Wnt/β-Catenin-Signaling Modulates Megakaryopoiesis at the Megakaryocyte-Erythrocyte Progenitor Stage in the Hematopoietic System

The bone marrow (BM) hematopoietic system (HS) gives rise to blood cells originating from hematopoietic stem cells (HSCs), including megakaryocytes (MKs) and red blood cells (erythrocytes; RBCs). Many steps of the cell-fate decision remain to be elucidated, being important for cancer treatment. To explore the role of Wnt/β-catenin for MK and RBC differentiation, we activated β-catenin signaling in platelet-derived growth factor b (Pdgfb)-expressing cells of the HS using a Cre-lox approach (Ctnnb1BM-GOF). FACS analysis revealed that Pdgfb is mainly expressed by megakaryocytic progenitors (MKPs), MKs and platelets. Recombination resulted in a lethal phenotype in mutants (Ctnnb1BM-GOFwt/fl, Ctnnb1BM-GOFfl/fl) 3 weeks after tamoxifen injection, showing an increase in MKs in the BM and spleen, but no pronounced anemia despite reduced erythrocyte counts. BM transplantation (BMT) of Ctnnb1BM-GOF BM into lethally irradiated wildtype recipients (BMT-Ctnnb1BM-GOF) confirmed the megakaryocytic, but not the lethal phenotype. CFU-MK assays in vitro with BM cells of Ctnnb1BM-GOF mice supported MK skewing at the expense of erythroid colonies. Molecularly, the runt-related transcription factor 1 (RUNX1) mRNA, known to suppress erythropoiesis, was upregulated in Ctnnb1BM-GOF BM cells. In conclusion, β-catenin activation plays a key role in cell-fate decision favoring MK development at the expense of erythroid production.

Innovative biodegradable dibutyrylchitin dressing for the treatment of ulcers occurring during chronic venous insufficiency in patients with type 2 diabetes

The aim of this study was to assess the course of the healing process following the use of dibutyrylchitin (DBC) dressing, a fully degradable material used in the treatment of ulcers which occur during chronic venous insufficiency common in patients suffering from type 2 diabetes. These diseases have a significant impact on the patients' standard of living, including the potential employment, and on the declining attendance at the current workplace. The implementation of this innovative therapeutic solution may positively affect the above-mentioned difficulties. An analysis of the healing process, following the application of the DBC dressing, was performed. Once the dressing was positioned on the wound, the analysis indicated that it underwent a process of degradation facilitated by the enzymes occurring naturally in the wound. When fully degraded, a further layer was applied. This process was repeated until the wound was fully healed. The study group consisted of 4 patients previously diagnosed with type 2 diabetes. During the observation period, the ulcers in all 4 cases had healed. The examined wound dressings adhered well to the wound surface and degraded within it. No side effects or adverse effects of the applied innovative therapy were observed. An addition of the biodegradable DBC dressing to the standard therapy procedure of ulcers occurring during chronic venous insufficiency among patients with type 2 diabetes indicate safe and effective treatment, which may have a direct reflection in the patient's professional capacity enhancement. It resulted in the complete healing of all ulcers in each of the observed cases. Int J Occup Med Environ Health. 2021;34(4):565-73.

Evaluation of the effectiveness of iodine prophylaxis in Poland based on over 20 years of observations of iodine supply in school-aged children in the central region of the country

INTRODUCTION

Due to the mild-to-moderate iodine deficiency in Poland, in 1997 iodine prophylaxis based on obligatory salt iodization was introduced. We attempted to evaluate the effectiveness of such prophylaxis, based on over 20 years of observations of iodine supply in school-aged children in Opoczno district (Central Poland).

MATERIAL AND METHODS

A group of 603 children (316 girls and 287 boys), aged 6-14, was examined at 4 time points: in the years 1994, 1999, 2010 and 2016. The children were tested for urine iodine concentration (UIC) and in each child the thyroid volume was measured ultrasonographically.

RESULTS

The median UIC in 1994 (45.5 μg/l) indicated moderate iodine deficiency, while after introducing prophylaxis it corresponded to adequate values (1999 - 101.1 μg/l, 2010 - 100.6 μg/l, 2016 - 288.3 μg/l); however, the last value was higher than the previous two. The thyroid size, assessed by ultrasonography and presented as volume/body surface area (V/BSA), in 1994 was 6.55 × 10^-6 m; this value was higher than at other time points (2.73 × 10^-6 m in 1999, 2.73 × 10^-6 m in 2010, and 2.70 × 10^-6 m in 2016).

CONCLUSIONS

Iodine prophylaxis has proved effective in eliminating iodine deficiency. In recent years, the diversification of iodine sources, despite the reduction of salt consumption, has led to an increase in median UIC to values close to the upper limit of UIC, accepted as normal. Further increase in iodine supply may be unfavourable for health; therefore constant monitoring of iodine prophylaxis is required.

Two-Dimensional Speckle Tracking Versus Applanation Tonometry in Evaluation of Subclinical Atherosclerosis in Children with Type 1 Diabetes Mellitus

Background

Patients with type 1 diabetes mellitus (T1DM) often develop atherosclerosis at an early age. In the subclinical stage of the process, minimal/non-morphological changes can be noticed, but the arterial wall function can be impaired. Applanation tonometry allows to assess the arterial tree stiffness; however, the Two-Dimensional Speckle Tracking (2DST) is an increasingly accepted alternative. This study evaluated arterial wall stiffness using these 2 techniques in children with T1DM.

Material/Methods

We performed applanation tonometry and carotid arteries sonography with evaluation of the carotid intima-media thickness (cIMT) and use of the 2DST in 50 children with T1DM and in 50 healthy sex- and age-matched controls. We also assessed the reliability of 2DST in 10 random subjects.

Results

Children with T1DM had increased arterial wall stiffness, which was confirmed by tonometry (PWV: p=0.0386) and 2DST (Strain: p=0.0004; Strain rate: p=0.0081). There was no significant difference in cIMT between groups (0.45±0.06 vs. 0.43±0.05, p=0.073 in children with T1DM and controls, respectively). 2DST presented good intraclass correlation coefficient between researchers and within a single researcher.

Conclusions

Children with T1DM presenting with subclinical stage of atherosclerosis were found to have arterial wall stiffening. The 2DST, the same as applanation tonometry, allows to recognize this condition but in a more accessible and reproducible manner.

Limitations of insulin resistance assessment in polycystic ovary syndrome

BACKGROUND

Though insulin resistance (IR) is common in polycystic ovary syndrome (PCOS), there is no agreement as to what surrogate method of assessment of IR is most reliable.

SUBJECTS AND METHODS

In 478 women with PCOS, we compared methods based on fasting insulin and either fasting glucose (HOMA-IR and QUICKI) or triglycerides (McAuley Index) with IR indices derived from glucose and insulin during OGTT (Belfiore, Matsuda and Stumvoll indices).

RESULTS

There was a strong correlation between IR indices derived from fasting values HOMA-IR/QUICKI, r = -0.999, HOMA-IR/McAuley index, r = -0.849 and between all OGTT-derived IR indices (e.g. r = -0.876, for IRI/Matsuda, r = -0.808, for IRI/Stumvoll, and r = 0.947, for Matsuda/Stumvoll index, P < 0.001 for all), contrasting with a significant (P < 0.001), but highly variable correlation between IR indices derived from fasting vs OGTT-derived variables, ranging from r = -0.881 (HOMA-IR/Matsuda), through r = 0.58, or r = -0.58 (IRI/HOMA-IR, IRI/QUICKI, respectively) to r = 0.41 (QUICKI/Stumvoll), and r = 0.386 for QUICKI/Matsuda indices. Detailed comparison between HOMA-IR and IRI revealed that concordance between HOMA and IRI was poor for HOMA-IR/IRI values above 75th and 90th percentile. For instance, only 53% (70/132) women with HOMA-IR >75th percentile had IRI value also above 75th percentile. There was a significant, but weak correlation of all IR indices with testosterone concentrations.

CONCLUSIONS

Significant number of women with PCOS can be classified as being either insulin sensitive or insulin resistant depending on the method applied, as correlation between various IR indices is highly variable. Clinical application of surrogate indices for assessment of IR in PCOS must be therefore viewed with an extreme caution.

Gestational diabetes - is diet and insulin the only solution?

Gestational diabetes (GDM) is a relatively common complication of pregnancy. Maternal hyperglycemia causes many serious side effects for mothers, fetuses and newborns. In 90% of women diagnosed with GDM, a dietary treatment results in satisfactory levels of blood glucose. The remaining 10% require insulin therapy to achieve the recommended glycemic levels. The majority of recent studies show the efficiency of metformin in gestational diabetes and prove that it is not a cause for any harmful side effects to the embryo and/or fetus. Metformin is an effective alternative to insulin in glycemic control in pregnant women. The implementation of metformin, as a routine procedure in gestational diabetes, requires further research, the results of which would unequivocally confirm its efficacy and safety for pregnant women and their offspring.

Working Group Guidelines on the nursing roles in caring for patients with Crohn's disease and ulcerative colitis in Poland

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, present a major challenge for present-day gastroenterology due to their increasing incidence, chronic nature, risk of permanent worsening of quality of life of patients, and the costs of conservative and invasive treatment. Basic and advanced nursing care are important parts of the multidisciplinary care for patients. The developed guidelines on the nursing care, which are compliant with the European guidelines published by Nurses-European Crohn's & Colitis Organisation (N-ECCO), were adjusted to the current situation in Poland. Significant issues that are important for nursing teams have been identified, with particular emphasis on the specificity of working in centres specialising in the care of IBD patients. The Working Group paid attention to the conditions that should be satisfied in order to optimise the nursing care for IBD patients, and the necessity to develop professional and scientific cooperation with European centres within European Crohn's & Colitis Organisation (ECCO) and N-ECCO.

Immune and inflammatory cell involvement in the pathology of idiopathic pulmonary arterial hypertension

RATIONALE

Pulmonary arterial hypertension (PAH) is characterized by vasoconstriction and vascular remodeling. Recent studies have revealed that immune and inflammatory responses play a crucial role in pathogenesis of idiopathic PAH.

OBJECTIVES

To systematically evaluate the number and cross-sectional distribution of inflammatory cells in different sizes of pulmonary arteries from explanted lungs of patients with idiopathic PAH versus healthy donor lungs and to demonstrate functional relevance by blocking stromal-derived factor-1 by the Spiegelmer NOX-A12 in monocrotaline-induced pulmonary hypertension in rats.

METHODS

Immunohistochemistry was performed on lung tissue sections from patients with idiopathic PAH and healthy donors. All positively stained cells in whole-lung tissue sections, surrounding the vessels, and in the different compartments of the vessels were counted. To study the effects of blocking SDF-1, rats with monocrotaline-induced pulmonary hypertension were treated with NOX-A12 from Day 21 to Day 35 after monocrotaline administration.

MEASUREMENTS AND MAIN RESULTS

We found a significant increase of the perivascular number of macrophages (CD68(+)), macrophages/monocytes (CD14(+)), mast cells (toluidine blue(+)), dendritic cells (CD209(+)), T cells (CD3(+)), cytotoxic T cells (CD8(+)), and helper T cells (CD4(+)) in vessels of idiopathic PAH lungs compared with control subjects. FoxP3(+) mononuclear cells were significantly decreased. In the monocrotaline model, the NOX-A12-induced reduction of mast cells, CD68(+) macrophages, and CD3(+) T cells was associated with improvement of hemodynamics and pulmonary vascular remodeling.

CONCLUSIONS

Our findings reveal altered perivascular inflammatory cell infiltration in pulmonary vascular lesions of patients with idiopathic pulmonary arterial hypertension. Targeting attraction of inflammatory cells by blocking stromal-derived factor-1 may be a novel approach for treatment of PAH.

Phosphodiesterase 10A upregulation contributes to pulmonary vascular remodeling

Phosphodiesterases (PDEs) modulate the cellular proliferation involved in the pathophysiology of pulmonary hypertension (PH) by hydrolyzing cAMP and cGMP. The present study was designed to determine whether any of the recently identified PDEs (PDE7-PDE11) contribute to progressive pulmonary vascular remodeling in PH. All in vitro experiments were performed with lung tissue or pulmonary arterial smooth muscle cells (PASMCs) obtained from control rats or monocrotaline (MCT)-induced pulmonary hypertensive (MCT-PH) rats, and we examined the effects of the PDE10 inhibitor papaverine (Pap) and specific small interfering RNA (siRNA). In addition, papaverine was administrated to MCT-induced PH rats from day 21 to day 35 by continuous intravenous infusion to examine the in vivo effects of PDE10A inhibition. We found that PDE10A was predominantly present in the lung vasculature, and the mRNA, protein, and activity levels of PDE10A were all significantly increased in MCT PASMCs compared with control PASMCs. Papaverine and PDE10A siRNA induced an accumulation of intracellular cAMP, activated cAMP response element binding protein and attenuated PASMC proliferation. Intravenous infusion of papaverine in MCT-PH rats resulted in a 40%-50% attenuation of the effects on pulmonary hypertensive hemodynamic parameters and pulmonary vascular remodeling. The present study is the first to demonstrate a central role of PDE10A in progressive pulmonary vascular remodeling, and the results suggest a novel therapeutic approach for the treatment of PH.

BCR expression is decreased in meningiomas showing loss of heterozygosity of 22q within a new minimal deletion region

Neurofibromin 2 (NF2), located on chromosome arm 22q, has been established as a tumor suppressor gene involved in meningioma pathogenesis. In our study, we investigated 149 meningiomas to determine whether there are additional tumor suppressor genes localized on chromosome 22q, apart from NF2, that might be involved in meningioma pathogenesis. The LOH analysis on chromosome 22q identified two regions of deletion: the first one, which is limited to the NF2 gene locus, and the second one, which is outside this location. The new minimal deletion region (MDR) included the following genes: BCR (breakpoint cluster region), RAB36 (a member of RAS oncogene family), GNAZ [guanine nucleotide binding protein (G protein), alpha-z polypeptide], and RTDR1 (rhabdoid tumor deletion region gene 1). The expression levels of all these genes, including NF2, were subsequently analyzed by quantitative real-time polymerase chain reaction. We observed a significantly lowered expression level of NF2 in meningiomas with 22q loss of heterozygosity (LOH) within NF2 region compared to the one in meningiomas with 22q retention of heterozygosity (ROH, P<0.05). Similarly, BCR showed a significantly lowered expression in meningiomas with 22q LOH within the new MDR compared to cases with 22q ROH (P<0.05). Our data, together with the already published information considering BCR function suggest that BCR can be considered as a candidate tumor suppressor gene localized on chromosome 22q which may be involved in meningioma pathogenesis.

Elimination of wild-type P53 mRNA in glioblastomas showing heterozygous mutations of P53

We screened 50 glioblastomas for P53 mutations. Five glioblastomas showed heterozygous mutations, while three were putatively heterozygous. Six of these eight glioblastomas showed elimination of wild-type P53 mRNA. These results strongly suggest that some sort of mechanism(s) favouring mutated over wild-type P53 mRNA exists in glioblastoma cells with heterozygous mutations of this gene.

Determinants of prostate volume changes following iodine-125 interstitial prostate implant

15563

Purpose: Prostate brachytherapy (PB) has been linked with increase in prostate volume (PV). This study evaluates post- operative PV changes and the variables that might affect prostate swelling. Methods: Twenty four patients (pts) were analyzed. Twelve were treated with PB only, 8 with external beam radiation (EBRT) prior to implant, and 4 with EBRT after PB. Pre-treatment PSA and Gleason score ranges were 1.9–10.8 and 5–8 respectively. Pre- implant and post-implant day 1, 9, 30, and 60 (PV0, PV1, PV9, PV30, and PV60) measurements were done using computed tomography. Univariate analysis of PV change and the following was done: PV0, number of needles, seeds, and needle insertion attempts, seed activity (0.3 vs 0.5mCi), hormonal ablation therapy, and prior EBRT. Urinary symptoms were assessed using International Prostate Scoring System (IPSS). Results: Ninety six PV measurements were done by a single observer. PV0 ranged from 27.1 to 89.4 cc (mean 48.2). Largest PV was observed on day 1 (40.1–118.7, mean 67.1). Successive PV measurements afterwards continued to decrease. Mean PV values on day 9, 30, and 60 were 58.6, 51.5, and 42.3cc respectively. The differences between PV0 and all successive PV’s were statistically significant. Mean increase in PV1 from PV0 was 18.9±16.8cc (p<0.001), PV0 and PV9 9.7cc, PV0 and PV30 2.6cc. PV60 was smaller than PV0 by an average of 6.6cc. Statistically significant positive correlation was found between PV increase and seed activity (p=0.02) while treatment with EBRT prior to PB was associated with less prostate swelling (p=0.043). Other variables were not significantly correlated with PV changes. Although the mean IPSS score increased from pre-implant value of 9.2 to 13.7 on day 60, the differences between IPSS values were not statistically significant. Conclusions: Maximum prostate size is observed on the first day after implant. Prostate begins to decrease in size between day 1 and day 9 and reaches pre-procedure volume after day 30. Higher seed activity results in greater prostate swelling, while less brachytherapy- induced swelling is observed in patients treated with external radiation prior to implant. Resolution of prostate swelling does not appear to parallel with improvement in urinary symptoms in the first 2 months after implant.

No significant financial relationships to disclose.

The impact of positron emission tomography/computed tomography in edge delineation of gross tumor volume for head and neck cancers

PURPOSE

To study anatomic biologic contouring (ABC), using a previously described distinct halo, to unify volume contouring methods in treatment planning for head and neck cancers.

METHODS AND MATERIALS

Twenty-five patients with head and neck cancer at various sites were planned for radiation therapy using positron emission tomography/computed tomography (PET/CT). The ABC halo was used in all PET/CT scans to contour the gross tumor volume (GTV) edge. The CT-based GTV (GTV-CT) and PET/CT-based GTV (GTV-ABC) were contoured by two independent radiation oncologists.

RESULTS

The ABC halo was observed in all patients studied. The halo had a standard unit value of 2.19 +/- 0.28. The mean halo thickness was 2.02 +/- 0.21 mm. Significant volume modification (>or=25%) was seen in 17 of 25 patients (68%) after implementation of GTV-ABC. Concordance among observers was increased with the use of the halo as a guide for GTV determination: 6 patients (24%) had a <or=10% volume discrepancy with CT alone, compared with 22 (88%) with PET/CT (p < 0.001). Interobserver variability decreased from a mean GTV difference of 20.3 cm3 in CT-based planning to 7.2 cm3 in PET/CT-based planning (p < 0.001).

CONCLUSIONS

Using the "anatomic biologic halo" to contour GTV in PET/CT improves consistency among observers. The distinctive appearance of the described halo and its presence in all of the studied tumors make it attractive for GTV contouring in head and neck tumors. Additional studies are needed to confirm the correlation of the halo with presence of malignant cells.

Modulation of Lrp action in Escherichia coli by leucine: effects on non-specific binding of Lrp to DNA

Lrp is a global regulator of metabolism in Escherichia coli that helps cells respond to changes in environmental conditions. The action of Lrp as a transcriptional activator or repressor is sometimes affected by whether the medium contains exogenous leucine. The abundance of Lrp in cells is relatively high (about 15 microM in monomer), and given the relatively high Lrp binding affinity in vitro for specific binding sites (nanomolar apparent dissociation constants), the expectation is that all binding sites will be saturated with Lrp in vivo. Here we consider the fraction of the total Lrp in cells that is free and the fraction that is bound to DNA. Using minicell-producing strains, we measured the distribution of Lrp between cytoplasm and nucleoid in cells grown under different nutritional conditions and in cells in different phases of growth. In E. coli cells grown in minimal medium to mid-log phase, the ratio of free to DNA-bound Lrp was about 0.67. This ratio decreased about threefold when the cells were grown in minimal medium supplemented with leucine. Our results also confirmed the previous finding that growth rate regulates lrp expression by as much as three to fourfold. Growth rate-regulated lrp expression, along with changes in the extent of non-specific binding, influences the level of free Lrp in vivo over a 16-fold range. We propose that the net effect of these processes is to regulate the relative concentrations of free Lrp hexadecamer and leucine-bound octamer, leading to promoter selection in response to environmental conditions.

E. coli hemolysin-induced lipid mediator metabolism in alveolar macrophages: impact of eicosapentaenoic acid

Escherichia coli hemolysin (HlyA) is a prototype of a large family of pore-forming proteinaceous exotoxins that have been implicated in the pathogenetic sequelae of severe infection and sepsis, including development of acute lung injury. In the present study in rabbit alveolar macrophages (AMs), subcytolytic concentrations of purified HlyA evoked rapid synthesis of platelet-activating factor, with quantities approaching those in response to maximum calcium ionophore challenge. In parallel, large quantities of leukotriene (LT) B(4) and 5-, 8-, 9-, 12-, and 15-hydroxyeicosatetraenoic acid (HETE) were liberated from HlyA-exposed AMs depending on exogenous arachidonic acid (AA) supply. Coadministration of eicosapentaenoic acid (EPA) dose dependently suppressed generation of the proinflammatory lipoxygenase products LTB(4) and 5-, 8-, 9-, and 12-HETE in parallel with the appearance of the corresponding EPA-derived metabolites LTB(5) and 5-, 8-, 9-, and 12-hydroxyeicosapentaenoic acid (HEPE). At equimolar concentrations, EPA turned out to be the preferred substrate over AA for these AM lipoxygenase pathways, with the sum of LTB(5) and 5-, 8-, 9-, and 12-HEPE surpassing the sum of LTB(4) and 5-, 8-, 9-, and 12-HETE by >80-fold. In contrast, coadminstration of EPA did not significantly reduce HlyA-elicited generation of the anti-inflammatory AA lipoxygenase product 15-HETE. We conclude that AMs are sensitive target cells for HlyA attack, resulting in marked proinflammatory lipid mediator synthesis. In the presence of EPA, lipoxygenase product formation is shifted from a pro- to an anti-inflammatory profile.

Simultaneous analysis of 4- and 5-series lipoxygenase and cytochrome P450 products from different biological sources by reversed-phase high-performance liquid chromatographic technique

Quantification of lipoxygenase and cytochrome P450 products of both arachidonic acid (AA) and eicosapentaenoic acid (EPA) is of broad interest due to the multiple biological activities of these compounds. We developed a method combining (i) solid-phase extraction, (ii) isocratic reversed-phase high-performance liquid chromatographic separation, and (iii) online photodiode array detection with spectrum analysis for identification and measurement of all main 4- and 5-series eicosanoids (leukotrienes, hydroxyeicosatetraenoic acids/hydroxyeicosapentaenoic acids, epoxyeicosatrienoic acids) within one run. With these procedures, standard mixtures of AA- and EPA-derived lipid mediators were recovered from different biological liquids, like lung perfusate, human bronchoalveolar lavage fluid, and cell supernatant with linear characteristics for each compound. Recoveries of the different lipid mediators exceeded 80% showing excellent reproducibility. Application of the method to isolated, perfused, and ventilated human lungs challenged with the calcium ionophore A23187 and to human neutrophils stimulated in the presence of arachidonic acid and eicosapentaenoic acid with N-formyl-methionyl-leucyl-phenylalanine demonstrated the generation of a large array of lipoxygenase and cytochrome P450 products. Thus, convenient quantification of 4- and 5-series eicosanoids in fluids of biological interest is achieved by a technique comprising solid-phase extraction, isocratic reversed-phase high-performance liquid chromatography, and photodiode array-based online spectrum analysis of eluting compounds.