The impact of age on the benefits and risks of aliskiren treatment: analyses of the 3A registry.

We aimed to analyze benefits and risks of aliskiren treatment in older adults (⩾ 65 years) in clinical practice. Patients (n = 14,986) were assigned to either aliskiren (ALIS), an angiotensin-converting-enzyme inhibitor or angiotensin receptor blocker (ACEi/ARB), or an agent not blocking the renin-angiotensin system (non-RAS). Older adults (n = 7396) had a longer history of hypertension (8.7 vs 4.7 years; P < 0.0001), lower mean diastolic blood pressure (DBP; 87.7 ± 11.0 vs 92.1 ± 11.0 mm Hg) and more renal (12.0 vs 5.6%; P < 0.0001) or cardiovascular disease (44.0 vs 18.9%; P < 0.0001); 4548 received aliskiren (68.8%), 1215 ACEi/ARBs (18.4%) and 850 non-RAS treatments (12.9%). Office BP at 1 year was reduced by 18.4 ± 21.5/7.2 ± 12.0 mm Hg. BP reductions were greater (19.5 ± 21.7/7.6 ± 12.1 mm Hg) in the aliskiren group than in the ACEi/ARB (15.6 ± 20.9/6.4 ± 11.9) and non-RAS groups (16.1 ± 20.7/6.5 ± 11.7 mm Hg), respectively (P<0.0001 for systolic BP (SBP) and <0.01 for DBP). After multivariable adjustment, differences in SBP reductions were clinically irrelevant and no differences were noted for DBP. Adverse effects were higher in older adults with no differences between treatment groups. In conclusion, the present analysis of a large, unselected cohort of patients in clinical practice from the 3A study, offers real-life evidence of the effectiveness and safety of aliskiren for the treatment of hypertension in older adults.

Ambulatory blood pressure monitoring: is it mandatory for blood pressure control in treated hypertensive patients?: prospective observational study.

OBJECTIVE: Twenty-four hour ambulatory blood pressure (ABP) is superior to office blood pressure (BP) in predicting cardiovascular events. However, its use to optimise BP control in treated hypertensive patients is less well examined. DESIGN AND METHOD: In this observational study conducted in 899 general practitioners' offices, 4078 hypertensive patients with uncontrolled office BP were included. Antihypertensive therapy was intensified and after 1 year office BP and 24-hour ABP were measured to categorise patients according to the ESC/ESH 2007 guidelines. RESULTS: In this cohort (mean office BP 156/90 mmHg, mean ABP 146/85 mmHg), 2059 out of 4078 patients (50.5%) had controlled office BP (<140/90 mmHg) at 1 year examination. Of these apparently controlled patients (N=2059), 1339 (65.8%) had 24-hour ABP ≥ 130/80 mmHg, indicating masked hypertension (32.9% of all treated patients). In the prespecified subgroups the prevalence of masked hypertension was the following: diabetes 28.2%, CVD 29.1%, and CKD 32.1%. White coat hypertension (24h-ABP<130/80 mmHg and office BP ≥ 140/90 mmHg) was found in 12.4% (N=233) of patients with elevated office BP (6.1% of all treated patients), and in 5.7% of the diabetic subgroup, 5.6% CVD and 7.1% CKD. Discrepancies in BP categorisation between office BP and 24-hour ABP were high; all subjects 52.8%, diabetes 50.0%, CVD 49.0% and CKD 50.4%. CONCLUSION: In hypertensive patients on therapy, 2 out of 3 with apparently controlled office BP had masked hypertension, suggesting a more aggressive therapy, and 1 out of 8 with elevated office BP had white coat hypertension potentially falsely forcing physicians to intensify therapy. The 3A Registry is listed under clinicaltrials.gov, NCT01454583.

Redundant functions of phospholipases D1 and D2 in platelet α-granule release.

BACKGROUND: Platelet activation and aggregation are crucial for primary hemostasis, but can also result in occlusive thrombus formation. Agonist-induced platelet activation involves different signaling pathways leading to the activation of phospholipases, which produce second messengers. The role of phospholipase C (PLC) in platelet activation is well established, but less is known about the relevance of phospholipase D (PLD). OBJECTIVE AND METHODS: The aim of this study was to determine a potential function of PLD2 in platelet physiology. Thus, we investigated the function of PLD2 in platelet signaling and thrombus formation, by generating mice lacking PLD2 or both PLD1 and PLD2. Adhesion, activation and aggregation of PLD-deficient platelets were analyzed in vitro and in vivo. RESULTS: Whereas the absence of PLD2 resulted in reduced PLD activity in platelets, it had no detectable effect on the function of the cells in vitro and in vivo. However, the combined deficiency of both PLD isoforms resulted in defective α-granule release and protection in a model of FeCl3 -induced arteriolar thrombosis, effects that were not observed in mice lacking only one PLD isoform. CONCLUSION: These results reveal redundant roles of PLD1 and PLD2 in platelet α-granule secretion, and indicate that this may be relevant for pathologic thrombus formation.

Arterial thrombus formation. Novel mechanisms and targets.

Platelet and coagulation factor-dependent thrombus formation is critical to limit posttraumatic blood loss at sites of vascular injury. However, under pathological conditions like rupture of an atherosclerotic plaque, it may also lead to vessel occlusion causing myocardial infarction or stroke. Therefore, antithrombotic treatment is the prime therapeutic option in the prophylaxis and treatment of ischaemic cardio- and cerebrovascular diseases. The use of existing antithrombotic agents is, however, limited by their inherent effect on primary haemostasis. In recent years, major advances have been made in understanding the mechanisms of thrombus formation in haemostasis and thrombosis and some studies raised the interesting possibility that occlusive thrombus formation and haemostasis may involve partially different mechanisms. This review briefly summarizes these developments and highlights newly identified mechanisms involved in platelet adhesion and activation, intracellular calcium signaling, integrin activation and initiation of coagulation. The suitability of these pathways as novel targets for antithrombotic therapy is discussed.

HLö 7 dimethanesulfonate, a potent bispyridinium-dioxime against anticholinesterases.

HLö 7 dimethanesulfonate (1-[[[4-(aminocarbonyl)pyridinio]methoxy]methyl]-2,4-bis [(hydroxyimino)methyl]pyridinium dimethanesulfonate) is a broad-spectrum reactivator against highly toxic organophosphorus compounds. The compound was synthesized by a new route with the carcinogenic bis(chloromethyl)ether being substituted by the non-mutagenic bis(methylsulfonoxymethyl)ether. The very soluble dimethanesulfonate of obidoxime was also prepared by this way. HLö 7 dimethanesulfonate is the first water-soluble salt of HLö 7 that should be suitable for the wet/dry autoinjector technology, because aqueous solutions of HLö 7 are not very stable (calculated shelf-life 0.2 years when stored at 8 degrees C, 1 M solution, pH 2.5). The crystalline preparation contains 96% of the syn/syn-isomer, less than 2% of the syn/anti-isomer and some minor identified by-products. HLö 7 was very efficient in reactivating acetylcholinesterase (AChE) blocked by organophosphates as long as ageing did not prevent dephosphylation. HLö 7 was superior to HI 6 (1-[[[4-(aminocarbonyl)pyridinio]methoxy]methyl]-2- [(hydroxyimino)methyl]pyridinium dichloride) in reactivating soman and sarin-inhibited AChE from erythrocytes, and literature data indicate that HLö 7 exceeds HI 6 by far in reactivating tabun-inhibited AChE. In atropine-protected, soman-poisoned mice HLö 7 was three times more potent than HI 6 (protective ratio 5 versus 2.5), and in sarin-poisoned mice HLö 7 was 10 times more potent than HI 6 (protective ratio 8 for both oximes). In atropine-protected guinea-pigs HLö 7 was less effective than HI 6 (protective ratio: 2.3 versus 5.2 for soman; 5.2 versus 6.8 for sarin; 4.3 versus 3.8 for tabun). The mean survival time of anaesthetized guinea-pigs exposed to 5 LD50 soman (6.3 min) was increased by atropine (27 min) and atropine + HLö (57 min). HLö 7 alone did not prolong the survival. The most impressive effect of HLö 7 was on respiration: 3 min after i.v. injection of HLö 7 and atropine, the depressed respiration increased rapidly to 60% of control and remained at that level during the observation period (60 min). With atropine alone, respiration recovered only slowly. Behavioural and physiologic parameters were determined in atropine-protected mice exposed to a sublethal soman dose. The running performance was significantly improved by HLö 7. Even central symptoms, e.g. hypothermia and convulsions, were decreased markedly by HLö 7 (evaluation 60 min after poisoning). The pharmacokinetic data for HLö 7 in male beagle dogs are similar to those of HI 6.(ABSTRACT TRUNCATED AT 400 WORDS)

The bispyridinium-dioxime HLö-7. A potent reactivator for acetylcholinesterase inhibited by the stereoisomers of tabun and soman.

Purification of (+)-tabun was accomplished by treatment with electric eel acetylcholinesterase (AChE) in order to bind contaminating (-)-tabun and with purified (+)-tabun shown similar properties in reactivation reactions with oximes (pH 7.5, 25 degrees). The bispyridinium-2,4-dioxime HLö-7 is a substantially active reactivator for these inhibited enzymes as well as for human erythrocyte AChE inhibited with (-)-tabun. In contrast, the corresponding bispyridinium-2-monooxime HI-6 does not show any activity at similar reaction conditions. HLö-7 is also much more active than HI-6 when used as a reactivator for electric eel AChE inhibited by some N-unsubstituted derivatives of tabun. Surprisingly, HLö-7 is highly active in reactivating human erythrocyte and rat diaphragm AChE inhibited by C(+)P(+/-)-and C(-)P(+/-)-soman, i.e. at least as active as HI-6, which is the most potent reactivator for soman-inhibited AChE reported so far. To our knowledge, HLö-7 is the first compound reported in literature that shows a potent reactivating activity towards both tabun-inhibited AChE and soman-inhibited AChE.

Study on the stability of the oxime HI 6 in aqueous solution.

HI 6 (Pyridinium, 1-[[[4-(aminocarbonyl)pyridinio]methoxy]methyl]-2-[(hydro xyimino) methyl]-dichloride is an effective antidote against poisoning with extremely toxic organophosphates. Because of conflicting reports on the stability of HI 6 in aqueous solutions, we studied the factors influencing its stability. HI 6 has been shown to be most stable in acidic solution between pH 2 and 3. At that pH, HI 6 decomposes probably by attack of nucleophiles on the methylene carbon atom of the animal-acetal bond of the "ether bridge". HI 6 decomposition follows first order kinetics. From Arrhenius plots of the decay of HI 6 at various concentrations it became obvious that the rate of decomposition increased with increasing HI 6 concentration with simultaneous decrease in the energy of activation. To decide whether the pyridinium compound itself or its anions are responsible for the enhanced decomposition, we studied the influence of chloride, phosphate and iodide. These anions stimulated the decay of HI 6 at increasing strength; their effect, however, was small as compared to that brought about by the pyridinium oxime itself. Since 1-methylisonicotinamide chloride had virtually no effect in contrast to 1-methylpyridinium-2-aldoxime chloride, we conclude that the oximate anion is responsible for the intermolecular attack on HI 6. At present, we recommend storage of HI 6 at concentrations not exceeding 0.1 M in aqueous solution at pH 2.5 and low temperatures. Under these conditions an apparent shelf-life of 20 years is calculated when HI 6 is stored at 8 degrees C.

Interactions of bisquaternary pyridine salts (H-oximes) with cholinergic receptors.

Certain recently developed antidotes of the bispyridinium type, commonly called "H-oximes" (HGG 12, 21, 42, 52, 65, 70, 89, and HGG 90) have been investigated as to their effects on muscarinic and nicotinic acetylcholine receptors. These compounds clearly discriminate between these two types of receptors being more potent inhibitors of the muscarinic receptor with inhibitory constants in the micromole range. (The corresponding values for the nicotinic receptor are in the range of 0.1 mM.) However, the inhibitory potency in the binding assay does not correlate with the ED50 values obtained against soman in mice. The site of antidotal action therefore appears not to be the nicotinic acetylcholine receptor. Binding to the muscarinic receptors may partially contribute to the effects against soman in vivo.

Synthesis of pyridinium analogues of acetylcholine and their interactions with intestinal muscarinic receptors.

N-(beta-Acetoxyethyl)pyridinium salts were synthesized and tested for muscarinic receptor interactions by the guinea pig ileum assay. Agonist activity indicates that receptor binding is substantially retained when the ammonium group of acetylcholine is formally replaced by a pyridinium ring. Introduction of alkyl groups into the ring yields antagonists. The 4-tert-butylpyridinium derivative is proved to have an activity superior to that of the 4-methylpyridinium salt. Competitive antagonism is favored by the more hydrophobic property of the tert-butyl group. A nonpolar area is suggested to be situated in the direct vicinity of the anionic binding sites of muscarinic receptors. The interaction of hydrophobic substituents with this area determines the antimuscarinic properties of pyridinium salts.

[Reactivation of phosphorylated acetylcholinesterase. Isomeric bisquaternary salts of pyridine aldoximes]. / Reaktivierung phosphorylierter Acetylcholin-Esterase. Isomere bisquartäre Salze von Pyridin-aldoximen.

Mono-quaternary salts Z have been prepared from pyridine-aldoximes and 1,3-dihalogen compounds. These were used to synthesize asymmetrical bis-quaternary pyridine-oximes with three-membered bridge. The effect of reactivation of phosphorylated AChE by these substances is less than that of obidoxim (Toxogonin).

[Betaines of quaternary salts of pyridine-2-and -4-aldoxim (author's transl)]. / Betaine quartärer Salze von Pyridin-2- und -4-aldoxim

The monobetaine derived from the AChE-ractivator bis-[4-hydroxyiminomethyl-pyridinium-(1)-methyl]-either dichloride (obidoxim; Toxogonin), was shown to be in solution an intramolecular CT-complex. Some betaines of quaternary salts of pyridine-aldoximes were isolated.

[Synthesis and Quaternation of Pyridine-aldoxim Alkylethers (author's transl)]. / Darstellung und Quaternierung von Pyridinaldoxim-alkyläthern

Using known procedures, alkylethers of pyridine-aldoxime not described as yet were prepared and transformed into pyridinium salts. The application of a solution of a,a'-di-iodo-dimethyl-ether proved especially useful in the synthesis of bisquarternary salts with formaldehyde-acetal bridge. All the new substances are ineffective in a paraoxon poisoning. On the other hand, some salts show protective action in soman intoxication.

[Reactivation of phosphorylated acetylcholinesterase (AChE): quaternary salts of vinylogous pyridinaldoxims (author's transl)]. / Reaktivierung phosphorylierter Acetylcholinesterase (AChE): Quartäre Salze vinyloger Pyridinaldoxime

Application of Wittig reaction to 4-pyridinecarboxaldehyde leads to 4-beta-formylvinylpyridine (62%). The corresponding oxime (4-(2)) can be quaternized with alpha,alpha'-bis-(chloromegonin), and with methyliodide one to 4-PAM (4-(3)). In this case the formal insertion of an ethylenic double bond between the pyridinium ring and the aldoxime group decreases the ability to reactivate phosphorylated acetylcholinesterase (AChE).