Hemodynamic improvement following levosimendan treatment in patients with acute myocardial infarction and cardiogenic shock*

Use of levosimendan in patients with ischemic heart disease following mechanical reperfusion

Cardiac failure is among the most significant conditions associated with acute coronary syndrome. In ischemic heart disease, serious hemodynamic problems are reported in patients with left ventricular dysfunction during the acute phase despite mechanical revascularization. Several positive inotropic agents in addition to intra-aortic balloon pump (IABP) are required to support patients with impaired left ventricular pump function during this phase. Intravenous inotropic agents, beta-mimetics, and phosphodiesterase inhibitors lead to increases in the incidence of arrhythmia and myocardial O(2) consumption owing to their effect of increasing intracellular calcium amount, although they produce rapid hemodynamic improvements in cardiac failure. This causes severe problems particularly in cardiac failure of ischemic origin. Recently, levosimendan, a calcium-sensitizing agent with cardioprotective properties, is being used alone or in combination with IABP in cases with severe left ventricular systolic dysfunction during mechanical revascularization procedures (percutaneous coronary interventions, coronary bypass surgery). This review includes studies with levosimendan in cases not recovering due to myocardial stunning in the acute phase despite mechanical approaches applied.

[New pharmacological treatment approaches to cardiogenic shock]

Cardiogenic shock after acute myocardial infarction continues to exhibit a high mortality rate. The prognosis can be improved with acute revascularization. Use of the intra-aortic balloon pump is also an established treatment concept. Administration of catecholamines should be limited as far as possible; monitoring hemodynamic parameters based on cardiac power output or cardiac power index can be very helpful. New treatment approaches such as the calcium sensitizer levosimendan, NO synthase inhibition, complement inhibition, or vasopressin therapy have not yet yielded convincing results. Future therapies will likely address the anti-inflammatory aspect of cardiogenic shock.

Differential signaling in presynaptic neurotransmitter release

Neuronal communication is tightly regulated by presynaptic signaling, thereby temporarily and locally secreting one or more transmitters in order to exert propagation or modulation of network activity. In the last 2 decades our insight into the molecular regulation of presynaptic transmitter vesicle traffic and fusion has exponentionally grown due to the identification of specific functional interactions between presynaptic proteins involved in these processes. In addition, a plethora of extracellular and intracellular messengers regulate neurotransmitter release, occasionally leading to short- or long-term adaptations of the synapse to altered environmental signals. Important in this respect is the ability of various nerve terminals to diverge their output by differentiation in secretion of co-localized transmitters. This divergence in presynaptic signaling may converge in the postsynaptic target neuron or spread to neighbouring cells. In this review differential presynaptic signaling mechanisms will be related to their potential divergent roles in transmitter release.

New approaches to therapy of cancers of the stomach, colon and pancreas based on peptide analogs

Cancers of the stomach, colon and exocrine pancreas are major international health problems and result in more than a million deaths worldwide each year. The therapies for these malignancies must be improved. The effects of gastrointestinal (GI) hormonal peptides and endogenous growth factors on these cancers were reviewed. Some GI peptides, including gastrin and gastrin-releasing peptide (GRP) (mammalian bombesin), appear to be involved in the growth of neoplasms of the GI tract. Certain growth factors such as insulin-like growth factor (IGF)-I, IGF-II and epidermal growth factor and their receptors that regulate cell proliferation are also implicated in the development and progression of GI cancers. Experimental investigations on gastric, colorectal and pancreatic cancers with analogs of somatostatin, antagonists of bombesin/GRP, antagonists of growth hormone-releasing hormone as well as cytotoxic peptides that can be targeted to peptide receptors on tumors were summarized. Clinical trials on peptide analogs in patients with gastric, colorectal and pancreatic cancers were reviewed and analyzed. It may be possible to develop new approaches to hormonal therapy of GI malignancies based on various peptide analogs.