Head-to-head comparison of three-dimensional navigator-gated magnetic resonance imaging and 16-slice computed tomography to detect coronary artery stenosis in patients

OBJECTIVES: The purpose of this research was to compare the diagnostic accuracy of three-dimensional navigator-gated magnetic resonance (MR) imaging and 16-slice multidetector row computed tomography (MDCT) versus quantitative coronary angiography (QCA) for the detection of coronary artery stenosis in patients. BACKGROUND: Both MR and MDCT are novel non-invasive tests, which have been proposed for noninvasive detection of coronary artery disease. Yet their diagnostic accuracy has not been directly compared in the same population. METHODS: Fifty-two patients underwent coronary MR and 16-slice MDCT before invasive coronary angiography. Diameter stenosis (DS) severity in vessels >1.5-mm reference diameter were graded visually and measured quantitatively on both MR and MDCT images. Diagnostic accuracy of both methods was compared using QCA as the reference test. RESULTS: According to QCA, 81 of 452 (18%) coronary segments with >1.5 mm diameter had >50% DS. By visual analysis, MR and MDCT had similar sensitivity (75% vs. 82%, p = NS), specificity (77% vs. 79%, p = NS), and diagnostic accuracy (77%, vs. 80%, p = NS) for detection of >50 % DS. Quantitative measures of DS by MR (r = 0.60, p < 0.001) and MDCT (r = 0.75, both p < 0.001) correlated well with QCA. Receiver-operating characteristic analysis demonstrated that quantification of DS severity improved the diagnostic accuracy of MDCT (area under curve [AUC] 0.81 vs. 0.92, p < 0.001) but not that of MR (AUC 0.78 vs. 0.83, p = NS). CONCLUSIONS: Visual assessment of coronary diameter stenosis severity by MR or MDCT allows identification of significant coronary artery disease with a similar high diagnostic accuracy. Quantitative analysis significantly further improves the diagnostic accuracy of MDCT but not that of MR.     

Investigation of vibration‐induced artifact in clinical diffusion‐weighted imaging of pediatric subjects

It has been reported that mechanical vibrations of the magnetic resonance imaging scanner could produce spurious signal dropouts in diffusion‐weighted images resulting in artifactual anisotropy in certain regions of the brain with red appearance in the Directionally Encoded Color maps. We performed a review of the frequency of this artifact across pediatric studies, noting differences by scanner manufacturer, acquisition protocol, as well as weight and position of the subject. We also evaluated the ability of automated and quantitative methods to detect this artifact. We found that the artifact may be present in over 50% of data in certain protocols and is not limited to one scanner manufacturer. While a specific scanner had the highest incidence, low body weight and positioning were also associated with appearance of the artifact for both scanner types evaluated, making children potentially more susceptible than adults. Visual inspection remains the best method for artifact identification. Software for automated detection showed very low sensitivity (10%). The artifact may present inconsistently in longitudinal studies. We discuss a published case report that has been widely cited and used as evidence to set policy about diagnostic criteria for determining vegetative state. That report attributed longitudinal changes in anisotropy to white matter plasticity without considering the possibility that the changes were caused by this artifact. Our study underscores the need to check for the presence of this artifact in clinical studies, analyzes circumstances for when it may be more likely to occur, and suggests simple strategies to identify and potentially avoid its effects. Hum Brain Mapp 36:4745–4757, 2015. © 2015 Wiley Periodicals, Inc.     

Late Pleistocene age and archaeological context for the hominin calvaria from GvJm-22 (Lukenya Hill,Kenya)

Kenya National Museums Lukenya Hill Hominid 1 (KNM-LH 1) is a Homo sapiens partial calvaria from site GvJm-22 at Lukenya Hill, Kenya, associated with Later Stone Age (LSA) archaeological deposits. KNM-LH 1 is securely dated to the Late Pleistocene, and samples a time and region important for understanding the origins of modern human diversity. A revised chronology based on 26 accelerator mass spectrometry radiocarbon dates on ostrich eggshells indicates an age range of 23,576–22,887 y B.P. for KNM-LH 1, confirming prior attribution to the Last Glacial Maximum. Additional dates extend the maximum age for archaeological deposits at GvJm-22 to >46,000 y B.P. (>46 kya). These dates are consistent with new analyses identifying both Middle Stone Age and LSA lithic technologies at the site, making GvJm-22 a rare eastern African record of major human behavioral shifts during the Late Pleistocene. Comparative morphometric analyses of the KNM-LH 1 cranium document the temporal and spatial complexity of early modern human morphological variability. Features of cranial shape distinguish KNM-LH 1 and other Middle and Late Pleistocene African fossils from crania of recent Africans and samples from Holocene LSA and European Upper Paleolithic sites.For Late Pleistocene African populations of modern humans, the constellation of behavioral changes encapsulated in the transition from the Middle Stone Age (MSA) to the Later Stone Age (LSA) ∼70–20 kya represents a series of some of the most pronounced changes in the archaeological record before the adoption of domesticated animals and plants and the use of ceramics for cooking and storage. It is among LSA sites that the strongest parallels with ethnographic and historic foragers are observed. Typical archaeological signatures include lithic technologies focused on the production of microliths (small flakes, blades, and bladelets with one edge blunted or “backed”) from bipolar, single-, and opposed-platform cores; an increased use of ground-stone tools; and implements made of wood and bone. These new technologies occur with the appearance of material correlates of social identity and networks of long-distance exchange, including ostrich eggshell (OES) beads, ochre, and nonlocal stone raw material, as well as increased dietary breadth, all consistent with larger, more dense, or more interconnected populations (1–9).This same interval of ∼70–20 kya witnessed a number of human dispersals across Africa, with eastern Africa host to one or more candidate populations for the expansion of Homo sapiens out of Africa (10–15). However, the eastern African hominin fossil record for this interval is extremely sparse and poorly dated, and it consists largely of isolated teeth or highly fragmentary crania and postcrania (16–18). Here, we reassess the age and context of the Kenya National Museums Lukenya Hill Hominid 1 (KNM-LH 1) partial calvaria from site GvJm-22 at Lukenya Hill, Kenya, the only eastern African fossil hominin from a Last Glacial Maximum [LGM; 19–26.4 kya (19)] LSA archaeological context. We construct a revised accelerator mass spectrometry (AMS) radiocarbon chronology built on 26 new dates on OES fragments. The revised chronology confirms the LGM age of KNM-LH 1 and expands the maximum age of the site to beyond the limits of the radiocarbon method. Increased radiometric age is consistent with new technological analyses that demonstrate previously unrecognized MSA elements that indicate assemblages spanning the MSA/LSA transition from deposits underlying KNM-LH 1. Morphometric analyses using a robust comparative dataset demonstrate the variability among African Late Pleistocene hominins, including candidate populations for out-of-Africa dispersals. They indicate that KNM-LH 1 is distinct from (i) modern Africans, (ii) H. sapiens from Holocene LSA sites, and (iii) European Upper Paleolithic modern humans, suggesting that it may sample a now extinct lineage.     

Rehabilitation Regimens Following Surgical Repair of Extensor Tendon Injuries of the Hand—A Systematic Review of Controlled Trials

There is no consensus on the most effective rehabilitation regimen following extensor tendon repair of the hand. This systematic review evaluates the outcomes of the various regimens. The Cochrane, MEDLINE, EMBASE, CINAHL, AMED, PEDro, OTseeker databases were searched for any prospective randomised clinical trials comparing rehabilitation regimens for acute extensor tendon injuries in adults. Five papers met the inclusion criteria. The regimens were static immobilisation, dynamic splinting and early active motion (EAM). There was no standard format of reporting. The sample size ranged from 27 to 100 patients. The duration of follow-up ranged from 8 to 24 weeks. Overall, patients’ total active motion improved with time. Early mobilisation regimens (active and passive) achieve quicker recovery of motion than static immobilisation but the long-term outcome appears similar. Given the comparable outcomes between dynamic splinting and EAM, we therefore favour EAM which is simpler and more convenient.

Electronic supplementary material

The online version of this article (doi:10.1007/s12593-012-0075-x) contains supplementary material, which is available to authorized users.     

Identification of cause of posttransplant cachexia by PCR

TO THE EDITOR: A man, 56 years of age, was admitted to the hospital for epigastric pain, fever, and fatigue 8 years after a cardiac transplant. His immunosuppressive regimen consisted of cyclosporine A, mycophenolate mofetil, and steroids. Clinical examination revealed a 4-kg weight loss within 3 months without peripheral lymph node enlargement.     

Acetylcysteine, coronary procedure and prevention of contrast-induced worsening of renal function: which benefit for which patient?

OBJECTIVES: This study was designed to determine whether acetylcysteine could provide a protective effect on renal function in a population of patients with normal renal function or mild to moderate chronic renal failure, usually referred for a coronary procedure. BACKGROUND: Contrast-induced nephropathy is a well-recognized complication of coronary angiography. Recent studies suggest that saline hydration and acetylcysteine reduce the incidence of contrast-induced worsening of renal function in patients with pre-existing chronic renal failure who are undergoing computed tomography examinations. METHODS: One hundred eight patients were blindly and randomly assigned to receive either acetylcysteine or placebo before and after administration of contrast agent in association with a moderate hydration protocol. Serum creatinine and urea nitrogen were measured before and 24 hours after coronary procedure. RESULTS: The mean serum creatinine concentration remained unchanged 24 hours after contrast agent administration in both groups: from 1.04 +/- 0.26 to 1.03 +/- 0.29 mg/dl in the acetylcysteine group and from 1.16 +/- 1.1 to 1.06 +/- 0.41 mg/dl in the control group (p = 0.29, for the comparison between two groups, NS). We divided the population into 3 subgroups according to their creatinine clearance: no significant change of serum creatinine concentration was observed in patients with normal renal function nor in patients with pre-existing mild to moderate chronic renal failure in both groups. There was no significant difference for the incidence of contrast-induced nephropathy between both groups (2 of the 53 patients in the acetylcysteine group and 3 of the 51 patients in the placebo group, p = 0.98, NS). CONCLUSIONS: Our data do not support the systematic use of acetylcysteine before a coronary procedure in patients with normal renal function or mild to moderate chronic renal failure, to prevent contrast-induced nephropathy.     

Effect of Dietary Lipids (Soybean Lecithin and Triacylglycerol) on Hepatic F-Actin Microfilaments in Cyclosporine A-Treated Rats

We studied and quantified the effect of cyclosporine A on hepatic F-actin on bile canalicular and basolateral membranes in rats fed either soybean lecithin, triacylglycerol-enriched diet, or low-fat diet by means of confocal laser scanning microscopy imaging. The phalloidin–FITC staining of F-actin was quite normal in the lecithin–cyclosporine A group but decreased significantly in the other cyclosporine A-treated groups (by 40% and 25% of control in triacylglycerol–cyclosporine A and cyclosporine A groups, respectively). The alteration of F-actin by cyclosporine A, related to cholestasis evidenced by a decrease in bile salt secretion, was prevented by dietary soybean lecithin and amplified by dietary soybean triacylglycerol.     

Bcl-2-modifying factor induces renal proximal tubular cell apoptosis in diabetic mice

This study investigated the mechanisms underlying tubular apoptosis in diabetes by identifying proapoptotic genes that are differentially upregulated by reactive oxygen species in renal proximal tubular cells (RPTCs) in models of diabetes. Total RNAs isolated from renal proximal tubules (RPTs) of 20-week-old heterozygous db/m+, db/db, and db/db catalase (CAT)-transgenic (Tg) mice were used for DNA chip microarray analysis. Real-time quantitative PCR assays, immunohistochemistry, and mice rendered diabetic with streptozotocin were used to validate the proapoptotic gene expression in RPTs. Cultured rat RPTCs were used to confirm the apoptotic activity and regulation of proapoptotic gene expression. Additionally, studies in kidney tissues from patients with and without diabetes were used to confirm enhanced proapoptotic gene expression in RPTs. Bcl-2-modifying factor (Bmf) was differentially upregulated (P<0.01) in RPTs of db/db mice compared with db/m+ and db/db CAT-Tg mice and in RPTs of streptozotocin-induced diabetic mice in which insulin reversed this finding. In vitro, Bmf cDNA overexpression in rat RPTCs coimmunoprecipated with Bcl-2, enhanced caspase-3 activity, and promoted apoptosis. High glucose (25 mmol/L) induced Bmf mRNA expression in RPTCs, whereas rotenone, catalase, diphenylene iodinium, and apocynin decreased it. Knockdown of Bmf with small interfering RNA reduced high glucose-induced apoptosis in RPTCs. More important, enhanced Bmf expression was detected in RPTs of kidneys from patients with diabetes. These data demonstrate differential upregulation of Bmf in diabetic RPTs and suggest a potential role for Bmf in regulating RPTC apoptosis and tubular atrophy in diabetes.