Recovery after long-term summer drought: Hydraulic measurements reveal legacy effects in trunks of Picea abies but not in Fagus sylvatica.

Climate change is expected to increase the frequency and intensity of summer droughts. Sufficient drought resistance, the ability to acclimate to and/or recover after drought, is thus crucial for forest tree species. However, studies on the hydraulics of mature trees during and after drought in natura are scarce. In this study, we analysed trunk water content (electrical resistivity: ER) and further hydraulic (water potential, sap flow density, specific hydraulic conductivity, vulnerability to embolism) as well as wood anatomical traits (tree ring width, conduit diameter, conduit wall reinforcement) of drought-stressed (artificially induced summer drought via throughfall-exclusion) and unstressed Picea abies and Fagus sylvatica trees. In P. abies, ER indicated a strong reduction in trunk water content after 5 years of summer drought, corresponding to significantly lower pre-dawn leaf water potential and xylem sap flow density. Vulnerability to embolism tended to be higher in drought-stressed trees. In F. sylvatica, only small differences between drought-stressed and control trees were observed. Re-watering led to a rapid increase in water potentials and xylem sap flow of both drought-stressed trees, and to increased growth rates in the next growing season. ER analyses revealed lower trunk water content in P. abies trees growing on throughfall-exclusion plots even 1 year after re-watering, indicating a limited capacity to restore internal water reserves. Results demonstrated that P. abies is more susceptible to recurrent summer drought than F. sylvatica, and can exhibit long-lasting and pronounced legacy effects in trunk water reserves.

Endothelial dysfunction following coronary artery bypass grafting : Influence of patient and procedural factors.

BACKGROUND: Angiopoietin-2 (Angpt2) mediates endothelial dysfunction (ED) following coronary artery bypass grafting (CABG). Its triggers are, however, poorly understood. METHODS: We examined the time course of ED beyond the early phase of postoperative recovery in 75 patients following CABG with a special focus on different cardiopulmonary bypass (CPB) modes as potential triggers of Angpt2 release. RESULTS: Nine patients (12.0%) underwent off-pump coronary artery bypass (OPCAB), 31 patients (41.3%) received minimized extracorporeal circulation (MECC), and 35 patients (46.6%) were operated on with (conventional) CPB. Angpt2 levels steadily increased across the observation period (1.7 [1.4-2.1] to 3.4 [2.5-6.1] ng/ml, p < 0.001). Angpt2 levels did not differ between the MECC and CPB groups (p = 0.564). There was no difference between MECC and CPB patients regarding net fluid balance (p = 0.821) and other surrogate markers of postoperative ED. The magnitude of Angpt-2 increase correlated more strongly with baseline C­reactive protein (r = 0.459, p < 0.001) than with any other parameter. Hospital length of stay correlated more strongly with baseline Angpt2 levels (r = 0.512, p = 0.005) than with follow-up Angpt2 levels and appeared not to be influenced by CPB mode (p = 0.428). CONCLUSION: CABG is associated with prolonged ED, which is determined by the patient's preoperative inflammatory state rather than by CPB modifications.

Diagnosis of ovarian tumour tissues by SR-FTIR spectroscopy: A pilot study.

Ovarian cancer is the seventh most common cancer among women across the world with very high mortality rates. Histology is considered the gold standard for tumour diagnosis. FTIR spectroscopy is relies on registering biochemical differences in the samples analysed, including biological specimens. Therefore, the Synchrotron radiation based-Fourier transform infrared spectroscopy (SR-FTIR) was used for the preliminary investigation of the molecular composition of the human, non-fixed ovarian neoplastic tissues with different type of biological potential. The study that was carried out on thin tissue sections, placed on barium fluoride infrared windows, was focused on investigating spatial distribution of the biochemical markers in various ovarian tumours. Since the structural constituents of tissues accumulate different molecules which may correspond to the specific type of ovarian tumours, the main goal of this study was to check if the mean intensities of the spectral lines of some bio-molecules can be treated as ovarian cancer bio-indicators. Moreover, an attempt to identify and understand the underlying biochemical changes associated with the disease was carried out. The major spectral differences in the frequency and intensities were identified as bonds of lipids, protein massif and nucleic acids. The results obtained suggest that Fourier transform infrared spectroscopy can be used as a supporting tool in the analysis of neoplastic ovarian tissue.

Magnesium from bioresorbable implants: Distribution and impact on the nano- and mineral structure of bone.

Biocompatibility is a key issue in the development of new implant materials. In this context, a novel class of biodegrading Mg implants exhibits promising properties with regard to inflammatory response and mechanical properties. The interaction between Mg degradation products and the nanoscale structure and mineralization of bone, however, is not yet sufficiently understood. Investigations by synchrotron microbeam x-ray fluorescence (µXRF), small angle x-ray scattering (µSAXS) and x-ray diffraction (µXRD) have shown the impact of degradation speed on the sites of Mg accumulation in the bone, which are around blood vessels, lacunae and the bone marrow. Only at the highest degradation rates was Mg found at the implant-bone interface. The Mg inclusion into the bone matrix appeared to be non-permanent as the Mg-level decreased after completed implant degradation. µSAXS and µXRD showed that Mg influences the hydroxyl apatite (HAP) crystallite structure, because markedly shorter and thinner HAP crystallites were found in zones of high Mg concentration. These zones also exhibited a contraction of the HAP lattice and lower crystalline order.

Fibre type composition in the lumbar perivertebral muscles of primates: implications for the evolution of orthogrady in hominoids.

The axial musculoskeletal system is important for the static and dynamic control of the body during both locomotor and non-locomotor behaviour. As a consequence, major evolutionary changes in the positional habits of a species are reflected by morpho-functional adaptations of the axial system. Because of the remarkable phenotypic plasticity of muscle tissue, a close relationship exists between muscle morphology and function. One way to explore major evolutionary transitions in muscle function is therefore by comparative analysis of fibre type composition. In this study, the three-dimensional distribution of slow and fast muscle fibres was analysed in the lumbar perivertebral muscles of two lemuriform (mouse lemur, brown lemur) and four hominoid primate species (white-handed gibbon, orangutan, bonobo, chimpanzee) in order to develop a plausible scenario for the evolution of the contractile properties of the axial muscles in hominoids and to discern possible changes in muscle physiology that were associated with the evolution of orthogrady. Similar to all previously studied quadrupedal mammals, the lemuriform primates in this study exhibited a morpho-functional dichotomy between deep slow contracting local stabilizer muscles and superficial fast contracting global mobilizers and stabilizers and thus retained the fibre distribution pattern typical for quadrupedal non-primates. In contrast, the hominoid primates showed no regionalization of the fibre types, similar to previous observations in Homo. We suggest that this homogeneous fibre composition is associated with the high functional versatility of the axial musculature that was brought about by the evolution of orthograde behaviours and reflects the broad range of mechanical demands acting on the trunk in orthograde hominoids. Because orthogrady is a derived character of euhominoids, the uniform fibre type distribution is hypothesized to coincide with the evolution of orthograde behaviours.

Implications of Internet availability of genomic information for public health practice.

Tensions in the field have emerged over how best to communicate to the public about genomic discoveries in an era of direct-to-consumer (DTC) DNA testing services available through the Internet. Concerns over what the psychological and behavioral response might be to a nuanced, multiplex risk message have spurred some to offer caution in communicating to the public about personalized risk until the necessary research has been completed on how to communicate effectively. The popularization of DTC testing services, along with a spreading Internet culture on transparency for personal data, may make 'waiting to communicate' a moot point. To steer communication efforts in the midst of increasing access to personal genomic information, a self-regulation framework is presented. The framework emphasizes the importance of presenting a coherent message in all communiqués about public health genomics. Coherence should be based on an evidence-based model of how the public processes information about health conditions and an emphasis on risk-to-action links. Recommendations from the President's Council of Advisors for Science and Technology are reviewed as a way of identifying targets of opportunity for structured communications both within the healthcare system and in the broader external ecosystem of publicly available health information technologies.

Colloid volume loading does not mitigate decreases in central blood volume during simulated haemorrhage while heat stressed.

Heat stress results in profound reductions in the capacity to withstand a simulated haemorrhagic challenge; however, this capacity is normalized if the individual is volume loaded prior to the challenge. The present study tested the hypothesis that volume loading during passive heat stress attenuates the reduction in regional blood volumes during a simulated haemorrhagic challenge imposed via lower-body negative pressure (LBNP). Seven subjects underwent 30 mmHg LBNP while normothermic, during passive heat stress (increased internal temperature ∼1◦C), and while continuing to be heated after intravenous colloid volume loading (11 ml kg⁻¹). Relative changes in torso and regional blood volumes were determined by gamma camera imaging with technetium-99m labelled erythrocytes. Heat stress reduced blood volume in all regions (ranging from 7 to 16%), while subsequent volume loading returned those values to normothermic levels. While normothermic,LBNP reduced blood volume in all regions (torso: 22 ± 8%; heart: 18 ± 6%; spleen: 15 ± 8%). During LBNP while heat stressed, the reductions in blood volume in each region were markedly greater when compared to LBNP while normothermic (torso: 73 ± 2%; heart: 72 ± 3%; spleen: 72 ± 5%, all P<0.001 relative to normothermia). Volume loading during heat stress did not alter the extent of the reduction in these blood volumes to LBNP relative to heat stress alone (torso: 73 ± 1%; heart: 72 ± 2%; spleen: 74 ± 3%, all P>0.05 relative to heat stress alone). These data suggest that blood volume loading during passive heat stress (via 11 ml kg⁻¹ of a colloid solution) normalizes regional blood volumes in the torso, but does not mitigate the reduction in central blood volume during a simulated haemorrhagic challenge combined with heat stress.

Immunolymphoscintigraphy for metastatic sentinel nodes: test of a model.

Aim. To develop a method and obtain proof-of-principle for immunolymphoscintigraphy for identification of metastatic sentinel nodes. Methods. We selected one of four tumour-specific antibodies against human breast cancer and investigated (1), in immune-deficient (nude) mice with xenograft human breast cancer expressing the antigen if specific binding of the intratumorally injected, radioactively labelled, monoclonal antibody could be scintigraphically visualized, and (2) transportation to and retention in regional lymph nodes of the radioactively labelled antibody after subcutaneous injection in healthy rabbits. Results and Conclusion. Our paper suggests the theoretical possibility of a model of dual isotope immuno-lymphoscintigraphy for noninvasive, preoperative, malignant sentinel node imaging.

[Disability assessment for the statutory pension insurance: significance, need for research, and opportunities]. / Sozialmedizinische Begutachtung im Rentenverfahren: Stellenwert, Forschungsbedarf und Chancen.

Disability assessment is a complex and multifaceted process of exploration and evaluation, which in terms of legal evidence can be of far-reaching consequence for the claimant, the statutory pension insurance and finally for society as well. In the article the specifics of the assignment, the assessment situation, and the process of evaluation are described. Based upon an analysis of the so far only little research activities, the future need for research is subdivided into 4 thematic groups: 1 Operationalization and validation of central dimensions of evaluation; 2 Investigation of the structure of the expert decision-making process and the factors influencing it; 3 Investigation of the influence of sociopolitical, labour market-related and economical aspects on the evaluation; 4 Quality assurance. On the other hand the article describes the special quality of disability assessment. In a unique way it offers an integrated reflection of the medical history, limitation in capacity and participation and options for treatment and rehabilitation. Beyond the assessment of functional capacity, it could be of use for the development of innovative forms of support for the rehabilitation of working capacity.

Nudging best practice: the HITECH act and behavioral medicine.

In February 2009, the US Congress passed the Health Information Technology for Economic and Consumer Health (HITECH) Act in order to stimulate the "meaningful use" of health information technology within medical practice. Economists have noted that other sectors in the economy have demonstrated substantive productivity improvements from investments in information technology but that the health sector lags behind. The "meaningful use" stipulation of the HITECH Act focuses systems redesign within the health sector on user's behavior, a provision that opens a window of contribution from specialists in behavioral medicine. There are several ways for behavioral medicine to become involved in the redesign. One is to help craft a health services environment that optimizes communication between providers and patients, between primary care and specialist care providers, and between patients and their caregivers. Another is to help practitioners and policy-makers create new "decisional architectures" for "nudging" behavior in positive ways through better incentives, understandable instructions, healthy defaults, instructive feedback, back-ups for error, and structured decision-making. New funding opportunities in research, implementation, and training may facilitate the involvement of behavioral medicine-an involvement that is crucial for ensuring the success of reform efforts in the long run.

Sentinel node detection in melanomas using contrast-enhanced ultrasound.

BACKGROUND: Sentinel node (SN) biopsy has proven to be a useful clinical method based on the combination of radionuclide tracer principles and the dye technique. Contrast-enhanced ultrasound (CEUS) has been used successfully for detection of SN in animals, but the use of CEUS has not been reported in humans. PURPOSE: To investigate the possible use of CEUS in detecting SN in patients with malignant melanomas (MM), and to improve the method by using different concentrations of contrast agent and various positions of the extremity. MATERIAL AND METHODS: Ten patients with MM on an extremity and one healthy volunteer were included. One milliliter of a contrast agent (Sonovue; Bracco, Milan, Italy) was injected subcutaneously on both sides of the scar from the excised tumor. Contrast-enhanced lymph channels and lymph nodes (LNs) were searched for using low-mechanical-index CEUS and by stimulated acoustic emission. Afterward, lymphoscintigraphy was performed and the patient operated. During surgery, the SNs were located via scintigraphic findings, gamma-probe signals, and blue-dye visualization of lymph channels and LNs. Before the human study, a study of 10 mice was performed to exclude possible tissue damage, as the contrast agent was not registered for subcutaneous administration. RESULTS: In one patient, two contrast-enhanced inguinal LNs were visualized by CEUS, corresponding to two inguinal SNs found by scintigraphic imaging. No contrast-enhanced lymph channels or LNs were visualized in any other patients or in the volunteer. No tissue damage was observed in the 10 mice. CONCLUSION: This study does not support the use of CEUS for detection of SNs in humans. However, the application of CEUS for the investigation of SNs is still not fully explored in humans, and an alternative setup and/or contrast agent might provide better results.

One-day or two-day procedure for sentinel node biopsy in melanoma?

PURPOSE: We compared the outcome of a 1-day and a 2-day sentinel node (SN) biopsy procedure, evaluated in terms of lymphoscintigraphic, surgical and pathological findings. METHODS: We studied 476 patients with melanoma from two melanoma centres using static scintigraphy and blue dye. A proportional odds model was used for statistical analysis. RESULTS: The number of SNs visualized at scintigraphy increased significantly with time from injection to scintigraphy and activity left in the patient at scintigraphy, and depended on the melanoma location. The number of SNs removed at surgery increased with the number of SNs visualized at scintigraphy and time from injection to surgery. The frequency of nodal metastasis increased with increasing thickness and Clark level of the melanoma, and was highest for two SNs visualized at scintigraphy. CONCLUSION: This study showed that early vs. late imaging and surgery do make a difference on the outcome of the SN procedure and confirmed the importance of the scintigraphic visualization of all true SNs.

[Rehabilitation in the view of small and midsized enterprises: knowledge, appreciation and possibilities to cooperate - results of the KoRB-project]. / Rehabilitation aus der Sicht kleiner und mittlerer Unternehmen: Wissen, Wertschätzung und Kooperationsmöglichkeiten - Ergebnisse des KoRB-Projektes.

UNLABELLED: The experiences of small and midsized enterprises (SME) with medical rehabilitation were investigated in the KoRB-Study (KoRB= KOoperation Rehabilitation und Betrieb) for the first time. Opportunities for a targeted cooperation between the statutory pension insurance and these enterprises were explored. Based on explorative interviews, Westphalian employers, members of the works council, occupational health practitioners and employees were interrogated about the image of and their appreciation of medical rehabilitation in the work setting. Experience with rehabilitation and the level of information on rehabilitation were recorded as well as the compatibility of rehabilitation with operative processes in the working site. In addition rehab hospitals were asked about their experience in cooperating with enterprises. 697 employers of small and midsized enterprises, 458 members of the works councils, 73 occupational health practitioners, 47 rehab hospitals and 3 509 employees, who are members of the German Pension Fund of Westphalia, took part in the survey. RESULTS: Especially employers perceived rehabilitation positively and reported good experiences. Among the employees, those who had taken part in rehabilitation showed the highest appreciation. Occupational health practitioners were more restrained in their appraisal. Some of them complained about a lack of sustainability. The different target groups of the survey felt differently well informed about rehabilitation - best ratings came from the occupational health practitioners, worst ratings from the employees. All groups would welcome more accessible information in case of need. Medical rehabilitation in its standard form of "3 weeks full-time" often causes severe logistic problems in SME (e. g., replacement of employee, loss of experience). However the financial burden is perceived as less problematic. Employers favour alternative rehab models, which allow part-time working. Many employees, who expressed a need for rehabilitation, refrained from applying for rehabilitation on account of worries about loosing their employment. Both rehab clinicians and occupational health practitioners argued in favour of improved communication and cooperation in order to adapt medical rehab to the specific requirements of the working place and to assure a smooth reintegration into work.

Recent advances in nuclear cardiology.

Nuclear cardiology is an essential part of functional, non-invasive, cardiac imaging. Significant advances have been made in nuclear cardiology since planar (201)thallium ((201)TI) scintigraphy was introduced for the evaluation of left ventricular (LV) perfusion nearly 40 years ago. The use of nuclear cardiology has been steadily increasing over the last 20 years with important steps being the introduction of (99m)technetium- ((99m)Tc)-labelled perfusion radiotracers, the change from only planar to now much more single photon emission computed tomography (SPECT) and positron emission tomography (PET), electrocardiogram gating of nuclear perfusion imaging, and finally introducing nuclear hybrid imaging using either SPECT or PET together with either computed tomography or magnetic resonance imaging. The indications have extended from nearly only coronary artery diseases to several non-coronary cardiac diseases. The advances in nuclear cardiology are discussed under the four headlines of: 1) myocardial perfusion, 2) cardiac performance including LV and right ventricular (RV) function, 3) myocardial metabolism, and 4) experimental nuclear cardiology.

Nuclear cardiology and coronary surgery.

Rising age, repeated percutaneous coronary revascularizations, and co-morbidity such as overweight, diabetes, and hypertension, characterize a change over the last 20-30 years in coronary patients referred to coronary artery bypass grafting (CABG). This patient group represents a great part of today's large and increasing patient population with heart failure, and their treatment remains a limited success. CABG may lead to symptomatic and prognostic improvement, but the limited risk of operative complications has to be balanced against the chances of symptomatic and prognostic benefit from the operation. Identification of culprit lesions and estimation of the severity of coronary stenoses of intermediate or uncertain degree are important in preoperative decision-making. Location and extent of a perfusion abnormality must reflect the anatomical distribution of an angiographic stenosis, supporting or arguing against the decision to revascularize . Myocardial perfusion imaging by single photon emission computed tomography or positron emission tomography before surgery will increase the level of information about coronary hemodynamics and myocardial viability before surgical intervention and is therefore highly recommended to increase the chances of successful coronary surgery, as well as to reduce the small risk of operative complications.

Use of neural networks to improve quality control of interpretations in myocardial perfusion imaging.

BACKGROUND: The aim of this study was to explore the feasibility of using a technique based on artificial neural networks for quality assurance of image reporting. The networks were used to identify potentially suboptimal or erroneous interpretations of myocardial perfusion scintigrams (MPS). METHODS: Reversible perfusion defects (ischaemia) in each of five myocardial regions, as interpreted by one experienced nuclear medicine physician during his daily routine of clinical reporting, were assessed by artificial neural networks in 316 consecutive patients undergoing stress/rest 99mTc-sestamibi myocardial perfusion scintigraphy. After a training process, the networks were used to select the 20 cases in each region that were more likely to have a false clinical interpretation. These cases, together with 20 control cases in which the networks detected no likelihood of false clinical interpretation, were presented in random order to a group of three experienced physicians for a consensus re-interpretation; no information regarding clinical or neural network interpretations was provided to the re-evaluation panel. RESULTS: The clinical interpretation and the re-evaluation differed in 53 of the 200 cases. Forty-six of the 53 cases (87%) came from the group selected by the neural networks, and only seven (13%) were control cases (P < 0.001). The disagreements between clinical routine interpretation by an experienced nuclear medicine expert and artificial networks were related to small and mild perfusion defects and localization of defects. CONCLUSION: The results demonstrate that artificial neural networks can identify those myocardial perfusion scintigrams that may have suboptimal image interpretations. This is a potentially highly cost-effective technique, which could be of great value, both in daily practice as a clinical decision support tool and as a tool in quality assurance.

A decision support system improves the interpretation of myocardial perfusion imaging.

PURPOSE: The aim of this study was to investigate the influence of a computer-based decision support system (DSS) on performance and inter-observer variability of interpretations regarding ischaemia and infarction in myocardial perfusion scintigraphy (MPS). METHODS: Seven physicians independently interpreted 97 MPS studies, first without and then with the advice of a DSS. Four physicians had long experience and three had limited experience in the interpretation of MPS. Each study was interpreted regarding myocardial ischaemia and infarction in five myocardial regions. The patients had undergone a gated MPS using a 2-day stress/gated rest (99m)Tc sestamibi protocol. The gold standard used was the interpretations made by one experienced nuclear medicine specialist on the basis of all available clinical and image information. RESULTS: The sensitivity for ischaemia of the seven readers increased from 81% without the DSS to 86% with the DSS (p = 0.01). The increase in sensitivity was higher for the three inexperienced physicians (9%) than for the four experienced physicians (2%). There was no significant change in specificity between the interpretations. The interpretations of ischaemia made with the advice of the DSS showed less inter-observer variability than those made without advice. CONCLUSION: This study shows that a DSS can improve performance and reduces the inter-observer variability of interpretations in myocardial perfusion imaging. Both experienced and, especially, inexperienced physicians can improve their interpretation with the advice from such a system.