Distinct pleiotropic effects of direct oral anticoagulants on cultured endothelial cells: a comprehensive review

Direct Oral Anticoagulants (DOACs) have simplified the treatment of thromboembolic disease. In addition to their established anticoagulant effects, there are indications from clinical and preclinical studies that DOACs exhibit also non-anticoagulant actions, such as anti-inflammatory and anti-oxidant actions, advocating overall cardiovascular protection. In the present study, we provide a comprehensive overview of the existing knowledge on the pleiotropic effects of DOACs on endothelial cells (ECs) in vitro and their underlying mechanisms, while also identifying potential differences among DOACs. DOACs exhibit pleiotropic actions on ECs, such as anti-inflammatory, anti-atherosclerotic, and anti-fibrotic effects, as well as preservation of endothelial integrity. These effects appear to be mediated through inhibition of the proteinase-activated receptor signaling pathway. Furthermore, we discuss the potential differences among the four drugs in this class. Further research is needed to fully understand the pleiotropic effects of DOACs on ECs, their underlying mechanisms, as well as the heterogeneity between various DOACs. Such studies can pave the way for identifying biomarkers that can help personalize pharmacotherapy with this valuable class of drugs.

Lysed Erythrocyte Membranes Promote Vascular Calcification

BACKGROUND

Intraplaque hemorrhage promotes atherosclerosis progression, and erythrocytes may contribute to this process. In this study we examined the effects of red blood cells on smooth muscle cell mineralization and vascular calcification and the possible mechanisms involved.

METHODS

Erythrocytes were isolated from human and murine whole blood. Intact and lysed erythrocytes and their membrane fraction or specific erythrocyte components were examined in vitro using diverse calcification assays, ex vivo by using the murine aortic ring calcification model, and in vivo after murine erythrocyte membrane injection into neointimal lesions of hypercholesterolemic apolipoprotein E-deficient mice. Vascular tissues (aortic valves, atherosclerotic carotid artery specimens, abdominal aortic aneurysms) were obtained from patients undergoing surgery.

RESULTS

The membrane fraction of lysed, but not intact human erythrocytes promoted mineralization of human arterial smooth muscle cells in culture, as shown by Alizarin red and van Kossa stain and increased alkaline phosphatase activity, and by increased expression of osteoblast-specific transcription factors (eg, runt-related transcription factor 2, osterix) and differentiation markers (eg, osteopontin, osteocalcin, and osterix). Erythrocyte membranes dose-dependently enhanced calcification in murine aortic rings, and extravasated CD235a-positive erythrocytes or Perl iron-positive signals colocalized with calcified areas or osteoblast-like cells in human vascular lesions. Mechanistically, the osteoinductive activity of lysed erythrocytes was localized to their membrane fraction, did not involve membrane lipids, heme, or iron, and was enhanced after removal of the nitric oxide (NO) scavenger hemoglobin. Lysed erythrocyte membranes enhanced calcification to a similar extent as the NO donor diethylenetriamine-NO, and their osteoinductive effects could be further augmented by arginase-1 inhibition (indirectly increasing NO bioavailability). However, the osteoinductive effects of erythrocyte membranes were reduced in human arterial smooth muscle cells treated with the NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide or following inhibition of NO synthase or the NO receptor soluble guanylate cyclase. Erythrocytes isolated from endothelial NO synthase-deficient mice exhibited a reduced potency to promote calcification in the aortic ring assay and after injection into murine vascular lesions.

CONCLUSIONS

Our findings in cells, genetically modified mice, and human vascular specimens suggest that intraplaque hemorrhage with erythrocyte extravasation and lysis promotes osteoblastic differentiation of smooth muscle cells and vascular lesion calcification, and also support a role for erythrocyte-derived NO.

Genotoxic effect of tocolytic drug ritodrine in combination with smoking during pregnancy

OBJECTIVE

Tocolytic drugs are used widely in order to prevent preterm birth. Ritodrine, is the only food and drug administration (FDA) approved drug for tocolytic use. We estimated the cytogenetic effect of ritodrine administered as maternal therapy, alone or in combination with smoking, in women and their neonates.

METHODS

Lymphocyte and fibroblasts cultures were evaluated and three indices were analyzed; sister chromatid exchanges (SCEs), proliferation rate index (PRI) and mitotic index (MI) as well as average generation time (AGT) and population doubling time (PDT). Campothacin (CPT-11) was used as a positive control.

RESULTS

Administration of ritodrine up to a month revealed significant reduction of SCEs/cell in neonates in the presence or absence of the mutagenic agent. A statistical significant increase on SCEs, for mothers and neonates, was noticed in neonate's lymphocytes when tocolytic therapy was over a month. Ritodrine revealed a cytoprotective action against smoking when the two factors were combined, but the synergistic action of ritodrine with smoking increased genotoxicity, cytostaticity and cytotoxicity of neonates after long administration (1-3 months).

CONCLUSIONS

The time-depended genotoxic, cytostatic and cytotoxic action of ritodrine alone or in combination with smoking suggests that its administration should not exceed the time period of a month.

Spot urine albumin to creatinine ratio outperforms novel acute kidney injury biomarkers in patients with acute myocardial infarction

BACKGROUND

Acute kidney injury (AKI) is a frequent complication in patients hospitalized for acute myocardial infarction (AMI), and is associated with in-hospital and long-term morbidity and mortality. We prospectively assessed the diagnostic performance of spot urine albumin to creatinine ratio (uACR) in an adequately sized multicenter cohort of patients admitted to hospital with AMI. We further compared uACR to novel renal injury associated biomarkers regarding their diagnostic ability.

METHODS

We enrolled 805 consecutive patients presenting with acute ST-elevation and non-ST elevation AMI. Patients were assessed for presence of AKI at 48h post-admission and at hospital discharge using the Acute Kidney Injury Network (AKIN), the Acute Dialysis Quality Initiative [Risk, Injury and Failure (RIFLE)] criteria and the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Blood and urine sampling for neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18), cystatin-C, and uACR assessment was performed during admission.

RESULTS

The predictive accuracy of uACR was good (Area Under the Curve (AUC), 0.725; 95% CI 0.676-0.774) and was better compared to urine NGAL (P=0.007), urine (P<0.001) and plasma Cystatin-C (P=0.001). ROC analysis identified concentrations of ≥66.7μg/mg as having the best diagnostic accuracy. The use of uACR exhibited good discriminating ability independent to possible cofounders and additive regarding the use of novel biomarkers.

CONCLUSIONS

The use of uACR can easily be applied in the clinical setting, allows for robust risk assessment and offers the potential to improve the management of AMI patients at risk for acute kidney injury.

The cytogenetic action of ifosfamide, mesna, and their combination on peripheral rabbit lymphocytes: an in vivo/in vitro cytogenetic study

Ifosfamide (IFO) is an alkylating nitrogen mustard, administrated as an antineoplasmic agent. It is characterized by its intense urotoxic action, leading to hemorrhagic cystitis. This side effect of IFO raises the requirement for the co-administration with sodium 2-sulfanylethanesulfonate (Mesna) aiming to avoid or minimize this effect. IFO and Mesna were administrated separately on rabbit's lymphocytes in vivo, which were later developed in vitro. Cytogenetic markers for sister chromatid exchanges (SCEs), proliferation rate index (PRI) and Mitotic Index were recorded. Mesna's action, in conjunction with IFO reduces the frequency of SCEs, in comparison with the SCEs recordings obtained when IFO is administered alone. In addition to this, when high concentrations of Mesna were administered alone significant reductions of the PRI were noted, than with IFO acting at the same concentration on the lymphocytes. Mesna significantly reduces IFO's genotoxicity, while when administered in high concentrations it acts in an inhibitory fashion on the cytostatic action of the drug.

Synergistic cytogenetic and antineoplastic effects by the combined action of esteric steroidal derivatives of nitrogen mustards

We studied the effect of five newly synthesized steroidal derivatives of nitrogen mustards. These derivatives have as alkylators either P-N, N-bis(2-chloroethyl)aminophenyl-butyrate (CHL) or P-N, N-bis(2-chloroethyl)aminophenyl-acetate (PHE) groups esterified with different modified steroidal nuclei. We examined them alone or in combination, on sister chromatid exchange rates and on human lymphocyte proliferation kinetics. The antitumor activity of these compounds, alone or in combination, was also tested on Leukemia P388-bearing mice. A pronounced cytogenetic and antineoplastic action was demonstrated by the compounds that contain either PHE or CHL as alkylators and are esterified with a steroidal nucleus having added a cholestene group in the 17 position of the D-ring. The exocyclical insertion of an -NHCO- group in the D-ring of the steroidal nucleus esterified with PHE (amide ester of PHE) yielded a compound demonstrating a distinct cytogenetic and antineoplastic effect. In contrast, the ketone group in the D-ring being inserted endocyclically in the steroidal nucleus (androstene) esterified with either CHL or with PHE gave negative cytogenetic and antineoplastic effects. However, the combined action of cholestene esterified with either CHL or with PHE in combination with either the androstene ester of PHE or with the androstene ester of CHL, respectively, gave synergistic cytogenetic and antineoplastic effects. Also the amide ester of PHE in combination with the androstene ester of CHL gave distinct cytogenetic and antineoplastic effects in a synergistic manner.

Distribution of ABO and Rh blood groups in Greece: an update

The aim of this study was to investigate and evaluate the frequency of the antigens classifying the ABO and Rh blood groups in the Greek population. In this study the 3.5% were first generation immigrants with both their parents immigrants from countries of the USSR, while 1.2% had only one immigrant parent, while the other one was Greek. We compared the frequency of distribution of blood groups ABO and Rh to previous studies conducted at a time before Greece became destination for refugees and immigrants from East and Northeast countries. Blood samples were collected from first year medical students. The frequency of distribution of the ABO and Rh blood groups was slightly differentiated in comparison to previous relevant studies. Significant increase was recorded with respect to the emergence of blood group B in the population investigated, and a considerable reduction was noted in blood group O. In reference to the remaining blood groups, no statistically significant difference was documented. The genetic pool and the genetic inventory of the population residing in Greece have been modified during the last years potentially due to the first generation immigrants. The results of this study could contribute significantly to the National Health System in aiding the prediction of percussions of certain diseases related to blood groups, as well as the requirement for certain blood groups within the blood donation program.

Cytogenetic evaluation and DNA interaction studies of the food colorants amaranth, erythrosine and tartrazine

Food coloring agents, amaranth, erythrosine and tartrazine have been tested at 0.02-8mM in human peripheral blood cells in vitro, in order to investigate their genotoxic, cytotoxic and cytostatic potential. Amaranth at the highest concentration (8mM) demonstrates high genotoxicity, cytostaticity and cytotoxicity. The frequency of SCEs/cell was increased 1.7 times over the control level. Additionally, erythrosine at 8, 4 and 2mM shows a high cytotoxicity and cytostaticity. Finally, tartrazine seems to be toxic at 8 and 4mM. No signs of genotoxicity were observed. Reversely, tartrazine showed cytotoxicity at 1 and 2mM. Furthermore, spectroscopic titration studies for the interaction of these food additives with DNA showed that these dyes bind to calf thymus DNA and distinct isosbestic points are observed clearly suggesting binding of the dyes to DNA. Additionally DNA electrophoretic mobility experiments showed that these colorants are obviously capable for strong binding to linear dsDNA causing its degradation. PCR amplification of all DNA fragments (which previously were pre-treated with three different concentrations of the colorants, extracted from agarose gel after separation and then purified), seems to be attenuated with a manner dye concentration-dependent reflecting in a delayed electrophoretic mobility due to the possible binding of some molecules of the dyes. Evaluation of the data and curves were obtained after quantitative and qualitative analysis of the lanes of the gel by an analyzer computer program. Our results indicate that these food colorants had a toxic potential to human lymphocytes in vitro and it seems that they bind directly to DNA.

Frequency of genetic diseases and health coverage of children requiring admission in a general pediatric clinic of northern Greece

BACKGROUND

In order to estimate the causes of pediatric morbidity in our area, with particular emphasis on diseases with a genetic background, we retrospectively categorized the admissions of all children hospitalized in the Department of Pediatrics of the University General Hospital of Alexandroupolis, in the area of Evros, Thrace, Greece over the three year period 2005-2007. Finally, in order to guide health care administrators to improve the delivery of pediatric health care services, we estimated the percentage of hospitalized children who were uninsured and the type of health insurance of those who had medical coverage.

PATIENTS AND METHODS

The causes of admission, as recorded in the medical records were categorized in terms of the major organ and/or system involved and/or the underlying pathology, with emphasis on diseases with a genetic background. Duplicate admissions, i.e., admissions of the same child for the same underlying disease were excluded. Additional information recorded was age, sex, and type of health insurance of all admitted children. Distribution of the causes of admission by study year was compared by chi-square. A p value < 0.05 was considered significant.

RESULTS

Over the study period, there were 4,947 admissions in 2,818 boys and 2,129 girls. Respiratory diseases were the most common accounting for 30%, while infectious diseases followed with 26.4%. The frequency of chromosomal abnormalities among the hospitalized children was only 0.06%. However, if we consider diseases with an underlying genetic background, this percentage rises to 5%. Approximately 10.3% of the admitted children had no health insurance.

CONCLUSIONS

The percentage of children hospitalized in our area due to a disease with an underlying genetic background was 5%. This percentage pertains to a Department of Pediatrics that has no inpatient subspecialty units and which is located within a General hospital, because hospitalizations for genetic diseases are more frequent in specialized pediatric hospitals, with competence in clinical genetics. The double figure of uninsured children is worrisome and dictates the need for governmental efforts for universal pediatric health coverage in our country.

Prognostic and predictive factors of invasive ductal breast carcinomas

PURPOSE

To investigate the significance of certain immunohistochemical markers, namely estrogen (ER) and progesterone receptors (PgR), c-erbB-2 oncogene, p53 tumor suppressor gene and E-cadherin adhesion molecule, in invasive ductal breast carcinomas.

METHODS

A series of 102 primary breast carcinomas of the ductal type and a standard immunohistochemical technique was used to detect the aforementioned biological markers. The findings were related to various clinical and pathological tumor characteristics, including lymph node metastases.

RESULTS

ER and E-cadherin were expressed more commonly in tumors of low histological grade and small number (< or =3) of metastatic lymph nodes, whereas c-erbB-2 and the p53 gene were usually expressed in breast tumors of high histological grade and increased number (>3) of metastatic lymph nodes. PgR, on the other hand, was detected frequently in patients with early menarche and metastases in <3 lymph nodes, but this tendency was not statistically significant.

CONCLUSION

The use of these biomarkers, preferably in combination, may provide additional prognostic and therapeutic information which may be proved useful in planning breast cancer treatment.