381 research outputs found
Das DreizÀhnige Knabenkraut ("Orchis tridentata") im Kreis Höxter
Das zur Familie der Orchideen gehörende DreizĂ€hnige Knabenkraut (Orchis tridentata Scop.) ist eine auffallende Pflanze unserer Kalk-Halbtrockenrasen. Ihretwegen besuchen alljĂ€hrlich zahlreiche Orchideenfreunde unsere Region. Manche Autoren fĂŒhren den deutschen, wie auch den lateinischen Namen der Pflanze auf die spitz zulaufenden, nach auĂen gebogenen Zipfel der drei Ă€uĂeren BlĂŒtenkronblĂ€tter zurĂŒck (WWW.ORCHIDEEN-KARTIERUNG.DE, AHO NRW 2001), andere auf die dreilappige Lippe (BAUMANN 2005; vgl. Abb. 1). Der Gattungsname (griechisch: Hoden) leitet sich von den an die Form von Hoden erinnernden Wurzelknollen der Pflanze ab
Overall survival after reirradiation of spinal metastases â independent validation of predictive models
Background: It is unknown if survival prediction tools (SPTs) sufficiently predict survival in patients who undergo palliative reirradiation of spinal metastases. We therefore set out to clarify if SPTs can predict survival in this patient population. Methods: We retrospectively analyzed spinal reirradiations performed (nâ=â58, 52 patients, 44 included in analysis). SPTs for patients with spinal metastases were identified and compared to a general palliative score and to a dedicated SPT to estimate prognosis in palliative reirradiation independent of site (SPT-Nieder). Results: Consistently in all tests, SPT-Nieder showed best predictive performance as compared to other tools. Items associated with survival were general condition (KPS), liver metastases, and steroid use. Other factors like primary tumor site, pleural effusion, and bone metastases were not correlated with survival. We adapted an own score to the data which performed comparable to SPT-Nieder but avoids the pleural effusion item. Both scores showed good performance in identifying long-term survivors with late recurrences. Conclusions: Survival prediction in case of spinal reirradiation is possible with sufficient predictive separation. Applying SPTs in case of reirradiation helps to identify patients with good life expectancy who might benefit from dose escalation or longer treatment courses
Zwischen den StĂŒhlen. Das Berliner Journal fĂŒr Soziologie in der gesellschaftlichen Transformation und Refiguration
Friedrich-Schiller-UniversitÀt Jena (1010)Peer Reviewe
Sublamina-specific organization of the blood brain barrier in the mouse olfactory nerve layer
Astrocytes constitute the main glial component of the mammalian blood brain barrier
(BBB). However, in the olfactory bulb (OB), the olfactory nerve layer (ONL) is almost
devoid of astrocytes, raising the question which glial cells are part of the BBB. We used
mice expressing EGFP in astrocytes and tdTomato in olfactory ensheathing cells
(OECs), a specialized type of glial cells in the ONL, to unequivocally identify both glial
cell types and investigate their contribution to the BBB in the olfactory bulb. OECs
were located exclusively in the ONL, while somata of astrocytes were located in deeper
layers and extended processes in the inner sublamina of the ONL. These processes surrounded blood vessels and contained aquaporin-4, an astrocytic protein enriched at
the BBB. In the outer sublamina of the ONL, in contrast, blood vessels were surrounded by aquaporin-4-negative processes of OECs. Transcardial perfusion of blood
vessels with lanthanum and subsequent visualization by electron microscopy showed
that blood vessels enwrapped by OECs possessed intact tight junctions. In acute olfactory bulb preparations, injection of fluorescent glucose 6-NBDG into blood vessels
resulted in labeling of OECs, indicating glucose transport from the perivascular space
into OECs. In addition, Ca2+ transients in OECs in the outer sublamina evoked vasoconstriction, whereas Ca2+ signaling in OECs of the inner sublamina had no effect on adjacent blood vessels. Our results demonstrate that the BBB in the inner sublamina of the
ONL contains astrocytes, while in the outer ONL OECs are part of the BBB
Internet and written respiratory questionnaires yield equivalent results for adolescents
This study compared results from Internet and written questionnaires about respiratory symptoms in order to find out if both forms of the survey yielded the same answers. One thousand seventy-one students, ages 13 to 17, were asked to complete either an Internet or a written questionnaire. The demographic characteristics of the participants equalled those of the general Dutch adolescent population. Participants were randomly assigned to fill out an electronic or written questionnaire. In addition to eight items from the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire, two items on doctor visits (medical attention) regarding asthma or allergic disease during the past 12 months were included. The participation rate was 87%. The Internet version of the questionnaire showed fewer missing answers than the written version, but this was not statistically significant. The respiratory items did not show statistically significant score differences between the Internet and written modes of administration, and there was no visible trend for higher respectively lower scores by either mode of questionnaire administration. From these results, we conclude that respiratory questionnaires may be provided to adolescents electronically rather than on paper, since both approaches yielded equal results. To generalize these findings, we recommend repeated studies in other settings
Genital invasion or perigenital spread may pose a risk of marginal misses for Intensity Modulated Radiotherapy (IMRT) in anal cancer
Background: While intensity modulated radiotherapy (IMRT) in anal cancer is feasible and improves high-dose conformality, the current RTOG/AGITG contouring atlas and planning guidelines lack specific instructions on how to proceed with external genitalia. Meanwhile, the RTOG-Protocol 0529 explicitly recommends genital sparing on the basis of specific genital dose constraints. Recent pattern-of-relapse studies based on conventional techniques suggest that marginal miss might be a potential consequence of genital sparing. Our goal is to outline the potential scope and increase the awareness for this clinical issue. Methods: We present and discuss four patients with perigenital spread in anal cancer in both early and advanced stages (three at time of first diagnosis and one in form of relapse). Genital/perigenital spread was observed once as direct genital infiltration and thrice in form of perigenital lymphatic spread. Results: We review the available data regarding the potential consequences of genital sparing in anal cancer. Pattern-of-relapse studies in anal cancer after conventional radiotherapy and the current use of IMRT in anal cancer are equivocal but suggest that genital sparing may occasionally result in marginal miss. An obvious hypothesis suggested by our report is that perigenital lymphovascular invasion might be associated with manifest inguinal N+ disease. Conclusions: Local failure has low salvage rates in recent anal cancer treatment series. Perigenital spread may pose a risk of marginal misses in IMRT in anal cancer. To prevent marginal misses, meticulous pattern-of-relapse analyses of controlled IMRT-series are warranted. Until their publication, genital sparing should be applied with caution, PET/CT should be used when possible and meeting genital dose constraints should not be prioritized over CTV coverage, especially (but not only) in stage T3/4 and N+ disease
Clinical outcome of hypofractionated breath-hold image-guided SABR of primary lung tumors and lung metastases
Background: Stereotactic Ablative RadioTherapy (SABR) of lung tumors/metastases has been shown to be an effective treatment modality with low toxicity. Outcome and toxicity were retrospectively evaluated in a unique single-institution cohort treated with intensity-modulated image-guided breath-hold SABR (igSABR) without external immobilization. The doseâresponse relationship is analyzed based on Biologically Equivalent Dose (BED). Patients and methods: 50 lesions in 43 patients with primary NSCLC (nâ=â27) or lung-metastases of various primaries (nâ=â16) were consecutively treated with igSABR with Active-Breathing-Coordinator (ABCÂź) and repeat-breath-hold cone-beam-CT. After an initial dose-finding/-escalation period, 5x12âGy for peripheral lesions and single doses of 5âGy to varying dose levels for central lesions were applied. Overall-survival (OS), progression-free-survival (PFS), progression pattern, local control (LC) and toxicity were analyzed. Results: The median BED2 was 83âGy. 12 lesions were treated with a BED2 of <80âGy, and 38 lesions with a BED2 of <80âGy. Median follow-up was 15 months. Actuarial 1- and 2-year OS were 67% and 43%; respectively. Cause of death was non-disease-related in 27%. Actuarial 1- and 2-year PFS was 42% and 28%. Progression site was predominantly distant. Actuarial 1- and 2âyear LC was 90% and 85%. LC showed a trend for a correlation to BED2 (pâ=â0.1167). Pneumonitis requiring conservative treatment occurred in 23%. Conclusion: Intensity-modulated breath-hold igSABR results in high LC-rates and low toxicity in this unfavorable patient cohort with inoperable lung tumors or metastases. A BED2 of <80âGy was associated with reduced local control
Detection of local recurrence with 3-tesla MRI after radical prostatectomy: A useful method for radiation treatment planning?
Background/Aim: Salvage radiotherapy improves biochemical control in patients with recurrence of prostate cancer after prostatectomy. Radiotherapy target volumes of the prostatic fossa are based on empirical data and differ between different guidelines. Localization of recurrence with multiparametric magnetic resonance imaging (MRI) might be a feasible approach to localize recurrent lesions. Patients and Methods: Twenty-one patients with biochemical recurrence after radical prostatectomy were included (median prostate-specific antigen (PSA) =0.17 ng/ml). Multi-parametric MRI was performed using a 3-T MR system. Results: Lesions were detected in seven patients with a median PSA of 0.86 ng/ml (minimum= 0.31 ng/ml). Patients without detectable recurrence had a median PSA of 0.12 ng/ml. All patients with detectable lesions responded to radiotherapy. Eleven out of 14 patients without detectable recurrence also responded. Plasma flow in suspicious lesions was correlated with PSA level. Conclusion: Detection of recurrence at the prostatic fossa with our approach was possible in a minority of patients with a low PSA level. Clinical relevance of plasma flow in suspicious lesions should be further investigated
Phantom-based evaluation of dose exposure of ultrafast combined kV-MV-CBCT towards clinical implementation for IGRT of lung cancer
Purpose: Combined ultrafast 90\ub0+90\ub0 kV-MV-CBCT within single breath-hold of 15s has high clinical potential for accelerating imaging for lung cancer patients treated with deep inspiration breath-hold (DIBH). For clinical feasibility of kV-MV-CBCT, dose exposure has to be small compared to prescribed dose. In this study, kV-MV dose output is evaluated and compared to clinically-established kV-CBCT. Methods: Accurate dose calibration was performed for kV and MV energy; beam quality was determined. For direct comparison of MV and kV dose output, relative biological effectiveness (RBE) was considered. CT dose index (CTDI) was determined and measurements in various representative locations of an inhomogeneous thorax phantom were performed to simulate the patient situation. Results: A measured dose of 20.5mGE (Gray-equivalent) in the target region was comparable to kV-CBCT (31.2mGy for widely-used, and 9.1mGy for latest available preset), whereas kVMV spared healthy tissue and reduced dose to 6.6mGE (30%) due to asymmetric dose distribution. The measured weighted CTDI of 12mGE for kV-MV lay in between both clinical presets. Conclusions: Dosimetric properties were in agreement with established imaging techniques, whereas exposure to healthy tissue was reduced. By reducing the imaging time to a single breathhold of 15s, ultrafast combined kV-MV CBCT shortens patient time at the treatment couch and thus improves patient comfort. It is therefore usable for imaging of hypofractionated lung DIBH patients
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