Longitudinal development in the preterm thalamus and posterior white matter: MRI correlations between diffusion weighted imaging and T2 relaxometry

Infants born prematurely are at increased risk of adverse neurodevelopmental outcome. The measurement of white matter tissue composition and structure can help predict functional performance. Specifically, measurements of myelination and indicators of myelination status in the preterm brain could be predictive of later neurological outcome. Quantitative imaging of myelin could thus serve to develop biomarkers for prognosis or therapeutic intervention; however, accurate estimation of myelin content is difficult. This work combines diffusion MRI and multi‐component T2 relaxation measurements in a group of 37 infants born very preterm and scanned between 27 and 58 weeks equivalent gestational age. Seven infants have longitudinal data at two time points that we analyze in detail. Our aim is to show that measurement of the myelin water fraction is achievable using widely available pulse sequences and state‐of‐the‐art algorithmic modeling of the MR imaging procedure and that a multi‐component fitting routine to multi‐shell diffusion weighted data can show differences in neurite density and local spatial arrangement in grey and white matter. Inference on the myelin water fraction allows us to demonstrate that the change in diffusion properties of the preterm thalamus is not solely due to myelination (that increase in myelin content accounts for about a third of the observed changes) whilst the decrease in the posterior white matter T2 has no significant component that is due to myelin water content. This work applies multi‐modal advanced quantitative neuroimaging to investigate changing tissue properties in the longitudinal setting. Hum Brain Mapp 37:2479–2492, 2016. © The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. .     

Nurse specialist treatment of eye emergencies: Five year follow up study of quality and effectiveness

The role of specialist nurses in triage, diagnosis and management of emergency eye conditions is well established, and encouraging reports of the safety and effectiveness of such services have been published. Specialist nurses in an emergency eye clinic in the UK seeing >7000 patients per year had been found at initial evaluation to treat 22% of the 1976 patients seen over a three month period without referring on to an ophthalmologist. A repeat of this evaluation five years later found this proportion had dropped to 17% (χ² = 16.7, p < 0.01).In addition, the initial evaluation had found no incident of any patient having been treated and discharged by the specialist nurses returning to the department due to incorrect diagnosis or mismanagement. By contrast, from the sample 5 years later, 3 patients were identified who returned to the department due to possible misdiagnosis or sub-optimal management.We suggest that provision must be made for continuing professional development of nurses in this type of extended role, and the commitment to ongoing education should be backed up by a system of monitoring and critical incident reporting to facilitate skill maintenance and the life long learning process for specialist nurses.     

kV-Cone Beam CT as an IGRT Tool in the Treatment of Early Stage Prostate Cancer: A Literature Review

Image-guided radiation therapy (IGRT) is an important quality assurance measure that can be used in tandem with conformal radiation therapy treatment. Cone beam computed tomography (CBCT) is a sophisticated IGRT technology that has recently been introduced to the clinical setting. Cone beam equipment includes kilovoltage (kV) CBCT that produces online, high-quality, three-dimensional images of the prostate gland. Interfractional displacements of the prostate can be quantified and adjustments made using kV-CBCT so that daily RT can be accurately delivered. In addition, the volumetric nature of CBCT allows deformations of the prostate gland and surrounding anatomy to be accounted for using adaptive radiation therapy strategies.This article provides an introduction to the main IGRT tools that can be used in parallel with conformal radiation therapy of prostate cancer. A literature review is performed to describe the major IGRT approaches; however, the focus will remain primarily on the technical and clinical applications of kV-CBCT. Important considerations including patient dose, resource implications, and possible changes to the radiation therapist's scope of practice are also discussed.     

Intravascular ultrasound: Virtual histology IVUS, integrated backscatter IVUS, and palpography

The concept of the vulnerable plaque is the focus of much research, although our knowledge of the histology, pathobiology, natural history, and therapy of vulnerable plaque remains incomplete. The evolving intravascular ultrasound technologies of virtual histology, integrated backscatter, and palpography have yielded complementary information to traditional grayscale intravascular ultrasound, and advanced our understanding of vulnerable plaque. Although each of these techniques has enjoyed success in the academic arena, none of these techniques has been sufficiently validated to the extent that would allow it to play a part in clinical decision-making. Their future role, both in regard to risk stratification and identification of vulnerable plaque, will depend upon additional rigorous studies of the natural history and treatment of vulnerable plaque.     

Large-scale blood group genotyping – clinical implications

The molecular background of blood group antigen expression of the major clinically significant blood group antigens has been largely accomplished. Despite this large body of work, blood group phenotype prediction by genotyping has a marginal supporting role in the routine blood bank. It has however had a major impact in the prenatal determination of fetal blood group status in the management of haemolytic disease of the fetus and newborn. In the past few years several high throughput systems have been in development that have the potential capacity to perform genotyping on a mass scale. Such systems have been designed for use on donor- and patient-derived DNA and provide much more comprehensive information regarding an individuals blood group than is possible by using serological methods alone. DNA-based typing methodology is easier to standardize than serology and has the potential to replace it as a front line diagnostic in blood banks. This review overviews the current situation in this area and attempts to predict how blood group genotyping will evolve in the future.     

Adenoviral transfer of HIF-1α enhances vascular responses to critical limb ischemia in diabetic mice

Diabetes is a major risk factor for ischemic disease. Treatment options for diabetic patients with peripheral arterial disease when revascularization is not possible are limited, resulting in a high incidence of limb amputation. We evaluated the therapeutic potential of AdCA5, an adenovirus encoding a constitutively active form of HIF-1α, in a diabetic model of critical limb ischemia. Diabetic db/db and nondiabetic db/+ mice were subjected to unilateral femoral artery ligation. Limb perfusion, tissue viability, and motor function were more severely impaired in db/db mice. Intramuscular injection of AdCA5 into the ischemic limb of db/db mice increased the recovery of limb perfusion and function, reduced tissue necrosis, rescued the diabetes-associated impairment of circulating angiogenic cells, enhanced endothelial nitric oxide synthase activation, and increased vessel density and luminal area in the ischemic limb.     

Associations of factor VIIIc,D‐dimer,and plasmin–antiplasmin with incident cardiovascular disease and all‐cause mortality

To examine the associations of three understudied hemostatic factors—D‐dimer, factor VIII_c, and plasmin‐antiplasmin (PAP) complex—with incident cardiovascular disease (CVD) and all cause mortality in the Multiethnic Study of Atherosclerosis cohort. Hemostatic factors were measured at baseline in 45–84‐year‐old patients (n = 6,391) who were free of clinically recognized CVD. Over 4.6 years of follow‐up, we identified 307 CVD events, 207 hard coronary heart disease events, and 210 deaths. D‐dimer, factor VIII_c, and PAP were not associated with CVD incidence after adjustment for other risk factors. In contrast, each factor was associated positively with total mortality, and D‐dimer and factor VIII_c were associated positively with cancer mortality. When modeled as ordinal variables and adjusted for risk factors, total mortality was greater by 33% (95% CI 15–54) for each quartile increment of D‐dimer, 26% (11–44) for factor VIIIc, and 20% (4–38) for PAP. This prospective cohort study did not find D‐dimer, factor VIII_c, or PAP to be risk factors for CVD. Instead, elevated levels of these three hemostatic factors were associated independently with increased risk of death. Elevated D‐dimer and factor VIII_c were associated with increased cancer death. Am. J. Hematol., 2009. © 2009 Wiley‐Liss, Inc.