Alexander Reinecke

Detection of Diverse Bacterial Signatures in Atherosclerotic Lesions of Patients With Coronary Heart Disease

Background— Bacterial infection has been discussed as a potential etiologic factor in the pathophysiology of coronary heart disease (CHD). This study analyzes molecular phylogenies to systematically explore the presence, frequency, and diversity of bacteria in atherosclerotic lesions in patients with CHD. Methods and Results— We investigated 16S rDNA signatures in atherosclerotic tissue obtained through catheter-based atherectomy of 38 patients with CHD, control material from postmortem patients (n=15), and heart-beating organ donors (n=11) using clone libraries, denaturating gradient gel analysis, and fluorescence in situ hybridization. Bacterial DNA was found in all CHD patients by conserved PCR but not in control material or in any of the normal/unaffected coronary arteries. Presence of bacteria in atherosclerotic lesions was confirmed by fluorescence in situ hybridization. A high overall bacterial diversity of >50 different species, among them Staphylococcus species, Proteus vulgaris, Klebsiella pneumoniae, and Streptococcus species, was demonstrated in >1500 clones from a combined library and confirmed by denaturating gradient gel analysis. Mean bacterial diversity in atheromas was high, with a score of 12.33±3.81 (range, 5 to 22). A specific PCR detected Chlamydia species in 51.5% of CHD patients. Conclusions— Detection of a broad variety of molecular signatures in all CHD specimens suggests that diverse bacterial colonization may be more important than a single pathogen. Our observation does not allow us to conclude that bacteria are the causative agent in the etiopathogenesis of CHD. However, bacterial agents could have secondarily colonized atheromatous lesions and could act as an additional factor accelerating disease progression.

Tissue-Specific Expression of a Rat Renin Transcript Lacking the Coding Sequence for the Prefragment and Its Stimulation by Myocardial Infarction1

An alternative transcript of the rat renin gene was recently characterized in the adrenal gland, in addition to the known messenger RNA (mRNA) coding for preprorenin. In the alternative transcript, exon 1 is replaced by exon 1A, a domain originating in intron 1. The reading frame of this mRNA, termed exon 1A-renin transcript, codes for a truncated prorenin that presumably remains intracellular, in contrast to preprorenin, which is targeted to the secretory pathway by its prefragment. We here demonstrate the tissue-specific regulation of expression of both transcripts by RT and PCR. In many tissues both transcripts are present, for example in the adrenal gland, spleen, liver, and hypothalamus. In some organs, however, only one of the renin mRNAs is found. In the kidney only the full-length mRNA coding for preprorenin is detected. In the heart exclusively the exon 1A-mRNA is expressed, but not the preprorenin transcript. After myocardial infarction, which is known to activate the intracardiac renin-angioten...

Functional, biochemical, and molecular investigations of renal kallikrein-kinin system in diabetic rats.

A reduction of renal kallikrein has been found in non-insulin-treated diabetic individuals, suggesting that an impaired renal kallikrein-kinin system (KKS) contributes to the development of diabetic nephropathy. We analyzed relevant components of the renal KKS in non-insulin-treated streptozotocin (STZ)-induced diabetic rats. Twelve weeks after a single injection of STZ, rats were normotensive and displayed hyperglycemia, polyuria, proteinuria, and reduced glomerular filtration rate. Blood bradykinin (BK) levels and prekallikrein activity were significantly increased compared with controls. Renal kallikrein activity was reduced by 70%, whereas urinary BK levels were increased up to threefold. Renal kininases were decreased as indicated by a 3-fold reduction in renal angiotensin-converting enzyme activity and a 1.8-fold reduction in renal expression of neutral endopeptidase 24.11. Renal cortical expression of kininogen and B2receptors was enhanced to 1.4 and 1.8-fold, respectively. Our data suggest that increased urinary BK levels found in severely hyperglycemic STZ-diabetic rats are related to increased filtration of components of the plasma KKS and/or renal kininogen synthesis in combination with decreased renal kinin-degrading activity. Thus, despite reduced renal kallikrein synthesis, renal KKS is activated in the advanced stage of diabetic nephropathy.A reduction of renal kallikrein has been found in non-insulin-treated diabetic individuals, suggesting that an impaired renal kallikrein-kinin system (KKS) contributes to the development of diabetic nephropathy. We analyzed relevant components of the renal KKS in non-insulin-treated streptozotocin (STZ)-induced diabetic rats. Twelve weeks after a single injection of STZ, rats were normotensive and displayed hyperglycemia, polyuria, proteinuria, and reduced glomerular filtration rate. Blood bradykinin (BK) levels and prekallikrein activity were significantly increased compared with controls. Renal kallikrein activity was reduced by 70%, whereas urinary BK levels were increased up to threefold. Renal kininases were decreased as indicated by a 3-fold reduction in renal angiotensin-converting enzyme activity and a 1.8-fold reduction in renal expression of neutral endopeptidase 24.11. Renal cortical expression of kininogen and B2 receptors was enhanced to 1.4 and 1. 8-fold, respectively. Our data suggest that increased urinary BK levels found in severely hyperglycemic STZ-diabetic rats are related to increased filtration of components of the plasma KKS and/or renal kininogen synthesis in combination with decreased renal kinin-degrading activity. Thus, despite reduced renal kallikrein synthesis, renal KKS is activated in the advanced stage of diabetic nephropathy.

Cardioprotective effects of the Na+/H+-exchange inhibitor cariporide in infarct-induced heart failure

OBJECTIVE We investigated the effect of chronic treatment with the new Na(+)/H(+)-exchange inhibitor, cariporide, on cardiac function and remodelling 6 weeks after myocardial infarction (MI) in rats. METHODS Treatment with cariporide was commenced either 1 week pre or 30 min, 3 h, 24 h or 7 days after ligation of the left ventricular artery and was continued until haemodynamic parameters were obtained 6 weeks after MI in conscious rats. RESULTS Compared to sham animals, untreated MI-controls developed pronounced heart failure after 6 weeks. Basal left ventricular end-diastolic pressure (in mmHg) was reduced in the groups in which cariporide was started 1 week pre (16.0+/-1.7) or 30 min (12.5+/-1.1), 3 h (11.8+/-1.0) and 24 h (13.0+/-2.5) after MI compared to untreated MI-controls (22. 4+/-1.5; P<0.01). Basal myocardial contractility (in 1000 mmHg/s) was only increased when treatment was initiated after 30 min (9. 0+/-0.7), 3 h (8.5+/-0.3) and 24 h (8.0+/-0.7) compared to untreated MI-controls (5.8+/-0.7; P<0.05-0.01). Infarct size (in % of left ventricular circumference) was 40.0+/-2.1 in MI-controls and was decreased when treatment was begun after 30 min (32.6+/-2.7) or 3 h (32.4+/-2.3) (P<0.05). In animals, in which cariporide was started 3 h after induction of MI, heart weight/body weight ratio was significantly decreased, indicating reduced cardiac hypertrophy. When treatment started 7 days after MI, cariporide did not exert any beneficial actions on structural and functional cardiac parameters. CONCLUSION Our results show for the first time that chronic treatment with the Na(+)/H(+)-exchange inhibitor cariporide engendered marked cardioprotective effects when commenced before and up to 24 h after MI. The optimal time for the start of treatment was between 30 min and 3 h post MI.

Multipotent Cells of Monocytic Origin Improve Damaged Heart Function

Recently, we generated cells with multipotent properties from blood monocytes that in vitro differentiate into various somatic cell types. This experimental study investigated whether these programmable cells of monocytic origin (PCMO) succeed to restore left ventricular function after myocardial infarction (MI).

Kinins are involved in the antiproteinuric effect of angiotensin-converting enzyme inhibition in experimental diabetic nephropathy.

The present study examined non-insulin-treated streptozotocin (STZ)-induced diabetic rats to determine the role of kinins in diabetic nephropathy. Their involvement in the renoprotective effect of the angiotensin-converting enzyme inhibitor (ACEI) ramipril was investigated using the bradykinin (BK) B(2)-receptor antagonist, icatibant (HOE 140), or a combination of the two drugs.Although, none of the treatments prevented the decline of the glomerular filtration rate (GFR) in diabetic rats, ramipril (3 mg/kg/day), but not icatibant (HOE 140; 500 microg/kg/day), prevented proteinuria in these animals. However, the antiproteinuric effect of ramipril was reduced by 45% when combined with icatibant. To explore whether the renal kallikrein-kinin system (KKS) belongs to the underlying mechanisms of these findings, we also determined urinary BK levels, renal kallikrein (KLK) and angiotensin-converting enzyme (ACE) activity as well as renal cortical mRNA levels of neutral endopeptidase 24.11 (NEP) and low-molecular weight (LMW) kininogen. STZ led to a reduction of renal KLK and ACE activity and NEP expression and to a three-fold increase of urinary BK excretion and renal kininogen expression. Icatibant given alone had no effect on these parameters. In contrast, ramipril treatment normalized urinary protein and BK excretion as well as kininogen mRNA expression without affecting NEP mRNA expression or KLK and ACE activity. Our data demonstrate that renal BK is increased in severe STZ-induced diabetes mellitus, but may affect glomerular regulation only to a minor degree under this condition. However, kinins are partly involved in the antiproteinuric action of ACEI at this stage of diabetic nephropathy.

Bradykinin excretion is increased in severely hyperglycemic streptozotocin-diabetic rats

The renal kallikrein-kinin system (KKS) was studied in pair-fed streptozotocin (STZ)-induced diabetic rats and compared with age-matched controls. Twelve weeks after STZ injection, rats were normotensive, showed hyperglycemia, proteinuria, polydipsia and reduced glomerular filtration rate (GFR) and body weight. The activities of urinary prekallikrein (PKLK) and kallikrein (KLK) were reduced accompanied by an up to 3-fold increase of bradykinin (BK) excretion compared to controls. The increased BK excretion suggests that the renal KKS in STZ-diabetes is activated and that the reduction in urinary PKLK and KLK activity may be due to an increased consumption of these enzymes or to a negative feedback mechanism. The stimulation of the renal KKS in STZ-diabetes could reflect an attempt of the organism to balance glomerular hypertension.

Effects of endothelin ETA receptor blocker LU 135252 on cardiac remodeling and survival in a hypertensive rat model of chronic heart failure

AbstractAim:To investigate whether the endothelin ETA receptor blocker provides similar benefit on cardiac remodeling and survival in a hypertensive rat model of chronic heart failure (CHF).Methods:Male stroke-prone spontaneously hypertensive (SHR-SP) rats were subjected to permanent ligation of the left coronary artery and were treated for 6 weeks with the endothelin ETA receptor blocker LU 135252 (30 mg·kg−1·d−1) starting 24 h after ligation or untreatment. Sham-operated rats served as normal controls. The mean arterial blood pressure (MAP), heart rate (HR), left ventricular end-diastolic pressure (LVEDP), left ventricular contractility (LV dp/dtmax), left ventricular inner diameter (LVD) and circumference (LVC), septal thickness, left ventricular interstitial collagen content (ICC) and heart weight (HW) were measured at the end of the treatment.Results:Compared with the untreated group, LU 135252 tended to increase HW (1.43 ± 0.03 vs 1.38 ±0.04 g; P>0.05), increased LVD (7.65±0.24 mm vs 6.58±0.14 mm; P<0.05), markedly increased LVC (30.11±0.83 mm vs 24.82±0.85 mm; P<0.01) and reduced left ventricular ICC (3.79%±0.09% vs 6.71%±0.11%; P<0.01), slightly lowered MAP (132±6 mmHg vs 142±4 mmHg; P>0.05), reduced LVEDP (14 4 mmHg vs 27±4 mmHg; P<0.05) and improved LV dp/dtmax(4230±450 mmHg/s vs 1950±400 mmHg/s; P<0.05); survival was not prolonged significantly (13% vs 11%; P=NS).Conclusion:In this hypertensive rat model of CHF, chronic endothelin ETA receptor blockade with LU 135252 improves cardiac hemodynamics, however, it does not affect long-term survival and worsens cardiac remodeling. Thus, endothelin ETA receptor antagonists are unlikely to have an important role in the management of patients with CHF.

Akutes Koronarsyndrom durch Diclofenac induzierte Koronarspasmen

We report about a 67-year old man, who was submitted to our clinic with acute coronary syndrome. The cardiac catheterization showed a proximal thrombus in the left anterior descending (LAD). The other coronary arteries did not have significant lesions. After percutaneous transluminal coronary angioplasty with stent-implantation into the proximal LAD the patient remained clinically stable. Cardiac enzymes confirmed no myocardial necrosis. Three days after the acute coronary syndrome the patient developed a podagra, which was treated with colchicinum, diclofenac and local cooling. Five hours after initial therapy the patient developed severe symptoms of angina pectoris and electrocardiographical signs of an acute posterior and anterior myocardial infarction. Immediate coronary angiography demonstrated extended vasospasm of the right coronary artery. Intracoronary application of verapamil and nitroglycerin resolved the coronary spasm. The patient reported about a self-indicated application of diclophenac six hours before hospital admission. This case demonstrates that oral application of diclofenac can provoke coronary vasospasm. Wir berichten über einen 67-jährigen Patienten, der mit dem Bild eines akuten Vorderwandmyokardinfarktes im Rahmen eines akuten Koronarsyndroms in die Klinik eingeliefert wurde. Die sofort durchgeführte Herzkatheteruntersuchung zeigte einen frischen Thrombus im proximalen Ramus interventrikularis anterior (RIVA) bei sonst unauffälligen Koronararterien. Nach PTCA mit Stent-Implantation in den proximalen RIVA war der Patient vollkommen beschwerdefrei. Die CK, CKMB sowie das Troponin T blieben im Normbereich. Im Verlauf entwickelte der Patient eine Podagra des rechten Großzehengrundgelenkes, welches mit Colchicin, Diclofenac und lokaler Kühlung behandelt wurde. Fünf Stunden nach Gabe von Colchicin sowie Diclofenac klagte der Patient über heftige Angina pectoris-Symptomatik mit elektrokardiographischen Zeichen eines akuten Hinterwand- und Vorderwandmyokardinfarktes. Eine erneute durchgeführte Herzkatheteruntersuchung zeigte ausgeprägte Vasospasmen der rechten Koronararterie. Nach intrakoronarer Verapamil- und Nitroglycerin-Gabe waren die Koronarspasmen deutlich rückläufig und der Patient war beschwerdefrei. Anamnestisch berichtete der Patient, dass er am Abend ca. 6 h vor dem akuten Koronarsyndrom ebenfalls Diclofenac eingenommen hätte. Bei zweimaliger in unmittelbarem Zusammenhang mit der Diclofenac-Einnahme stehenden akuten Koronarsymptomatik ist von einem Diclofenac induziertem Vasospasmus auszugehen.

Prevalence, Diagnosis, Perioperative Monitoring and Treatment of Right Ventricular Dysfunction and/or Pulmonary Arterial Hypertension in Cardiac Surgical Patients in Germany—A Postal Survey

Background Sparse data are available on the prevalence of right ventricular dysfunction and/or pulmonary arterial hypertension in patients scheduled for cardiac surgery in Germany as well as on the intensity and modalities used for diagnosis, perioperative monitoring, and treatment of these comorbidities. Methods A postal survey including questions on the prevalence of preoperative right ventricular dysfunction and/or pulmonary arterial hypertension in patients undergoing cardiac surgery in 2009 was sent to 81 German heart centers. Total 47 of 81 (58%) heart centers returned the questionnaires. The centers reported data on 51,095 patients, and 49.8% of the procedures were isolated coronary artery bypass grafting. Results Data on the prevalence of preoperative pulmonary hypertension and/or right ventricular dysfunction were not available in 54% and 64.6% of centers. In the remaining hospitals, 19.5% of patients presented right heart dysfunction and 10% pulmonary arterial hypertension. Preoperative echocardiography was performed in only 45.3% of the coronary artery bypass grafting cases. Preoperative pharmacologic treatment of pulmonary hypertension or right ventricular dysfunction with oral sildenafil, inhaled prostanoids, or nitric oxide was initiated in 71% and 95.7% of the centers, respectively. Intra‐ and postoperative treatment was most frequently accomplished with phosphodiesterase‐III inhibitors. Conclusion The prevalence of preoperative right heart dysfunction and pulmonary arterial hypertension in cardiac surgical patients in Germany seems to be substantial. However, in more than 50% of the patients, no preoperative data on right ventricular function and pulmonary arterial pressure are available. This may lead to underestimation of perioperative risk and inappropriate management of this high‐risk population.