Induced sphaerococcoid mutations in triticum aestivum and their phylogenetic and breeding significance

This article does not have an abstract

Coronary microvascular resistance: methods for its quantification in humans

Coronary microvascular dysfunction is a topic that has recently gained considerable interest in the medical community owing to the growing awareness that microvascular dysfunction occurs in a number of myocardial disease states and has important prognostic implications. With this growing awareness, comes the desire to accurately assess the functional capacity of the coronary microcirculation for diagnostic purposes as well as to monitor the effects of therapeutic interventions that are targeted at reversing the extent of coronary microvascular dysfunction. Measurements of coronary microvascular resistance play a pivotal role in achieving that goal and several invasive and noninvasive methods have been developed for its quantification. This review is intended to provide an update pertaining to the methodology of these different imaging techniques, including the discussion of their strengths and weaknesses

Protocol for measuring myocardial blood flow by PET/CT in cats

PURPOSE: The aim of this study was to establish a protocol for measuring myocardial blood flow (MBF) by PET/CT in healthy cats. The rationale was its future use in Maine Coon cats with hypertrophic cardiomyopathy (HCM) as a model for human HCM. METHODS: MBF was measured in nine anaesthetized healthy cats using a PET/CT scanner and (13)NH(3) at rest and during adenosine infusion. Each cat was randomly assigned to receive vasodilator stress with two or three adenosine infusions at the following rates (mug/kg per minute): 140 (Ado 1, standard rate for humans), 280 (Ado 2, twice the human standard rate), 560 (Ado 4), 840 (Ado 6) and 1,120 (Ado 8). RESULTS: The median MBF at rest was 1.26 ml/min per g (n = 9; range 0.88-1.72 ml/min per g). There was no significant difference at Ado 1 (n = 3; median 1.35, range 0.93-1.55 ml/min per g; ns) but MBF was significantly greater at Ado 2 (n = 6; 2.16, range 1.35-2.68 ml/min per g; p < 0.05) and Ado 4 (n = 6; 2.11, 1.92-2.45 ml/min per g; p < 0.05). Large ranges of MBF values at Ado 6 (n = 4; 2.53, 2.32-5.63 ml/min per g; ns) and Ado 8 (n = 3; 2.21, 1.92-5.70 ml/min per g; ns) were noted. Observed adverse effects, including hypotension, AV-block and ventricular premature contractions, were all mild, of short duration and immediately reversed after cessation of the adenosine infusion. CONCLUSION: MBF can be safely measured in cats using PET. An intravenous adenosine infusion at a rate of 280 mug/kg per minute seems most appropriate to induce maximal hyperaemic MBF response in healthy cats. Higher adenosine rates appear less suitable as they are associated with a large heterogeneity in flow increase and rate pressure product, most probably due to the large variability in haemodynamic and heart rate response

2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease

The recommendations listed in this document are, whenever possible, evidence based. An extensive evidence review was conducted as the document was compiled through December 2008. Repeated literature searches were performed by the guideline development staff and writing committee members as new issues were considered. New clinical trials published in peer-reviewed journals and articles through December 2011 were also reviewed and incorporated when relevant. Furthermore, because of the extended development time period for this guideline, peer review comments indicated that the sections focused on imaging technologies required additional updating, which occurred during 2011. Therefore, the evidence review for the imaging sections includes published literature through December 2011

Absence of individual chromosomes and radiation sensitivity of bread wheat

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Effect of induced awn mutations on yield in wheat

From comparisons between sister lines of the same parental derivation segregating in awn character and from experiments using backcrosses, awns have been found to have a positive function as regards grain yield in varieties of bread wheat. A spontaneous awned mutant isolated by Mackey in the variety JScandia III outyielded the parent strain in trials carried out over a period of 5 years. Awns have been supposed to influence yield by increasing assimilation and transpiration and thereby the size of the grains. Fully awned mutants frequently occur when varieties belonging to the tipped 1 class of Watkins and Elleron (that is, awns 1-2 cm. in length and confined to the uppermost spikelets) are treated with both ionizing radiations and chemical mutagens. Several such mutants were found by us in the M2 progenies of the varieties N.P. 799 and N.P. 809 treated with phosphorus-32 and sulphur-35 (both 5 &#956;c. per seed), X-rays (16,000 and 22,000 r.) and different dosages of fast and thermal neutrons. Both these varieties have the dominant epistatic gene B1 on chromosome 5A (nomenclature of Sears) and the established awn mutations behaved as monogenic changes in genetic studies. The mutants had the somatic chromosome number 42 and no prominent change could be detected in their karyotypes

Dobutamine‐induced hyperaemia inversely correlates with coronary artery stenosis severity and highlights dissociation between myocardial blood flow and oxygen consumption

OBJECTIVES: To compare the relationship between dobutamine myocardial blood flow (MBF), rate–pressure product (RPP) and stenosis severity in patients with coronary artery disease (CAD). METHODS: 27 patients with single‐vessel CAD were allocated to three groups based on stenosis severity: group 1, 50–69% (n  =  9); group 2, 70–89% (n  =  9); and group 3, ⩾ 90% (n  =  9). Nine normal volunteers served as controls. Resting and dobutamine MBF were measured by positron emission tomography in the territory subtended by the stenosis (Isc) and remote myocardium (Rem). Mean left ventricular MBF was used for controls. RESULTS: In group 1, mean dobutamine MBF‐Isc (2.48 (SD 0.48 ml/min/g)) and dobutamine MBF‐Rem (2.70 (0.50) ml/min/g, NS) were comparable. In groups 2 and 3, dobutamine MBF‐Isc (1.91 (0.44) and 1.22 (0.21) ml/min/g) was significantly lower than dobutamine MBF‐Rem (2.27 (0.28) and 1.98 (0.25) ml/min/g, p < 0.02 and p < 0.005, respectively). An inverse relation between dobutamine MBF and stenosis severity existed both in Isc (r  =  0.79, p < 0.001) and in Rem territories (r  =  0.71, p < 0.001). For any given RPP, dobutamine MBF was greater in controls than in Rem (p < 0.05), which in turn was greater than in Isc (p < 0.05). CONCLUSION: Dobutamine MBF inversely correlated with stenosis severity and achieved significant flow heterogeneity for coronary stenoses > 70%. Dobutamine MBF and RPP were dissociated in both Isc and Rem segments in patients compared with controls