[Healthcare in Germany: Including Physician Assistants into the Team of Physicians]. / Gesundheitsversorgung in Deutschland durch Mitarbeit von Physician Assistants im ärztlichen Team.

BACKGROUND: Physicians in Germany are overburdened. Delegation of tasks to Physician Assistants (PA) is one way of providing relief. Although PA work in Germany since 2012, few data are available. We studied advantages and disadvantages from those physicians point of view, who cooperate with PA since years, as well as working conditions, satisfaction and duration of work processes of PA. METHOD: Semi-quantitative cross-sectional survey on a course of PA graduates and the physicians they work with since three years. Retrospective analysis of patients´ waiting time and duration of stay in an emergency department. RESULTS: Physicians were very satisfied with PA and reported a high degree of relief from workload. PA were highly satisfied with their job. Processing time in the emergency department was not longer when a PA was involved in patient care. CONCLUSION: Physicians are satisfied with PA as they are relieved from a heavy workload. More data on effectiveness and efficiency of PA in Germany are needed.

[What is the contribution of physician assistants to health care in Germany? A differentiation between physician assistants and physicians in training]. / Welchen Beitrag können Physician Assistants zur Gesundheitsversorgung leisten? Eine Abgrenzung zu Ärztinnen und Ärzten in Weiterbildung.

BACKGROUND: Physicians in training are major contributors to the German health care system. After graduation from medical school, physicians in training qualify for a certain specialty. The workload of physicians in training in Germany is so high that they have expressed their need for support. One opportunity to support physicians in training is by delegating tasks to physician assistants (medical assistants qualified by a specific course of study, graduated from universities of applied sciences). However, there is a lack of knowledge about the qualification of physician assistants and the conditions which allow support of physicians in training by physician assistants in Germany. METHODS: Based on a focused internet search, this paper describes the development of the profession physician assistance in Germany and the currently offered graduation courses including their duration and qualification requirements. Furthermore, we present available recommendations for the content of physician assistants' education and characterize conditions for the support of physicians in training by physician assistants. RESULTS: In Germany, physician assistance has been an academic discipline since 2005, the profession is, however, still quite seldom. Qualification requirements and the duration of education are determined by the universities. The aim is to qualify students for several competencies, which enable physician assistants to perform tasks of physicians under delegation. The conditions for delegation to physicians in training and to physician assistants are quite similar, resulting in partly comparable practice. Major differences relate to the so called "physician reservation" or physicians' core area, both of which define tasks that may only be carried out by physicians. DISCUSSION: Integrating physician assistants into a medical team means supporting the specialists by delegating tasks, thus reducing the workload of all physicians in the team, including physicians in training. Currently, there are no data on and no outcomes of the performance of physician assistants in Germany. CONCLUSION: In everyday practice, health care delivered by physician assistants and by physicians in training is similar, at least as regards activities and tasks that do not need physician supervision.

Dealing with foreign cultural paradigms: A systematic review on intercultural challenges of international medical graduates.

OBJECTIVES: An increasing number of International Medical Graduates (IMG), who are defined to be physicians working in a country other than their country of origin and training, immigrate to Western countries. In order to ensure safe and high-quality patient care, they have to take medical and language tests. This systematic review aims to (1) collect all empiric research on intercultural communication of IMGs in medical settings, (2) identify and categorize all text passages mentioning intercultural issues in the included studies, and (3) describe the most commonly reported intercultural areas of communication of IMGs. METHODS: This review was based on the PRISMA-Guidelines for systematic reviews. We conducted a broad and systematic electronic literature search for empiric research in the following databases: MEDLINE, BIOSIS Citation Index, BIOSIS Previews, KCI-Korean Journal Database and SciELO Citation Index. The search results were synthesized and analyzed with the aid of coding systems. These coding systems were based on textual analysis and derived from the themes and topics of the results and discussion sections from the included studies. A quality assessment was performed, comparing the studies with their corresponding checklist (COREQ or STROBE). Textual results of the studies were extracted and categorized. RESULTS: Among 10,630 search results, 47 studies were identified for analysis. 31 studies were qualitative, 12 quantitative and 4 studies used mixed methods. The quality assessment revealed a low level of quality of the studies in general. The following intercultural problems were identified: IMGs were not familiar with shared decision-making and lower hierarchies in the health care system in general. They had difficulties with patient-centered care, the subtleties of the foreign language and with the organizational structures of the new health care system. In addition, they described the medical education in their home countries as science-oriented, without focusing on psychosocial aspects. CONCLUSION: There is a need for a better training of IMGs on culture-related and not culture-related topics in the new workplace country. The topics that emerged in this review constitute a basis for developing these courses. Further empiric research is needed to describe the findings of this review more precisely and should be in accordance with the existing reporting guidelines.

Focal gene induction in the liver of rats by a heat-inducible promoter using focused ultrasound hyperthermia: preliminary results.

OBJECTIVE: We sought to examine high-intensity focused ultrasound (HIFU)-induced hyperthermia in the liver of a rat model to focally induce green-fluorescent protein (GFP). MATERIALS AND METHODS: A total of 25 Copenhagen rats were included in this study. Rats were divided into groups treated with an adenovirus coding for green fluorescent protein (GFP) under the control of a hsp70B promoter and a CMV promoter. Ad-CMV-GFP-treated rats served as positive control. Untreated controls only subjected to MRI +/- HIFU-treatment served to find out optimal power of HIFU in the target area of the liver. Temperature was noninvasively monitored by temperature sensitive magnetic resonance imaging (MRI). RESULTS: Rats treated with Ad-hsp70B-GFP demonstrated localized gene induction within the liver parenchyma, in good correlation with MRI and histology. Applying an acoustic power of 1.92 W a relatively uniform focal temperature up to 42 +/- 5 degrees C within the liver parenchyma could be documented. 3 x 10(9) plaque-forming units proved to account for a very homogeneous liver infection. Number of fluorescent cells in the region of hyperthermia was similar to the control group treated with Ad-CMV-GFP. CONCLUSION: Using the introduced parameters spatially controlled gene induction within a parenchymal organ such as the liver in rats using HIFU under control of MRI is feasible.

Simple models improve the discrimination of prostate cancers from the peripheral gland by T1-weighted dynamic MRI.

Evaluation of the accuracy of descriptive and physiological parameters calculated from signal intensity-time curves using T1-weighted dynamic contrast enhanced MRI (DCE MRI) to differentiate prostate cancers from the peripheral gland. Twenty-seven patients with prostate cancers were examined with DCE MRI prior radical prostatectomy. Regions of interest were defined in tumors and non-affected areas in the peripheral zone. Dynamic data were parameterized in amplitude and exchange rate constant (kep) using a two-compartment model. Additionally, relative slope during 26, 39, 52 and 65 s, areas under the curve (AUC) and time to start of signal intensity increase (tlag) were determined. Vessel density (VD) of excised prostates was quantified in tumor areas using a CD34 stain. The parameter slope52 showed 20% higher values (P<0.001) in tumors than in the peripheral gland and compared with the other parameters the largest area under the ROC curve (0.81). The minimum total error rate was attained at a cut-point of 0.021, yielding a sample value of sensitivity and specificity of 70% and 88%, respectively, and a bias-corrected sum of sensitivity and specificity of 1.54. In addition, amplitude (P<0.001), kep (P=0.03) and AUC (P<0.001) were significantly higher in tumors. tlag did not discriminate carcinomas from glandular tissue. VD was higher in tumors than in the non-affected peripheral prostate (P=0.05). However, none of the dynamic parameters in carcinomas showed a significant correlation with VD or Gleason score. Although pharmacokinetic modeling in DCE MRI showed potential to discriminate prostate cancers from peripheral prostate tissue, descriptive parameters of the early signal enhancement after contrast media injection reached higher sensitivity and specificity.

Dynamic contrast-enhanced magnetic resonance imaging rapidly indicates vessel regression in human squamous cell carcinomas grown in nude mice caused by VEGF receptor 2 blockade with DC101.

The purpose of our study was the investigation of early changes in tumor vascularization during antiangiogenic therapy with the vascular endothelial growth factor (VEGF) receptor 2 antibody (DC101) using dynamic contrast-enhanced magnetic resonance imaging (DCE MRI). Subcutaneous heterotransplants of human skin squamous cell carcinomas in nude mice were treated with DC101. Animals were examined before and repeatedly during 2 weeks of antiangiogenic treatment using Gd-DTPA-enhanced dynamic T1-weighted MRI. With a two-compartment model, dynamic data were parameterized in "amplitude" (increase of signal intensity relative to precontrast value) and k(ep) (exchange rate constant). Data obtained by MRI were validated by parallel examinations of histological sections immunostained for blood vessels (CD31). Already 2 days after the first DC101 application, a decrease of tumor vascularization was observed, which preceded a reduction of tumor volume. The difference between treated tumors and controls became prominent after 4 days, when amplitudes of treated tumors were decreased by 61% (P =.02). In line with change of microvessel density, the decrease in amplitudes was most pronounced in tumor centers. On day 7, the mean tumor volumes of treated (153 +/- 843 mm(3)) and control animals (596 +/- 384 mm(3)) were significantly different (P =.03). After 14 days, treated tumors showed further growth reduction (83 +/- 93 mm(3)), whereas untreated tumors (1208 +/- 822 mm(3)) continued to increase (P =.02). Our data underline the efficacy of DC101 as antiangiogenic treatment in human squamous cell carcinoma xenografts in nude mice and indicate DCE MRI as a valuable tool for early detection of treatment effects before changes in tumor volume become apparent.

Sensitive noninvasive monitoring of tumor perfusion during antiangiogenic therapy by intermittent bolus-contrast power Doppler sonography.

Intermittent bolus-contrast power Doppler ultrasound was used for noninvasive, quantitative monitoring of tumor perfusion during antiangiogenic therapy. Subcutaneous heterotransplants of human squamous cell carcinoma cells in nude mice were treated with a blocking antibody to vascular endothelial growth factor receptor 2 (DC101) and repeatedly examined at weekly intervals. Using replenishment kinetics of microbubbles (Levovist) tumor vascularization, including capillary blood flow, was clearly visualized by this dynamic ultrasound method allowing the determination of a comprehensive functional status of tumor vascularization (blood volume, blood flow, perfusion, and mean blood velocity) in all examined tumors. DC101 treatment decreased tumor blood flow (-64%) and volume (-73%) compared with untreated controls (+409% and +185%, respectively). Regression of functional vessel parameters was observed early well before reduction of tumor size. The treatment-related amount of reduction in tumor volume was directly correlated for the initial tumor blood flow before start of therapy and the perfusion calculated at the preceding examination. The vessel density (immunofluorescence staining with CD31 antibody at different time points) showed an excellent correlation with the calculated relative blood volume (k = 0.84, P < 0.01), thereby validating intermittent sonography as a useful monitoring method. We conclude that intermittent sonography is a promising tool for comprehensive monitoring of antiangiogenic or proangiogenic therapies, especially during early stages of treatment, thus yielding information regarding a prospective evaluation of therapy effects beyond the follow up of tumor size.

A multivessel model describing replenishment kinetics of ultrasound contrast agent for quantification of tissue perfusion.

To improve the quantification of tissue perfusion using intermittent sonography, a new model describing replenishment kinetics of microbubbles is proposed. The new approach takes into account the variability of blood flow velocities found in vivo, especially in tumors, and consistently describes the refilling process of microbubbles. Based upon this model, blood volume, blood velocity, blood flow and perfusion in 17 experimental tumors were calculated, and compared with the results obtained with the established, phenomenologically derived exponential kinetic model. In contrast to the existing model, our approach describes tissue vascularization more physiologically and allows deduction of a consistent new hyperbolic model for quantification of intermittent sonography. Blood volume and mean blood velocity did significantly correlate between both the new and the established model (k=0.99; k=0.94, both p<0.001). However, mean tumor blood velocity was lower (-19%, p<0.01) with the established model compared to the newly developed model. In addition, the range and distribution of blood flow velocities found in vivo can be estimated with the new model. Furthermore, it uses simpler mathematical fitting routines and allows easier data acquisition, which may allow a more practicable clinical application of intermittent sonography. In conclusion, a more valid, detailed and accurate calculation of perfusion parameters, especially of tumors, can be derived in vivo with the new multivessel model of intermittent sonography.

Comparing dynamic parameters of tumor vascularization in nude mice revealed by magnetic resonance imaging and contrast-enhanced intermittent power Doppler sonography.

RATIONALE: Angiogenesis is essential for spread and growth of malignant tumors. Because noninvasive methods for observing tumor vascularization are limited, most of previous results were based on histologic findings alone. In this study, dynamic parameters obtained using intermittent contrast-enhanced Doppler sonography and dynamic MRI were compared and correlated with microvessel density. METHODS: Eleven tumor-bearing nude mice were examined with dynamic T(1)-weighted sequences using Gd-DTPA in a 1.5 T magnetic resonance (MR) scanner and with intermittent power Doppler sonography after a single bolus of galactose based contrast agent. After examination 6 tumors were harvested for immunofluorescence microscopy using a CD31 stain. Using a 2-compartment model, the MR parameters amplitude (reflecting plasma volume) and k(ep) (influenced by the vessel permeability) were calculated and compared with maximal enhancement (max) and perfusion P measured with ultrasound. RESULTS: The MR amplitude correlated with the ultrasound parameter max significantly (r = 0.61; P = 0.01). Max (r = 0.67; P = 0.01), amplitude (r = 0.72; P = 0.01), and perfusion (r = 0.62; P = 0.05) correlated with the microvessel density. k(ep) moderately correlated with max, but not with perfusion and microvessel density. CONCLUSIONS: Dynamic MRI and contrast enhanced ultrasound are supplementing methods for examining perfusion and vascularity of experimental tumors.