interestingly, the MI incidence in current smokers was unaffected (p=0.145 and p=0.104, respectively) by NOx and PM10 pollution.

Conclusion

This study is the first to show significant associations between the air pollutants NOx (same day level) and PM10 (3 day preceding average level) and MI incidence in Berlin. MI incidence varied with these pollutants at single digit percentage points. A causal relationship appears likely, as continuously self-intoxicating smokers did not exhibit this association.

Funding Acknowledgement

Type of funding sources: None.

[Constellations of findings and derived treatment interventions in telemedical monitoring of patients with heart failure, cardiac arrhythmia or increased risk for sudden cardiac death : Recommendations of the working group 33 telemonitoring of the German Cardiac Society]

The specification of standard operating procedures (SOPs) is a basic requirement for a successful implementation of telemonitoring with implanted cardiac devices and with external measuring devices in patients with heart failure, cardiac arrhytmia or increased risk of sudden cardiac death. The following article summarizes the possibilities of telemonitoring from a technical and organizational point of view and descibes basic requirements on SOPs. these basic requirements should be further specified and anchored in the organizational structure of the individual telemonitoring concept. Moreover, they should de understood as a basic guideline fpr the actions of telemonitoring center (TMC) employees.

[The telemedical service centre as an essential element of the conceptual approach for telemonitoring of cardiac patients : Requirements on the service, quality, and technical realization of telemonitoring]

Telemonitoring as part of a treatment strategy supports and facilitates the monitoring, disease management and education of patients with heart failure and cardiac arrhythmias. Therefore, telemonitoring affects quality and success of the therapy. Thus, meeting the needs of the patients and of the involved health care professionals is important for the success of the telemonitoring service. Moreover, a high quality of the service has to be ensured. The following article describes several configuration options for telemonitoring services considering technical as well as quality- and service-related aspects.

Untersuchungen über Isopolychromate

The infra-red absorption spectrum and laser raman spectrum of crystalline potassium trichromate are reported and compared with the corresponding spectra of potassium dichromate. It is shown that the state of aggregation of acid and concentrated aqueous chromate solutions can be investigated by use of laser raman spectroscopy. Trichromate ions are found to exist in acid dichromate solutions having concentrations ≧ 3 M and acidity pH ≪ 0, and in aqueous solutions of chromium trioxide provided concenrations are ≧ 2 M.

[Cardiac resynchronization in narrow QRS and less affected exercise capacity]

Cardiac resynchronization (CRT) through atrio-biventricular pacemaker therapy is now a well established treatment option for severely symptomatic patients with advanced systolic heart failure (HF) and intraventricular conduction delay, especially left bundle branch block. The purpose of this article is to address possible applications of biventricular pacing beyond the classical CRT indication. In particular, a summary is given of available information on CRT in patients with symptomatic systolic HF, but narrow QRS complex, and those with wide QRS, but less pronounced or even absent clinical HF signs.

Bifocal versus unifocal right atrial pacing under plasma level controlled sotalol to prevent atrial fibrillation in patients with symptomatic sinus bradycardia and paroxysmal atrial fibrillation

AIMS

Bifocal right atrial pacing (BP) has been reported to increase arrhythmia-free intervals in patients with paroxysmal atrial fibrillation (PAF) under antiarrhythmic drugs. This study compares AF burden with unifocal pacing (UP) vs BP under sotalol.

METHODS

In 19 patients with PAF a DDDR pacemaker with right atrial lateral and CS ostial leads was implanted. Sotalol was initiated. After a 3 month back-up pacing period patients were randomized to continuous UP or BP for 3 months and crossed over for 3 more months. Primary endpoint was AF burden. Secondary endpoints included number of episodes, time to first recurrence and safety of BP.

RESULTS

The intention to treat analysis revealed 12.4% AF during back-up, 6.2% during UP and BP (p=0.91 UP vs BP, p=0.08 back-up vs UP and p=0.07 back-up vs BP). Per protocol analysis showed no advantage of either pacing mode (UP 4.8% and BP 5.4% AF, p=0.64). Overdrive pacing reduced AF burden to 6.2 vs 8.8% during back-up (p=0.09). Septal lead dislodgement occurred in 3 patients.

CONCLUSION

Atrial pacing tends to reduce AF burden in patients with PAF under sotalol. An incremental effect of BP vs UP cannot be confirmed. BP may be complicated by elevated lead dislodgement rates.

Evidence for parallel photocycles and implications for the proton pump in bacteriorhodopsin

In order to account for the large variety of kinetic phenomena in the light-induced reactions of bacteriorhodopsin's retinal chromophore (BR), a scheme of parallel photocycles has been proposed [W. Eisfeld, C. Pusch, R. Diller, R. Lohrmann and M. Stockburger, Biochemistry, 32 (1993) 7196-7215]. In the present study an experimental test for the validity of this model is described which is based on the fact that in the alkaline region the longest-living intermediates M(f), M(S) or N in each of the proposed cycles have significantly different lifetimes. A condition for the existence of parallel cycles would be that the population of M(f), M(S) or N is accompanied by a respective depletion of BR in each individual cycle. Dual-beam laser experiments were performed which showed that this condition is fulfilled. It is concluded that those proton transfer steps which are important for the function as a proton pump are the same for all cycles.

[Strategies to avoid complications and to solve technical problems during the implantation of CRT and CRT-D systems]

Cardiac resynchronization with or without antitachycardiac treatment is now an established option to improve the functional status, morbidity and mortality of patients with severe symptomatic systolic heart failure, ventricular conduction delay and asynchrony. Increasing implant numbers are to be expected. The transvenous left ventricular lateral lead placement can now be achieved in up to 97% of patients. But due to the coronary venous anatomy it may still constitute a challenge even for experienced pacemaker and ICD implanters. In addition, it confers a considerable risk for complications like coronary sinus dissection and perforation, diaphragmatic stimulation and lead dislodgement. An overview is given on possible technical problems, solutions, complications and preventive strategies.

Akuttherapie anhaltender hämodynamisch tolerierter Kammertachykardien

Sustained monomorphic ventricular tachycardia is a potentially life-threatening ventricular tachycardia. The arrhythmia can be treated with antiarrhythmic drugs, when the patient is hemodynamically stable. Class IC antiarrhythmic drugs like flecainide and propafenon or ajmaline (class IA/IC) are very effective. The use of lidocaine is obsolete. Sotalol is also effective, however, caution is advised because of its significant beta-sympatholytic properties. Amiodaron is frequently used, although it has never been studied in the setting of stable ventricular tachycardia. Earlier studies have demonstrated that it is effective in the treatment of recurrent, hemodynamically unstable ventricular tachycardia. When a particular drug does not terminate tachycardia, further drugs should not be given. Electrical cardioversion is preferred.

Time and pH dependence of the L-to-M transition in the photocycle of bacteriorhodopsin and its correlation with proton release

The pH dependence of the L-to-M transition in the photocycle of bacteriorhodopsin was studied in pump-probe resonance Raman (RR) flow experiments in the range pH 3.5-7.8 on a time scale of 0-700 micros. For pH < 5, following the initial decay of L to M, the two intermediates approach nearly constant levels. From a specially designed perturbation-relaxation experiment at pH 4.6, in which the composition of L and M is perturbed by photoreversal of M, it could be concluded that the incomplete decay of L is due to an intermediate equilibration between L and M. It was found, by both RR and optical transient spectroscopy, that the maximum level of M (approximately 500 micros) increases with pH according to a pKa of 5. 6 (150 mM Na+). Since the proton release from an internal group XH to the extracellular surface is determined by nearly the same pKa of 5.7 [Zimanyi, L., Varo, G., Chang, M., Ni, B., Needleman, R., and Lanyi, J. K. (1992) Biochemistry 31, 8535-8543], it is concluded that this increase is controlled by the dissociation of XH. From the analysis of the perturbation-relaxation experiments and the multiexponential rise of M, a kinetic scheme with two sequential L-M equilibria is proposed for the L-M transition. By comparison with the time behavior of proton release [Heberle, J., and Dencher, N. A. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 5996-6000], it is suggested that it is the second equilibrium which is further shifted toward the M state by the dissociation of XH. From the magnitude of this shift, it is concluded that the L-M transition and proton release are not as strongly coupled as is generally assumed. Instead, it is proposed that structural changes during the photocycle are the dominating factors which reduce the pKa of XH to approximately 5.7 so that proton release becomes possible under normal conditions.

Sensory rhodopsin I photocycle intermediate SRI380 contains 13-cis retinal bound via an unprotonated Schiff base

Sensory rhodopsin I (SRI), the mutated derivative SRI-D76N and the complex of SRI with its transducer HtrI were overexpressed in Halobacterium salinarium and analyzed by resonance Raman spectroscopy. In the initial state SRI contains all-trans retinal bound via a protonated Schiff base as confirmed by retinal extraction which yields 95 +/- 3% all-trans retinal. The photocycle intermediate absorbing maximally at 380 nm (SRI380) contains a Schiff base linkage between the protein and 13-cis retinal. Extraction of illuminated SRI yields up to 93% 13-cis retinal. Neither the mutation D76N nor HtrI changed the vibrational pattern of the chromophore.

Resonance Raman and optical transient studies on the light-induced proton pump of bacteriorhodopsin reveal parallel photocycles

The photocycle of bacteriorhodopsin (bR) was studied at ambient temperature in aqueous suspensions of purple membranes using time-resolved resonance Raman (RR) and optical transient spectroscopy (OTS). The samples were photolyzed, and the fractional concentrations of the retinylidene chromophore in its parent state, BR570, and in the intermediate states L550, M412, N560, and O640 were determined in the time domain 20 microseconds-1 s and in the pH range 4-10.5. Two kinetically different L components could be identified. At pH 7 one fraction of L (approximately 65%) decays in 80 microseconds to M (deprotonation of the Schiff base), whereas the residual part is converted in approximately 0.5 ms to N. The RR spectra reveal only minor structural changes of the chromophore in the L-->N transition. These were attributed to a conformational change of the protein backbone [Ormos, P., Chu, K., & Mourant, J. (1992) Biochemistry 31, 6933]. With decreasing pH the L-->N transition is delayed to > 2 ms following a titration-like function with pKa approximately 6.2. The decay of M412 monitored by OTS can be fitted for each pH value by two different amplitudes and time constants (Mf, tau f; Ms, tau s; f = fast, s = slow). Both Mf and Ms consist of subcomponents which can be distinguished by their different reaction pathways (but not by OTS). Mf occurs in the reaction sequences L-->Mf-->N-->BR and L-->Mf-->O-->BR. The population of the first sequence, in which N is formed with the time constant tau f (approximately 2-4 ms, pH 6-10.5), increases with pH. Ms is also found in two different reaction sequences of the form L-->Ms-->BR. The quantitative analysis reveals that each "titration effect" can be related to a certain fraction of bR. It is proposed that each fraction can be identified with a "subspecies" of bR which undergoes an independent and individual cyclic reaction. A complete reaction scheme is set up which represents the manifold of observed phenomena. It is concluded from the pH dependence of the lifetimes of Ms and N that the reconstitution of BR570 in the reaction steps Ms-->BR and N-->BR requires the uptake of a proton from the external phase. It is argued that this proton catalyzes the reisomerization of retinal, whereas the Schiff base is internally reprotonated from Asp-85. A model for proton pumping is proposed in which the proton taken up from the external phase to catalyze the reisomerization of retinal is the one which is pumped through the membrane during the photocycle of bR.

Cytochrome c at charged interfaces. 2. Complexes with negatively charged macromolecular systems studied by resonance Raman spectroscopy

We have analyzed the structure of cytochrome c (cyt c) bound in a variety of complexes in which negatively charged molecular groups interact with the positively charged binding domain around the heme crevice of cyt c. Using resonance Raman spectroscopy, we could demonstrate that these interactions induce the same conformational changes as they were observed in the surface-enhanced resonance Raman experiments of cyt c adsorbed on the Ag electrode [Hildebrandt & Stockburger (1989) Biochemistry (preceding paper in this issue)]. When cyt c is bound to (As4W40O140)27-, state II is stabilized, whereas in complexes with phosvitin and cytochrome b5 state I is formed. The complexes with phospholipid vesicles and inverted micelles reveal a mixture of both states. It is suggested that these systems as well as cyt c adsorbed on the Ag electrode may be regarded as model systems for the physiological complexes of cyt c with cytochrome oxidase and cytochrome reductase. On the basis of our findings it is proposed that the biological electron-transfer reactions are controlled by electric field induced conformational transitions of cyt c upon complex formation with its physiological redox partners.

Cytochrome c at charged interfaces. 1. Conformational and redox equilibria at the electrode/electrolyte interface probed by surface-enhanced resonance Raman spectroscopy

The structure and the electron-transfer properties of cytochrome c (cyt c) absorbed on a silver electrode were analyzed by surface-enhanced resonance Raman spectroscopy. It was found that the absorbed cyt c exists in various conformational states depending on the electrode potential. In state I the native structure of the heme protein is fully preserved and the redox potential (+0.02 V vs saturated calomel electrode) is close to the value for cyt c in solution. In state II the heme iron exists in a mixture of five-coordinated high-spin and six-coordinated low-spin configurations. It had been shown that these configurations form a thermal equilibrium [Hildebrandt, P., & Stockburger, M. (1986) J. Phys. Chem. 90,6017]. It is demonstrated that these equilibria strongly depend on the charge distribution within the electrical double layer of the silver electrode/electrolyte interface, indicating that the changes in the coordination shell are induced by electrostatic interactions. The structural alterations in state II are apparently restricted to the heme crevice, which assumes an open conformation compared to the close structure in state I. This leads to a strong decrease of the redox potentials, which were determined to be -0.31 and -0.41 V for the five-coordinated high-spin and six-coordinated low-spin configurations, respectively. On the other hand, gross distortions of the protein structure can be excluded since the reversible proton-induced conformational change of cyt c as found in solution at low pH also takes place in state II of the absorbed cyt c. The linkage of cyt c molecules to the surface is mediated by charged amino acid groups, and it depends on the potential which groups are thermodynamically favored to form such a molecular binding site. The conformational states I and II, which are in potential-dependent equilibrium, therefore refer to two different molecular binding sites. At potentials below zero charge (less than approximately -0.6 V) a rapid denaturation of the absorbed cyt c is noted, which is reflected by drastic and irreversible changes in the surface-enhanced resonance Raman spectrum. Our results are discussed on the background of previous electrochemical studies of cyt c at electrodes.

Resonance Raman study of the cytochrome P-450 LM2-halothane intermediate complex

Resonance Raman (RR) and absorption spectroscopic studies of purified rabbit liver cytochromes P-450 show that the form 2 isomer (LM2) but not the form 4 isomer (LM4) forms a long-lived complex with halothane after dithionite reduction, absorbing light at 470 nm, in which ferric 6-coordinated heme iron in the low-spin configuration is liganded to 2-chloro-1,1-difluoroethylene. The RR data exclude the possibility that the CF3CHCl- carbanion is a ligand and are consistent with the involvement of an active-site pocket in the cytochrome P-450 polypeptide.

Surface enhanced resonance Raman study of phenobarbital-induced rabbit liver cytochrome P-450 LM2

Surface enhanced resonance Raman (SERR) spectroscopy has been used to study the vibrational spectra of the heme of purified rabbit liver cytochrome P-450 LM2 which was adsorbed on colloidal silver suspensions or on a silver electrode. Bases on a comparison with the resonance Raman (RR) spectra of the 'solute' species the high sensitivity of the SERR technique is demonstrated. Two different features were chosen in order to determine the structural and functional integrity of the adsorbed P-450. Both, substrate-induced spin state changes on the oxidized P-450 and the effect of the thiolate ligand on the oxidation state marker band v4 in the reduced P-450 could be observed in the SERR spectra of the adsorbed as well as in the RR spectra of the dissolved enzyme. These findings indicate that the protein structure near the substrate binding site and the coordination by thiolate are not affected by the interaction with the metal surface. Both structural elements are crucial for the function of P-450. Thus the elementary processes of the enzymatic action of P-450 can be investigated by this highly sensitive version of RR spectroscopy.

Structure of bacteriorhodopsin in the acidified membrane and at high ionic strength: resonance Raman study

Resonance Raman (RR) spectra of the retinylidene Schiffs base (SB) chromophore of bacteriorhodopsin (BR) were obtained from purple membrane (PM) suspensions of Halobacteriumhalobium in three different equilibrium states: (1) the native state at neutral pH; (2) BR-605, the acidified membrane at pH 2; (3) BR-565(Cl−) or BR-545 (F−), at low pH and high ionic strength. In the native state the retinyl chromophore is stabilized by an ion-pair complex of the protonated SB group with a negative carboxylate counterion (A−) of the protein, giving [Formula: see text]. In the acidic form, BR-605, it is inferred from the RR spectra that the chromophore is immobilized. This is ascribed to a breakdown of the ionic interaction by protonation of A−. In the two (3) forms the RR spectra show that the original structure of the chromophore in the native state is reestablished, which is attributed to the formation of [Formula: see text] complexes with the anions. It thus turns out from RR spectroscopic evidence that the retinyl chromophore in BR is largely governed by the [Formula: see text] ion-pair formation, which is stabilized by surrounding water molecules.

Photochemical cycle of bacteriorhodopsin studied by resonance Raman spectroscopy

Individual species of the photochemical cycle of bacteriorhodopsin, a retinal-protein complex of Halobacteria, were studied in aqueous suspensions of the "purple membrane" at room temperature by resonance Raman (RR) spectroscopy with flow systems. Two pronounced deuterium shifts were found in the RR spectra of the all-trans complex BR-570 in H2O-D2O suspensions. The first is ascribed to C=NH+ (C=ND+) stretching vibrations of the protonated Schiff base which links retinal to opsin. The second is assigned tentatively to an "X-H" ("X-D") bending mode, where "X" is an atom which carries an exchangeable proton. A RR spectrum of the 13-cis-retinal complex "BR-548" could be deduced from spectra of the dark-adapted purple membrane. The RR spectrum of the M-412 intermediate was monitored in a double-beam pump-probe experiment. The main vibrational features of the intermediate M' in the reaction M-412 in equilibrium hv M' leads to delta BR-570 could be deduced from a photostationary mixture of M-412 and M'. Difference procedures were applied to obtain RR spectra of the L-550 intermediate and of two new long-lived species, R1'-590 and R2-550. From kinetic data it is suggested that T1'-590 links the proton-translocating cycle to the "13-cis" cycle of BR-548. The protonation and isomeric states of the different species are discussed in light of the new spectroscopic and kinetic data. It is found that conformational changes during the photochemical cycle play an important role.