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1.
PURPOSE: To compare commercial treatment-planning systems (TPS) for inverse planning (IP) and to assess constraint variations for specific IMRT indications. MATERIAL AND METHODS: For IP, OTP, XiO and BrainSCAN were used and step-and-shoot intensity-modulated radiotherapy (IMRT) delivery was assumed. Based on identical constraints, IP was performed for a prostate, head and neck, brain, and gynecologic case. IMRT plans were compared in terms of conformity/homogeneity, dose-volume histograms (DVHs), and delivery efficiency. For ten patients each of a class of indications, constraint variations were evaluated. RESULTS: IMRT plans were comparable concerning minimum target dose, homogeneity, conformity, and maximum doses to organs at risk. Larger differences were seen in dose gradients outside the target, monitor units, and segment number. Using help structures proved efficient to shape isodoses and to reduce segmentation workload. For IMRT class solutions, IP constraint variations depended on anatomic site. CONCLUSION: IP systems requiring doses as input and having objective functions based on physical parameters had a very similar performance. Constraint templates can be established for a class of IMRT indications.  相似文献   
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OBJECTIVE: The authors described the influence of specific medical conditions on clinical remission and response of major depression (MDD) in a clinical trial evaluating a care-management intervention among older primary-care patients. METHODS: Adults age 60 years and older were randomly selected and screened for depression. Participants were randomly assigned to Usual Care or to an Intervention with a depression care-manager offering algorithm-based care for MDD. In all, 324 adults meeting criteria for MDD were included in these analyses. Remission and response was defined by a score on the Hamilton Rating Scale for Depression <10 and by a decrease from baseline of > or =50%, respectively. Medical comorbidity was ascertained through self-report. Cognitive impairment was defined by a score <24 on the Mini-Mental State Exam (MMSE). RESULTS: In Usual Care, rates of remission were faster in persons who reported atrial fibrillation (AF) than in persons who did not report AF and slower in persons who reported chronic pulmonary disease than in persons who did not report chronic pulmonary disease; rates of response were less stable in persons with MMSE <24 than in those with MMSE > or =24. In the Intervention condition, none of the specific chronic medical conditions were significantly associated with outcomes for MDD. CONCLUSIONS: Because disease-specific findings were observed in persons who received Usual Care but not in persons who received more intensive treatment in the Intervention condition, our results suggest that the association of medical comorbidity and treatment outcomes for MDD may be determined by the intensity of treatment for depression.  相似文献   
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PURPOSE, MATERIAL AND METHODS: The dose calculation accuracy of the voxel-based Monte Carlo (VMC++) electron dose module of Oncentra MasterPlan (Nucletron B.V., Veenendaal, The Netherlands) was verified by measurements in homogeneous water phantoms. RESULTS: Measured and calculated dose maxima on the central beam axis (calculations with 10,000-20,000 incident electron histories per cm(2)) agree well using standard applicator configurations as well as individually shaped inserts. Profile scans with higher electron energies (>/= 15 MeV) reveal differences up to 5% especially in the penumbra region. Depth dose curves agree best in the vicinity of maximum depths. In the buildup region energy-dependent differences up to 5% in both directions could be observed. In the decay region of depth dose curves calculated doses were up to 10% higher than measured values. CONCLUSION: Good VMC++ accuracy combined with moderate computing times of 1-15 min per beam satisfy all clinical needs. VMC++ allows, for the first time, accurate routine dose evaluations of radiation therapy with electrons. Adequate positioning of the dose reference point is essential. Even small displacements may significantly influence the calculation of monitor units.  相似文献   
4.
In a selected group of human immunodeficiency virus (HIV)-infected patients we confirm the expansion of a CD8+ T-lymphocyte subset, i.e., the CD8+/Leu7+ cells, which account for 30% of the lymphocytes, compared to 3% in the control donors. In addition, a CD8+ T-lymphocyte subset that coexpresses class II (DR) antigens, i.e., CD8+/DR+ cells, is also increased from 1.5% in controls to 27% in the HIV-infected patients. Using three-color immunofluorescence and flow cytometry we can demonstrate that the CD8+/Leu7+ and the CD8+/class II+ cells are not distinct but overlapping subsets. In the HIV-infected patients 42% of the CD8+/Leu7+ cells were strongly positive for class II and these CD8+/Leu7+/class II+ cells accounted for 13% of all lymphocytes. These findings indicate that the expanded CD8+/Leu7+ cells are activated and hence might be actively involved in immune defense in acquired immune deficiency syndrome (AIDS).  相似文献   
5.
A multicentre study was undertaken to define novel assays with increased inter-assay concordance, sensitivity, specificity and predictive value for serological diagnosis of human herpesvirus type 8 (HHV-8) infection. A total of 562 sera from European and Ugandan human immunodeficiency virus (HIV)-infected or uninfected individuals with or without Kaposi's sarcoma (KS) and blood donors were examined under code by 18 different assays in seven European laboratories. Sera from KS patients and all non-KS sera found positive by at least 70%, 80%, or 90% of the assays were considered "true positive." The validity of the assays was then evaluated by univariate logistic regression analysis. Two immunofluorescence assays (IFA) for detection of antibodies against HHV-8 lytic (Rlyt) or latent (LLANA) antigens and two enzyme-linked-immunosorbent assays (ELISA) (M2, EK8.1) for detection of antibodies against HHV-8 structural proteins were found to be highly concordant, specific, and sensitive, with odds ratios that indicated a high predictive value. When used together, the two IFA (Rlyt-LLANA) showed the best combination of sensitivity (89.1%) and specificity (94.9%). The performance of these assays indicate that they may be used for the clinical management of individuals at risk of developing HHV-8 associated tumours such as allograft recipients.  相似文献   
6.
 Patients suffering from the acquired immune deficiency syndrome (AIDS) have a 20000-fold increased risk of developing a severe form of Kaposi’s sarcoma (KS), a previously rare malignancy involving sharply defined nodular lesions of the skin and/or oral mucosa. Epidemiological evidence has long suggested that an infectious agent is the probable cause of KS. Recently sequences from a putative new herpesvirus have been found to be associated with KS in virtually 100% of the cases analyzed. The suspected etiological agent, a new human herpesvirus termed Kaposi’s sarcoma associated herpes virus (human herpes virus 8) has now been propagated in cell culture. This significant advance should form the basis for a detailed analysis of the pathogenetic mechanisms involved in the development of KS. Received: 4 June 1996 / Accepted: 5 August 1996  相似文献   
7.
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Partizipation zu ermöglichen ist Teil des Auftrags der Offenen Kinder- und Jugendarbeit. Dazu gehört die Einbindung der...  相似文献   
8.
Journal of Community Health - Tattoos of formerly gang-involved and incarcerated individuals can negatively impact their ability to reintegrate into society. Laser tattoo removal is essential to...  相似文献   
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