Miracle-dz/UniFAR-FTUs huggingface dataset:
Biphasic Blood Pool Contrast Agent-Enhanced Whole-Body MR Angiography for Treatment Planning in Patients With Significant Arterial Stenosis

Objective:To prospectively evaluate diagnostic accuracy of first pass and combined first pass and steady state high-spatial-resolution whole-body magnetic resonance (MR) angiography with a blood pool contrast agent for quantification of arterial stenosis in different vascular territories. Materials and Methods:After Institutional Review Board approval and informed consent, 50 patients with known 50% or greater stenosis in at least one vascular territory; as shown by the standard-of-reference (14 digital subtraction angiographies, 4 computed tomographies, 32 ultrasound examinations), were included. The patients underwent MR angiography at 1.5 Tesla, using a standardized nonbody-weight-adapted i.v. bolus injection of 11 mL gadofosveset trisodium. First pass imaging with 4 different table positions in a whole-body MR scanner (MAGNETOM Avanto, Siemens Healthcare), using individual circulation time determined by a test bolus, was performed. Steady state imaging was performed using an isometric spatial resolution of 1.0 mm. Image quality was rated. Each vascular segment in MR angiography was evaluated by 2 independent and blinded reviewers and the stenosis degree was compared with the preferred standard-of-reference, using a 5-point scale. Differences between first pass and combined MR angiography were assessed with a 95% confidence interval (CI) by applying the adjusted modified &khgr;2 test. Changes in therapy based on the whole-body examination strategy were evaluated. Results:The number of nondiagnostic territories was 24 of 197 (12.2%) for first pass MR angiography and decreased to 3 of 197 (1.5%) after addition of steady state MR angiography. The diagnostic accuracy for quantification of arterial stenosis in combined MR angiography (94.7%; 95% CI: 92.4–97.1) was superior to first pass MR angiography (81.7%; 95% CI: 73.7–89.8; statistically significant). Patient management was changed in 12 of 49 patients, in 7 of 12 patients the change was applied to an additional lesion detected by the whole-body examination strategy. Conclusion:The quantification and detection of arterial stenosis is improved by the steady state high-resolution gadofosveset trisodium-enhanced MR angiography. Additional lesions detected by whole-body examination strategy or differences in stenosis quantification may lead to changes in therapy.
A Biological Phantom for Contrast-Media-Based Perfusion Studies With CT

Objectives:Perfusion computed tomography (PCT) is increasingly getting popular with the advent of computed tomography (CT) systems with adequate temporal resolution and spatial coverage. We sought to develop a biological phantom for perfusion measurements in CT to design, improve, and validate scan protocols and postprocessing algorithms in vitro. Materials and Methods:A special technique was applied to prepare and preserve a fresh porcine kidney. The kidney was connected to an open circuit driven by a peristaltic pump with the option to inject contrast material. We evaluated repeated dynamic contrast-enhanced CT acquisitions with different input flow rates and the relation to calculated parenchymal flow results of the phantom. Flow was calculated with 2 different algorithms. Identical scans were performed with a time interval of 1 year to check long-term stability of the phantom. Different bolus geometries were designed and bolus dispersion was measured for the setup using a tubing array. Results:We found a linear relationship between the input flow rate of the circuit and the calculated phantom tissue flow with a correlation coefficient rr2 = 0.99 for both algorithms. Both algorithms resulted in very similar absolute values, the mean difference was 3.1 mL/100 mL/min. Perfusion measurements with contrast material injection and storage did not alter the phantom. The enhancement properties did not change over the time of 1 year. With our setup, it was possible to design typical bolus geometries as they occur in clinical practice. Bolus dispersion was small: peak enhancement and bolus width changed by about only 5% over 2-m tube length. Conclusions:A phantom for parenchymal flow measurements suitable for repeated measurements over a long period of time was developed. The setup allows the design of diverse bolus geometries with negligible dispersion.
Ultrasound‐guided peripheral venous access for therapeutic apheresis procedures reduces need for central venous catheters

Therapeutic and donor apheresis requires adequate vascular access to achieve inlet flow rates of ∼50—100 mL/min. While central dialysis‐type venous catheters can usually provide such access, their use includes several associated risks. Some of these risks can be avoided or diminished if adequate peripheral venous access can be established. Some patients have adequate peripheral veins for apheresis that cannot be readily identified visually or by palpation. We hypothesized that ultrasound‐guided peripheral venous access would benefit such patients and would lead to placement of fewer central venous catheters. The technique of ultrasound‐guided peripheral access for apheresis has been in use at Houston Methodist Hospital since 2012. We performed a prospective review of patients undergoing inpatient and outpatient apheresis at Houston Methodist Hospital from July 1, 2015 to September 30, 2015, to assess its benefit. During this time, we performed 831 procedures on 186 patients, including 787 therapeutic plasma exchanges, three red blood cell exchanges, 41 peripheral stem cell collections. Ultrasound‐guided vascular access was used for 68 procedures (8% of all procedures), including 62 therapeutic plasma exchanges, 4 peripheral stem cell collections, and 2 red blood cell changes. Use of ultrasound‐guided peripheral access prevented the placement of central venous catheters in 37 (20%) patients, demonstrating its utility in a busy transfusion service.
Constriction of the Vasa Recta, the Vessels Supplying the Area at Risk for Acute Kidney Injury, By Four Different Iodinated Contrast Media, Evaluating Ionic, Nonionic, Monomeric and Dimeric Agents

Objective:Iodinated contrast media (CM) can potentially cause contrast-induced nephropathy (CIN). It is not clear, however, whether particular types of CM are more prone to cause CIN than others. In this study we compare 4 types of CM (ionic vs. nonionic; monomer vs. dimer) on their effects on the microvessels that supply the area at risk for renal damage in CIN (outer medullary descending vasa recta–DVR). Material and Methods:Using microdissection techniques, single DVR were isolated from rats and perfused using a set of concentric pipettes. After stabilization, perfusate was exchanged for a buffered solution containing either vehicle, or amidotrizoate (an ionic/monomeric CM), ioxaglate (an ionic/dimeric CM), iopromide (a nonionic/monomeric CM), and iodixanol (a nonionic/dimeric CM). The final iodine concentration was 23 mg iodine/mL, a concentration similar to that expected for coronary interventions. At this dilution, properties of CM solutions like viscosity and osmolarity are similar to the vehicle solution. To rule out further influence of CM-osmolarity and viscosity, the DVR bath solution was kept isoosmolar to the perfusate. Angiotensin II dose response curves were performed after the 20 minutes of perfusion. Digital videomicroscopy was used for measurements of luminal diameter. Results:All types of CM reduced luminal diameter of perfused DVR in a similar manner. After 20 minutes of perfusion, size of DVR were: 45% ± 7% of initial diameter for the amidotrizoate-group; 53% ± 6% for the ioxaglate-group; 63% ± 11% for the iopromide-group; and 49% ± 8% for the iodixanol-group. Control group remained at 96% ± 4% of initial diameter. The angiotensin II dose response curves showed greater reactivity for amidotrizoate, iopromide and iodixanol, when compared with controls. Conclusion:Under conditions where effects of osmolarity and viscosity are kept insignificant, perfusion of DVR using different types of iodinated CM leads to similar constriction of DVR. The response to angiotensin II was enhanced in 3 of the tested CM. This may be an important mechanism in the pathophysiology of CIN.
Optimization-based reconstruction of sparse images from few-view projections

In this work, we investigate optimization-based image reconstruction from few-view (i.e. less than ten views) projections of sparse objects such as coronary–artery specimens. Using optimization programs as a guide, we formulate constraint programs as reconstruction programs and develop algorithms to reconstruct images through solving the reconstruction programs. Characterization studies are carried out for elucidating the algorithm properties of ‘convergence’ (relative to designed solutions) and ‘utility’ (relative to desired solutions) by using simulated few-view data calculated from a discrete FORBILD coronary–artery phantom, and real few-view data acquired from a human coronary–artery specimen. Study results suggest that carefully designed reconstruction programs and algorithms can yield accurate reconstructions of sparse images from few-view projections.
Increased troponin I is associated with fatal outcome in acquired thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) has >90% mortality without therapeutic plasma exchange (TPE). Despite TPE, approximately 10% of patients still die, presumably from cardiac ischemia. We sought clinical or laboratory parameters associated with death by reviewing the records of all patients hospitalized with acquired TTP in our institution for 10 years, and collect demographics and results for hemoglobin, platelet count, creatinine, lactate dehydrogenase, transaminases, total bilirubin, creatinine kinase (CK), CK‐MB, and troponin I. Sixty‐eight patients were admitted 88 times, and 11 died. Survivors and non‐survivors were similar in terms of sex, ethnicity, thrombocytopenia, and degree of anemia at presentation, while the latter were older, had worse renal function and higher CK, CK‐MB, and troponin I (univariate analysis). However, only troponin I remained significant on multivariate analyses. We propose that patients with TTP should be monitored with troponin I to detect significant myocardial ischemia that could predict death despite TPE.
An evaluation of the appropriateness and safety of nurse and midwife prescribing in Ireland.

AIM To evaluate the clinical appropriateness and safety of nurse and midwife prescribing practice. BACKGROUND The number of countries introducing nurse and midwife prescribing is increasing; however, concerns over patient safety remain. DESIGN A multi-site documentation evaluation was conducted using purposeful and random sampling. The sample included 142 patients' records and 208 medications prescribed by 25 Registered Nurse Prescribers. METHODS Data were extracted from patient and prescription records between March-May 2009. Two expert reviewers applied the modified Medication Appropriate Index tool (8 criteria) to each drug. The percentage of appropriate or inappropriate responses for each criterion was reported. Reviewer concordance was measured using the Cohen's kappa statistic (inter-rater reliability). RESULTS Nurse or midwife prescribers from eight hospitals working in seventeen different areas of practice were included. The reviewers judged that 95-96% of medicines prescribed were indicated and effective for the diagnosed condition. Criteria relating to dosage, directions, drug-drugs or disease-condition interaction, and duplication of therapy were judged appropriate in 87-92% of prescriptions. Duration of therapy received the lowest value at 76%. Overall, reviewers indicated that between 69 (reviewer 2)-80% (reviewer 1) of prescribing decisions met all eight criteria. CONCLUSION The majority of nurse and midwife prescribing decisions were deemed safe and clinically appropriate. However, risk of inappropriate prescribing with the potential for drug errors was detected. Continuing education and evaluation of prescribing practice, especially related to drug and condition interactions, is required to maximize appropriate and safe prescribing.
Beam characteristics and stopping-power ratios of small radiosurgery photon beams

Small megavoltage (MV) photon fields of dimensions less than 3 × 3 cm2 are increasingly being used in modern radiation therapy. To our knowledge, small beam characteristics and dosimetric parameters, such as the energy spectra, particle fluence, and water-to-air stopping-power ratios (SPRs) directly affect the accuracy of small field dosimetry. This study presents the characteristics of small photon beams and investigates the variations of energy spectra of photons and electrons as a function of field size and their effects on the water-to-air SPRs for field sizes ranging from a small 4 mm diameter circular field to a 10 × 10 cm2 field. It sheds light on the differences between small fields collimated by the cone accessory and X- and Y-jaws and on beam characteristics outside the primary radiation fields. In addition, we also investigated the use of an ‘intermediate machine-specific-reference field’ (Alfonso et al 2008 Med. Phys. 35 5179–86) to determine if the variations between a small and a reference field can be eased by introducing an intermediate 4 × 4 cm2 field instead of a standard 10 × 10 cm2 reference field. The Monte Carlo simulation codes BEAMnrc, DOSXYZnrc and SPRRZnrc were used in this study. The accelerator head and circular cone accessory were simulated in detail including two designs of flattening filters: one for a standard-dose rate (100–600 MU min−1) and the other for a high-dose rate (1000 MU min−1) 6 MV beam. The mean energy of photons at depths (1.5–30 cm) in water are 1.72–2.36 MeV, 1.55–1.97 MeV, and 1.44–1.74 MeV for field sizes of 4 mm diameter, 4 × 4 cm2, and 10 × 10 cm2, respectively. The mean energy also varies significantly for electrons at depths (1.5–30 cm): 0.99–1.25 MeV, 0.94–1.09 MeV, and 0.93–1.04 MeV for field sizes of 4 mm, 4 × 4 cm2, and 10 × 10 cm2, respectively. The calculated water-to-air SPRs at depths (1.5–30 cm) are 1.120–1.113, 1.121–1.117, and 1.122–1.119 for field sizes of 4 mm, 4 × 4 cm2 and 10 × 10 cm2, respectively. Although the differences in mean energy are > 20% for photons and > 5% for electrons between 4 mm field and 10 × 10 cm2, the effects on the water-to-air SPRs are small (<0.5%). For detectors with responses to energy changes that are not negligible, significant energy variations between small fields and the reference 10 × 10 cm2 field may have a significant impact on the dosimetry accuracy. However, the use of an intermediate field is capable of greatly reducing these energy variations. This study also found negligible differences in dosimetric parameters between beams with different flattening filters and different incident electron energies on the target when each has the same beam quality kQ values specified by %dd(10)x.
Improving SAR estimations in MRI using subject-specific models

To monitor and strategically control energy deposition in magnetic resonance imaging (MRI), measured as a specific absorption rate (SAR), numerical methods using generic human models have been employed to estimate worst-case values. Radiofrequency (RF) sequences are therefore often designed conservatively with large safety margins, potentially hindering the full potential of high-field systems. To more accurately predict the patient SAR values, we propose the use of image registration techniques, in conjunction with high-resolution image and tissue libraries, to create patient-specific voxel models. To test this, a matching model from the archives was first selected. Its tissue information was then warped to the patient's coordinates by registering the high-resolution library image to the pilot scan of the patient. Results from studying the models’ 1 g SAR distribution suggest that the developed patient model can predict regions of elevated SAR within the patient with remarkable accuracy. Additionally, this work also proposes a voxel analytical metric that can assist in the construction of a patient library and the selection of the matching model from the library for a patient. It is hoped that, by developing voxel models with high accuracy in patient-specific anatomy and positioning, the proposed method can accurately predict the safety margins for high-field human applications and, therefore maximize the safe use of RF sequence power in high-field MRI systems.
Measurement of the mass energy-absorption coefficient of air for x-rays in the range from 3 to 60 keV

For the first time the absolute photon mass energy-absorption coefficient of air in the energy range of 10 to 60 keV has been measured with relative standard uncertainties below 1%, considerably smaller than those of up to 2% assumed for calculated data. For monochromatized synchrotron radiation from the electron storage ring BESSY II both the radiant power and the fraction of power deposited in dry air were measured using a cryogenic electrical substitution radiometer and a free air ionization chamber, respectively. The measured absorption coefficients were compared with state-of-the art calculations and showed an average deviation of 2% from calculations by Seltzer. However, they agree within 1% with data calculated earlier by Hubbell. In the course of this work, an improvement of the data analysis of a previous experimental determination of the mass energy-absorption coefficient of air in the range of 3 to 10 keV was found to be possible and corrected values of this preceding study are given.
Inner strength as a mediator of the relationship between disease and self-rated health among old people.

AIM To explore inner strength as a mediator of the relationship between disease and self-rated health among older people. BACKGROUND Qualitative research has indicated that inner strength is an essential resource for an individual affected by disease. A hypothesis of inner strength as a mediator of the relationship between disease and self-rated health was proposed. The theoretical framework of inner strength was based on the Model of Inner Strength. DESIGN A cross-sectional design was used. METHOD The sample included 6119 participants from Finland and Sweden, in the ages of 65, 70, 75 and 80 years. The GERDA-Botnia questionnaire, which included the Inner Strength Scale and items related to diseases and self-rated health, was sent out between October and December 2010. Structural equation modelling was used to test a hypothesized model. RESULTS The result indicated that having a disease was associated with poorer self-rated health and a lower degree of inner strength and a higher degree of inner strength was associated with better self-rated health. The result supported the hypothesis by indicating that inner strength partially mediated the relationship between disease and self-rated health. CONCLUSION This large cross-sectional study with participants from 65 to 80 years of age from Finland and Sweden showed that inner strength can be a resource for older people affected by disease. Increasing inner strength in older people affected by disease may be one intervention to support experiences of health despite disease.
Students' and families' expenditures to attend a nursing programme in 2011-2012: a comparison of five southern European countries.

AIM To compare students' and families' nursing education expenditures across Europe. BACKGROUND Nursing education costs are affected by investments in public education. The remaining costs fall on the shoulders of students and their families. While remaining somewhat understudied, public and student expenditure for nursing education is becoming critical in the current crisis context. Comparative studies on education costs are inevitably affected by a currency bias. Therefore, a standard measure named the Purchasing Power Standard, which has received no attention in nursing research, has been introduced. DESIGN A mixed-method study incorporating qualitative and quantitative study designs was undertaken in 2011-2012. METHODS Five nursing faculties located in the Czech Republic, Greece, Italy, Slovakia and Slovenia were included in the study. A questionnaire evaluating students' expenditures was developed in five languages and validated. Six hundred and twenty-five full-time students were recruited. RESULTS A Slovakian student wishing to pursue a nursing career is required to commit an amount of money per year that corresponds to 15% of the average annual income of a Slovakian citizen. Lower percentages were required by students in Greece (10%), Italy (11%) and Slovenia (12%), while Czech students bore the lowest costs (5%). CONCLUSION None of the countries involved was supporting nursing students through either direct or indirect financial incentives. Students in some countries were also required to buy and maintain uniforms. There is a need to develop supportive policies, especially in those countries where nursing programmes are expensive and may not be accessible to all talented and motivated students due to limited public support in education and the current economic context.
MMP‐14 mediated MMP‐9 expression is involved in TGF‐beta1‐induced keratinocyte migration

The importance of expression of matrix metalloproteinase (MMP) in keratinocyte migration is well established, but its role remains unclear. Here we investigated the function of MMP‐14 in TGF‐β1‐induced keratinocyte migration. TGF‐β1 stimulated cell migration and the expression of MMP‐2, ‐9 in HaCaT human keratinocyte cells. When we lowered MMP‐14 mRNA with siRNA, cell migration, and MMP‐9 expression decreased. Furthermore, the MMP‐14 siRNA also reduced activation of JNK in response to TGF‐β1, and a JNK‐specific inhibitor decreased both cell migration and MMP‐9 expression. Taken together, these results suggest that TGF‐β1‐induced HaCaT cell migration is mediated by MMP‐14, which regulates MMP‐9 expression via JNK signaling. J. Cell. Biochem. 104: 934–941, 2008. © 2008 Wiley‐Liss, Inc.
Involvement of the role of Chk1 in lithium‐induced G2/M phase cell cycle arrest in hepatocellular carcinoma cells

Lithium, a therapeutic agent for bipolar disorder, can induce G2/M arrest in various cells, but the mechanism is unclear. In this article, we demonstrated that lithium arrested hepatocellular carcinoma cell SMMC‐7721 at G2/M checkpoint by inducing the phosphorylation of cdc2 (Tyr‐15). This effect was p53 independent and not concerned with the inhibition of glycogen synthase kinase‐3 and inositol monophosphatase, two well‐documented targets of lithium. Checkpoint kinase 1 (Chk1), a critical enzyme in DNA damage‐induced G2/M arrest, was at least partially responsible for the lithium action. The lithium‐induced phosphorylation of cdc2 and G2/M arrest was abrogated largely by SB218078, a potent Chk1 inhibitor, as well as by Chk1 siRNA or the over‐expression of kinase dead Chk1. Furthermore, lithium‐induced cdc25C phosphorylation in 7721 cells and in vitro kinase assay showed that the activity of Chk1 was enhanced after lithium treatment. Interestingly, the increase of Chk1 activity by lithium may be independent of ataxia telangiectasia mutated (ATM)/ATM and Rad3‐related (ATR) kinase. This is because no elevated phosphorylation on Chk1 (Ser‐317 and Ser‐345) was observed after lithium treatment. Moreover, caffeine, a known ATM/ATR kinase inhibitor, relieved the phosphorylation of cdc2 (Tyr‐15) by hydroxyurea, but not that by lithium. Our study's results revealed the role of Chk1 in lithium‐induced G2/M arrest. Given that Chk1 has been proposed to be a novel tumor suppressor, we suggest that the effect of lithium on Chk1 and cell cycle is useful in tumor prevention and therapy. J. Cell. Biochem. 104: 1181–1191, 2008. © 2008 Wiley‐Liss, Inc.