[Prognostic relevance of tissue oxygen saturation in patients in the early stage of multiple organ dysfunction syndrome]. / Prognostische Relevanz der Gewebesauerstoffsättigung bei Patienten in der Frühphase eines Multiorgandysfunktionssyndroms.

BACKGROUND: Patients in circulatory shock exhibit insufficient peripheral perfusion to ensure adequate oxygenation of vital organs such as the heart and brain. Early detection of reduced tissue oxygen saturation (StO2) could be used for rapid therapeutic intervention and thus improve the prognosis of patients in the early stage of multiple organ dysfunction syndrome (MODS). MATERIALS AND METHODS: A total of 60 patients in the early stage of MODS (APACHE [Acute Physiology and Chronic Health Evaluation] II score ≥20) were investigated in a monocentric, prospective, randomized phase II study. StO2 was measured using the InSpectraTM StO2 system and compared with known indicators of hypoxia (peripheral oxygen saturation [SpO2], arterial oxygen saturation [SaO2], central venous oxygen saturation [ScvO2], pH, serum lactate). Clinical endpoints of the study were 28-day and 6­month mortality as well as the need for invasive mechanical ventilation and renal replacement therapy during the hospital stay, respectively. RESULTS: An increased 28-day and 6­month mortality is found for patients with StO2 <75% in contrast to patients with StO2 ≥75%. Correlations of StO2 with SpO2, ScvO2, and serum lactate are confirmed. Patients with reduced StO2 tend to show a higher disease severity as measured by APACHE II score. CONCLUSION: StO2 shows prognostic relevance in patients at the early stage of MODS. Thus, the rapid and noninvasive assessment of StO2 could be useful in risk stratification of these patients.

Extracellular ATP attenuates ischemia-induced caspase-3 cleavage in human endothelial cells.

BACKGROUND: Apoptotic death of endothelial cells (EC) plays a crucial role for the development of ischemic injury. In the present study we investigated the impact of extracellular Adenosine-5'-triphosphate (ATP), either released from cells or exogenously added, on ischemia-induced apoptosis of human EC. METHODS AND RESULTS: To simulate ischemic conditions, cultured human umbilical vein endothelial cells (HUVEC) were exposed to 2 h of hypoxia (Po(2)<4mm Hg) in serum-free medium. Ischemia led to a 1.7-fold (+/-0.4; P<0.05) increase in EC apoptosis compared to normoxic controls as assessed by immunoblotting and immunocytochemistry of cleaved caspase-3. Ischemia-induced apoptosis was accompanied by a 2.3-fold (+/-0.5; P<0.05) increase of extracellular ATP detected by using a luciferin/luciferase assay. Addition of the soluble ecto-ATPase apyrase, enhancing ATP degradation, increased ischemia-induced caspase-3 cleavage. Correspondingly, inhibition of ATP breakdown by addition of the selective ecto-ATPase inhibitor ARL67156 significantly reduced ischemia-induced apoptosis. Extracellular ATP acts on membrane-bound P2Y- and P2X-receptors to induce intracellular signaling. Both, ATP and the P2Y-receptor agonist UTP significantly reduced ischemia-induced apoptosis in an equipotent manner, whereas the P2X-receptor agonist αß-me-ATP did not alter caspase-3 cleavage. The anti-apoptotic effects of ARL67156 and UTP were abrogated when P2-receptors were blocked by Suramin or PPADS. Furthermore, extracellular ATP led to an activation of MEK/ERK- and PI3K/Akt-signaling pathways. Accordingly, inhibition of MEK/ERK-signaling by UO126 or inhibition of PI3K/Akt-signaling by LY294002 abolished the anti-apoptotic effects of ATP. CONCLUSION: The data of the present study indicate that extracellular ATP counteracts ischemia-induced apoptosis of human EC by activating a P2Y-receptor-mediated signaling reducing caspase-3 cleavage.

Transient hypoxia induces ERK-dependent anti-apoptotic cell survival in endothelial cells.

Ischemia-induced apoptosis of endothelial cells may contribute to tissue injury, organ failure, and transplantation rejection. However, little is known about survival mechanisms capable to counteract endothelial apoptosis. This study investigated the potential role of an endogenous anti-apoptotic response elicited by transient hypoxia, capable to avert ongoing apoptosis in endothelial cells. Experiments were carried out in three different types of cultured endothelial cells (human umbilical vein, pig aorta, and from rat coronary microvasculature). As a pro-apoptotic challenge endothelial cells were cultured in serum-free medium and subjected to hypoxia for 2 h. We found that transient hypoxia reduced caspase 3 activation within 1 h of hypoxia. Accordingly, the number of apoptotic cells was reduced after 24 h of reoxygenation. This was true for all three cell types analyzed. Analysis of Akt and mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathways revealed that hypoxia induced a transient activation of ERK 2 but not of Akt. ERK 2 phosphorylation preceded the phosphorylation of pro-apoptotic molecule Bad at Ser112, an inhibitory phosphorylation site specific for ERK. The protective effects of hypoxia regarding Bad phosphorylation, caspase 3 activation, and apoptosis were abolished by MEK 1/2 inhibitors, PD98059 or UO126, as well as by antisense oligonucleotides directed against ERK 1/2. Furthermore, inhibition of this pathway inhibited hypoxia-induced increase in mitochondrial membrane potential. The present study demonstrates that transient hypoxia induces a novel survival mechanism that protects endothelial cells against apoptosis. This endogenous process involves MEK/ERK-mediated inhibition of the pro-apoptotic molecule Bad and caspase 3.

Extracellular ATP induces assembly and activation of the myosin light chain phosphatase complex in endothelial cells.

OBJECTIVES: Extracellular ATP stabilizes the endothelial barrier and inactivates the contractile machinery of endothelial cells. This inactivation relies on dephosphorylation of the regulatory myosin light chain (MLC) due to an activation of the MLC phosphatase (MLCP). To date, activation and function of MLCP in endothelial cells are only partially understood. METHODS: Here, the mechanism of extracellular ATP-mediated activation of MLCP was analyzed in human endothelial cells from umbilical veins. Cells were transfected with the endogenous protein phosphatase 1 (PP1)-specific inhibitor-2 (I-2). RESULTS: Overexpression of I-2 led to inhibition of PP1 activity and abrogation of the ATP-induced dephosphorylation of MLC. This indicates that the PP1 catalytic subunit is the principal phosphatase catalyzing the MLC dephosphorylation induced by extracellular ATP. As demonstrated by immunoprecipitation analysis, extracellular ATP recruits the PP1delta catalytic subunit and the myosin phosphatase targeting subunit (MYPT1) to form a complex. ATP stimulated dephosphorylation of MYPT1 at the inhibitory phosphorylation sites threonine 850 and 696. However, extracellular ATP failed to stimulate MYPT1 dephosphorylation in I-2-overexpressing cells. CONCLUSIONS: The present study shows for the first time that, in endothelial cells, extracellular ATP causes activation of MLCP through recruitment of PP1delta and MYPT1 into a MLCP holoenzyme complex and PP1-mediated reduction of the inhibitory phosphorylation of MYPT1.

Opposite effect of cAMP signaling in endothelial barriers of different origin.

cAMP-mediated signaling mechanisms may destabilize or stabilize the endothelial barrier, depending on the origin of endothelial cells. Here, microvascular coronary [coronary endothelial cells (CEC)] and macrovascular aortic endothelial cell (AEC) monolayers with opposite responses to cAMP were analyzed. Macromolecule permeability, isometric force, activation state of contractile machinery [indicated by phosphorylation of regulatory myosin light chains (MLC), activity of MLC kinase, and MLC phosphatase], and dynamic changes of adhesion complex proteins (translocation of VE-cadherin and paxillin) were determined. cAMP signaling was stimulated by the adenosine receptor agonist 5'-N-(ethylcarboxamido)-adenosine (NECA), the beta-adrenoceptor agonist isoproterenol (Iso), or by the adenylyl cyclase activator forskolin (FSK). Permeability was increased in CEC and decreased in AEC on stimulation with NECA, Iso, or FSK. The effects could be inhibited by the PKA inhibitor Rp-8-CPT-cAMPS and imitated by the PKA activator Sp-cAMPS. Under cAMP/PKA-dependent stimulation, isometric force and MLC phosphorylation were reduced in monolayers of either cell type, due to an activation of MLC phosphatase. In CEC but not in AEC, FSK induced delocalization of VE-cadherin and paxillin from cellular adhesion complexes as indicated by cell fractionation and immunofluorescence microscopy. In conclusion, decline in contractile activation and isometric force contribute to cAMP/PKA-mediated stabilization of barrier function in AEC. In CEC, this stabilizing effect is overruled by cAMP-induced disintegration of cell adhesion structures.

MEK/MAPK as a signaling element in ATP control of endothelial myosin light chain.

Phosphorylation of endothelial myosin light chains (MLC) is a key mechanism in control of endothelial contractile machinery. Extracellular ATP influences endothelial MLC phosphorylation by either activation of Ca(2+)-dependent MLC kinase or Ca(2+)-independent MLC phosphatase. Here, the role of the MEK/MAPK pathway in this signaling was investigated in porcine aortic endothelial cells. Phosphorylation of ERK2 and phosphorylation of MLC were analyzed in cultured aortic endothelial cells. ATP (10 microM) increased ERK2 phosphorylation from basal 17 +/- 3 to 53 +/- 4%, an effect suppressed in the presence of the MEK inhibitors PD-98059 (20 microM) or U0126 (10 microM). Phosphorylation of ERK2 was not dependent on the ATP-induced cytosolic Ca(2+) rise, because it was unaltered when this was suppressed by the Ca(2+) chelator BAPTA (10 microM) or xestospongin C (3 microM), an inhibitor of the inositol 1,4,5-trisphosphate-sensitive Ca(2+) release mechanism of the endoplasmic reticulum. Phosphorylation of ERK2 was neither induced by the adenosine analog 5'-(N-ethylcarboxamido)adenosine (1 microM) nor inhibited in the presence of the adenosine receptor antagonist 8-phenyltheophylline (10 microM). ATP increased MLC kinase activity, and this was blocked in presence of PD-98059. ATP also increased MLC phosphatase activity, which was not inhibited by PD-98059. The MEK/MAPK pathway is a Ca(2+)-independent part of ATP signaling toward MLC kinase but not of ATP signaling toward MLC phosphatase.

An evaluation of hybrid methods for matching biomedical terminologies: mapping the gene ontology to the UMLS.

Integration of disparate biomedical terminologies is becoming increasingly important as links between biological science and clinical medicine grow. Mapping concepts in the Gene Ontology (GO) to the UMLS may help further this integration and allow for more efficient information exchange among researchers. Using a gold standard of GO term--UMLS concept mappings provided by the NCI, we examined the performance of various published and combined mapping techniques, in order to maximize precision and recall. We found that for the previously published techniques precision varied between (0.61-0.95), and recall varied from (0.65-0.90), whereas for the hybrid techniques, precision varied between (0.66-0.97), and recall from (0.59-0.93). Our study reveals the benefits of using mapping techniques that incorporate domain knowledge, and provides a basis for future approaches to mapping between distinct biomedical vocabularies.

Linking biomedical language information and knowledge resources: GO and UMLS.

Integration of various informatics terminologies will be an essential activity towards supporting the advancement of both the biomedical and clinical sciences. The GO consortium has developed an impressive collection of biomedical terms specific to genes and proteins in a variety of organisms. The UMLS is a composite collection of various medical terminologies, pioneered by the National Library of Medicine. In the present study, we examine a variety of techniques for mapping terms from one terminology (GO) to another (UMLS), and describe their respective performances for a small, curated data set attained from the National Cancer Institute, which had precision values ranging from 30% (100% recall) to 95% (74% recall). Based on each technique's performance, we comment on how each can be used to enrich an existing terminology (UMLS) in future studies and how linking biological terminologies to UMLS differs from linking medical terminologies.

Human transcription factors IIIC2 , IIIC1 and a novel component IIIC0 fulfil different aspects of DNA binding to various pol III genes.

Human transcription factor IIIC2 interacts with the TFIIIA-5S DNA complex and forms a ternary TFIIIA/IIIC2-5S DNA complex. Formation of this complex does not preclude simultaneous binding of TFIIIC2to the B-box sequence of a second template. This suggests that the domain(s) or subunit(s) required for indirect recognition of the 5S promoter by TFIIIC2 are different from those necessary for direct binding of TFIIIC2 to B-box-containing pol III promoters. Whereas TFIIIC2 is only required for transcription of the 'classical' pol III genes, TFIIIC1 is generally required for transcription of all pol III genes, including that of the U6 gene. The activity of TFIIIC1 strongly enhances specific binding of basal pol III factors TFIIIA, TFIIIC2 and the PSE binding protein (PBP) to their cognate promoter elements and it acts independently of the corresponding termination regions. Moreover, we characterize an activity, TFIIIC0, purified from phosphocellulose fraction C, which shows strong DNase I protection of the termination region of several pol III genes and which is functionally and chromatographically distinct from TFIIIC1 and TFIIIC2.

[Masked depression and internal medicine]. / Larvierte Depression und Innere Medizin.

1. Larvate depressions (LD) are a particular type of significance of endogenic depressions. 2. Somatic-vegetative symptoms are mostly uppermost and involve the risk of diagnostic and therapeutic errors. Therefore it is particularly to be thought of the diagnosis of a larvate depression in non-psychiatric subjects. 3. Diagnostically decisive is the comprehension of the discretely existing endomorphous cyclothymic fundamental syndrome. 4. The therapy is that of the endogenic depression. Essential fundaments are the administration of psychopharmacologic agents, particularly tricyclic antidepressive drugs, the consequent psychic management of the patients, at the beginning emphasized in the sense of tranquilizing assurances and the consideration of social points of view.

[Psychopharmacotherapy and internal medicine]. / Psychopharmakotherapie und internistische Praxis.

The application of psychopharmacotherapy is admissable only after diagnostic clarification. Run-in period of tricyclic antidepressive agents and highly potent neuroleptic agents are to be taken into consideration, use low-potent neuroleptic drugs for rapid relaxation. At first always exhaust monotherapy, instead of application of tranquilizers application of low-dose neuroleptic agents for permanent therapy. Using small initial doses and gradually increasing to optimum amounts is to be preferred for the establishment of the individual disposition. When a danger of habit formation is existing neuroleptic drugs are to be preferred. In all psychoreactive disturbances at first ventilate psychotherapy [5], only then prescription of remedies in the basic psychotherapeutic concept. The patients must be comprehensively informed about the aim of the treatment, the effects and side-effects and the fitness for driving, when being under psychopharmacotherapy.

Cognitive dysfunction and imipramine in outpatient depressive.

A group of moderately depressed, nonpsychotic outpatients had impaired performance on a short-term item-recognition memory task (compared with a group of matched normal controls) without evidence of impaired speed or attention on two simpler tasks. Compared with placebo, treatment with imipramine hydrochloride in a multiple crossover design using three-week treatment periods led to improved performance on the memory task without either clinically apparent improvement in depression or significantly improved performance on the other task rather than a specific impairment of short-term memory, but the data do support the presence of cognitive dysfunction in depression, even in ambulatory patients without substantial impairments of attention or motor functioning. The results also indicate that antidepressant drugs can produce improvement in cognitive function, possibly as a forerunner of clinical improvement.

Single-dose study of nabilone in anxious volunteers.

The effects of single oral doses of nabilone, a synthetic cannabinoid, were studied in eight anxious volunteer subjects. Each subject had two exposures to placebo and three dose levels of nabilone at one-week intervals in a single-blind balanced Latin-square design after the nabilone dose range was determined by each subject's response to a test dose. Heart rate and blood pressure were monitored. The Profile of Mood States (POMS), a self-rating adjective checklist, was used as the quantitative measure of subjective effects. Four subjects performed a continuous avoidance procedure. High doses (4 or 5 mg) of nabilone produced orthostatic hypotension in these subjects. Mild dose-related increases in heart rate also occurred. Despite the occurrence of highly significant levels of sedation, there were no significant effects of nabilone on the continuous avoidance procedure. Two of these four subjects experienced an antianxiety effect from low (1 or 2 mg) nabilone doses. Four other subjects received comparatively lower doses of nabilone and performed on three behavioral tasks at intervals before and after drug: a recognition memory procedure, a task requiring spaced responding at a controlled rate, and a reaction time task. In these subjects there were no reliable effects on blood pressure or heart rate, no significant subjective effects on the POMS, and no antianxiety effects. Drug effects were also minimal on the three behavioral tasks.

Reinforcement, skin conductance, and performance in a vigilance-reaction time task.

Three experiments were conducted using normal adults to assess the effects of contingencies of reinforcement on vigilance-reaction time performance and skin conductance. There was a significant, direct relationship between rate of skin conductance responding and speed of performance. Performance was faster and skin conductance responses were more frequent when response-contingent monetary reinforcement was available than when either feedback alone or no feedback was provided. The data suggest that central facilitating mechanisms are activated by complex interactions among several factors, including the likely consequences of task performance.

A single dose study of nabilone, a synthetic cannabinoid.

The effects of single oral doses of nabilone, a synthetic cannabinoid, were studied in four anxious volunteer subjects. Each subject had two exposures to placebo and three dose levels of nabilone at 1 week intervals in a single blind balanced Latin square design after the nabilone dose range was determined by each subject's response to a test dose. The Profile of Mood States (POMS), a self-rating adjective checklist, was used as the quantitative measure of subjective effects. The subjects performed a continuous avoidance procedure. High doses (4 or 5 mg) of nabilone produced orthostatic hypotension. Small dose-related increases in heart rate also occurred. Despite the occurrence of highly significant levels of subjective sedation, there were no significant effects of nabilone on behavior maintained by the continuous avoidance procedure. Two of these subjects experienced an anti-anxiety effect from low (1 or 2 mg) nabilone doses, but there was no statistically significant effect on the mean POMS anxiety factor for the group as a whole. In a follow-up experiment, four other anxious subjects received comparatively lower doses of nabilone. In these subjects there were no important effects on blood pressure or heart rate, and also no anti-anxiety effects.