In vivo haploid induction (HI) triggered by pollination with special intraspecific genotypes, called inducers, is unique to Zea mays L. within the plant kingdom and has revolutionized maize breeding during the last decade. However, the molecular mechanisms underlying HI in maize are still unclear. To investigate the genetic basis of HI, we developed a new approach for genome-wide association studies (GWAS), termed conditional haplotype extension (CHE) test that allows detection of selective sweeps even under almost perfect confounding of population structure and trait expression. Here, we applied this test to identify genomic regions required for HI expression and dissected the combined support interval (50.34 Mb) of the QTL qhir1, detected in a previous study, into two closely linked genomic segments relevant for HI expression. The first, termed qhir11 (0.54 Mb), comprises an already fine-mapped region but was not diagnostic for differentiating inducers and noninducers. The second segment, termed qhir12 (3.97 Mb), had a haplotype allele common to all 53 inducer lines but not found in any of the 1482 noninducers. By comparing resequencing data of one inducer with 14 noninducers, we detected in the qhir12 region three candidate genes involved in DNA or amino acid binding, however, none for qhir11. We propose that the CHE test can be utilized in introgression breeding and different fields of genetics to detect selective sweeps in heterogeneous genetic backgrounds.KEYWORDS in vivo haploid induction; selective sweep; genome-wide association study; population structure; Zea mays L T HE double haploid (DH) technology based on in vivo haploid induction (HI) has become one of the most important tools in maize breeding during the past decade and is replacing the conventional method of line development by recurrent selfing . The success of this new technology became possible, because dozens of maize inducer lines have been developed worldwide (reviewed in Supplemental Material, File S1) which, when used as pollinators, trigger the production of seeds with haploid embryo at an acceptable rate, i.e., .2% . Double fertilization followed by elimination of the inducer chromosomes in the embryo at later developmental stages (Li et al. 2009;Xu et al. 2013) as well as parthenogenesis (Sarkar and Coe 1966;Beckert et al. 2008) HI in maize, but a proof of these hypotheses requires profound knowledge about the genetic and physiological factors underlying this phenomenon. All previous QTL mapping studies for unraveling the genetic architecture of HI detected a major QTL on chromosome 1 (Röber 1999;Beckert et al. 2008; Prigge et al. 2012). The most comprehensive study with four biparental populations (Prigge et al. 2012) mapped this QTL, termed qhir1, to bin 1.04 and hypothesized that it is required for HI, but QTL positions and 1-LOD support intervals differed substantially among populations. In another study with population 1680 3 UH400, Dong et al. (2013) fine mapped a 3.57-Mb region between markers umc1917 and bnlg1811, w...
Aim — to compare the features of diastolic dysfunction (DD) with preserved left ventricular (LV) ejection fraction (EF) in patients with diabetes mellitus type 2 (DM2) with arterial hypertension (AH) and in patients with essential hypertension (EH) without diabetes.Material and methods. The study involved 87 patients with DD with preserved LV EF: 53 patients with DM2 with AH and 34 patients EH without diabetes. Transthoracic echocardiography was performed by ultrasonic imaging system iE33 xMATRIX («Philips», USA). DD was determined in a complex: type on the basis of the ratio parameters of pulsed-wave (E/A) and tissue (e/a) Doppler; and severity on the Е/e values and pulmonary capillary wedge pressure (PCWP). Myocardial contractile function was assessed by traditional LVEF by Simpson and more exactly, in details on the basis of the longitudinal, radial and circular deformation of the LV myocardium by speckle-tracking echocardiography (using the program Q-lab 3.0 Advanced Ultrasound Quantification software).Results. The groups were comparable in clinical characteristics. The average level of HbA1c in patients with DM2 was 8.2±1.7%. The average LV EF by Simpson in the EH group was 59.9±8.1, in DM2 — 58.3±6.7 (p=0.228). There were more severe disorders of LV Diastolic function in DM2 patients: the values of E/e (p=0.000) and PCWP (p=0.001) were significantly higher in diabetic patients (14,1±5,5 and 15,3±4,7 mm Hg) than in EH (9.7±2.3 and 11.9±1.3 mm Hg). Although that the LV EF (by traditional echocardiographic method of Simpson) was preserved in both groups , the LV global longitudinal strain (12.4±3.0) was significantly lower in DM2 (p=0.005), than patients with EH (16.6±2.0) by speckle-tracking echocardiography.Conclusion. Severity of LV DD are harder in Patients with diabetes and hypertension, than in patients with EH with the similarity of clinical manifestations and data of traditional echocardiographic methods. There were found initial disorders of LV longitudinal myocardial fibers contraction by speckle-tracking echocardiography in patients with DM and preserved LV EF. The combination of impairment of systolic and diastolic function in diabetes is inseparable. Early development of combined systolic and diastolic dysfunction in DM2 is associated with a poor prognosis: a higher risk of early development of atrial fibrillation, ventricular arrhythmias and progressive heart failure.
Отдел кардиологии, Эндокринологический научный центр Росмедтехнологий, Москва Цель. Оценить влияние карведилола на риск развития гипогликемий у больных сахарным диабетом 2-го типа (СД2) с хронической сердечной недостаточностью (ХСН), получающих ингибиторы ангиотензинпревращающего фермента (ИАПФ). Материал и методы. В исследование включено 13 больных (10 мужчин, 3 женщины, возраст 59,8±6,7 лет) СД2 с ХСН, обусловленной ишемической болезнью сердца (ИБС). Все больные до включения в исследование получали терапию ИАПФ и различными бета-блокаторами (атенолол, метопролол, бисопролол). Пациентам проводили замену β-блокатора на карведилол. Исходно, во время приема карведилола и после его отмены выполняли эхокардиографию, контроль артериального давления, мониторинг гликемии, определение уровня гликозилированного гемоглобина (HbA 1c). Результаты. Карведилол уменьшает частоту и длительность эпизодов гипогликемии. При приеме карведилола не возникает эпизодов тяжелой гипогликемии. Заключение. Карведилол уменьшает риск развития гипогликемий при совместном использовании с ИАПФ у больных СД2 и ХСН.
It is now well established that clinical use of statins for primary and secondary prevention of cardiovascular complications in patientswith diabetes mellitus (DM) increases life expectancy. At the same time, meta-analysis of major randomized trials shows statins to increaseglycemic levels and incidence of diabetic symptoms, especially in patients at risk for developing glycemic disorders. However,comparison of positive and negative effects of statins suggests prevalence of clinically beneficial factors.
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