Next-Generation Sequencing-Based Genomic Profiling of Children with Acute Myeloid Leukemia.

Pediatric acute myeloid leukemia (AML) represents a major cause of childhood leukemic mortality, with only a limited number of studies investigating the molecular landscape of the disease. Here, we present an integrative analysis of cytogenetic and molecular profiles of 75 patients with pediatric AML from a multicentric, real-world patient cohort treated according to AML Berlin-Frankfurt-Münster protocols. Targeted next-generation sequencing of 54 genes revealed 17 genes that were recurrently mutated in >5% of patients. Considerable differences were observed in the mutational profiles compared with previous studies, as BCORL1, CUX1, KDM6A, PHF6, and STAG2 mutations were detected at a higher frequency than previously reported, whereas KIT, NRAS, and KRAS were less frequently mutated. Our study identified novel recurrent mutations at diagnosis in the BCORL1 gene in 9% of the patients. Tumor suppressor gene (PHF6, TP53, and WT1) mutations were found to be associated with induction failure and shorter event-free survival, suggesting important roles of these alterations in resistance to therapy and disease progression. Comparison of the mutational landscape at diagnosis and relapse revealed an enrichment of mutations in tumor suppressor genes (16.2% versus 44.4%) and transcription factors (35.1% versus 55.6%) at relapse. Our findings shed further light on the heterogeneity of pediatric AML and identify previously unappreciated alterations that may lead to improved molecular characterization and risk stratification of pediatric AML.

Influence of Vitamin D on the Vasoactive Effect of Estradiol in a Rat Model of Polycystic Ovary Syndrome.

We examined the vasoactive effect of estradiol in a rat model of early PCOS and the influence of vitamin D deficiency (VDD). We created a model of chronic hyperandrogenism and VDD in adolescent female Wistar rats (N = 46) with four experimental groups: vitamin D supplemented (T-D+), VDD (T-D-), hyperandrogenic and vitamin D supplemented (T+D+), and hyperandrogenic and VDD (T+D-). T+ groups received an 8-week-long transdermal Androgel treatment, D-animals were on vitamin D-reduced diet and D+ rats were supplemented orally with vitamin D3. Estrogen-induced vasorelaxation of thoracic aorta segments were measured with a wire myograph system with or without the inhibition of endothelial nitric oxide synthase (eNOS) or cyclooxygenase-2 (COX-2). The distribution of estrogen receptor (ER), eNOS and COX-2 in the aortic wall was assessed by immunohistochemistry. VDD aortas showed significantly lower estradiol-induced relaxation independently of androgenic status that was further decreased by COX-2 inhibition. COX-2 inhibition failed to alter vessel function in D+ rats. Inhibition of eNOS abolished the estradiol-induced relaxation in all groups. Changes in vascular function in VDD were accompanied by significantly decreased ER and eNOS staining. Short-term chronic hyperandrogenism failed to, but VDD induced vascular dysfunction, compromised estrogen-dependent vasodilatation and changes in ER and eNOS immunostaining.

Network analysis of the left anterior descending coronary arteries in swim-trained rats by an in situ video microscopic technique.

BACKGROUND: We aimed to identify sex differences in the network properties and to recognize the geometric alteration effects of long-term swim training in a rat model of exercise-induced left ventricular (LV) hypertrophy. METHODS: Thirty-eight Wistar rats were divided into four groups: male sedentary, female sedentary, male exercised and female exercised. After training sessions, LV morphology and function were checked by echocardiography. The geometry of the left coronary artery system was analysed on pressure-perfused, microsurgically prepared resistance artery networks using in situ video microscopy. All segments over > 80 µm in diameter were studied using divided 50-µm-long cylindrical ring units of the networks. Oxidative-nitrative (O-N) stress markers, adenosine A2A and estrogen receptor (ER) were investigated by immunohistochemistry. RESULTS: The LV mass index, ejection fraction and fractional shortening significantly increased in exercised animals. We found substantial sex differences in the coronary network in the control groups and in the swim-trained animals. Ring frequency spectra were significantly different between male and female animals in both the sedentary and trained groups. The thickness of the wall was higher in males as a result of training. There were elevations in the populations of 200- and 400-µm vessel units in males; the thinner ones developed farther and the thicker ones closer to the orifice. In females, a new population of 200- to 250-µm vessels appeared unusually close to the orifice. CONCLUSIONS: Physical activity and LV hypertrophy were accompanied by a remodelling of coronary resistance artery network geometry that was different in both sexes.

Vitamin D Deficiency Cause Gender Specific Alterations of Renal Arterial Function in a Rodent Model.

Vitamin D deficiency shows positive correlation to cardiovascular risk, which might be influenced by gender specific features. Our goal was to examine the effect of Vitamin D supplementation and Vitamin D deficiency in male and female rats on an important hypertension target organ, the renal artery. Female and male Wistar rats were fed with Vitamin D reduced chow for eight weeks to induce hypovitaminosis. Another group of animals received normal chow with further supplementation to reach optimal serum vitamin levels. Isolated renal arteries of Vitamin D deficient female rats showed increased phenylephrine-induced contraction. In all experimental groups, both indomethacin and selective cyclooxygenase-2 inhibition (NS398) decreased the phenylephrine-induced contraction. Angiotensin II-induced contraction was pronounced in Vitamin D supplemented males. In both Vitamin D deficient groups, acetylcholine-induced relaxation was impaired. In the female Vitamin D supplemented group NS398, in males the indomethacin caused reduced acetylcholine-induced relaxation. Increased elastic fiber density was observed in Vitamin D deficient females. The intensity of eNOS immunostaining was decreased in Vitamin D deficient females. The density of AT1R staining was the highest in the male Vitamin D deficient group. Although Vitamin D deficiency induced renal vascular dysfunction in both sexes, female rats developed more extensive impairment that was accompanied by enzymatic and structural changes.