Neonatal testosterone imprinting affects thymus development and leads to phenotypic rejuvenation and masculinization of the peripheral blood T-cell compartment in adult female rats

Exposure of female rodents to testosterone in the critical neonatal period produces defeminization/masculinization of the hypothalamo–pituitary–gonadal (HPG) axis, i.e. neonatal androgenization and postpones axis maturation. To address the hypothesis that HPG axis signaling is involved in the programming of thymic maturation/involution and sexual differentiation we studied the impact of neonatal androgenization on thymic cellularity, development of effector and regulatory T cells, and phenotypic characteristics of peripheral blood T lymphocytes in adult rats. A single injection of testosterone on postnatal day 2 postponed thymic maturation/involution as revealed by organ hypercellularity, increased cellularity of the most mature (CD4+CD8? and CD4?CD8+) TCRαβ^high thymocyte and both recent thymic emigrant (RTE) subsets and caused phenotypic defeminization/masculinization of thymic (decreased CD4+CD8?TCRαβ^high/CD4?CD8+TCRαβ^high cell ratio) and peripheral blood T-cell compartments (decreased CD4+RTE/CD8+RTE and CD4+/CD8+ cell ratio). In addition, neonatal androgenization increased the relative and absolute numbers of both CD4+CD25+Foxp3+ and natural killer (NK) regulatory T cells in peripheral blood. These findings, in conjunction with thymocyte overexpression of Thy-1 that is assumed to reduce negative selection affecting self-reactive cell generation, suggest a new relationship between self-reactive and regulatory T cells. In conclusion, our study provides additional evidence for a role of HPG signals (i.e. sex steroids and gonadotropins) in programming the kinetics of thymic maturation/involution and in establishing immunological sexual dimorphism.     

Abrupt cessation of one-year clopidogrel treatment is not associated with thrombotic events

We aimed to examine the rate of thrombotic events after discontinuation of one year clopidogrel therapy in patients with implanted coronary stent, and to determine platelet aggregability by multiple electrode analyzer after cessation of clopidogrel. This prospective, multicenter study enrolled 200 patients subjected to coronary stent implantation and treated with aspirin + clopidogrel one year after the stent placement. Platelet aggregation was measured using 3 agonists [adenosine diphosphate with PGE(1) (ADPHS), arachidonic-acid (ASPI), and thrombin receptor activating peptide (TRAP)] on the day of cessation of clopidogrel and at 10, 45, and 90 days after clopidogrel was stopped. Two thrombotic events were registered during the 6-months follow up (one ischemic stroke and one myocardial infarction; incidence of 1%). The mean values of ADP + PGE(1)- and ASPI-induced aggregation 10 - 90 days after the cessation of clopidogrel were significantly higher than values obtained before the termination of the drug (P < 0.001, all). Cessation of clopidogrel did not influence the TRAP-induced aggregation, which reached the plateau in all measurements. In conclusion, the incidence of thrombotic events after the cessation of one-year clopidogrel treatment might be lower than expected in patients with implanted coronary stent.     

Immune responses in the skin in old age

A marked increase in the susceptibility to cutaneous infections and malignancies has been observed in older humans indicating that cutaneous immunity becomes defective with age. In this review we will focus on recent developments in the understanding of age-related changes in immune function of the skin with a particular emphasis on how alterations in the interaction between cells involved in innate and adaptive immunity leads to decreased cutaneous antigen-specific T cell immunosurveillance.     

Engineered heart tissue model of diabetic myocardium

Myocardial infarction resulting in irreversible loss of cardiomyocytes (CMs) is a leading cause of heart failure. Previously, we reported an in vitro test-bed for screening cell integration between injected test cells and host CM using the engineered heart tissue as a recipient. The objective of this study is to expand our system to diabetic cardiomyopathy conditions. Patients with diabetes show dysfunction of CMs independent of myocardial infarction, indicating that diabetes directly affects CMs. However, the underlying mechanisms are not fully understood, and developing a diabetic CM test-bed could enable drug screening studies specific to the diabetic heart. Diabetic cardiac conditions were mimicked by cultivating neonatal rat CMs seeded onto collagen scaffolds in normal or high glucose with or without insulin. Our results show that high glucose conditions, which mimic diabetic hearts, display poor electrical properties. Gene expression profiles from diabetic, adult, and neonatal rat hearts as well as engineered heart tissues under different conditions were compared. The diabetic rat heart and high glucose conditions increased the ratio of myosin heavy-chain isoform β to α indicative of diseased states; thus, this model system captures some molecular aspects of diabetic cardiomyopathy. Moreover, thiazolidinedione diabetic drug treatment improved electrical excitabilities and exhibited anti-apoptotic effects.     

Sexual dimorphism in the catecholamine-containing thymus microenvironment: a role for gonadal hormones

The study was undertaken to explore whether there were: i) apart from neural and circulatory, some other sources of catecholamines (CAs) in rat thymus and ii) gender-specific differences in thymic CA levels, and if so to elucidate the role of sex steroids in this phenomenon. Tyrosine hydroxylase (TH) immunoreactivity was found in thymocytes and thymic epithelial cells (some of which showed morphological features of nurse cells). The density of CA-synthesizing cells was greater in male than in female rats. Noradrenaline (NA), but not dopamine (DA), was detected in thymocytes. NA and DA levels in thymi, and the NA level in thymocytes, were higher in male rats. To explore the putative role of sex steroids in this dichotomy in the thymi of adult rats gonadectomized (Gx) or sham-Gx at the age of 30 days the density of TH+ cells and CA levels were measured. Gonadectomy abolished sexual dimorphism in the density of thymic TH+ cells (diminishing their density in male rats) and thymic CA levels (the NA levels were reduced in rats of both sexes and also the DA level in male rats). Therefore, it can be assumed that testicular and ovarian hormones control thymic NA and DA levels via different mechanisms. Moreover, in Gx rats, despite the decrease in the overall thymic NA level, an increase in the thymocyte NA level was found indicating that gonadal hormones exert differential effects on the NA level in distinct thymic cellular compartments.     

Differentiated thyroid carcinoma with distant metastases: probability of survival and its predicting factors

The purpose was to analyze survival and its predicting factors in differentiated thyroid carcinoma (DTC) patients with distant metastases (M1). Radioiodine ((131)I) therapy was performed in 363 DTC patients from 1977 to 2000. Among 75 patients, 44 patients had M1 at the time of initial therapy and 31 patients had M1, which developed during the follow up. The probability of survival and its predicting factors were tested by Kaplan-Meier's method. Seventy five DTC patients with M1 included 49 (65.3%) women and 26 (34.7%) men; 30 (40%) patients were < 45 years old and 45 (60%) patients were >or= 45 years old (range 8-70 years; mean age = 45.5 years); 52 papillary carcinomas, 22 follicular carcinomas, and one inconclusive finding. Probability of survival after appearance of M1 was 60.7% at 5 years, 51.2% at 10, and 38.4% at 15 and 20 years. Some predicting factors showed significant influence on the survival: age (p = 0.0001), histological type (p = 0.0138), and initial therapy (p = 0.0351), while gender had no influence (p = 0.2046). We can conclude that patients' age, histopathology of the tumor, and initial therapy significantly influence the survival. Longer survival of DTC patients with M1 could be achieved by adequate surgery followed by 131I therapy.     

Targeting CXCR4 and FAK reverses doxorubicin resistance and suppresses invasion in non-small cell lung carcinoma

Background

Current high lung cancer mortality rates are mainly due to the occurrence of metastases and therapeutic resistance. Therefore, simultaneous targeting of these processes may be a valid approach for the treatment of this type of cancer. Here, we assessed relationships between CXC chemokine receptor type 4 (CXCR4) and focal adhesion kinase (FAK) gene expression levels and expression levels of the drug resistance-related genes ABCB1 and ABCC1, and tested the potential of CXCR4 and FAK inhibitors to reverse doxorubicin (DOX) resistance and to decrease the invasive capacity of non-small cell lung carcinoma (NSCLC) cells.

Methods

qRT-PCR was used for gene expression analyses in primary lung tissue samples obtained from 30 NSCLC patients and the human NSCLC-derived cell lines NCI-H460, NCI-H460/R and COR-L23. MTT, flow cytometry, cell death and β-galactosidase activity assays were used to assess the in vitro impact of CXCR4 and FAK inhibitors on DOX sensitivity. In addition, invasion and gelatin degradation assays were used to assess the in vitro impact of the respective inhibitors on metastasis-related processes in combination with DOX treatment.

Results

We found that ABCB1 over-expression was significantly associated with CXCR4 and FAK over-expression, whereas ABCC1 over-expression was associated with increased FAK expression. We also found that CXCR4 and FAK inhibitors strongly synergized with DOX in reducing cell viability, arresting the cell cycle in the S or G₂/M phases and inducing senescence. Additionally, we found that DOX enhanced the anti-invasive potential of CXCR4 and FAK inhibitors by reducing gelatin degradation and invasion.

Conclusions

From our data we conclude that targeting of CXCR4 and FAK may overcome ABCB1 and ABCC1-dependent DOX resistance in NSCLC cells and that simultaneous treatment of these cells with DOX may potentiate the anti-invasive effects of CXCR4 and FAK inhibitors.

     

Determinants of preventive health behavior in relation to cervical cancer screening among the female population of Belgrade

Identifying the factors that deter or stimulate the women to participate in screening activities is very important in order to design effective education and motivation strategies, particularly in the countries without an organized system. The study employed a case-control design. The participants were recruited in four primary health care institutions in Belgrade over a month. The study group comprised all women aged 18-70 years, who demonstrated an initiative for a PAP- smear. The controls were women with no Pap smears within the last 4 years, matched by age (±2 years), education and marital status with the study group participants. The study instrument was the 62-item self-administered questionnaire. According to multivariate analysis, adherence to cervical cancer screening practices is significantly related to better financial status [odds ratio (OR) = 10.8, P = 0.001], no gender preference for a gynecologist (OR = 3.1, P = 0.015), consultations with a gynecologist (OR = 4.7, P = 0.029), conversation with the women with cervical cancer about that disease (OR = 2.8, P = 0.029) and higher media exposure to information about cervical cancer prevention (OR = 5.0, P = 0.004). Open communication, social networks and improving social-economic status of women in our society are the most prominent factors, most of which are mainly outside the health services' domain and require multisectoral collaboration to improve women's reproductive health.