Aberrant DNA methylation is a dominant mechanism in MDS progression to AML

Myelodysplastic syndromes (MDSs) are clonal hematologic disorders that frequently represent an intermediate disease stage before progression to acute myeloid leukemia (AML). As such, study of MDS/AML can provide insight into the mechanisms of neoplastic evolution. In 184 patients with MDS and AML, DNA methylation microarray and high-density single nucleotide polymorphism array (SNP-A) karyotyping were used to assess the relative contributions of aberrant DNA methylation and chromosomal deletions to tumor-suppressor gene (TSG) silencing during disease progression. Aberrant methylation was seen in every sample, on average affecting 91 of 1505 CpG loci in early MDS and 179 of 1505 loci after blast transformation (refractory anemia with excess blasts [RAEB]/AML). In contrast, chromosome aberrations were seen in 79% of early MDS samples and 90% of RAEB/AML samples, and were not as widely distributed over the genome. Analysis of the most frequently aberrantly methylated genes identified FZD9 as a candidate TSG on chromosome 7. In patients with chromosome deletion at the FZD9 locus, aberrant methylation of the remaining allele was associated with the poorest clinical outcome. These results indicate that aberrant methylation can cooperate with chromosome deletions to silence TSG. However, the ubiquity, extent, and correlation with disease progression suggest that aberrant DNA methylation is the dominant mechanism for TSG silencing and clonal variation in MDS evolution to AML.     

Molecular activity of sirolimus and its possible application in tuberous sclerosis treatment

Sirolimus is one of the intensively investigated drugs with pluripotent activities. It binds to its intracellular receptor FKBP12 (FK506-binding protein 12), a member of the family of FK506-binding proteins, and inhibits the activity of mTOR, a serine/threonine kinase involved in numerous cell processes linked to cell growth control. The drug is currently registered for the prophylaxis of organ rejection and for use in coronary stents. However, unique characteristics of sirolimus make it a good candidate for anti-cancer therapy. Indeed, phase II and III clinical studies in humans with several types of neoplasms are already under way. The review describes molecular activity of sirolimus and its analogs, characteristic for specific applications, in view of very recent advances involving tuberous sclerosis complex (TSC)-mediated signaling pathways. Current studies with sirolimus performed in tuberous sclerosis animal models are presented. Possible application of sirolimus for treating tuberous sclerosis, disease caused by mutations of TSC proteins, is discussed.     

Mycobacterium tuberculosis complex and mycobacterial heat shock proteins in lymph node tissue from patients with pulmonary sarcoidosis

We demonstrated that not whole Mycobacterium tuberculosis but its particular antigens, hsp70(Mtb), hsp65(Mtb), and hsp16(Mtb), are present in lymph node tissues of patients with sarcoidosis (SA). hsp16(Mtb) occurs in the early stage of SA, whereas hsp70(Mtb) occurs in stage II of SA. hsp65(Mtb) is highly expressed in the capillary vessels in lymph node tissues in patients with SA.     

Effect of environmental pollutants on oxytocin synthesis and secretion from corpus luteum and on contractions of uterus from pregnant cows

Chloro-organic compounds are persistent environmental pollutants and affect many reproductive processes. Oxytocin (OT) synthesized in luteal cells is a local regulator of ovarian activity and uterine contractions. Therefore the effect of xenobiotics on the OT prohormone synthesis, secretion of OT and progesterone (P4) from luteal cells and on myometrial contractions during early pregnancy in cows was investigated.Luteal cells and myometrial strips from a cow at early pregnancy were treated with polychlorinated biphenyl 77 (PCB 77), dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE) and hexachlorocyclohexane (HCH) (1 or 10 ng/ml). The mRNA expression of neurophysin-I/oxytocin (NP-I/OT) and peptidyl-glycine-α-amidating mono-oxygenase (PGA) and concentration of OT and P4 were determined by RT-PCR and EIA, respectively. Moreover, the effect of xenobiotics given with P4 (12 ng/ml) on the basal and OT (10⁻⁷ M) stimulated contractions of myometrial strips was studied.Xenobiotics increased (P < 0.05) OT secretion but DDE only stimulated P4 secretion. The ratio of P4 to OT in culture medium was decreased by all xenobiotics during 9-12 weeks of pregnancy. All xenobiotics, except HCH, increased (P < 0.05) mRNA expression of NP-I/OT during all stages of pregnancy and all treatments decreased (P < 0.05) expression of mRNA for PGA during 9-12 weeks of pregnancy. Myometrial strips were relaxed (P < 0.01) after pre-incubation with P4, while each of the xenobiotics jointly with P4 increased (P < 0.01) myometrial contractions.In conclusion, the xenobiotics used increased both expression of mRNA for genes involved in OT synthesis and secretion of OT from luteal cells. This decreases the ratio of P4 to OT and presumably, in this manner, the chloro-organic compounds can influence uterine contractions and enhance risk of abortions in pregnant females.     

Omega-3 Polyunsaturated Fatty Acids Increase Plasma Adiponectin to Leptin Ratio in Stable Coronary Artery Disease

Background

Growing evidence suggests a cardioprotective role of omega-3 polyunsaturated fatty acids (PUFA). However, the exact mechanisms underlying the effects of omega-3 PUFA in humans have not yet been fully clarified.

Purpose

We sought to evaluate omega-3 PUFA-mediated effects on adipokines in patients with stable coronary artery disease (CAD) undergoing elective percutaneous coronary intervention (PCI).

Methods

We conducted a prospective, double-blind, placebo-controlled, randomized study, in which adiponectin, leptin and resistin were determined at baseline, 3–5 days and 30 days during administration of omega-3 PUFA 1 g/day (n?=?20) or placebo (n?=?28).

Results

As compared to controls administration of omega-3 PUFA resulted in increase of adiponectin by 13.4 % (P?<?0.0001), reduction of leptin by 22 % (P?<?0.0001) and increase of adiponectin to leptin (A/L) ratio by 45.5 % (P?<?0.0001) at 30 days, but not at 3–5 days. Compared with placebo adiponectin was 12.7 % higher (P?=?0.0042), leptin was 16.7 % lower (P?<?0.0001) and A/L ratio was 33.3 % higher (P?<?0.0001) in the omega-3 PUFA group at 30 days. Resistin decreased similarly in both groups after 1 month, without intergroup differences (P?=?0.32). The multivariate model showed that the independent predictors of changes in adiponectin at 1 month (P?<?0.001) were: omega-3 PUFA treatment, baseline platelet count, total cholesterol and those in leptin (P?<?0.0001) were: omega-3 PUFA treatment and waist circumference. Independent predictors of A/L ratio changes (P?<?0.0001) were: assigned treatment, current smoking and hyperlipidemia.

Conclusions

In high risk stable coronary patients after PCI omega-3 PUFA supplementation improves adipokine profile in circulating blood. This might be a novel, favourable mechanism of omega-3 PUFA action.     

Shortening baroreflex delay in hypertrophic cardiomyopathy patients – an unknown effect of β-blockers

Aims

Hypertrophic cardiomyopathy (HCM) is characterized by left ventricular hypertrophy and impaired diastolic and systolic function. Abnormal sympathetic–parasympathetic balance is a potential stimulus for left ventricular hypertrophy in HCM patients. β-Blockers are routinely used in HCM for their strong negative inotropic effect; however, these drugs also influence the sympathetic–parasympathetic balance. This study aimed to determine the autonomic control of the cardiovascular system and the autonomic effects of β-blockers in HCM patients treated or untreated with β-blockers.

Methods

Among 51 HCM outpatients (18–70 years old; 29 men) there were 19 individuals with no medication and 32 subjects treated with a β-blocker. Fourteen age- and gender-matched (23–70 years old; nine men) healthy volunteers were enrolled in the control group. Continuous, non-invasive finger blood pressure was recorded during supine rest for 30 min. Autonomic regulation of the cardiovascular system was measured by heart rate variability and spontaneous baroreflex function (cross-correlation sequence method).

Results

The mean pulse interval, time domain and spectral measures of heart rate variability and baroreflex sensitivity were comparable between HCM patients, treated or not with β-blockers, and the control group. However, the delay of the baroreflex was significantly longer in HCM patients who were not treated with β-blockers [2.0 (1.6–2.3) s] in comparison with HCM patients receiving β-blockers [1.4 (1.1–1.8) s; P = 0.0072] or control subjects [1.2 (0.8–1.8) s; P = 0.0025]. This delay did not differ between HCM patients treated with β-blockers and the control group.

Conclusions

Hypertrophic cardiomyopathy not treated with β-blockers is accompanied by prolonged baroreflex delay. The use of β-blockers normalizes this delay.     

StudHeart-diabetes mellitus t.2 risk factors in senior medical students

Introduction. StudHeart research was performed to evaluate the risk of diabetes mellitus type 2 (T2DM) amongst the senior medical students. Material and methods. The research involved 506 students aged 22–27 (mean age 23.96±1.52 yrs) in their 5^th and 6^th year of the medical faculties at the Medical University of Lodz. Each of the examined students has filled out an anonymous survey comprising 12 questions, which enabled us to use the FINDRISC scale in estimation of the risk for T2DM. Analysis was performed in relation to gender. Results. Overall in 16.80% of respondents the body mass index (BMI) was >25 kg/m². Almost all students (93.48%) admitted to drinking alcohol and 9.68% smoked cigarettes. Only 13.64% of participants exercised daily (women 8.16% vs. men 21.30%; P=0.000). Everyday consumption of fruit and vegetables was reported by 55.34% of the respondents whereas 6.92% of them (women 4.42% vs. men 10.40%; P=0.026) ate fast-food 2–3 times a week. The overall risk for T2DM was elevated in 17.2% of examined students. It is predicted that by the time participants will reach age of 45, 40.52% of them (mostly men) will have their risk of T2DM elevated. Conclusion. Despite the awareness of risk factors for T2DM among senior medical students, their lifestyle remains unchanged. In the given population it is predicted that the risk of T2DM will enhance about 2.5-fold in the next 20 years.     

Real-time 3D single-molecule localization microscopy analysis using lookup tables

Herein, we present a new algorithm for real-time analysis of 3D single molecule localization microscopy images with a small impact on fitting accuracy using lookup-tables with discrete xyz-positions. The algorithm realizes real-time visualization during acquisition. We demonstrate its performance on simulated and measured data. Additionally, combining real-time fitting with a feedback loop controlling the activation laser pulse keeps the number of emitters per image frame constant.     

Phospho-STAT5 expression pattern with the MPL W515L mutation is similar to that seen in chronic myeloproliferative disorders with JAK2 V617F

Abnormal nuclear megakaryocytic staining for phospho-STAT5 (pSTAT5) correlates with JAK2 V617F mutational status in non-chronic myelogenous leukemia chronic myeloproliferative disorders. However, a proportion of wild-type JAK2 non-chronic myelogenous leukemia chronic myeloproliferative disorders cases also demonstrate this abnormal pSTAT5 expression pattern. We report a patient with a JAK2 V617F-negative myeloproliferative/myelodysplastic syndrome who had abnormal megakaryocytic pSTAT5 expression and a MPL W515L mutation. The patient was a 71-year-old man with anemia and thrombocythemia on laboratory examination. His peripheral blood smear demonstrated occasional dysplastic neutrophils. Bone marrow biopsy revealed hypercellular marrow with features consistent with myeloproliferative/myelodysplastic syndrome. Immunohistochemistry for pSTAT5 showed abnormal nuclear megakaryocyte positivity. Cytogenetic analysis revealed a normal karyotype, fluorescence in situ hybridization for BCR-ABL was negative, and JAK2 genotyping demonstrated wild-type JAK2. However, MPL genotyping showed a MPL W515L mutation. Abnormal nuclear megakaryocytic staining for pSTAT5 expression, previously associated with the JAK2 V617F mutation, is also associated with MPL W515L, likely reflecting activation of the JAK-STAT signaling pathway.