Long-term in-vitro precision of direct digital X-ray radiogrammetry

Digital X-ray radiogrammetry (DXR) calculates peripheral bone mineral density (BMD) from hand radiographs. The short-term precision for direct DXR has been reported to be highly satisfactory. However, long-term precision for this method has not been examined. Thus, the aim of this study was to examine the long-term in-vitro precision for the new direct digital version of DXR. The in-vitro precision for direct DXR was tested with cadaver phantoms on four different X-ray systems at baseline, 3 months, 6 months, and in one machine also at 12 months. At each time point, 31 measurements were performed. The in-vitro longitudinal precision for the four radiographic systems ranged from 0.22 to 0.43% expressed as coefficient of variation (CV%). The smallest detectable difference (SDD) ranged from 0.0034 to 0.0054 g/cm(2). The in vitro long-term precision for direct DXR was comparable to the previous reported short-term in-vitro precision for all tested X-ray systems. These data show that DXR is a stable method for detecting small changes in bone density during 6-12 months of follow-up

Outcome of ATP-based tumor chemosensitivity assay directed chemotherapy in heavily pre-treated recurrent ovarian carcinoma

BACKGROUND: We wished to evaluate the clinical response following ATP-Tumor Chemosensitivity Assay (ATP-TCA) directed salvage chemotherapy in a series of UK patients with advanced ovarian cancer. The results are compared with that of a similar assay used in a different country in terms of evaluability and clinical endpoints. METHODS: From November 1998 to November 2001, 46 patients with pre-treated, advanced ovarian cancer were given a total of 56 courses of chemotherapy based on in-vitro ATP-TCA responses obtained from fresh tumor samples or ascites. Forty-four patients were evaluable for results. Of these, 18 patients had clinically platinum resistant disease (relapse < 6 months after first course of chemotherapy). There was evidence of cisplatin resistance in 31 patients from their first ATP-TCA. Response to treatment was assessed by radiology, clinical assessment and tumor marker level (CA 125). RESULTS: The overall response rate was 59% (33/56) per course of chemotherapy, including 12 complete responses, 21 partial responses, 6 with stable disease, and 15 with progressive disease. Two patients were not evaluable for response having received just one cycle of chemotherapy: if these were excluded the response rate is 61%. Fifteen patients are still alive. Median progression free survival (PFS) was 6.6 months per course of chemotherapy; median overall survival (OAS) for each patient following the start of TCA-directed therapy was 10.4 months (95% confidence interval 7.9-12.8 months). CONCLUSION: The results show similar response rates to previous studies using ATP-TCA directed therapy in recurrent ovarian cancer. The assay shows high evaluability and this study adds weight to the reproducibility of results from different centre

Early changes in bone mineral density measured by digital X-ray radiogrammetry predict up to 20 years radiological outcome in rheumatoid arthritis

ABSTRACT: INTRODUCTION: Change in bone mineral density (BMD) in the hand, as evaluated by digital X-ray radiogrammetry (DXR) of the II-IV metacarpal bones, has been suggested to predict future joint damage in rheumatoid arthritis (RA). This study's objective was to investigate if DXR-BMD loss early in the disease predicts development of joint damage in RA patients followed for up to 20 years. METHODS: 183 patients (115 women and 68 men) with early RA (mean disease duration 11 months) included from 1985 to 1989 were followed prospectively (the Lund early RA cohort). Clinical and functional measures were assessed yearly. Joint damage was evaluated according to the Larsen score on radiographs of hands and feet taken in years 0 to 5, 10, 15 and 20. These radiographs were digitized and BMD of the II-IV metacarpal bones was evaluated by DXR (Sectra, Linkoping. Sweden). Early DXR-BMD change rate (bone loss) per year calculated from the first 2 radiographs taken on average 9 months apart (SD 4.8) were available for 135 patients. Mean values of right and left hand were used. RESULTS: Mean early DXR-BMD loss during the first year calculated was -0.023 g/cm2 (SD 0.025). Patients with marked bone loss, i.e. early DXR-BMD loss above the median for the group, had significantly worse progression of joint damage at all examinations during the 20-year period. CONCLUSIONS: Early DXR-BMD progression rate predicted development of joint damage evaluated according to Larsen at year one and further onwards up to 20 years in this cohort of early RA patients

Capecitabine and mitomycin C as third-line therapy for patients with metastatic colorectal cancer resistant to fluorouracil and irinotecan

Protracted venous infusion 5-fluorouracil (5FU) combined with mitomycin C (MMC) has demonstrated significant activity against metastatic colorectal cancer. Owing to potential synergy based upon upregulation of thymidine phosphorylase by MMC, the combination of capecitabine and MMC may improve outcomes in irinotecan-refractory disease. Eligible patients with progressive disease during or within 6 months of second-line chemotherapy were treated with capecitabine (1250 mg m−2 twice daily) days 1–14 every 3 weeks and MMC (7 mg m−2 IV bolus) once every 6 weeks. A total of 36 patients were recruited, with a median age of 64 years (range 40–77), and 23 patients (78%) were performance status 0–1. The objective response rate was 15.2%. In all, 48.5% of patients had stable disease. Median failure-free survival was 5.4 months (95% CI 4.6–6.2). Median overall survival was 9.3 months (95% CI: 6.9–11.7). Grade 3 toxicities were palmar-plantar erythema 16.7%, vomiting 8.3%, diarrhoea 2.8%, anaemia 8.3%, and neutropenia 2.8%. No patients developed haemolytic uraemic syndrome. Symptomatic improvement occurred for pain, bowel symptoms, and dyspnoea. Capecitabine in combination with MMC is an effective regimen for metastatic colorectal cancer resistant to 5FU and irinotecan with an acceptable toxicity profile and a convenient administration schedule

Chemotaxis Based Virtual Fence for Swarm Robots in Unbounded Environments

This paper presents a novel swarm robotics application of chemotaxis behaviour observed in microorganisms. This approach was used to cause exploration robots to return to a work area around the swarm’s nest within a boundless environment. We investigate the performance of our algorithm through extensive simulation studies and hardware validation. Results show that the chemotaxis approach is effective for keeping the swarm close to both stationary and moving nests. Performance comparison of these results with the unrealistic case where a boundary wall was used to keep the swarm within a target search area showed that our chemotaxis approach produced competitive results

Bone mineral density by digital X-ray radiogrammetry is strongly decreased and associated with joint destruction in long-standing Rheumatoid Arthritis: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>The aims were to explore bone mineral density (BMD) by digital X-ray radiogrammetry (DXR) in postmenopausal women with long-lasting rheumatoid arthritis (RA) in relation to dual x-ray absorptiometry (DXA)-BMD, joint destruction by conventional radiographs and disease related variables in a cross-sectional study.</p> <p>Methods</p> <p>Seventy-five postmenopausal women with RA were examined by DXA measuring DXA-BMD of the forearm, total hip and lumbar spine, by scoring joint destruction on plain radiographs by the method of Larsen and by DXR-BMD in metacarpals two to four. The DXR-BMD results of the RA women were compared with an age and sex-matched reference database. A function of DXR-BMD in relation to age and disease duration was created. Associations were investigated by bivariate and multiple linear regression analyses.</p> <p>Results</p> <p>DXR-BMD was strongly decreased in RA patients compared to the reference database (p < 0.001). Calculations showed that DXR-BMD was not markedly influenced the first years after diagnosis of RA, but between approximately 5-10 years of disease there was a steep decline in DXR-BMD which subsequently levelled off. In multiple regression analyses disease duration, CRP and DXR-BMD were independent variables associated with Larsen score (R²= 0.64). Larsen score and BMD forearm were independent determinants of DXR-BMD (R²= 0.79).</p> <p>Conclusions</p> <p>DXR-BMD was strongly reduced and associated with both Larsen score and DXA-BMD forearm in these postmenopausal women with RA implying that DXR-BMD is a technique that reflects both the erosive process and bone loss adjacent to affected joints.</p

Optimization of MicroCT Imaging and Blood Vessel Diameter Quantitation of Preclinical Specimen Vasculature with Radiopaque Polymer Injection Medium

Vascular networks within a living organism are complex, multi-dimensional, and challenging to image capture. Radio-angiographic studies in live animals require a high level of infrastructure and technical investment in order to administer costly perfusion mediums whose signals metabolize and degrade relatively rapidly, diminishing within a few hours or days. Additionally, live animal specimens must not be subject to long duration scans, which can cause high levels of radiation exposure to the specimen, limiting the quality of images that can be captured. Lastly, despite technological advances in live-animal specimen imaging, it is quite difficult to minimize or prevent movement of a live animal, which can cause motion artifacts in the final data output. It is demonstrated here that through the use of postmortem perfusion protocols of radiopaque silicone polymer mediums and ex-vivo organ harvest, it is possible to acquire a high level of vascular signal in preclinical specimens through the use of micro-computed tomographic (microCT) imaging. Additionally, utilizing high-order rendering algorithms, it is possible to further derive vessel morphometrics for qualitative and quantitative analysis

Regulation of mammary gland branching morphogenesis by the extracellular matrix and its remodeling enzymes.

A considerable body of research indicates that mammary gland branching morphogenesis is dependent, in part, on the extracellular matrix (ECM), ECM-receptors, such as integrins and other ECM receptors, and ECM-degrading enzymes, including matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs). There is some evidence that these ECM cues affect one or more of the following processes: cell survival, polarity, proliferation, differentiation, adhesion, and migration. Both three-dimensional culture models and genetic manipulations of the mouse mammary gland have been used to study the signaling pathways that affect these processes. However, the precise mechanisms of ECM-directed mammary morphogenesis are not well understood. Mammary morphogenesis involves epithelial 'invasion' of adipose tissue, a process akin to invasion by breast cancer cells, although the former is a highly regulated developmental process. How these morphogenic pathways are integrated in the normal gland and how they become dysregulated and subverted in the progression of breast cancer also remain largely unanswered questions

In the shadow of bad news – views of patients with acute leukaemia, myeloma or lung cancer about information, from diagnosis to cure or death

BACKGROUND: Many studies have been published about giving and receiving bad messages. However, only a few of them have followed the patients all the way through a disease as is done in this study. Many studies have been written about patients' coping strategies. In this study we will keep within the bounds of coping through information only. The aim of the study is to investigate patients' views of information during the trajectory of their disease, whether their reactions differ from each other and whether they differ in different phases of the disease. METHODS: Twelve patients with malignant haematological diseases or lung cancer were followed with interviews from diagnosis to recovery or into the terminal phase or at most for two years. The method is qualitative, using semi-structured interviews. Setting: Örebro University Hospital or the patient's home. RESULTS: All patients described themselves as well informed from the start but in later phases of their disease some of them came to express a great uncertainty about the progressing disease and about the approaching death. Most of them, regardless of whether they had a haematological malignancy or lung cancer, expressed a wish to be well informed all through the disease and even when the messages were bad. Different strategies for coping with information, however, affected how they then dealt with the information received. Four such coping strategies were found: 1) Information-dependent and accepting; 2) Information-dependent but denying; 3) Medically informed and accepting; 4) Medically informed but denying. CONCLUSION: To several patients there was an unmet need for information about the progressing disease and the approaching death. To optimize the care of these patients it seems important that the physician is aware of patients' need for information even when the news is bad. Knowing the patient's information strategy could probably function as a key for the physician to communicate with patients on these matters