[Seeing others is believing-analgesic placebo effects through observational learning?]

Hintergrund

Es gibt viele Studien zur Placeboanalgesie und deren zugrundliegenden Wirkmechanismen, die eine Behandlung von Patient:innen mit chronischen Schmerzen signifikant verbessern können. Beobachtungslernen als ein Wirkmechanismus wurde hingegen noch wenig untersucht.

Fragestellung

Das Ziel der Arbeit ist es, einen Überblick über die aktuelle Forschungslage zu Placeboanalgesie durch Beobachtungslernen zu geben. Dabei soll geklärt werden, ob Beobachtungslernen überhaupt einen signifikanten Placeboeffekt auslösen kann und durch welche Faktoren dieses Lernen beeinflusst wird.

Material und Methoden

Dafür wurden die Forschungsdatenbanken nach Studien zur Placeboanalgesie durch Beobachtungslernen durchsucht.

Ergebnisse

Nach der Anwendung der Ein- und Ausschlusskriterien verblieben 12 Studien. Es gab nur eine Studie, die an Patient:innen mit chronischen Schmerzen durchgeführt wurde. Die geringe Anzahl an Studien lässt noch keine allgemeingültigen Aussagen zu, aber es gibt erste Hinweise für die folgenden Aussagen: Beobachtungslernen von Placeboeffekten ist unter Laborbedingungen möglich und eine Aufmerksamkeitslenkung ist wichtig. Die Effektstärken reichen von klein bis groß. Die Effekte von klassischer Konditionierung und Beobachtungslernen sind vergleichbar. Live-Modelle, Videoaufnahmen und Bilder lösen ähnliche Effekte aus. Beobachtungslernen führt zu einer Erwartungsänderung.

Diskussion

Die vorliegende Evidenz liefert die Grundlage dafür, dass theoretisch und auch praktisch klinisch signifikante Effekte möglich sind. Weitere Studien sind nötig, um diese Aussagen verlässlich auch auf chronische Schmerzpatient:innen zu beziehen.

Analgetische Placeboeffekte und Implikationen für die Behandlung chronischer Schmerzen

Die Behandlung von chronischen Schmerzen kann langwierig sein. Erste Ansätze zur Nutzung von Placeboeffekten bei der Behandlung von chronischen Schmerzen zeigen erfolgversprechende Ergebnisse und können dazu beitragen, die z. T. frustranen Therapieoptionen zu verbessern. Daher sollten Placeboeffekte zur verbesserten Behandlung genutzt werden. Im derzeitigen Modell zur Entstehung von Placeboeffekten spielt die Erwartung eine zentrale Rolle. Eine positive oder negative Erwartung wird durch psychologische und biologische „State“- und „Trait“-Faktoren der Patient:innen sowie die früheren Lernerfahrungen, die der:die Patient:in mitbringt, beeinflusst. Aus diesem Modell ergeben sich Implikationen für die klinische Praxis: Positive Erwartungen sollten unterstützt werden, wobei unrealistische Erwartungen wiederum den Placeboeffekt reduzieren. Negative Erwartungen sollten kritisch diskutiert werden. Es sollte im interdisziplinären Team eine gemeinsame Botschaft an die Patient:innen vermittelt werden. Open-Label-Placebos können als Intervention genutzt werden, um die Selbstwirksamkeit zu steigern.

[Placebo effects in pain therapy]

In the past few decades, research on pain and placebo analgesia has gained importance both scientifically and clinically. In this article, the current findings and focus of research as well as the significance of placebo research for assessing the effectiveness of pain medication are illustrated. The underlying mechanisms of placebo analgesia not only have implications for theoretical models but also offer clinically relevant guidelines for everyday interventions in pain treatment. However, many placebo phenomena are not fully understood and have to be investigated further in order to exploit the full potential of placebo effects. Interindividual differences and their inclusion in treatment will play a major role in this aspect.

Abstract P5-05-07: Expression of the cocaine- and amphetamine-regulated transcript (CART) recruits SWI/SNF chromatin remodelling complexes to the estrogen receptor

Introduction

Cocaine- and amphetamine-regulated transcript (CART) peptides are neuropeptides involved in regulating physiological processes, such as feeding and drug reward. Recent studies have associated high CART expression with worse overall survival in patients with small-bowel carcinoid tumours and estrogen receptor-positive (ER+), lymph node-negative breast cancer. CART was also shown to be associated with poor patient response to tamoxifen, suggesting CART may play a role in conferring tamoxifen resistance.

Materials and methods

We have previously demonstrated that CART can impact the transcriptional activity of ERα through the use of western blotting and qPCR for specific ERα gene targets. RNA sequencing was carried out using a stable CART-inducible cell line model to identify genes which are upregulated/downregulated in cells expressing CART. Further, using our stable CART-inducible cell line model, we preformed ERα-Immunoprecipitation followed by in-solution mass spectrometry to identify differentially recruited protein complexes +/- CART expression.

Results and discussion

RNA sequencing revealed 156 significantly downregulated, and 100 significantly upregulated, genes in cells expressing CART (p<0.05). Through mining of publicly available ERα ChIP-seq data sets, both upregulated and downregulated gene sets were found to contain genes which have previously been shown to contain ERα binding events within their promotor regions. Mass spectrometry analysis revealed that the majority of proteins recruited to ERα in the presence of CART were members of the SWI/SNF (BAF) chromatin remodelling complex. The identification of SMARCD1 within this complex was of particular interest to this study, as this protein has previously been reported to be a critical mediator of nuclear receptor function. Further in silico analysis demonstrated high expression of SMARCD1 correlates with poor overall survival (OS) (p<0.00001) and distant metastasis free survival (DMFS) (p=0.00708) in a cohort of ER+ breast cancer patients. Intriguingly, SMARCD1 expression did not correlate with poor OS or DMFS in a cohort of ER- breast cancer patients, suggesting that this negative impact on survival is dependent on ER status.

Conclusion

In conclusion, we suggest that CART expression results in the recruitment of chromatin remodelling complexes to ERα in order to facilitate the regulation of receptor function and this impacts on patient outcome.

Citation Format: O'Connor DP, Mooney B, Das S, Klinger R, Moran B, Ni Chonghaile T, Cagney G, Bracken A, Gallagher WM. Expression of the cocaine- and amphetamine-regulated transcript (CART) recruits SWI/SNF chromatin remodelling complexes to the estrogen receptor [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-05-07.

Suitability of Wild Boar (Sus scrofa) as a Bioindicator for Environmental Pollution with Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic Acid (PFOS)

Wildlife species, such as roe deer, moose, brown hare, wild boar, etc., are known to accumulate persistent environmental contaminants and thus are useful as bioindicators for environmental pollution. Wild boars become exposed to perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) from flora, fauna, water, and soil. The main exposure pathway to PFOA and PFOS is assumed to be the oral intake. From studies in domestic pigs (belonging to the same species Sus scrofa), it has been established that the oral exposure results in the liver accumulation of PFOA and PFOS. Thus, we posit that wild boars can be quantitatively used as suitable bioindicators for the presence of these substances in the environment. After the environmental pollution case in the Hessian region Sauerland in 2006, monitoring programs of individual Federal States from 2007 to 2013 showed that almost all wild boar liver samples contained PFOA and PFOS. In 2014, the analyses of PFOA and PFOS in liver of wild boars hunted in the south, north, and west of Germany showed liver concentrations at the same level among regions. Overall, an average ratio of PFOS:PFOA concentration in liver of 20.5:1 was found. To estimate the actual ratio of PFOS:PFOA in the wild boars' dietary exposure, we performed toxicokinetic modeling. According to the model, the PFOS exposure is only 2.2 times that of PFOA (because PFOS has slower elimination kinetics and higher affinity for the liver than PFOA). Overall, the determination of PFOA and PFOS in liver of wild boars indicates that both substances are ubiquitously distributed in the environment. At the same time, higher exposures were found for animals living in closer proximity to dense human populations.

Treatment history and placebo responses to experimental and clinical pain in chronic pain patients

BACKGROUND

Placebo analgesia refers to the reduction in pain due to the administration of an inert treatment. It is induced by expectations of pain relief which are enhanced by learning mechanisms. In healthy humans, prior positive experiences enhance the placebo response. However, the effects of patients' prior experiences with treatment on placebo responses have not yet been examined. This study investigated how verbal information, learning and treatment history influence the magnitude of placebo analgesia in chronic pain.

METHODS

We administered a pharmacological placebo intervention in a sample of chronic pain patients (n = 49) who were seeking treatment in an outpatient pain clinic. Analyses were based on placebo responders.

RESULTS

We found that verbal information about a potent pain-relieving effect of the intervention induced a large placebo analgesic response to both acute experimental (F(1,44) = 43.35, p < 0.001) and chronic pain (F(1,44) = 37.72, p < 0.001). However, the placebo responses to experimental and chronic pain were not significantly related (r = 0.012, p = 0.95). An additional conditioning procedure did not significantly enhance placebo analgesia. Treatment history modulated the magnitude of the placebo response: patients with a more negative pain-related treatment history reported significantly larger placebo responses to their own chronic pain (τ = 0.271, p = 0.044).

CONCLUSIONS

We could show that placebo responses to both acute and chronic pain are high in pain treatment settings and that treatment history modulates this effect. Different mechanisms might underlie placebo responses to acute and chronic pain. Our findings highlight the necessity of considering placebo responses and treatment history in the treatment of chronic pain. WHAT DOES THIS STUDY ADD?: Placebo analgesia following verbal information of potent pain relief is high in chronic pain patients in a clinical setting. It is modulated by treatment history. Different mechanisms might underlie placebo analgesia to acute and chronic pain.

Abstract PD3-01: CDK7: A marker of poor prognosis and tractable therapeutic target in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is defined by absent expression of estrogen receptor (ER), progesterone receptor (PR) and non-overexpression of human epidermal growth factor receptor 2 (HER2), representing a heterogeneous subgroup of breast cancer with substantial genotypic and phenotypic diversity. TNBC patients commonly exhibit poor prognosis and high relapse rates at early stages after conventional treatments. Currently, there is a lack of biomarkers and targeted therapies for the management of TNBC. During tumour development and progression, alterations in cellular behaviour are frequently linked with kinase expression and activity. Here, we aimed to identify novel kinase targets that may play a pivotal role in the progression of TNBC and, thus, offer new therapeutic vantage points.

We initially focused on identifying kinases correlated with differential outcome. Using publicly available transcriptomic data from a collated set of TNBC patients (n = 483), we identified 9 kinases that were significantly associated with survival at the mRNA level. From this in silico screen, CDK7 (cyclin-dependent kinase 7) was found to be correlated with poor recurrence-free survival. CDK7's trait as a marker of poor prognosis was further validated within another TNBC cohort (n=109) via assessment of a tissue microarray generated as part of the RATHER Consortium (www.ratherproject.com). At the protein level, high CDK7 expression was associated with poor breast cancer-specific, recurrence-free and distant recurrence-free survival.

To evaluate CDK7 as a therapeutic target in TNBC, two TNBC cell lines (BT-549 and MDA-MB-231) were selected to evaluate phenotypic alterations post shRNA-mediated CDK7 knockdown. CDK7 silencing led to decreased cell proliferation, colony formation and migration in vitro. CDK7 down-regulation also increased TNBC cell sensitivity to doxorubicin. BS-181 and THZ1, two highly specific CDK7 inhibitors, attenuated TNBC tumour growth by inducing G2/M phase cell cycle arrest and apoptosis, as well as down-regulation of RNAPII phosphorylation, an indication of global RNA transcription inhibition. Moreover, the covalent CDK7 inhibitor THZ1 demonstrated 1000-fold higher potency than BS-181. Inhibition of global RNA transcription preferentially affects proteins with short half-lives. Accordingly, we detected a reduction in the expression of the anti-apoptotic protein MCL-1 in both cell lines.

Next, we assessed anti-apoptotic dependence in MDA-MB-231 cells following treatment with THZ1 via BH3 profiling technology, and observed an increased response to the BAD and HRK peptides, inferring an elevated survival dependence on BCL-2/BCL-XL. We subsequently evaluated the combination of the BCL-2/BCL-XL inhibitor ABT-263 with THZ1 and discovered a synergistic inhibition of cell growth and apoptosis. Resulting combination index (CI) values demonstrated that synergistic cell death occurred following combined treatment with THZ1 and ABT-263/ABT-199 at various doses in both TNBC cell lines tested.

Our data implicate high CDK7 expression as a promising biomarker of poor prognosis in TNBC. Moreover, these findings suggest that targeting CDK7, combined with the BCL-2/BCL-XL inhibitor ABT-263, may be a useful therapeutic strategy for TNBC.

Citation Format: Gallagher WM, Li B, Ni Chonghaile T, Fan Y, Klinger R, O'Connor AE, Conroy E, Tarrant F, O'Hurley G, Mallya Udupi G, Gaber A, Chin S-F, Schouten PC, Dubois T, Linn S, Jirstrom K, Caldas C, Bernards R, O'Connor DP. CDK7: A marker of poor prognosis and tractable therapeutic target in triple-negative breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr PD3-01.

[Quality assurance in therapy of chronic pain. Results obtained by a taskforce of the German Section of the Association for the Study of Pain on psychological assessment of chronic pain. V. Instruments for the assessment of pain-related cognitions and coping with pain.]

The present paper is one of a series of publications, reviewing German instruments for psychological assessment of pain. Their main focus is on the results of a task force on quality testing for each subject. This paper describes and comments on methods regarding self-reporting of pain cognitions and both cognitive and behavioral strategies for coping with pain. Concerning pain cognitions one focus is on patients' attributions of causes of pain and the modes of controlling pain (subjective pain model). The other focus is on instruments recording "pain beliefs" in the sense of dysfunctional congitions associated with the experience of pain. Each instrument was examined with reference to approved psychometric criteria, empirical foundation and clinical relevance. It was noted that several instruments are deficient in their psychometric criteria and their empirical foundations. We used these data as a basis to elaborate a specific and differential recommendation. A similar procedure was followed with instruments for the assessment of pain-related coping strategies. According to our research there are two subgroups of coping instruments, one more specifically for cognitive coping with pain, and the other combined with behavioral coping strategies. Once again, we elaborated a specific and differential recommendation, giving priority to instruments taking account of both cognitive and behavioral dimensions of coping with pain.

[Comparative psychological aspects of itching and pain]

Itching is a major symptom of chronic skin diseases such as atopic dermatitis and leads to considerable psychological strain. Chronic itching lowers patient's quality of life similar to chronic pain and influences the medical treatment. The frequently resulting scratching behavior (short-term avoidance of itch) leads to continuation and exacerbation of the disease, just as with specific pain behavior. For the development of itching and pain psychosocial factors have been identified in addition to somatic ones. However, recent data suggest that there is a complex interaction between pain and itching and comparable mechanisms of neuronal sensitization. In contrast to traditional biomedical one-dimensional models which focus mainly on physical and not psychological factors of a disease, recent data support a biopsychosocial model of development and maintenance for itching and pain. Biopsychosocial understanding of a disease should consequently be taken as the basis for treatment and the importance of interdisciplinary treatment is emphasized. This article will focus on chronic itching and pain with particular consideration of psychological factors.

[Can failed back surgery be prevented? Psychological risk factors for postoperative pain after back surgery]

Aside from the surgical technique used, the development of peri- and postoperative pain and impairments in patients following intervertebral disk surgery is also determined to a crucial extent by psychological factors. Based on a systematic literature review, we checked whether evidence-based recommendations could be deduced on how to take into account psychological risk factors in back surgery in order to avoid postoperative complications, such as failed back surgery syndrome. The current state of research suggests three groups of risk factors: (1) negative psychological factors, (2) preexisting pain chronification, and (3) psychological disorders. In the case of elective intervertebral disk surgery, these factors should therefore be determined and identified preoperatively and taken into account in the indication for surgery. Multimodal treatments could conceivably prove to be more effective, or else psychological pain management therapy might be considered prior to surgery so as to avoid postoperative complications. If surgery is medically unavoidable despite existing risk factors, postoperative treatment should incorporate psychological pain management therapy at an early stage in the context of a multidisciplinary approach.

The interaction of disturbances and small mammal community dynamics in a lowland forest in Belize

1. Three floods (July 2000, August 2002, September 2003) and a hurricane (October 2001) that occurred in a lowland forest in the southern Maya Mountains of Belize presented an opportunity to evaluate the influence of these disturbances on the structure of a small mammal assemblage. 2. Four terrestrial and four primarily scansorial/arboreal species were trapped July 2000-March 2005 in six grids over 14 irregularly spaced trapping periods. 3. Community dynamics were characterized more by changes in species composition than changes in diversity. The dynamics were driven by species-specific variation in abundance, with changes in composition generally, but not exclusively, due to the occurrence or disappearance of species at low abundance. Despite the disturbances, species richness remained relatively constant. Evenness within the assemblage was consistently low, primarily as a result of dominance by one species, Heteromys desmarestianus. 4. Effects of flooding on community structure were direct but relatively brief (< 1 year), and varied with the duration and intensity of flooding. Effects from the hurricane were indirect but long-lasting and strongly related to severely reduced food resources. 5. This study suggests that long-term dynamics in the structure of many animal communities in the tropics often results from interactions between direct and indirect effects of disturbance. It also suggests that community resistance will depend on variation in disturbance type and regime, but resilience will be determined by the life-history characteristics of each species.

The interaction of disturbances and small mammal community dynamics in a lowland forest in Belize

1. Three floods (July 2000, August 2002, September 2003) and a hurricane (October 2001) that occurred in a lowland forest in the southern Maya Mountains of Belize presented an opportunity to evaluate the influence of these disturbances on the structure of a small mammal assemblage. 2. Four terrestrial and four primarily scansorial/arboreal species were trapped July 2000-March 2005 in six grids over 14 irregularly spaced trapping periods. 3. Community dynamics were characterized more by changes in species composition than changes in diversity. The dynamics were driven by species-specific variation in abundance, with changes in composition generally, but not exclusively, due to the occurrence or disappearance of species at low abundance. Despite the disturbances, species richness remained relatively constant. Evenness within the assemblage was consistently low, primarily as a result of dominance by one species, Heteromys desmarestianus. 4. Effects of flooding on community structure were direct but relatively brief (< 1 year), and varied with the duration and intensity of flooding. Effects from the hurricane were indirect but long-lasting and strongly related to severely reduced food resources. 5. This study suggests that long-term dynamics in the structure of many animal communities in the tropics often results from interactions between direct and indirect effects of disturbance. It also suggests that community resistance will depend on variation in disturbance type and regime, but resilience will be determined by the life-history characteristics of each species.

Impact of low back pain on functional limitations, depressed mood and quality of life in patients with rheumatoid arthritis

Low back pain (LBP) and rheumatoid arthritis (RA) are common orthopedic problems, but there is little information on the importance of LBP in RA patients. The aim of this study was to investigate how LBP affects functional limitations, depressed mood, and quality of life in patients with RA. A complex questionnaire was answered by 281 RA patients, including questions about their RA and their experience of LBP. Functional limitations were assessed using the Hannover Activities of Daily Living questionnaire (ADL), depressed mood using the Center for Epidemiological Studies Depression Scale (CES-D) and health-related quality of life using the Short Form 12 health questionnaire (SF-12). The prevalence of LBP in RA patients was 53.4%. RA patients with LBP displayed a significantly higher degree of disability and depression than RA patients without LBP. There were no differences between the two groups with regard to the duration of RA, the number of operations or medication. LBP is an important factor for the physical and psychological behavior of RA patients. Therefore, the onset of LBP should not be overlooked or underestimated.

Proatrial natriuretic peptide (1-98), but not cystatin C, is predictive for occurrence of acute renal insufficiency in critically ill septic patients

INTRODUCTION

N-terminal prohormone of atrial natriuretic peptide ((proANP(1-98)) has been extensively analyzed in patients with chronic renal failure. It has been found to be closely related to the renal function and to interdialytic hydration status. The clinical relevance of proANP(1-98) and cystatin C, a novel marker of glomerular filtration, has not been investigated in the subgroup of critically ill septic patients with no history of chronic renal impairment.

METHODS

We measured plasma level ofproANP(1-98) and cystatin C in 29 critically ill septic patients on admittance to the surgical intensive care unit and correlated it with the occurrence of acute renal failure.

RESULTS

The proANP(1-98) plasma level was significantly higher in the group of patients who developed renal failure (12,722 +/- 12,421 vs. 2,801+/- 2,023 fmol/ml, p < 0.05). Multiple regression analysis shows that proANP(1-98) on the first day in the intensive care unit has a superior predictive value for the occurrence of renal failure to diuresis, calculated creatinine clearance or cystatin C (r = 0.42, p < 0.039). proANP(1-98) is also higher in non-survivors (9,303.8 +/- 11,053 vs. 2,448.5 +/- 1,803 fmol/ml, p < 0.018).

CONCLUSION

proANP(1-98) is possibly a better predictor of acute renal failure to calculated creatinine clearance or diuresis among critically ill septic patients. Cystatin C was not correlated with occurrence of acute renal failure in this subgroup of patients.

Influence of the sagittal advancement of mandibulae on myofibrillar ATPase activity and myosin heavy chain content in the masticatory muscles of pigs

Endurance muscle stress leads to polymorphic expression of myosin heavy chains (MyHC). Histochemical and electrophoretic analyses were performed on different masticatory muscles (masseter, temporal, geniohyoid and medial pterygoid) of 10 weeks old pigs after 28 days of chronic sagittal advancement of the mandibulae. The differentiation between fiber types was investigated histochemically with the myofibrillar ATPase (mATPase) method and by immunohistochemistry. Expression of different MyHC isoforms was also assessed by means of immunoblotting with monoclonal antibodies. The results of both methods were compared. Chronic sagittal advancement of the mandibulae led to an increase in the cross-sectional area of type I fibers and type I MyHC in the anterior part of the masseter, the distal part of the temporal and the medial pterygoid muscle. In the present study, clear differentiation between type I and type II muscle fibers in all histological analyses was possible. However, mATPase classification of subtypes of type II fibers may lead to misinterpretations. Additionally, a direct correlation between the type I MyHC concentration and the type I fibers was seen in enzyme histochemical and immunohistochemical staining. The defined cross section of fibers is important for the histological investigation in small muscles. The immunoblot method seems to be more sensitive and less subjective for measurement of muscle changes. It can be concluded that the immunoblot method used for measuring the MyHC content is a valid alternative for fiber typing in small muscles as it is less time-consuming and more sensitive than qualitative histochemistry.

[Guidelines in pain treatment--methodical quality of guidelines for treatment of pain patients]

The committee for quality assurance of the German IASP chapter (DGSS) evaluated all relevant guidelines concerning pain treatment. Quality of guidelines was analysed according to the checklist "Methodical quality of guidelines" by Ollenschläger and the user manual released by the German Medical Centre for Quality Assurance. The guideline for the treatment of back pain released by the German Medical Association was examined as well as the one released by the German Association for physical therapy and rehabilitation, the guideline on cervical and lumbal nerve root compression syndrome of the German Association of Neurosurgeons, the guideline for cancer pain of the Drug Committee of the German Medical Association was compared with the one of the German Interdisciplinary Association for Pain Treatment. The guideline for the treatment of chronic headache and facial pain of the Medical Association was evaluated and the guideline for the treatment of trigeminal neuralgia of the German Association of Neurosurgery and Neurology, also the guideline for the treatment of acute postoperative and posttraumatic pain. All guidelines show deficiencies in different aspects and of different severity. At first there are deficiencies in interdisciplinary formulation of the guidelines and identification and interpretation of evidence of multimodal pain treatment options. The most prominent deficiency is the lack of implementation and application trials or impulses by all author associations. This way all expenditure on releasing guidelines is given away without improving quality of pain treatment. The authors' recommendation is to adjust to guidelines and, if they are working or not, tell the authors and improve interdisciplinary in pain treatment guidelines.

Pro-atrial natriuretic peptide hormone from right atria is correlated with cardiac depression in septic patients

N-terminal pro-atrial natriuretic peptide [proANP(1-98)] has been extensively investigated in patients with chronic heart failure and ishemic heart disease. It is found to be a better marker of cardiac dysfunction than atrial natriuretic peptide (ANP). The possible involvement of proANP(1-98) in cardiac depression caused by sepsis has not been studied yet. Therefore, we analyzed atrial plasma concentration of proANP(1-98) in 17 septic patients with hemodynamic variables measured or calculated using pulmonary artery catheter. The results of altogether 96 measurements show a significant negative correlation of proANP(1-98) and cardiac index (p<0.024), oxygen delivery (p<0.03) and oxygen consumption (p<0.03). There is also a positive correlation with pulmonary vascular resistance (p<0.03). ProANP(1-98) is significantly higher in patients who developed acute respiratory distress syndrome (ARDS) (p<0.001). This study implies that proANP(1-98) is a possible novel hormone marker of cardiac depression caused by sepsis that could be used for prediction of ARDS.

The carcinostatic and proapoptotic potential of 4-hydroxynonenal in HeLa cells is associated with its conjugation to cellular proteins

BACKGROUND

Previous studies have shown that the lipid peroxidation product 4-hydroxynonenal (HNE) acts as a cell growth modulator if used at low, physiological concentrations being strongly cytotoxic at higher concentrations for a number of cells. These effects of HNE also appeared to be mutually dependent on the effects of serum growth factors. The aim of this investigation was to study the concentration-dependent response of human cervical carcinoma (HeLa) cells in vitro with respect to the intracellular uptake of exogenous HNE, the cellular energy metabolism, DNA synthesis, overall gene expression and susceptibility to apoptosis.

MATERIALS AND METHODS

MTT assay was applied as an index of energy metabolism and the replicative activity was quantitated by the 3H-thymidine incorporation assay. The occurence and intracellular distribution was studied with monoclonal antibodies directed against HNE-protein conjugates. Binding of HNE to serum proteins was determined with the same antibodies by Western blotting. Differential gene expression was studied by differential display RT-PCR while a novel photometric assay, denoted Titer-TACS, was used for in situ detection and quantitation of apoptosis in monolayer cell cultures.

RESULTS

A physiological concentration of HNE (1 microM) had hardly any effect on the parameters of the replicative activity and the energy metabolism. No morphological changes were observed and the number of HNE-positive cells was not significantly different when compared to the untreated control cells, while most of the aldehyde appeared to be bound to serum proteins (albumin fraction). A ten-fold higher concentration (10 microM) was found to be cytostatic. Spindle-shaped cells with a picnotic nucleus were observed occasionally, as well as membrane blebs, which were HNE-positive. The number of HNE-positive cells was significantly increased compared both to the control cells and cells treated with 1 microM HNE, but in the presence of serum the effects of 10 microM HNE were negated due to its binding to the serum proteins. Finally, 100 microM HNE was cytotoxic for the HeLa cells. Most of the cells were picnotic, together with a few spindle-shaped or oval cells. The staining for HNE was diffuse and strong (90% of the cells were HNE-positive) while even binding of the aldehyde to serum proteins did not prevent its cytotoxic effects. This concentration of HNE caused acute stress response of the cells resulting in the decreased expression of several as yet unidentified genes. The altered pattern of gene expression was followed by programmed cell death, i.e. an increased number of apoptotic cells after treatment with low (1 and 10 microM) concentrations of HNE. A rebound effect was observed, i.e. a decrease of apoptotic cells after 24 hours followed by an overshooting increase after 48 hours.

CONCLUSIONS

For HeLa carcinoma cells there appears to be a concentration range of HNE where it does not cause necrosis but preferentially apoptosis. At this concentration range HNE is cytochemically detectable within the cells as a protein conjugate. It is proposed that a possible differential sensitivity of cancer cells and their normal counterparts to the cytostatic activity of HNE should be explored.

Anionic phospholipids are involved in membrane targeting of PI 3-kinase gamma

Phosphoinositide 3-kinases (PI 3-kinases) have critical roles in diverse cellular signaling processes and in protein trafficking. In contrast to the class I PI 3-kinases alpha, beta, and delta which bind via src homology 2 (SH2) domains of adaptor proteins to tyrosine kinase receptors, the mechanism of recruitment of the PI 3-kinase gamma to membranes is unknown. We report in vitro experiments using immobilized proteins and small unilamellar vesicles which suggest an involvement of anionic phospholipids in membrane association of PI 3-kinase gamma. Furthermore we provide evidence that the enzyme displays beside the catalytic center a phospholipid binding domain which is essential for enzyme activity.

Multiple PIP2 binding sites in Kir2.1 inwardly rectifying potassium channels

Inwardly rectifying potassium channels require binding of phosphatidylinositol-4,5-bisphosphate (PIP2) for channel activity. Three independent sites (aa 175-206, aa 207-246, aa 324-365) were located in the C-terminal domain of Kir2.1 channels by assaying the binding of overlapping fragments to PIP2 containing liposomes. Mutations in the first site, which abolished channel activity, reduced PIP2 binding of this fragment but not of the complete C-terminus. Point mutations in the third site also reduced both, channel activity and PIP2 binding of this segment. The relevance of the third PIP2 binding site provides a basis for the understanding of constitutively active Kir2 channels.

Retinoic acid induces selective expression of phosphoinositide 3-kinase gamma in myelomonocytic U937 cells

Retinoic acid provokes growth inhibition and differentiation of the human leukemic cell line U937 to macrophage-like cells. We report that treatment of U937 cells with all-trans retinoic acid (ATRA), but not the phorbol ester 12-O-tetradecanoylphorbol-13-acetate, results in an increased gene expression of the phosphoinositide 3-kinase (PI3K) species PI3Kgamma. PI3Kgamma expression was transcriptionally elevated, indicating that the PI3Kgamma gene may be a direct target for ATRA. In contrast to its effect on PI3Kgamma expression, ATRA did neither affect the levels of the PI3K species beta and delta nor the adapter proteins p85 and p101. Enhanced expression by ATRA of PI3Kgamma correlated with an increase of PI3K lipid kinase activity. Additionally, ATRA induced significant and lasting stimulation of mitogen-activated protein kinase/Erk2 activity. This effect was sensitive to the PI3K inhibitors wortmannin or LY294002 and, therefore, attributed to the upregulation of PI3Kgamma expression. Our findings suggest that sustained MAPK activation via PI3Kgamma precedes ATRA -dependent differentiation or growth inhibition.

Identification of 55 kDa phosphatidylinositol 4-kinase in HaCaT cells: comparison with the epithelial cell line A431

Phosphatidylinositol kinases play a crucial role in signal transduction in many cell types. The 55 kDa isoform of phosphatidylinositol 4-kinases is a key enzyme in the metabolism of phosphoinositides, which work as regulators of cell function itself or as precursors of signal molecules. The experiments with HaCaT cells presented suggest that the phosphatidylinositol 4-kinase activity in this cell line corresponds to the 55 kDa isoform concerning kinetic parameters and specific activity in comparison with the malignant cell line A431. Km (for ATP and phosphatidyl-inositol) and Ki values (for Ca2+ and adenosine) are in good agreement with the parameters described for other cells. The findings support the idea that the 55 kDa phosphatidylinositol 4-kinase represents a key enzyme in the inositide signal transduction pathway.

[Quality control in the therapy of chronic pain. Results obtained by a task force of the German Section of the International Association for the Study of Pain on psychological assessment of chronic pain. XI. Assessment and multiaxial classification of pain]

This paper reviews instruments in German language for the psychological assessment and classification of pain. Usually chronic pain syndromes are classified within the International Classification of Diseases (ICD). Instead of the psychiatric chapter of the ICD, it is possible to use the Diagnostic and Statistical Manual of Mental Disorders (DSM). The proposed classification system of the International Association of the Study of Pain (IASP) is based on a multiaxial solution. The numerous ways to classify chronic pain include many problems and limits, especially in the case of an interdisciplinary assessment. They provide no specific system for classifying pain syndromes. They are impractical to handle and restrict classifying pain as either somatogenic or psychogenic. It is not possible to describe both sides in one diagnosis without loss of information. As a result of this situation, a task force of the German Chapter of the International Association for the Study of Pain developed a Multiaxial Classification of Pain (Multiaxiale Schmerzklassifikation; MASK) as an advanced system of pain assessment and an alternative to the common classification systems. MASK embraces a somatic (MASK-S) and a psychological (MASK-P) part. Both parts constitute an 'interdisciplinary diagnosis'. MASK-S enables classifying a pain syndrome using hierarchical levels, with progredient specific degrees of differentiation. In addition there are 6 axes to describe pain syndromes qualitatively and quantitatively (e.g. localization, quality). The psychosocial part (MASK-P) embraces 5 main levels (1. behavioral, 2. emotional, 3. cognitive, 4. stress-related, 5. habitual personal factors) and 2 additional levels (6. functional coherence, 7. ICD/DSM-diagnosis additional). The MASK-P part of the diagnosis is composed of graduation on these levels. Differential axis of the pain syndromes are described phenomenologically and specifically. MASK provides the possibility of establishing an integrative, interdisciplinary diagnosis.

Dependence on intracellular Ca2+ on mass and turnover of phosphoinositides and phosphatidate in human erythrocytes

Effects of a calcium-load on mass and turnover of phosphoinositides and phosphatidate were investigated in human erythrocytes by short-term labeling with [32P]Pi. The labeling of phosphatidate was accelerated at normal mass by short-term elevation of free intracellular [Ca2+] up to 1 microM and inhibited by the reduction of normal free [Ca2+]. Thus, the labeling of phosphatidate is a Ca2+-regulated process and not only the consequence of a net synthesis of diacylglycerol by other Ca2+-dependent reactions. Persisting elevation of free intracellular [Ca2+] between 1-40 microM induced an increase of the mass of phosphatidylinositol 4-phosphate with a concomitant decrease of the mass of phosphatidylinositol 4,5-bisphosphate. Under these conditions, the normal steady-state turnover of phosphoinositides was not altered by Ca2+, but mass and turnover of phosphatidate continuously rose. The increase in phosphatidate mass by far exceeded the decrease of the mass of phosphoinositides, indicating that phosphatidate was generated to a great extent by hydrolysis of other phospholipids in addition to the action of phosphoinositidase C with subsequent phosphorylation of diacylglycerol to phosphatidate. The results demonstrate that different phospholipid phosphodiesterases of human erythrocytes are activated by Ca2+-concentrations in the microM range as is known from various other cell types. In contrast to current explanations, Ca2+-dependent phospholipid phosphodiesterases of human erythrocytes did not exhibit an unusually low affinity against rising cytosolic Ca2+-concentrations.

Lipid kinase and protein kinase activities of G-protein-coupled phosphoinositide 3-kinase gamma: structure-activity analysis and interactions with wortmannin

Signalling via seven transmembrane helix receptors can lead to a massive increase in cellular PtdIns(3,4,5)P3, which is critical for the induction of various cell responses and is likely to be produced by a trimeric G-protein-sensitive phosphoinositide 3-kinase (PI3Kgamma). We show here that PI3Kgamma is a bifunctional lipid kinase and protein kinase, and that both activities are inhibited by wortmannin at concentrations equal to those affecting the p85/p110alpha heterodimeric PI3K (IC50 approx. 2 nM). The binding of wortmannin to PI3Kgamma, as detected by anti-wortmannin antisera, closely followed the inhibition of the kinase activities. Truncation of more than the 98 N-terminal amino acid residues from PI3Kgamma produced proteins that were inactive in wortmannin binding and kinase assays. This suggests that regions apart from the core catalytic domain are important in catalysis and inhibitor interaction. The covalent reaction of wortmannin with PI3Kgamma was prevented by preincubation with phosphoinositides, ATP and its analogues adenine and 5'-(4-fluorosulphonylbenzoyl)adenine. Proteolytic analysis of wortmannin-prelabelled PI3Kgamma revealed candidate wortmannin-binding peptides around Lys-799. Replacement of Lys-799 by Arg through site-directed mutagenesis aborted the covalent reaction with wortmannin and the lipid kinase and protein kinase activities completely. The above illustrates that Lys-799 is crucial to the phosphate transfer reaction and wortmannin reactivity. Parallel inhibition of the PI3Kgamma-associated protein kinase and lipid kinase by wortmannin and by the Lys-799-->Arg mutation reveals that both activities are inherent in the PI3Kgamma polypeptide.

[Quality assurance in chronic pain therapy. Results obtained by a task force of the German Chapter of the International Association for the Study of Pain on psychological Assessment of chronic Pain. Psychological instruments for the assessment of pediatric pain]

The present paper is one in a series of publications reviewing German instruments for the psychological assessment of pain. Part X deals with pain measurement of acute and chronic pain in infants and children. German assessment instruments of pediatric pain together with frequently used instruments of American origin are examined and described. The survey contains self-report and behavioral pain measures. Multidimensional pain interviews for both children and parents, diaries and rating scales, as well as observation measures especially for infants, are examined. Since the selection of pain-assessment instruments is dependent on the age and cognitive level of the children, for each instrument a minimum age limit is given. In cases in which quantitative indices of reliability, validity and objectivity are still needed, the evaluation is based on qualitative quotations.

Dependence on intracellular pH and Mg2+ of metabolic compartmentation of phosphoinositides in human erythrocytes

Effects of intracellular pH and Mg2+ on turnover and extent of metabolic compartmentation of phosphomonoester groups of phosphoinositides and phosphatidate were investigated in human erythrocytes by short-term and equilibrium labeling with [32P]Pi under steady-state conditions. At pH 6.7, the specific radio-activities of phosphoinositides reached apparent equilibrium values, in the range of 70% of that ATP-gamma-P after long-term labelling. At pH 7.2, these values were in the range of 40-50% of that ATP-gamma-P. This demonstrates a decreased accessibility of phosphoinositides to enzymatic phosphorylation and dephosphorylation at the transition from acidic to normal incubation conditions. These changes were more pronounced at pH 7.8. High intracellular [Mg2+] initially activated the turnover of phosphoinositides at pH 7.2. The activation changed into an inhibition and an increase of metabolic compartmentation after three hours preincubation of erythrocytes at high [Mg2+]. The long-term Mg2+ effects are reversible to a great extent by a subsequent re-reduction of [Mg2+]. In conclusion, deprotonation of phosphoinositides by low [H+] or high intracellular [Mg2+] at normal pH induces a decreased accessibility for their specific lipid kinases and phosphatases. This effect may be the result of lateral phase separation of acidic phospholipids as a consequence of divalent cation complexation under both experimental conditions, high pH and high [Mg2+] at normal pH.

[Quality assurance in therapy of chronic pain. Results obtained by a task force of the German Section of the Association for the Study of Pain on psychological assessment of chronic pain. IX. Multidimensional instruments for the assessment of aspects relating to pain and recommendations on standard procedures for diagnosis]

Four multidimensional inventories used as instruments for the assessment of pain are examined: "Fragebogen zur Erfassung der Schmerzverarbeitung' [Questionnaire for Assessment of Level of Coping with Pain], "Kieler Schmerzverarbeitungs-Inventar' [Kiel Inventory of Coping with Pain], "Fragebogen zur Schmerzregulation' [Questionnaire on Pain Regulation], and the German version of the "Multidimensional Pain Inventory'. None of these questionnaires assesses all domains that are important in chronic pain. The recommended standardized assessment routine for pain centres includes the use of a diary, the rating of actual, average and maximum pain intensity, the application of the PDI, a measure of disability, and the FESV, which records cognitive processing and coping. As measures of general psychological dysfunction the ADS for the assessment of depression and the B-L, a symptom checklist, are suggested as instruments suitable for routine use in diagnosis and evaluation.

[Quality assurance in therapy of chronic pain. Results obtained by a taskforce of the German Section of the Association for the Study of Pain on psychological assessment of chronic pain : VI. Instruments for the assessment of disability VII. Psychological instruments for the assessment of pain relevant aspects of social interaction and communication.]

Disability is a central aspect in the assessment of chronic pain patients. Disability questionnaires in German (developed or adapted) are examined and selected for different purposes. The "Funktionsfragebogen Hannover" and the "Pain Disability Index" are recommended for both research and clinicalapplication while the "Sickness Impact Profile" is suitable only for research purposes.Four different German questionnaires for the assessment of social interaction and communication in pain patients and their significant others are examined in part VII. There are some empirical data for three of them. Only the "Inventory of Familial Adaptability and Cohesion" has achieved a certain degree of empirical maturity. Further research and developmental activity in this area of pain assessment are urgently needed.