Genetic Variation in The Age of Demarcation Between Juvenile And Mature Wood in Douglas-Fir

Variation in the age of demarcation between juvenile and mature wood based on wood density was studied in 180 Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) trees. Ring density profiles were generated from X-ray densitometry of increment cores from each of 3 randomly selected trees from each of 30 wind-pollinated families (parent trees) grown in 2 replication blocks. The families represented 10 provenances (3 families per provenance). Two boundary points were determined: the age at which a significant change occurred in the slope of the density-age relationship (using piecewise regression techniques), and the age at which species average density was reached. The period of juvenile wood production ranged from 11 to 37 years among the trees sampled. Most of the variation was among trees-within-plots; however, significant differences among families-within-provenances indicated that the period of juvenile wood production for this population of Douglas-fir was under appreciable genetic control

Intra-Ring Variations in Mature Douglas-Fir Trees From Provenance Plantations

Variations in seven intra-ring characteristics were studied in juvenile and mature wood from two Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] genetic plantations. Samples were collected from 30 families representing 10 provenances with two replicates in each plantation. The following characteristics were determined by X-ray densitometry: earlywood density (EWD), latewood density (LWD), average ring density (RD), earlywood width (EWW), latewood width (LWW), total ring width (RW), and latewood proportion (LWP). Variation patterns were analyzed by two models: (1) families pooled across provenances and (2) provenances and families-within-provenances.Differences between plantations were significant for all traits except juvenile RD and mature RW and EWD. Variance components associated with families (pooled across provenances) remained the same with stand development and were biased upwards as a result of provenance variation. Genetic variation resulting from provenances was evident for RD and EWD, but (except for LWP) was relatively unimportant for RW parameters. Selection for families within populations can contribute to juvenile RW, as well as to mature RD and LWP

Antigen-specific Treg cells in immunological tolerance: implications for allergic diseases

Allergic diseases are chronic inflammatory disorders in which there is failure to mount effective tolerogenic immune responses to inciting allergens. The alarming rise in the prevalence of allergic diseases in recent decades has spurred investigations to elucidate the mechanisms of breakdown in tolerance in these disorders and means of restoring it. Tolerance to allergens is critically dependent on the generation of allergen-specific regulatory T (Treg) cells, which mediate a state of sustained non-responsiveness to the offending allergen. In this review, we summarize recent advances in our understanding of mechanisms governing the generation and function of allergen-specific Treg cells and their subversion in allergic diseases. We will also outline approaches to harness allergen-specific Treg cell responses to restore tolerance in these disorders

Noninvasive rapid cardiac magnetic resonance for the assessment of cardiomyopathies in low-middle income countries

INTRODUCTION: Cardiac Magnetic Resonance (CMR) is a crucial diagnostic imaging test that redefines diagnosis and enables targeted therapies, but the access to CMR is limited in low-middle Income Countries (LMICs) even though cardiovascular disease is an emergent primary cause of mortality in LMICs. New abbreviated CMR protocols can be less expensive, faster, whilst maintaining accuracy, potentially leading to a higher utilization in LMICs. AREAS COVERED: This article will review cardiovascular disease in LMICs and the current role of CMR in cardiac diagnosis and enable targeted therapy, discussing the main obstacles to prevent the adoption of CMR in LMICs. We will then review the potential utility of abbreviated, cost-effective CMR protocols to improve cardiac diagnosis and care, the clinical indications of the exam, current evidence and future directions. EXPERT OPINION: Rapid CMR protocols, provided that they are utilized in potentially high yield cases, could reduce cost and increase effectiveness. The adoption of these protocols, their integration into care pathways, and prioritizing key treatable diagnoses can potentially improve patient care. Several LMIC countries are now pioneering these approaches and the application of rapid CMR protocols appears to have a bright future if delivered effectively

Comparison between oxytocin, ergometrine and misoprostol in active management of the third stage of labour: a randomized controlled trial

Background: The aim of the present study was to compare the effectiveness of sublingual misoprostol, intravenous infusion of oxytocin, and intravenous infusion of Ergometrine in reducing blood loss during the third stage of labor.Methods: This is a no-random trial study conducted in in Ribat University Hospital, Khartoum among 150 laboring ladies with a healthy singleton pregnancy. After obtaining their written informed consent to participate in the study, they were randomly assigned to one of three possible treatment groups: 400 μg of sublingual misoprostol; 10 IU of intravenous infusion oxytocin; and 0.5 mg of intravenous infusion of Ergometrine. Blood loss was estimated by weighing the collected blood and converting the weight to milliliters.Results: The shortest mean duration of the third stage of labor was seen in patients who received misoprostol (3.89±0.37 min), followed by oxytocin (4.6±0.9 min), and Ergometrine (5.45±0.9 min). The lowest mean blood loss was seen in the patients who received 400 µg misoprostol (168.36±24.83 ml), followed by those who received 10 IU oxytocin (205.56±34.82 ml), and 0.5 mg Ergometrine (214.49±35.97 ml).Conclusions: Present study showed that 400 µg sublingual misoprostol was more effective than the conventional parenteral uterotonics in reducing the amount of the blood loss during the third stage of labor and has comparable effect to that of 10 IU intravenous oxytocin in shortening the duration of third stage of labor. It also showed that the use of misoprostol reduces the need for extra-uterotonics and blood transfusion

Detection of metallic cobalt and chromium liver deposition following failed hip replacement using T2* and R2 magnetic resonance

BACKGROUND: Failed hip prostheses can cause elevated circulating cobalt and chromium levels, with rare reports of fatal systemic organ deposition, including cobalt cardiomyopathy. Although blood cobalt and chromium levels are easily measured, organ deposition is difficult to detect without invasive biopsy. The T2* magnetic resonance (MR) method is used to quantify tissue iron deposition, and plays an important role in the management of iron-loading conditions. Cobalt and chromium, like iron, also affect magnetism and are proposed MR contrast agents. CASE PRESENTATION: We describe a case of a 44-year-old male with a failed hip implant and very elevated blood cobalt and chromium levels. Despite normal cardiac MR findings, liver T2* and R2 values were abnormal, triggering tissue biopsy. Liver tissue analysis, including X-ray fluorescence, demonstrated heavy elemental cobalt and chromium deposition in macrophages, and no detectable iron. CONCLUSIONS: Our case demonstrates T2* and R2 quantification of liver metal deposition in a patient with a failed hip implant. Further work is needed to investigate the role of T2* and R2 MR in the detection of metal deposition from metal on metal hip prostheses

Impact of microvascular obstruction on semiautomated techniques for quantifying acute and chronic myocardial infarction by cardiovascular magnetic resonance

AIMS: The four most promising semiautomated techniques (5-SD, 6-SD, Otsu and the full width half maximum (FWHM)) were compared in paired acute and follow-up cardiovascular magnetic resonance (CMR), taking into account the impact of microvascular obstruction (MVO) and using automated extracellular volume fraction (ECV) maps for reference. Furthermore, their performances on the acute scan were compared against manual myocardial infarct (MI) size to predict adverse left ventricular (LV) remodelling (≥20% increase in end-diastolic volume). METHODS: 40 patients with reperfused ST segment elevation myocardial infarction (STEMI) with a paired acute (4±2 days) and follow-up CMR scan (5±2 months) were recruited prospectively. All CMR analysis was performed on CVI42. RESULTS: Using manual MI size as the reference standard, 6-SD accurately quantified acute (24.9±14.0%LV, p=0.81, no bias) and chronic MI size (17.2±9.7%LV, p=0.88, no bias). The performance of FWHM for acute MI size was affected by the acquisition sequence used. Furthermore, FWHM underestimated chronic MI size in those with previous MVO due to the significantly higher ECV in the MI core on the follow-up scans previously occupied by MVO (82 (75-88)% vs 62 (51-68)%, p<0.001). 5-SD and Otsu were precise but overestimated acute and chronic MI size. All techniques were performed with high diagnostic accuracy and equally well to predict adverse LV remodelling. CONCLUSIONS: 6-SD was the most accurate for acute and chronic MI size and should be the preferred semiautomatic technique in randomised controlled trials. However, 5-SD, FWHM and Otsu could also be used when precise MI size quantification may be adequate (eg, observational studies)

T1 mapping and T2 mapping at 3T for quantifying the area-at-risk in reperfused STEMI patients

BACKGROUND: Whether T1-mapping cardiovascular magnetic resonance (CMR) can accurately quantify the area-at-risk (AAR) as delineated by T2 mapping and assess myocardial salvage at 3T in reperfused ST-segment elevation myocardial infarction (STEMI) patients is not known and was investigated in this study. METHODS: 18 STEMI patients underwent CMR at 3T (Siemens Bio-graph mMR) at a median of 5 (4–6) days post primary percutaneous coronary intervention using native T1 (MOLLI) and T2 mapping (WIP #699; Siemens Healthcare, UK). Matching short-axis T1 and T2 maps covering the entire left ventricle (LV) were assessed by two independent observers using manual, Otsu and 2 standard deviation thresholds. Inter- and intra-observer variability, correlation and agreement between the T1 and T2 mapping techniques on a per-slice and per patient basis were assessed. RESULTS: A total of 125 matching T1 and T2 mapping short-axis slices were available for analysis from 18 patients. The acquisition times were identical for the T1 maps and T2 maps. 18 slices were excluded due to suboptimal image quality. Both mapping sequences were equally prone to susceptibility artifacts in the lateral wall and were equally likely to be affected by microvascular obstruction requiring manual correction. The Otsu thresholding technique performed best in terms of inter- and intra-observer variability for both T1 and T2 mapping CMR. The mean myocardial infarct size was 18.8 ± 9.4 % of the LV. There was no difference in either the mean AAR (32.3 ± 11.5 % of the LV versus 31.6 ± 11.2 % of the LV, P = 0.25) or myocardial salvage index (0.40 ± 0.26 versus 0.39 ± 0.27, P = 0.20) between the T1 and T2 mapping techniques. On a per-slice analysis, there was an excellent correlation between T1 mapping and T2 mapping in the quantification of the AAR with an R2 of 0.95 (P < 0.001), with no bias (mean ± 2SD: bias 0.0 ± 9.6 %). On a per-patient analysis, the correlation and agreement remained excellent with no bias (R2 0.95, P < 0.0001, bias 0.7 ± 5.1 %). CONCLUSIONS: T1 mapping CMR at 3T performed as well as T2 mapping in quantifying the AAR and assessing myocardial salvage in reperfused STEMI patients, thereby providing an alternative CMR measure of the the AAR