Towards optimization in digital chest radiography using Monte Carlo modelling

A Monte Carlo based computer model of the x-ray imaging system was used to investigate how various image quality parameters of interest in chest PA radiography and the effective dose E vary with tube voltage (90-150 kV), additional copper filtration (0-0.5 mm), anti-scatter method (grid ratios 8-16 and air gap lengths 20-40 cm) and patient thickness (20-28 cm) in a computed radiography (CR) system. Calculated quantities were normalized to a fixed value of air kerma (5.0 microGy) at the automatic exposure control chambers. Soft-tissue nodules were positioned at different locations in the anatomy and calcifications in the apical region. The signal-to-noise ratio, SNR, of the nodules and the nodule contrast relative to the contrast of bone (C/C(B)) as well as relative to the dynamic range in the image (C(rel)) were used as image quality measures. In all anatomical regions, except in the densest regions in the thickest patients, the air gap technique provides higher SNR and contrast ratios than the grid technique and at a lower effective dose E. Choice of tube voltage depends on whether quantum noise (SNR) or the contrast ratios are most relevant for the diagnostic task. SNR increases with decreasing tube voltage while C/C(B) increases with increasing tube voltage.     

Pulmonary gas exchange is reduced by the cardiovascular diving response in resting humans

The diving response reduces the pulmonary O(2) uptake in exercising humans, but it has been debated whether this effect is present at rest. Therefore, respiratory and cardiovascular responses were recorded in 16 resting subjects, performing apnea in air and apnea with face immersion in cold water (10 degrees C). Duration of apneas were predetermined to be identical in both conditions (average: 145 s) and based on individual maximal capacity (average: 184 s). Compared to apnea in air, an augmented diving response was elicited by apnea with face immersion. The O(2) uptake from the lungs was reduced compared to the resting eupneic control (4.6 ml min(-1)kg(-1)), during apnea in air (3.6 ml min(-1)kg(-1)) and even more so during apnea with face immersion (3.4 ml min(-1)kg(-1)). We conclude that the cardiovascular adjustments of the diving response reduces pulmonary gas exchange in resting humans, allowing longer apneas by preserving the lungs' O(2) store for use by vital organs.     

Paths taken towards NK cell–mediated immunotherapy of human cancer—a personal reflection

The discovery that NK cells are able to specifically recognize cells lacking the expression of self‐MHC class I molecules provided the first insight into NK cell recognition of tumour cells. It started a flourishing field of NK cell research aimed at exploring the molecular nature of NK cell receptors involved in tumour cell recognition. While much of the important early work was conducted in murine experimental model systems, studies of human NK cells rapidly followed. Over the years, human NK cell research has swiftly progressed, aided by new detailed molecular information on human NK cell development, differentiation, molecular specificity, tissue heterogeneity and functional capacity. NK cells have also been studied in many different diseases aside from cancer, including viral diseases, autoimmunity, allergy and primary immunodeficiencies. These fields of research have all, indirectly or directly, provided further insights into NK cell‐mediated recognition of target cells and paved the way for the development of NK cell‐based immunotherapies for human cancer. Excitingly, NK cell‐based immunotherapy now opens up for novel strategies aimed towards treating malignant diseases, either alone or in combination with other drugs. Reviewed here are some personal reflections of select contributions leading up to the current state‐of‐the‐art in the field, with a particular emphasis on contributions from our own laboratory. This review is part of a series of articles on immunology in Scandinavia, published in conjunction with the 50th anniversary of the Scandinavian Society for Immunology.     

Prophylactic incisional negative pressure wound therapy shows promising results in prevention of wound complications following inguinal lymph node dissection for Melanoma: A retrospective case-control series

BackgroundInguinal lymphadenectomy (ILND) for melanoma is associated with a number of complications including seroma, surgical site infection (SSI), and lymphedema. Incisional negative pressure wound therapy (iNPWT) has shown promising results in preventing postoperative morbidity across a wide variety of surgical procedures, but these results are yet to be investigated in patients undergoing ILND for melanoma.MethodsIn this study, we reviewed the data of 55 melanoma patients treated with ILND between January 2015 and January 2017 at Odense University Hospital. Patients were followed up until April 2018 for the occurrence of seroma, SSI, and lymphedema. We used prophylactic iNPWT after ILND in 14 patients and compared their morbidity outcomes with the 41 patients receiving standard postoperative wound care in the same period.ResultsThe iNPWT intervention significantly reduced seroma compared to the control group (28.6% vs. 90.3%, p < 0.001) and had a trending impact on wound infection (42.9% vs. 65.9%, p = 0.13). The effect was not significant for the prevention of lymphedema (35.7% vs. 51.2%, p = 0.33). Because the iNPWT group had relatively fewer incidences of seroma, SSI, and lymphedema, the iNPWT intervention was more cost-effective than conventional wound care (US$911.2 vs. US$2542.7, p < 0.05).ConclusionThe use of prophylactic iNPWT significantly reduced seroma formation following ILND. These promising results, however, need to be confirmed in a future prospective randomized trial.     

The motor cortex is causally related to predictive eye movements during action observation

We examined the hypothesis that predictive gaze during observation of other people's actions depends on the activation of corresponding action plans in the observer. Using transcranial magnetic stimulation and eye-tracking technology we found that stimulation of the motor hand area, but not of the leg area, slowed gaze predictive behavior (compared to no TMS). This result shows that predictive eye movements to others' action goals depend on a somatotopical recruitment of the observer's motor system. The study provides direct support for the view that a direct matching process implemented in the mirror-neuron system plays a functional role for real-time goal prediction.     

Identifying Unmet Rehabilitation Needs in Patients After Stroke With a Graphic Rehab-CompassTM

Background

Unmet rehabilitation needs are common among stroke survivors. We aimed to evaluate whether a comprehensive graphic “Rehab-Compass,” a novel combination of structured patient-reported outcome measures, was feasible and useful in facilitating a capture of patients' rehabilitation needs in clinical practice.

The significance of control models: intentional and unintentional effects

Organization and control research has largely focused on the reform work and changes in the public sector. Many studies have focused on the reasons for reforms rather than on their significance. In this article, the authors deal with a control model applied in maternity health and based on remuneration for performance. At the end of the article, the authors note that formal control models are significant. Staff members have adapted to the model, but the model has also been adjusted to suit reality. This change has meant intentional effects, in the sense that the work has been adapted to suit the conditions given, but also unintentional effects in the form of attempts to outwit the system.     

Prostate specific antigen based biennial screening is sufficient to detect almost all prostate cancers while still curable

PURPOSE: We evaluated whether biennial screening with prostate specific antigen (PSA) only is sufficient to detect prostate cancer while still curable. MATERIALS AND METHODS: In G?teborg, Sweden 9,972 men 50 to 65 years old were randomized to PSA screening. During 1995 and 1996 these men were invited for a first PSA screening and invited during 1997 and 1998 for a second screening. The screening procedure included PSA measurement in all men and in those with a PSA of 3 ng./ml. or greater also it included digital rectal examination, transrectal ultrasound and sextant biopsies. RESULTS: In the first screening 5,854 men participated and 145 cancers were detected. In the second screening 5,267 men participated and 111 cancers were detected. Only 9 interval cancers were diagnosed. In the second screening 102 cancers (92%) were associated with PSA less than 10 ng./ml. Of 465 men with increased PSA and who underwent biopsy with a benign outcome in the first screening 50 had cancer at the second screening. Of 241 men in whom PSA increased between screenings 1 and 2 cancer was detected in 46. None of the 2,950 men with an initial PSA of less than 1 ng./ml. had a PSA of greater than 3 ng./ml. or interval cancer. CONCLUSIONS: In men with a PSA of less than 2 ng./ml. it seems safe to offer repeat screening after 2 years with PSA only. Men with a PSA of 2 to 3 ng./ml. or a value of greater than 3 ng./ml. with negative biopsy may be better served by a shorter screening interval. Thus, different screening intervals are implied depending on baseline PSA.     

Radical prostatectomy--long-term oncological outcome from a community hospital

OBJECTIVE: Radical prostatectomy has recently been shown to prolong cancer-specific survival compared to watchful waiting in patients with localized prostate cancer. Most patients who seek medical advice for this disease are treated in hospitals in which the operation is performed relatively infrequently. The aim of this study is to report the oncological outcome at intermediate- to long-term follow-up after radical prostatectomy performed in a community hospital. MATERIAL AND METHODS: A total of 148 patients underwent radical prostatectomy at Ryhov County Hospital between 1985 and 1997. Patients without T3 tumours, prostate-specific antigen (PSA) >10 ng/ml or poorly differentiated tumours were judged to be in a low-risk group, those with one risk factor to be in an intermediate group and those with two or more factors to be in a high-risk group. The projected biochemical disease free- and cancer-specific survival rates were compared between these risk groups. RESULTS: Median follow-up was 96 months for surviving patients. Patients in the low- and intermediate risk groups had equal 10-year PSA-free survival rates of 68.8%, while that in the high-risk group was only 19.3% (9-year data). Corresponding cancer-specific survival rates were 93% and 84%, respectively. CONCLUSIONS: The oncological outcome seems comparable to that reported in the literature, even when the operation is performed in a low-volume community-based setting.