[Differences between German and Turkish-speaking participants in a chronic heart failure management program]. / Unterschiede zwischen deutsch- und türkischsprachigen Teilnehmenden an einem strukturierten Herzinsuffizienz-Versorgungsmodell.

BACKGROUND: German and Turkish-speaking patients were recruited for a chronic heart failure management program. So far little is known about the special needs and characteristics of Turkish-speaking patients with chronic heart failure; therefore, the aim of this study was to examine sociodemographic and illness-related differences between German and Turkish-speaking patients with chronic heart failure. METHODS: German and Turkish-speaking patients suffering from chronic heart failure and insured with the AOK Rheinland/Hamburg or the BARMER GEK health insurance companies and living in Cologne, Germany, were enrolled. Recruitment took place in hospitals, private practices and at information events. Components of the program were coordination of a guideline-oriented medical care, telemonitoring (e.g., blood pressure, electrocardiogram, and weight), a 24-h information hotline, attendance by German and Turkish-speaking nurses and a patient education program. Data were collected by standardized interviews in German or Turkish language. Data were analyzed with descriptive measures and tested for significance differences using Pearson's χ2-test and the t­test. RESULTS: A total of 465 patients (average age 71 years, 55 % male and 33 % Turkish-speaking) were enrolled in the care program during the study period. Significant differences between German and Turkish-speaking patients were found for age, education, employment status, comorbidities, risk perception, knowledge on heart failure and fear of loss of independence. DISCUSSION: The response rate could be achieved with the help of specific measures for patient enrollment by Turkish-speaking integration nurses. The differences between German and Turkish-speaking patients should in future be taken into account in the care of people with chronic heart failure.

[Qualitative Research in Health Services Research - Discussion Paper, Part 3: Quality of Qualitative Research]. / Qualitative Studien in der Versorgungsforschung - Diskussionspapier, Teil 3: Qualität qualitativer Studien.

The third and final discussion paper of the German Network of Health Services Research's (DNVF) "Qualitative Methods Working Group" demonstrates methods for the evaluation and quality of qualitative research in health services research. In this paper we discuss approaches described in evaluating qualitative studies, including: an orientation to the general principles of empirical research, an approach-specific course of action, as well as procedures based on the research-process and criteria-oriented approaches. Divided into general and specific aspects to be considered in a qualitative study quality evaluation, the central focus of the discussion paper undertakes an extensive examination of the process and criteria-oriented approaches. The general aspects include the participation of relevant groups in the research process as well as ethical aspects of the research and data protection issues. The more specific aspects in evaluating the quality of qualitative research include considerations about the research interest, research questions, and the selection of data collection methods and types of analyses. The formulated questions are intended to guide reviewers and researchers to evaluate and to develop qualitative research projects appropriately. The intention of this discussion paper is to ensure a transparent research culture, and to reflect on and discuss the methodological and research approach of qualitative studies in health services research. With this paper we aim to initiate a discussion on high quality evaluation of qualitative health services research.

Can a stressed oncologist be good in a consultation? A qualitative study on the oncologists' perception.

The aim of this exploratory study was to examine how the working conditions and job stress of private practice oncologists (PPOs) affect their interaction with patients. Data for the study were collected through semi-structured interviews with PPOs selected based on purposeful sampling criteria. The data were evaluated using content analysis. Factors perceived by PPOs to influence their level of stress and patient care were some of their own personal characteristics as well as working conditions both within and outside their practices. Apart from being able to name specific stressors (e.g., dysfunctional organisational workflow and interruptions during medical encounters), the oncologists also mentioned individual and organisational resources (e.g., professional experience, well-educated nurses and good work organisation) for coping with job stress and improving interaction with patients. Within this study, we identified some obstacles on the individual and organisational level for good patient care, as working conditions which might lead to time pressure and stress, which subsequently have an impact on quality in patient care (e.g., less time for personal issues during patient consultations). Future stress research should conduct a more in-depth investigation of these and other interventions at both the individual and organisational levels in order to improve patient care.

[Thrombolysis for acute stroke--a nationwide analysis of regional medical care]. / Thrombolyse des akuten Schlaganfalls--Eine deutschlandweite Analyse der regionalen Versorgung.

BACKGROUND: This study aims at investigating ischaemic stroke therapy in Germany by using secondary data. The focus lies on the performance of thrombolysis. METHODS: Statutory quality report data for 2010 were obtained. All hospitals (n = 1302) treating patients suffering from an ischaemic stroke either on a neurological, internal, geriatric or intensive care unit were analysed. The treatment situation, defined as the experience in performing thrombolysis, was displayed cartographically. Potential variables that may influence the thrombolysis rate were analysed. RESULTS: 78 % of the 198,500 ischaemic stroke cases were treated on a ward specialised in the stroke treatment (i. e., a stroke unit). The mean thrombolysis rate in neurological departments was 9.1 %. Thrombolysis rates between departments ranged from 0 to 38 %. Significant factors influencing the thrombolysis rate were the total number of ischaemic strokes treated as well as the existence of a stroke unit. DISCUSSION: In Germany, to date regional differences in the treatment of ischaemic stroke exist. Experience in the treatment of ischaemic stroke patients and the availability of a stroke unit both increase the thrombolysis rate. Data suggest that in Germany there is still room for improvement of appropriate ischaemic stroke treatment.

[Qualitative research in health services research - discussion paper, Part 1: What is the idea?]. / Qualitative Studien in der Versorgungsforschung - Diskussionspapier, Teil 1: Gegenstandsbestimmung.

In this first part of a 3-part discussion paper the working group "Qualitative Methods" in the German Network of Health Services Research (DNVF) identifies the potentials and opportunities qualitative research methods provide for health services research. Many research questions relevant for health services research require the use of qualitative methods. However, the potential of and need for qualitative research in health services research has not yet received sufficient attention from funding bodies. We discuss the applicability and importance of qualitative research for the field of health services research. We then move on to describe the key characteristics of qualitative research that need to be taken into account in health services research. We discuss characteristics such as open-ended (qualitative) data, interpretation of meanings, the search for contradictions, closeness to everyday life, openness towards change or modification of the research question and processes in the context of health services research. To ensure a high-quality approach in qualitative methods for the health services research, sufficient competency in methods and appropriate settings that account for the peculiarities of qualitative methods need to be developed. These include an appropriate time frame and sufficient and qualified personnel to conduct qualitative research. Qualitative research is not a research paradigm in itself rather it comprises of many different and diverging approaches. The goal of this paper is to show the diversity of qualitative research methods, its importance for health services research, and to open up the discussion on strategies for integrating qualitative methods into health services research.

[Qualitative research in health services research - discussion paper, Part 2: Qualitative research in health services research in Germany - an overview]. / Qualitative Studien in der Versorgungsforschung - Diskus-sionspapier, Teil 2: Stand qualitativer Versorgungsforschung in Deutschland - ein exemplarischer Überblick.

BACKGROUND: This is the second part of a 3-part discussion paper by the working group on "Qualitative Methods" in the German network of health services research (DNVF) that shall contribute to the development of a memorandum concerning qualitative health services research. It aims to depict the different types of qualitative research that are conducted in health services research in Germany. In addition, the authors present a specific set of qualitative data collection and analysis tools to demonstrate the potential of qualitative research for health services research. QUALITATIVE RESEARCH IN HEALTH SERVICES RESEARCH - AN OVERVIEW: To give an overview of the types of qualitative research conducted in German health services research, the abstracts of the 8th German Conference on Health Services Research were filtered to identify qualitative or mixed-methods studies. These were then analysed by looking at the context which was studied, who was studied, the aims of the studies, and what type of methods were used. Those methods that were mentioned most often for data collection and analysis are described in detail. QUALITATIVE RESEARCH AT THE CONFERENCE FOR HEALTH SERVICES RESEARCH 2009: Approximately a fifth of all abstracts (n=74) had a qualitative (n=47) or a mixed-methods approach combining quantitative and qualitative methods (n=27). Research aims included needs assessment (41%), survey development (36%), evaluation (22%), and theorizing (1%). Data collection mostly consisted of one-on-one interviews (n=45) and group discussions (n=29). Qualitative content analysis was named in 35 abstracts, 30 abstracts did not reference their method of analysis. In addition to a quantitative summary of the abstract findings, the diversity of fields addressed by qualitative methods is highlighted. CONCLUSION: Although drawing conclusions on the use of qualitative methods in German health services research from the analysis of conference abstracts is not possible, the overview we present demonstrates the diversity of methods used for data collection and analysis and showed that a few select methods are extensively used. One of the tasks a memorandum of qualitative health services research should accomplish is to highlight underutilized research methods, which may help to develop the potential of qualitative methodology in German health services research.

[Methods for organisational health services research]. / Methoden für die organisationsbezogene Versorgungsforschung.

On 1 July 2009, the German Network for Health Services Research [Deutsches Netzwerk Versorgungsforschung e. V. (DNVF e. V.)] approved the Memorandum III "Methods for Health Services Research", supported by the member societies mentioned below and published in this journal (Gesundheitswesen 2009; 71: 505-510). The focus of this part of the Memorandum III "Methods for health services research" is on the questions and methods of organisational health services research. In a first step, we describe the central questions which are at the core of organisational health services research. In a second step, we describe the methodological standards and requirements with regard to a) sampling, b) measurement and c) research design. We present a phase model for complex intervention trials. This model allows to conduct high quality organisational health services research, to integrate different methods of social research and to show in which phase they are of special importance.

Rhabdomyosarcoma spheroids with central proliferation and differentiation.

A novel type of multicellular spheroids was established and characterized with regard to growth behavior, proliferation, and differentiation. The spheroids were grown from clonal rat rhabdomyosarcoma cells using the spinner flask technique. The cell aggregates showed several unique properties that were different from those observed in most of the spheroids investigated to date. These properties include a non-Gompertzian volume growth; the coexistence of undifferentiated mononuclear cells and of differentiated, myotube-like giant cells with numerous nuclei; a relatively homogeneous intraspheroidal distribution of proliferating mononuclear cells with thymidine labeling even in the center of spheroids greater than 1 mm; the absence of necrosis in such large spheroids, and the accumulation of myotube-like cells in the center of these spheroids instead. There was a decrease in the overall proliferative activity of the mononuclear cells with increasing proportion of giant cells in the rhabdomyosarcoma spheroids.

Pathophysiological approaches to identifying tumor hypoxia in patients.

The present report summarizes observations of the authors on tumor oxygenation and on techniques for characterizing tumor hypoxia in patients. Cryospectrophotometric measurements of HbO2 saturations in tumor microvessels allow for estimates of the proportion of well oxygenated tissue regions. Labeling of tissue areas at oxygen (O2) tensions (pO2) less than 10 mm Hg with misonidazole may be used for a general characterization of the oxygenation status in patient tumors rather than for the determination of the radiobiologically hypoxic cell fraction. Quantitative bioluminescence and single photon imaging make it possible to determine ATP concentrations in absolute terms with a spatial resolution at the cellular level. It is shown that the ATP distribution reflects the efficiency of the O2 supply to tumors. Since all these techniques rely on biopsy material, the measured values can be assessed in relation to the histological structure and vascular pattern of the tumors. Such a direct interrelationship is not obtained when using polarographic microelectrodes in tumor tissue. However, a novel technology, the "computerized pO2 histography" has enabled direct polarographic measurements of pO2 values in patients, in extended and systematic clinical trials. Preliminary results in cervix and breast cancers demonstrate that pO2 values are lower in tumors than in adjacent normal tissues, and that great intra- and intertumoral differences occur even among tumors of the same clinical stages and histological grades, illustrating the necessity of such a pathophysiological approach to an "individualization" of tumor therapy.

Cloning and characterization of two human polyspecific organic cation transporters.

Previously we cloned a polyspecific transporter from rat (rOCT1) that is expressed in renal proximal tubules and hepatocytes and mediates electrogenic uptake of organic cations with different molecular structures. Recently a homologous transporter from rat kidney (rOCT2) was cloned but not characterized in detail. We report cloning and characterization of two homologous transporters from man (hOCT1 and hOCT2) displaying approximately 80% amino acid identity to rOCT1 and rOCT2, respectively. Northern blots showed that hOCT1 is mainly transcribed in liver, while hOCT2 is found in kidney. Using in situ hybridization and immunohistochemistry, expression of hOCT2 was mainly detected in the distal tubule where the transporter is localized at the luminal membrane. After expression in Xenopus laevis oocytes, hOCT1 and hOCT2 mediate tracer influx of N-1-methylnicotinamide (NMN), tetraethylammonium (TEA), and 1-methyl-4-phenylpyridinium (MPP). For cation transport by hOCT2 apparent K(m) and K(i) values were determined in tracer flux measurements. In addition, electrical measurements were performed with voltage-clamped oocytes. Similar to rOCT1, cation transport by hOCT2 was pH independent, electrogenic, and polyspecific; however, the cation specificity was different. In voltage-clamped hOCT2-expressing oocytes, inward currents were induced by superfusion with MPP, TEA, choline, quinine, d-tubocurarine, pancuronium, and cyanine863. Cation transport in distal tubules is indicated for the first time. Here hOCT2 mediates the first step in cation reabsorption. hOCT1 may participate in hepatic excretion of organic cations.

Cellular and paracellular calcium transport in the rat ileum and the influence of 1 alpha, 25-dihydroxyvitamin D3 and dexamethasone.

Concentration dependence of unidirectional calcium fluxes across the rat ileum freed from the serosa and the muscularis externa were measured in a modified Ussing-chamber. Mucosa (m) to serosa (s) calcium flux showed a saturable component, whereas s to m calcium flux was linearly related to the calcium concentration between 0.125 mmol/l and 5 mmol/l. At all calcium concentrations used net secretion of calcium was observed. The s to m flux of the simultaneously measured paracellular marker mannitol at all calcium concentrations was remarkably higher than the m to s flux, resulting in net mannitol secretion. The results obtained from the calcium fluxes when clamping the transepithelial electrical potential agree well with those of the concentration dependence of the calcium fluxes: 1. Only m to s flux has a voltage independent, transcellular component. 2. Calcium s to m flux is totally voltage dependent, i.e. diffusive. 3. Diffusional s to m calcium flux is about 80% greater than the diffusional fraction of the m to s flux. Omitting glucose from the bathing solution effected a decrease of the transepithelial electrical potential and of the short circuit by 91% and 85% respectively; net calcium secretion was almost abolished and net mannitol secretion remarkably reduced. Addition of glucose, which stimulates water absorption in the ileum as a metabolic substrate, activated m to s but significantly more pronounced s to m calcium flux parallel to that of mannitol.(ABSTRACT TRUNCATED AT 250 WORDS)

Strontium transport in the rat colon.

Concentration dependence of strontium (Sr) fluxes across the colon ascendens and descendens of the rat were measured in a modified Ussing-chamber. Mucosa (m) to serosa (s) and s to m Sr fluxes across both colonic segments were linearly related to the Sr concentration from 0.125 mmol/l to 10 mmol/l. In the colon ascendens m to s Sr fluxes were slightly higher than the fluxes in the opposite direction, resulting in net Sr absorption. In the colon descendens s to m fluxes were higher than the ms fluxes, resulting in net Sr secretion. Neither Sr nor calcium (Ca) showed a concentration dependent interaction with respect to their unidirectional fluxes in both parts of the colon. Only in the colon ascendens Sr at the highest concentration (10 mmol/l) inhibited m to s calcium transport. Experiments, in which the voltage dependence of the unidirectional Sr fluxes was measured confirmed the results obtained from the concentration dependence: The unidirectional fluxes of Sr across the colon ascendens and descendens were totally voltage dependent, i.e. diffusive. In the colon descendens the voltage dependence of the s to m flux was steeper than the flux from m to s. It is hypothesized that this prevalence is caused by an anomalous solvent drag effect. 1.25-Dihydroxyvitamin D3 [1.25 (OH)2D3] stimulated m to s calcium flux in the colon descendens but had no effect on Sr flux. The results demonstrate that Sr and Ca in the rat colon are transported by different mechanisms. In contrast to the Ca transport the Sr flux is only diffusive and insensitive to 1.25 (OH)2D3.

Influence of serosal hydrostatic pressure on net water and electrolyte transport across the isolated rat colonic mucosa exposed to different secretagogues.

The influence of 2 cm and 7 cm hydrostatic pressure applied upon the serosal side on net water and electrolyte transport and paracellular permeability was investigated in everted sacs of stripped rat colon mucosa exposed to different secretagogues. A 2 cm pressure abolished net fluid absorption in the presence of deoxycholic acid, bisacodyl, ethacrynic acid and rhein and reduced absorption in the tissue pretreated with cholera toxin. The paracellular permeability was increased by deoxycholic acid, bisacodyl and ethacrynic acid and diminished under the influence of rhein and cholera toxin. At a pressure of 7 cm H2O fluid movement was directed toward the mucosal side parallel to the increase of the paracellular permeability. The fluid appearing at the mucosal side was isotonic in the presence of deoxycholic acid, ethacrynic acid and rhein but hypotonic when the tissue was pretreated with cholera toxin. From the pressure-induced net water flow and the composition of the transferred fluid secretagogues acting predominantly on paracellular pathway can be distinguished from secretagogues acting on basis of other mechanisms.

The role of the paracellular pathway in the net transport of calcium across the colonic mucosa.

Concentration dependent calcium fluxes across the colon descendens of the rat were measured in a modified Ussing chamber. Mucosa (m) to serosa (s) calcium flux showed a saturable component, whereas s to m calcium flux was linearly related to the calcium concentration. At low calcium concentrations net absorption and at concentration above 2.5 mmol/l net secretion of calcium was observed. The results obtained from the unidirectional calcium fluxes when clamping the transepithelial electrical potential agree well with those of the concentration dependence of the calcium fluxes: Only m to s flux has a voltage independent component. Calcium s to m movement is totally voltage dependent. Diffusional s to m calcium flux is greater than the diffusional fraction of the m to s calcium flow. Dexamethasone, known to stimulate water absorption in the colon descendens by an activation of sodium transport, had no effect on the cellular mediated m to s calcium transport but significantly increased paracellular s to m flux parallel to that of the extracellular marker mannitol. This increase in paracellular s to m calcium and mannitol flux was completely abolished by amiloride, which is known to suppress the dexamethasone-induced stimulation in sodium and water absorption. The results demonstrate that the increased paracellular s to m calcium and mannitol flow is oppositely directed to the dexamethasone-induced net fluid movement as it could be expected on the basis of Ussing's "anomalous solvent drag" effect.

Proliferation and oxygenation status of widr spheroids in different lactate and oxygen environments.

Human colon adenocarcinoma cells WiDr were cultured as monolayers or multicellular spheroids in 5% or 20% (v/v) oxygen and in various external lactate concentrations of 0-20 mM. Doubling times and H-3-thymidine labeling indices of exponential monolayer cells indicated that there was no difference in growth behavior between the two oxygen environments, yet these parameters reflected a growth retardation upon elevation of lactate. Growth of WiDr spheroids was retarded in both low oxygen and high lactate concentrations. There was a tendency towards a decrease in the thickness of the viable cell rim with increasing lactate in 20% O-2, whereas the width of the viable rim increased significantly as a function of external lactate in 5% O-2. Intraspheroidal oxygen tensions (Po-2) measured with microelectrodes were less in 5% O-2 than in 20% O-2, yet did not vary systematically as a function of external lactate. Po-2 values in the spheroid center dropped to 0 mm Hg prior to the emergence of central necrosis under all conditions investigated. Unlike numerous other spheroid types investigated up to now, WiDr spheroids mimic tumor microregions with hypoxia-induced necrosis and with nonproliferating cells at very low oxygen pressure.

Interrelationship among morphology, metabolism, and proliferation of tumor cells in monolayer and spheroid culture.

The proliferative activity of tumor cells is positively correlated with the cellular respiration rate. Thus, a decrease in the proliferative fraction during monolayer growth of EMT6 cells is associated with a decrease in the oxygen consumption rate both per cell and per cellular volume. These changes are paralleled by variations in the morphology of the tumor cells. The cellular volume, the cytoplasmic volume, the number and volume of mitochondria is decreased, whereas the volume of the nucleus remains relatively constant during the transition of cells from the exponential to the plateau growth phase. Similar observations have been made in outer, highly proliferative and inner non-proliferating cells in EMT6 spheroids. However, the local oxygen consumption in this three dimensional, tissue-like assemblage of cells is obviously modified by the cellular packing density leading to a rather uniform oxygen uptake in the proliferating and non-proliferating cell areas.

New clinical and experimental aspects of intestinal magnesium transport.

Mg transport across various segments of the rat small and large bowel was measured in the absence of electrochemical gradients and using the voltage clamp technique. In the mucosa-to-serosa (ms) Mg flux across the duodenum, ileum, and colon a cellular part is involved, amounting to 40-70% of the total ms Mg flux measured across the short-circuited tissue. However, serosa-to-mucosa (sm) Mg flux is purely passive, suggesting that net Mg transport is largely determined by convectively driven Mg flux across the paracellular pathway. Mg is absorbed across the colon and ileum but in the duodenum paracellularly it is secreted due to an 'anomalous solvent drag effect'. Mg in the caecum decreases cellular ms Ca transport but in the other segments only passive ms Ca flux is reduced by a decrease of the paracellular permeability for Ca, or by a Mg-induced decrease in water absorption. Mg transport across all segments is insensitive to 1,25(OH)2D3. Dexamethasone abolishes cellular Ca transport but stimulates paracellular ms Mg flux in the duodenum. It is concluded that in the rat (a) Mg and Ca are transported by distinct cellular and paracellular mechanisms; (b) Mg transport is largely confined to the paracellular pathway; (c) the ileum and the colon are the major sites for the gut regulation of Mg homeostasis.

[A rare cause of hepatic coma]. / Seltene Ursache eines hepatisch bedingten Komas.

CASE REPORT: A 65-year-old female patient was admitted to the hospital in somnolent state. During physical examination, she had an increase in blood pressure and a positive bilateral Babinski's sign. Laboratory findings showed elevated liver enzymes, metabolic alkalosis and slightly elevated kidney values. 3 h hours later she lapsed into a hepatic coma (ammonia > 400 micrograms/dl). Subsequently, indirect anamnesis revealed the following affections: ureterosigmoidostomy in 1942, cystectomy in 1943, and right-sided nephrectomy in 1950. DISCUSSION: This case presents with an uncommon origin of the hepatic encephalopathy: in the operated colon, bacterial overgrowth (bacteriogenic ureapoiesis) developed, which led to a hyperammonemia. Furthermore, in mild alcoholic liver disease--as in this case--ammonia cannot be metabolized to urea and leads to hepatic encephalopathy. We considered making this part of the colon poor in bacteria (by consequent administration of antibiotics), thus reducing the formation of ammonia.