Early diagnosis of solitary functioning kidney: comparing the prognosis of kidney agenesis and multicystic dysplastic kidney

BACKGROUND

Individuals with congenital solitary functioning kidney (SFK) are at an increased risk of kidney damage. According to some studies, the risk is higher in unilateral kidney agenesis (UKA) than in unilateral multicystic dysplastic kidney (UMCDK). We hypothesized that with early detection of children with UKA and UMCDK, there would be no difference in the presence of hypertension, proteinuria, and reduced glomerular filtration rate (GFR) between UKA and UMCDK.

METHODS

Based on a long-term follow-up protocol, we evaluated a cohort of 160 children followed from birth for SFK (84 with UKA and 76 with UMCDK) detected by prenatal or routine neonatal ultrasound screening. Hypertension, proteinuria, and reduced GFR were monitored as markers of kidney damage. We compared the characteristics and outcomes of the subgroups of children with UKA and UMCDK.

RESULTS

GFR was reduced in 42 (26.2%) children, of whom 41 showed only mild reduction. Hypertension and proteinuria were found in 22 (13.8%) and 14 (8.8%) children, respectively. Combined kidney damage was present in 57 (35.6%) children. The UMCDK and UKA subgroups differed in GFR at final examination, with UMCDK patients being significantly more likely to have normal GFR compared to UKA patients (82% vs. 67%; p = 0.039).

CONCLUSIONS

One third of the children showed signs of SFK damage, albeit mild. Patients with UKA had reduced GFR significantly more often than those with UMCDK, but did not differ in the rates of hyperfiltration injury or congenital anomalies of the kidneys and urinary tract (CAKUT) in SFK.

The interplay of inflammation and placenta in maternal diabetes: insights into Hofbauer cell expression patterns

Introduction

Inflammation of the placenta is harmful to both the fetus and the mother. Inflammation is strongly associated with diabetes, a common complication of pregnancy. Hofbauer cells (HBCs), unique immune system cells of fetal origin in the placenta, play complex roles, including growth of placental villi and their branching, stromal remodelling, and angiogenesis.

Methods

Our study investigated the expression of IL-1β, IL-10, CYP2C8, CYP2C9, CYP2J2 and sEH in HBCs from patients with type 1 diabetes mellitus (T1DM) and gestational diabetes mellitus (GDM) compared to healthy controls using immunohistochemistry. We also assessed the structure of the villus stroma using Masson´s trichrome.

Results

In T1DM, HBCs showed inflammatory activation characterised by increased IL-1β and decreased CYP epoxygenase expression compared to normal placentas. Conversely, significant inflammation in HBCs appeared less likely in GDM, as levels of IL-1β and CYP epoxygenases remained stable compared to normal placentas. However, GDM showed a significant increase in sEH expression. Both types of diabetes showed delayed placental villous maturation and hypovascularisation, with GDM showing a more pronounced effect.

Conclusion

The expression profiles of IL-1β, CYP epoxygenases and sEH significantlly differ between controls and diabetic placentas and between T1DM and GDM. These facts suggest an association of the CYP epoxygenase-EETs-sEH axis with IL-1β expression as well as villous stromal hypovascularisation. Given the stable high expression of IL-10 in both controls and both types of diabetes, it appears that immune tolerance is maintained in HBCs.

PTEN and soluble epoxide hydrolase in intestinal cell differentiation

Intestinal epithelial differentiation is a highly organised process. It is influenced by a variety of signalling pathways and enzymes, such as the PI3K pathway and soluble epoxide hydrolase (sEH) from arachidonic acid metabolism. We investigated the changes in the expression of enzymes and lipid messenger from the PI3K pathway, including PTEN, during intestinal cell differentiation in vitro using HT-29 and Caco2 cells and compared them with immunohistochemical patterns of these proteins in human colon. To investigate the possible crosstalk between the PI3K pathway and sEH, we treated HT-29 and Caco2 cells with the sEH inhibitor TPPU. Administration of TPPU to differentiated cells decreased the expression of PTEN, thus reversing the change in its expression observed during cell differentiation. In addition, multiplex immunofluorescence staining confirmed the relationship between the expression of PTEN and villin, a marker of intestinal cell differentiation, ranging from a moderate correlation in undifferentiated cells to a very strong correlation in differentiated cells treated with TPPU. Furthermore, we confirm that PTEN and sEH mirrored their expression patterns in samples of prenatal and adult human intestine compared to tumours using immunohistochemical staining. Taken together, it appears that PTEN and sEH cooperate in the process of intestinal cell differentiation. A better understanding of the crosstalk between the PI3K pathway and sEH and its consequences for cell differentiation is highly desirable, as several sEH inhibitors are under clinical investigation for the treatment of various diseases.

Fibrates Affect Levels of Phosphorylated p38 in Intestinal Cells in a Differentiation-Dependent Manner

Fibrates are widely used hypolipidaemic agents that act as ligands of the peroxisome proliferator-activated receptor α (PPARα). p38 is a protein kinase that is mainly activated by environmental and genotoxic stress. We investigated the effect of the PPARα activators fenofibrate and WY-14643 and the PPARα inhibitor GW6471 on the levels of activated p38 (p-p38) in the colorectal cancer cell lines HT-29 and Caco2 in relation to their differentiation status. Fibrates increased p-p38 in undifferentiated HT-29 cells, whereas in other cases p-p38 expression was decreased. HT-29 cells showed p-p38 predominantly in the cytoplasm, whereas Caco2 cells showed higher nuclear positivity. The effect of fibrates may depend on the differentiation status of the cell, as differentiated HT-29 and undifferentiated Caco2 cells share similar characteristics in terms of villin, CYP2J2, and soluble epoxide hydrolase (sEH) expression. In human colorectal carcinoma, higher levels of p-p38 were detected in the cytoplasm, whereas in normal colonic surface epithelium, p-p38 showed nuclear positivity. The decrease in p-p38 positivity was associated with a decrease in sEH, consistent with in vitro results. In conclusion, fibrates affect the level of p-p38, but its exact role in the process of carcinogenesis remains unclear and further research is needed in this area.

The epigenetic impact of suberohydroxamic acid and 5‑Aza‑2'‑deoxycytidine on DNMT3B expression in myeloma cell lines differing in IL‑6 expression

Gene inactivation of the cyclin-dependent kinase inhibitors p16^INK4a, p15^INK4b and p21^WAF is frequently mediated by promoter gene methylation, whereas histone deacetylases (HDACs) control gene expression through their ability to deacetylate proteins. The effect of suberohydroxamic acid (SBHA) and 5-Aza-2′-deoxycytidine (Decitabine) (DAC) treatments on the transcription of CDKN2A, CDKN2B and CDKN1A genes, and their effects on molecular biological behavior were examined in two myeloma cell lines, RPMI8226 and U266, which differ in p53-functionality and IL-6 expression. In both tested myeloma cell lines, a non-methylated state of the CDKN2B gene promoter region was detected with normal gene expression, and the same level of p15^INK4b protein was detected by immunocytochemical staining. Furthermore, in myeloma cells treated with SBHA and DAC alone, the expression of both p15^INK4b and p21^WAF was significantly upregulated in RPMI8226 cells (p53-functional, without IL-6 expression), whereas in the U266 cell line (p53 deleted, expressing IL-6) only p21^WAF expression was significantly increased. Moreover, the analysis revealed that treatment with DAC induced DNMT3B enhancement in U266 cells. In conclusion, in myeloma cells with IL-6 expression, significantly increased DNMT3B expression indicated the tumorigenic consequences of 5-Aza-2′deoxycytidine treatment, which requires careful use in diseases involving epigenetic dysregulation, such as multiple myeloma (MM).

Lipid Messenger Phosphatidylinositol-4,5-Bisphosphate Is Increased by Both PPARα Activators and Inhibitors: Relevance for Intestinal Cell Differentiation

Simple Summary

Fibrates, such as fenofibrate, are widely used drugs for dyslipidaemia treatment. It is known that they activate peroxisome proliferator-activated receptor α (PPARα) which serves as a lipid sensor in the organism. This article addresses how activators and inhibitor of the PPARα could affect differentiation of intestinal cells. Carcinogenesis is a disruption of normal differentiation process and colorectal carcinoma is the third most common cancer in terms of incidence, but the secondp in terms of mortality. One of the important signalling pathways in intestinal cell differentiation as well as carcinogenesis is PI3K/Akt/PTEN. We showed that PPARα activators as well as inhibitor affected the levels of one member of this pathway called phosphatidylinositol-4,5-bisphosphate. This molecule is important for formation of microvilli, the essential structures of fully differentiated intestinal cells.

Abstract

We investigated the effects of PPARα activators fenofibrate and WY-14643 as well as the PPARα inhibitor GW6471 on the PI3K/Akt/PTEN pathway of intestinal cell differentiation. Our previous study showed that all these compounds increased the expression of villin, a specific marker of intestinal cell differentiation in HT-29 and Caco2 cells. Our current results confirmed the central role of lipid messenger phosphatidylinositol-4,5-bisphosphate (PIP2), a known player in brush border formation, in mediating the effects of tested PPARα ligands. Although all tested compounds increased its levels, surprisingly, each of them affected different PIP2-metabolizing enzymes, especially the levels of PIP5K1C and PTEN. Moreover, we found a positive relationship between the expression of PPARα itself and PIP2 as well as PIP5K1C. By contrast, PPARα was negatively correlated with PTEN. However, the expression of antigens of interest was independent of PPARα subcellular localization, suggesting that it is not directly involved in their regulation. In colorectal carcinoma tissues we found a decrease in PTEN expression, which was accompanied by a change in its subcellular localization. This change was also observed for the regulatory subunit of PI3K. Taken together, our data revealed that fenofibrate, WY-14643, and GW6471 affected different members of the PI3K/Akt/PTEN pathway. However, these effects were PPARα-independent.

When Activator and Inhibitor of PPARα Do the Same: Consequence for Differentiation of Human Intestinal Cells

Peroxisome proliferator-activated receptor α (PPARα) is a ligand-dependent transcription factor that plays a role in various processes including differentiation of several cell types. We investigated the role of PPARα in the differentiation of intestinal cells using HT-29 and Caco2 cell lines as a model as well as human normal colon and colorectal carcinoma tissues. We detected a significant increase in PPARα expression in differentiated HT-29 cells as well as in normal surface colon epithelium where differentiated cells are localised. Thus, it seems that PPARα may play a role in differentiation of intestinal cells. Interestingly, we found that both PPARα activators (fenofibrate and WY-14643) as well as its inhibitor (GW6471) regulated proliferation and differentiation of HT-29 cells in vitro in the same way. Both compounds led to a decrease in proliferation accompanied by a significant increase in expression of villin, intestinal alkaline phosphatase (differentiation markers). Moreover, the same trend in villin expression was observed in Caco2 cells. Furthermore, villin expression was independent of subcellular localisation of PPARα. In addition, we found similar levels of PPARα expression in colorectal carcinomas in comparison to adjacent normal epithelium. All these findings support the hypothesis that differentiation of intestinal epithelium is PPARα-independent.

Acceptance of a vaccine against COVID-19 - a systematic review of surveys conducted worldwide

OBJECTIVES

The most promising strategy for managing COVID-19 pandemic is achieving sufficient vaccination rate worldwide. The question is how many people will be willing to get vaccinated.

STUDY DESIGN

We systematically reviewed peer-reviewed manuscripts monitoring people´s intention to receive a vaccine against COVID-19.

METHODS

Up to December 28, 2020 we identified 62 relevant peer-reviewed articles in PubMed, Web of Science, Scopus and GoogleScholar.

RESULTS

Total sample size was 118 855 respondents with overall average COVID-19 vaccine acceptance rate of 72.5% which is "just" the level estimated to be sufficient for reaching herd immunity threshold. Surprisingly, healthcare workers showed smaller interest in receiving the vaccine when compared to general adult population and university students. On the other hand, their attitude to vaccination did not change over time. In case of general adult population, the longer the pandemic lasts, the smaller proportion of population wants to get vaccinated. Vaccination intentions were independent of gross domestic product and human development index.

CONCLUSION

Willingness of population to receive COVID-19 is just at the herd immunity threshold and it is decreasing over time (Tab. 2, Fig. 3, Ref. 110).  Keywords: vaccination, survey, COVID-19, pandemic, review.

The anti-inflammatory role of placental Hofbauer cells is altered in patients with chorioamnionitis: Are CYP2C8 and soluble epoxide hydrolase involved in immunomodulation?

AIMS

Hofbauer cells (HBCs) are placental macrophages playing various roles during normal and complicated pregnancies, and of the latter, chorioamnionitis is the most frequent.

METHODS

In placenta with chorioamnionitis, we examined immunohistochemical expression profiles of IL-1β, IL-10, and their potential regulators, CYP2C8 and soluble epoxide hydrolase (sEH), in Hofbauer cells and compared the results with our previously published data for normal placenta.

RESULTS

We found that the expression profiles of the studied proteins in Hofbauer cells in chorioamnionitis differs from normal placenta. In chorioamnionitis, HBCs showed a moderate expression of IL-1β together with a weak expression of IL-10 and CYP2C8. Contrary to normal placenta, HBCs in chorioamnionitis express sEH. We demonstrated a moderate positive correlation between the expression of CYP2C8 and sEH in chorioamnionitis (Spearman r = 0.5654), suggesting enhanced degradation of anti-inflammatory epoxyeicosatrienoic acids. Moreover, the relations of IL-1β and IL-10 to CYP2C8, previously described in normal placenta, disappeared. Furthermore, a weak expression of anti-inflammatory IL-10 in chorioamnionitis was accompanied by change in circularity of HBCs (Spearman r = 0.8193).

CONCLUSION

Taken together, these findings suggest a possible alteration of the anti-inflammatory role of HBCs and its regulation in chorioamnionitis.

Students´ preparedness, learning habits and the greatest difficulties in studying Histology in the digital era: A comparison between students of general and dental schools

INTRODUCTION

There are only sporadic references in literature regarding general medicine and dentistry student´s preparedness for Histology, study resources and how students might use them in the era of virtual microscopy.

METHODS

A structured questionnaire was used to evaluate students´ opinion, with 192 students of general medicine and 82 students of dentistry responding.

RESULTS

The dentistry students evaluate their previous knowledge of basic high school disciplines as less helpful when compared to their general medicine colleagues, but this difference diminishes during the first year of medical school studies. Students of dentistry display a better orientation in the amount of study resources (electronic vs printed) and also the ways of their use (practical vs theoretical preparation). The main problems surfacing in the study of Histology have been: the lack of time due to the high demands of Anatomy, problems with correct identification of structures in specimens and correct orientation in a large number of available study resources. Students indicate that they would appreciate the introduction of interactive exercise tests to verify practical and theoretical knowledge.

CONCLUSION

We revealed significant differences between students of general medicine and dentistry in terms of student´s preparedness and learning habits. According to our findings, it is still necessary to further develop teaching methods utilising virtual microscopy, taking into account the needs of both general medicine and dental school students.

Comparative Analysis of Immunohistochemical Staining Intensity Determined by Light Microscopy, ImageJ and QuPath in Placental Hofbauer Cells

Software based analyses of immunohistochemical staining are designed for obtaining quantitative, reproducible, and objective data. However, often times only a certain type of positive cells or structures need to be quantified thus whole image analysis cannot be performed. Such an example is Hofbauer placental cells, which show positivity of some antigens together with trophoblast, but only Hofbauer cells represent the regions of interest (ROIs). Two independent observers evaluated the immunohistochemical staining intensity of Hofbauer cells in placenta samples stained for cytoplasmic antigens by ImageJ, QuPath and light microscopy. Thus, the precise manual determination of ROIs, i.e. Hofbauer cells, was necessary. We detected low inter-observer variability in staining intensity. Almost perfect agreement between observers was reached for ImageJ and QuPath whilst substantial agreement was reached for light microscopy evaluation. As for the comparison of ImageJ, QuPath and light microscopy, the agreement of all three methods (identical immunohistochemical intensity) was achieved for 38.1% samples. The almost perfect agreement of staining intensities was reached between ImageJ and QuPath, and moderate agreement for comparison of the light microscopy to both software. Software analyses are much more time-consuming, thus their utilization is at least questionable to evaluate ROIs with selection.

Soluble Epoxide Hydrolase as an Important Player in Intestinal Cell Differentiation

There is growing evidence that soluble epoxide hydrolase (sEH) may play a role in cell differentiation. sEH metabolizes biologically highly active and generally cytoprotective epoxyeicosatrienoic acids (EETs), generated from arachidonic acid metabolism by CYP epoxygenases (CYP2C and CYP2J subfamilies), to less active corresponding diols. We investigated the effect of sEH inhibitor (TPPU) on the expression of villin, CYP2C8, CYP2C9, CYP2J2, and sEH in undifferentiated and in vitro differentiated HT-29 and Caco2 cell lines. The administration of 10 μM TPPU on differentiated HT-29 and Caco2 cells resulted in a significant decrease in expression of villin, a marker for intestinal cell differentiation. It was accompanied by a disruption of the brush border when microvilli appeared sparse and short in atomic force microscope scans of HT-29 cells. Although inhibition of sEH in differentiated HT-29 and Caco2 cells led to an increase in sEH expression in both cell lines, this treatment had an opposite effect on CYP2J2 expression in HT-29 and Caco2 cells. In addition, tissue samples of colorectal carcinoma and adjacent normal tissues from 45 patients were immunostained for sEH and villin. We detected a significant decrease in the expression of both proteins in colorectal carcinoma in comparison to adjacent normal tissue, and the decrease in both sEH and villin expression revealed a moderate positive association. Taken together, our results showed that sEH is an important player in intestinal cell differentiation.

The expression patterns of IL-1β and IL-10 and their relation to CYP epoxygenases in normal human placenta

INTRODUCTION

The success of pregnancy depends on the regulation of immunological processes in the placenta. Important mediators of an immune response include pro- and anti-inflammatory interleukins which may be regulated by CYP epoxygenases and their metabolites. The relation between interleukins and CYP epoxygenases expression in human placenta has not yet been studied vastly.

MATERIAL AND METHODS

We investigated the expression patterns of IL-1β and IL-10 in embryonic (n=8), early foetal (n=16) and term (n=7) human placenta tissue by an immunohistochemical method and evaluated the results by Kruskal-Wallis test. The obtained data was correlated using Spearman's correlation coefficient to our previously published data of CYP epoxygenases expression in the same samples. To confirm that Hofbauer cells express IL-10 and IL-1β as well as CYP2C8 and IL-10 together, and thus there is a relation between proteins of interests, we used multiplex immunofluorescent staining.

RESULTS

The expression of IL-1β decreased with gestational age in cytotrophoblast, syncytiotrophoblast, as well as in Hofbauer cells whilst IL-10 decreased in cytotrophoblast, remained at the same levels in syncytiotrophoblast and increased in Hofbauer cells. In trophoblast cells, we found a statistically significant positive correlation between the expression of CYP2J2 and CYP2C9 with IL-1β, whereas there was no relation between IL-10 and any of the tested CYP epoxygenases. In Hofbauer cells, we found a significant positive correlation between CYP2C8 and IL-10 and a significant negative correlation between CYP2C8 and IL-1β.

CONCLUSION

Our results showed that the exact role and relation of interleukins and CYP epoxygenases and their metabolites is dependent on their respective cellular context. Because of IL-10, IL-1β, as well as HBCs play a role in various pathological conditions, further investigation of the exact role of CYP epoxygenase, interleukins and their relations is needed.

Morphometric analysis of Hofbauer cells in normal placenta and chorioamnionitis in humans

Hofbauer cells are macrophages residing in the stroma of placental villi and play a number of roles during normal pregnancy, as well as pathological conditions. A morphometric analysis of Hofbauer cells, in particular to investigate the number of cells, their size and shape in samples of normal human placenta from 1st trimester, term and with chorioamnionitis was performed. Tissue samples were immunostained for CD206 antigen and evaluated using ImageJ software. We detected significant changes in number and morphology of HBCs between normal placenta and placenta with chorioamnionitis samples. In chorioamnionitis, the cells were unevenly distributed within the villi, generally present in higher numbers, larger and more elongated than those in normal 1st trimester and term placenta.

HT-29 and Caco2 Cell Lines Are Suitable Models for Studying the Role of Arachidonic Acid-Metabolizing Enzymes in Intestinal Cell Differentiation

INTRODUCTION

Cytochrome (CYP) epoxygenases (CYP2C and CYP2J) and soluble epoxide hydrolase (sEH) participate in the metabolism of arachidonic acid and may also have a potential role in enterocyte differentiation. The first critical step in the study of intestinal cell differentiation is the determination of a suitable in vitro model, which must be as similar as possible to the conditions of a living organism. It is known that HT-29 and Caco2 cell lines derived from human colorectal carcinomas can differentiate into enterocyte-like cells in appropriate culture conditions.

MATERIAL AND METHODS

We tested 4 different approaches of enterocyte-like differentiation and determined the most appropriate culture conditions for each model. Subsequently, the changes in the expression of CYP epoxygenases and sEH in undifferentiated and differentiated cells were measured by In-Cell ELISA. These results were compared with immunohistochemical profiles of expression of CYP epoxygenases and sEH in samples of human embryonic and fetal intestines as well as adult duodenum and colon.

RESULTS

Our results show that sodium butyrate (NaBt)-differentiated HT-29 cells and spontaneously differentiated Caco2 cells resemble CYP epoxygenases and sEH profiles, corresponding with different types of intestines.

CONCLUSION

Our study revealed that the most suitable models for the study of the role of CYP epoxygenases and sEH expression in differentiation of intestinal epithelium are NaBt-differentiated HT-29 cells and spontaneously differentiated Caco2 cells.

Cell Membrane Nanostructure is Altered by Heat-Induced Antigen Retrieval: A Possible Consequence for Immunocytochemical Detection of Membranous Antigens

Heat-induced antigen retrieval (HIAR) treatment improves the antigen immunodetection in formalin-fixed, paraffin-embedded tissue samples and it can also improve the detection of intracellular antigens in alcohol-fixed cytological samples, although it could deleteriously impact immunodetection, particularly that of membranous antigens. We examined the differences in cell surface topography on MCF7 cells fixed in methanol/acetone (M/A) or 4% paraformaldehyde (4% PFA), as well as the changes caused by HIAR treatment at three different temperatures (60, 90, and 120°C), using atomic force microscopy. Furthermore, the consequences for immunostaining of five membranous antigens [epidermal growth factor receptor (EGFR), E-cadherin, CD9, CD24, and CD44] were examined. Our results illustrate that while there was no one single optimal immunostaining condition for the tested antibodies, the surface topography could be an important factor in successful staining. Generally, the best conditions for successful immunostaining were M/A fixation with no HIAR treatment, whereas in 4% PFA-fixed cells, HIAR treatment at 120°C was optimal. These conditions showed similarity in cell surface skewness. A correlation factor between successful immunocytochemical staining and the skewness parameter was 0.8000. Our results indicate that the presence of valleys, depressions, scratches, and pits on the cell surface is unfavorable for the successful immunodetection of cell surface antigens.

Congenital fetal heart defect - an agreement between fetal echocardiography and autopsy findings

AIMS

To determine the frequency of pregnancy terminations due to prenatal congenital heart defect (CHD) and assess the agreement fetal echocardiography (FECHO) and autopsy findings.

METHODS

The data were retrospectively assessed between 2008 and 2017 in a population of 116 698 live births. The correlations between the FECHO and autopsy findings were classified into five levels of agreement: complete, partial, altered diagnosis, disagreement, and unfeasible autopsy.

RESULTS

Totally, 293 CHDs were identified and 49% of families (143/293) decided to terminate the pregnancy. In 1% (2/143) of cases, the autopsy could not be performed, for the other 99% (141/143), the pathologist confirmed the presence of CHDs. Complete agreement between FECHO and autopsy was achieved in 85% (122/143). In 10% (14/143) of cases, the pathologist found minor findings, which were not described in the FECHO. In 4% (5/143) of cases, the pathologist changed the main diagnosis.

CONCLUSION

Altogether, the results indicated that FECHO is a highly sensitive method for the prenatal detection of CHD but is incapable of detecting the complete spectrum of cardiac defects. Autopsies verified the diagnosis, confirmed the overall impairment in the fetus, and provided data for further counselling of the affected family.

Estimation of ABCB1 concentration in plasma membrane

The interaction between ABCB1 transporter and its substrates takes place in cell membranes but the available data precludes quantitative analysis of the interaction between transporter and substrate molecules. Further, the amount of transporter is usually expressed as a number of ABCB1 molecules per cell. In contrast, the substrate concentration in cell membranes is estimated by determination of substrate-lipid partition coefficient, as examples. In this study, we demonstrate an approach, which enables us to estimate the concentration of ABCB1 molecules within plasma membranes. For this purpose, human leukemia K562 cells with varying expression levels of ABCB1 were used: drug selected K562/Dox and K562/HHT cells with very high transporter expression, and K562/DoxDR2, K562/DoxDR1, and K562/DoxDR05 cells with gradually decreased expression of ABCB1 derived from K562/Dox cells using RNA interference technology. First, we determined the absolute amount of ABCB1 in cell lysates using immunoblotting and recombinant ABCB1 as a standard. We then determined the relative portion of transporter residing in the plasma membrane using immunohistochemistry in nonpermeabilized and permeabilized cells. These results enabled us to estimate the concentration of ABCB1 in the plasma membrane in resistant cells. The ABCB1 concentrations in the plasma membrane of drug selected K562/Dox and K562/HHT cells containing the highest amount of transporter reached millimolar levels. Concentrations of ABCB1 in the plasma membrane of resistant K562/DoxDR2, K562/DoxDR1, and K562/DoxDR05 cells with lower transporter expression were proportionally decreased.

Evaluation of the effectiveness of the presentation of virtual histology slides by students during classes. Are there any differences in approach between dentistry and general medicine students?

INTRODUCTION

Virtual microscopy, used as a method to teach histology, has many undeniable advantages. However, the usefulness of this method is somewhat limited by the difficulties students face in finding their way through huge amounts of digital data, compounded by decreased interaction between students and teachers. We describe the results of a recent pilot project which combined the modern teaching methods of active learning, where students themselves present histological slides and make use of the virtual microscopy system.

METHODS

Students' responses to a structured questionnaire and examination results were evaluated.

RESULTS

We found that a combination of both electronic materials and textbooks was commonly used by students to prepare for practical teaching sessions, with electronic resources being used regularly by the majority of students. No statistically relevant differences were found between the approaches of dentistry vs general medicine students. Cooperation between students' groups during the preparation for individual presentations was seen to be beneficial by a majority of dentistry students; they reported that the introduction of student-led presentations improved their quality of preparation for practical lessons, as well as increasing their participation and activity level in the lessons themselves. These different approaches and motivations between students of dentistry and general medicine are reflected in the test results where dentistry students are more successful.

CONCLUSION

We confirm that there are differences in motivation, approaches and examination results between both groups of students, which should be taken into account and which could lead to differentiation of future curricula for both study courses.

Influence of fixation method and duration of archiving on immunohistochemical staining intensity in embryonic and fetal tissues

INTRODUCTION

In this study we detail the effect of different fixation agents and the duration of storage has on the immunohistochemical staining positivity of samples of archival embryonic and fetal tissues.

MATERIALS AND METHODS

The samples were stained by indirect two-step immunohistochemistry (IHC) method for Ki-67, cyclin A and β-actin.

RESULTS

Irrespective of the length of tissue archiving, tissue fixation with 10% neutral buffered formalin had better IHC intensity results in all cases when compared to methacarn-fixed tissues. In the case of β-actin, this difference was statistically significant, while differences in Ki-67 and cyclin A were not. The second aspect studied was which effect tissue block archiving duration has on the IHC reactivity. We demonstrated a statistically significant decrease in IHC positivity for all studied antigens between the samples that were archived for 10-19 or 20-45 years, regardless the fixative solution.

CONCLUSION

To the best of our knowledge, the influence that the duration of tissue block archiving has on IHC positivity in human embryo and fetal tissue material has not yet been studied. Although the causes of the IHC positivity decline in archived tissue blocks are not well understood, a possible decrease in IHC over time should be considered, particularly in retrospective studies.

Macrophages of the subcutaneous and omental fatty tissue in obese patients: Immunohistochemical phenotyping of M2 subtypes in relation to type 2 diabetes

BACKGROUND AND AIMS

Macrophages are linked to the initiation of the chronic inflammation believed to underlie the changes taking place in the white fatty tissue of obese people. Both the number of macrophages, but their functional status, play an important role in the development of inflammation. Classically, macrophages are divided into two types: pro-inflammatory (M1) and anti-inflammatory (M2) types, and based on current immunological studies, further views on the functional distribution of macrophages are suggested. In this study, we evaluated the M1 and M2 macrophages ratio in obese subjects with, or without diabetes. To identify all macrophages, we used CD68 expression, while CD204 expression is typically used for the M2 macrophage.

MATERIALS AND METHODS

During bariatric surgery, carried out in obese people with and without type 2 diabetes (T2D), we obtained subcutaneous adipose tissue from the navel and omental adipose tissue. We also obtained the same tissue from people with a physiological range of BMI from a judicial autopsy. Applying immunohistochemical staining anti-CD68 and anti-CD204, we carried out a quantitative evaluation of the number of macrophages.

RESULTS

We found CD68+ and CD204+ positive macrophages in perivascular spaces and between fat cells, both isolated and in larger infiltrates. They were also present in so-called "crown-like structures" (CLS) around dying adipocytes. Quantitative analysis showed an increased number of macrophages in all obese patients compared to the control group of non-obese, individuals without T2D. The most striking observation was the macrophage increase in the visceral fatty tissue of diabetics. The number of CD68 and CD204 positive macrophages was statistically significantly smaller in patients without T2D.

CONCLUSION

We demonstrated a significantly greater number of macrophages in visceral adipose tissue, especially in patients with T2D. Our results also show a positive correlation between the presence of T2D and the total number of macrophages; a significantly greater number of macrophages were found in visceral adipose tissue, especially in patients with T2D.

Time-dependent expression pattern of cytochrome P450 epoxygenases and soluble epoxide hydrolase in normal human placenta

CYP2C and CYP2 J enzymes, commonly named as cytochrome P450 (CYP) epoxygenases, convert arachidonic acid to four regioisomeric epoxyeicosatrienoic acids (EETs), biologically active eicosanoids with many functions in organism. EETs are rapidly hydrolysed to less active dihydroxyeicosatrienoic acids (DHETs) by soluble epoxide hydrolase (sEH). We investigated spatio-temporal expression pattern of CYP2C8, CYP2C9, CYP2 J2 and sEH in normal human placenta by immunohistochemical method. In the villous trophoblast, CYP2C8 was the most abundant protein. Its expression is higher than the CYP2C9 and CYP2 J2 in the cytotrophoblast in the embryonic stage of development and remains higher in syncytiotrophoblast of term placenta. Unlike to CYP2C8, CYP2C9 and CYP2 J2 expression decrease in term placenta. sEH expression increases with gestation age and is strictly limited to cytotrophoblast in embryonic and foetal stages of the development. Moreover, CYP2C8 shows more intensive staining than the other protein monitored in Hofbauer cells in villous stroma. Specific information regarding the exact role of EETs and DHETs functions in a normal placenta is still unknown. Based on CYP epoxygenases and sEH localization and well known information about the functions of placental structures during development, we suggest that these enzymes could play different roles in various cell populations in the placenta. As the placenta is absolutely crucial for prenatal development, arachidonic acid is essential part of human nutrient and CYP epoxygenases expression can be affected by xenobiotics, further investigation of the exact role of CYP epoxygenases, sEH, and their metabolites in normal pregnancy and under pathological conditions is needed.

Prognostic role of serum C-reactive protein in patients with advanced-stage NSCLC treated with pemetrexed

Pemetrexed is an intravenously administered antifolate cytostatic agent targeting several folate-dependent enzymatic pathways, widely used in the treatment of patients with advanced non-small cell lung cancer (NSCLC). It has been previously demonstrated that the superiority of pemetrexed is limited to patients with non-squamous histology. Aside from the non-squamous histology, there is still no available molecular biomarker predicting treatment efficacy of pemetrexed-based chemotherapy. The aim of our retrospective study was to evaluate the association of baseline serum levels of C-reactive protein (CRP) with outcomes in a large cohort of patients with non-squamous NSCLC treated with pemetrexed. Clinical data of 325 patients were analysed. Serum samples were collected within one week before the initiation of treatment. The median progression-free (PFS) and overall survival (OS) for patients with high CRP was 2.1 and 9.5 compared to 4.2 and 20.5 months for those with normal CRP (p=0.002 and p<0.001, respectively). The multivariable Cox proportional hazards model revealed that serum CRP (HR=1.46, p=0.002) was significantly associated with PFS and also with OS (HR=1.95, p<0.001). In conclusion, the study results suggest that pretreatment serum CRP is associated with poor outcome of non-squamous NSCLC patients treated with pemetrexed.

Stimulating effect of normal-dosing of fibrates on cell proliferation: word of warning

BACKGROUND

Fibrates are widely used hypolipidemic drugs, which serve as ligand of peroxisome proliferator-activated receptor α (PPARα). Recently, they have also been considered as potential anticancer agents. We studied effect of fibrates treatment on cell proliferation, expression of CYP2J2 and concomitant changes in expression of cell cycle regulatory proteins in three different human cell lines: HEK293, HepG2, and HT-29.

METHODS

We used WST-1 viability test, western blot and immunocytochemistry for detection of proteins of interests and analysis of cell cycle.

RESULTS

Our results showed that at lower concentrations of all tested fibrates, viability of all tested cell lines is increased, whereas at higher concentrations, repression is apparent. Unfortunately, the viability of tested cells is predominantly increased in a range of concentration which is reached in patient plasma. This phenomenon is accompanyed by elevation of CYP2J2, increased number of cyclin E-positive cells and decreased number of Cdc25A-positive cells in all tested cell lines, and elevated cyclin A expression in HepG2 and HT-29. These changes are concentration-dependent. We suppose that increased level of CYP2J2 could explain enhanced cell proliferation in lower concentration of fibrates.

CONCLUSION

Based on our results, we suggested there is no anti-cancer effect of fibrates in tested carcinoma cell lines.

Soluble Epoxide Hydrolase as a Potential Key Factor for Human Prenatal Development

Soluble epoxide hydrolase (sEH) converts highly active epoxyeicosatrienoic acids (EETs) generated by cytochrome P450 (CYP) epoxygenases from arachidonic acid to less active dihydroxyeicosatrienoic acids. Because of the role of EETs in processes potentially relevant to the development of organisms, EETs could be suggested as potential morphogens. Unfortunately, only little is known about sEH expression during human intrauterine development (IUD). We investigated the spatio-temporal expression pattern of sEH in human embryonic/foetal intestines, liver and kidney from the 6th to the 20th week of IUD by two-step immunohistochemistry. sEH was expressed during the whole tested period of prenatal development and its level of expression remained more or less the same during the estimated period of IUD. Distribution of CYP epoxygenases and sEH in the intestinal epithelium and the nephrogenic zone of the kidney suggests an influence of EETs on cell proliferation and differentiation and, consequently, on the development of intestines and kidney. Thus, alterations in the strict spatio-temporal pattern of expression of CYP epoxygenases and/or sEH during human prenatal development by xenobiotics could have a harmful impact for developing organisms.

Spatio-temporal expression of peroxisome proliferator-activated receptor α during human prenatal development

Peroxisome proliferator-activated receptor α (PPARα) is a ligand-dependent transcription factor which is activated by various endogenous as well as exogenous compounds. It is involved in the regulation of a variety of biological processes, such as nutrient metabolism, energy homoeostasis, immunological response and xenobiotic metabolism. Little is known about its expression during human prenatal development. We examined the spatio-temporal expression pattern of PPARα in human embryonic/foetal intestines, liver and kidney from the 5th to 20th week of prenatal life by indirect two-step immunohistochemistry. PPARα expression can already be detected in the early stages of prenatal development; as early as the 7th week of intrauterine development (IUD) in the intestines, 5th week of IUD in the liver and 6th week of IUD in the kidney. We found age-dependent changes in the PPARα expression pattern in the intestines and kidney. These events occur approximately at the commencement of function of these organs. In the intestines, we detected an obvious change of the PPARα expression pattern along the crypt-villous axis in the 11th week of IUD. In the kidney, the most apparent change was increased expression of PPARα in glomeruli in the 12th week of IUD. Moreover, in the liver, we detected a strong positivity in part of the developing blood elements. Information about the spatio-temporal expression pattern of PPARα could be the first step in evaluating the potential harmful impact of a wide range of environmental or pharmaceutical compounds which serve as PPARα ligands on the developing human organism.

Time-dependent expression of cytochrome p450 epoxygenases during human prenatal development

There is growing evidence that some members of cytochrome P450 enzymes contribute to regulation of normal prenatal development. CYP epoxygenases (CYP2C and CYP2J subfamilies) convert arachidonic acid into four regioisomeric epoxyeicosatrienoic acids (EETs), biologically active molecules involved in mitogenesis and cell signaling. Almost nothing is known about localization of their expression in tissues during human prenatal development. The spatio-temporal expression pattern of CYP2C8, CYP2C9, CYP2C19 and CYP2J2 in human embryonic/fetal intestines, liver, and kidney was investigated by immunohistochemical method. CYP epoxygenases are expressed already in early stages of development in these embryonic/fetal tissues (as early as 7th week of IUD in the intestines, 5th week of IUD in the liver, and 6th week of IUD in the kidney). In kidney, CYP epoxygenases are expressed in the metanephrogenic blastema (but not in the uninduced mesenchyme) and in the tubular system. In the intestines, diverse CYP epoxygenases distribution along crypt-villus axis could suggest role in cell differentiation. Moreover, we detected higher CYP2J2 level in these organs than in adult tissue samples.