Milena Jovic

Epicutaneous exposure to anticoagulant rodenticide warfarin modulates local skin activity in rats.

Dermatotoxic effects of epicutaneous application of a first generation anticoagulant, warfarin (WF), were examined in rats. Selected parameters of skin activity were determined 24 hours following warfarin application by histomorphological and immunohistochemical analysis and by assessing some aspects of immunomodulatory potential of warfarin in skin. Increased number of mast cells, with degranulation at higher doses of warfarin was noted in warfarin treated skin. Mast cell presence coincided with changes in blood vessels and fibroblast appearance suggesting mast cell activity in warfarin treated skin. Signs of nuclear hypertrophy and anysonucleosys were noted by analysis of PCNA+ cells in epidermis following warfarin application. Histomorphological changes were accompanied by immunemodulating activity in warfarin treated skin. This was judged by slightly increased numbers of CD3+ cells in epidermis and superficial dermis and by production of organ cultured full thickness skin explants of factors with costimulatory activity in T-cell activation/proliferation assay. Presented data demonstrates the potential of warfarin to modulate local skin activity in rats.

A subpopulation that may correspond to granulocytic myeloid-derived suppressor cells reflects the clinical stage and progression of cutaneous melanoma

Seventy-eight melanoma patients and 10 healthy individuals were examined. Follow-up examinations of all melanoma patients were performed regularly every three months. Myeloid-derived suppressor cells (MDSC) were defined as lineage negative (CD3(-), CD19(-), CD56(-)), HLA-DR(-/low), CD11b(+) and CD33(+). Classification of granulocytic (GrMDSC) and monocytic (MoMDSC) subsets was based on the CD15 and CD14 expression, respectively. Unlike the MoMDSC, that were present in 60% of healthy controls and 15% of melanoma patients, the GrMDSC were present in all examined participants, and the melanoma patients were found to have statistically higher frequencies compared with healthy controls. Accordingly, we kept focused on GrMDSC frequencies in relation to the melanoma stages and course of the disease. The GrMDSC values are highest in stage IV melanoma patients, with statistical significance compared with stages IA, IB, IIA and IIB. Patients with progression had statistically higher GrMDSC counts comparing with those with stable disease (P = 0.0079). Patients who had progression-free interval (PFI) < 12 months showed significantly higher GrMDSC values compared with those with PFI > 12 months (P = 0.0333). GrMDSC showed significant negative correlation with PFI intervals (P = 0.0095). The GrMDSC subset was predominant in all our patients. We confirmed that GrMDSC do accumulate early in the peripheral blood of melanoma patients and their frequencies correlate narrowly with the clinical stage and the spread of the disease. The increase in GrMDSC frequencies correlates well with a progressive disease and could be considered a potential predictive biomarker of high-risk melanoma cases that are more likely to have a shorter PFI.

Local proinflammatory effects of repeated skin exposure to warfarin, an anticoagulant rodenticide in rats.

OBJECTIVE To evaluate the effects of epicutaneous application of anticoagulant warfarin, by examining the presence of tissue injury and immune/inflammatory activity in exposed skin. METHODS Rats were exposed to warfarin by applying 10 μg of warfarin-sodium to 10-12 cm(2) skin (range 0.8-1 μg per 1 cm(2)) for 3 consecutive days. Tissue injury was evaluated by lipid peroxidation, histomorphological changes and signs of reparative activity in skin. T cell infiltration and selected aspects of epidermal cell activity were examined as indicators of immune/inflammatory skin response to warfarin application. RESULTS Repeated warfarin application exerted no effect on skin metabolic viability, but resulted in tissue injury (increased malondialdehyde, MDA, production, evident histo-morphological changes in epidermis and dermis depicting cell injury and death). Increased numbers of proliferating cell nuclear antigen (PCNA(+)) cells indicated reparative processes in injured skin. Infiltration of CD3(+) cells (T lymphocytes) along with the increased production of tumor necrosis factor-a (TNF-a) by epidermal cells from warfarin-treated skin and their co-stimulatory effect in an in vitro T-cell activation assay demonstrated immunomodulatory effects of epicutaneous warfarin. CONCLUSION Presented data have documented tissue damage associated with immune/inflammatory activity in skin exposed to warfarin. Observed effects are relevant to immunotoxic potential of this anticoagulant in settings of external exposure.

Skin response to epicutaneous application of anticoagulant rodenticide warfarin is characterized by differential time- and dose-dependent changes in cell activity.

Abstract Context: Skin is the target of both acute and chronic exposure to warfarin, coumarin anticoagulant. Single exposure of rat skin to this agent induces early (24 h following epicutaneous administration) local response which might be part of inflammatory/reparatory homeostatic program or introduction to pathological events in exposed skin. Objective: To examine time-dependent changes in skin of rats exposed to epicutaneously applied warfarin. Materials and methods: The effect of low (10 μg) and high (100 μg) doses of warfarin on histologically evident changes of epidermis (epidermal thickness) and dermis (numbers of mesenchymal cells and dermal capillaries), skin cell proliferative activity (Ki67+ and PCNA+ cells) and apoptotic (TUNEL+) and necrotic (ultra structural appearance) cells was examined one, three and seven days after the application. Results: Both warfarin doses affected the majority of skin cell activity, but with differential time-course of skin epidermal and dermal cells state/activity. The occurrence of necrotic/apoptotic epidermal and dermal cells was noted the first day after the application and the activities which point to tissue reparation/remodeling were observed seven days after skin exposure to this agent. Discussion: The observed pattern of changes (early evidence of cell/tissue injury which was later followed by signs of cell activity characteristic for tissue reparation/remodeling) implied warfarin-induced toxicity in skin cells as stimulus for subsequent activities relevant for tissue homeostasis. Conclusion: The data presented provide new and additional information concerning skin responses to warfarin that gains access to this tissue.

Skin vascularisation field by the ascending branch of the peroneal artery ramus perforans

BACKGROUND/AIM Soft tissue defects in the distal third of the lower leg are persistent and constitute a major problem in the reconstructive surgery. This study presents an analysis of the anatomical vascularization filed of ascending branch of the peroneal artery ramus perforans (PARS). The aim of this study was to assess reliability of the distal flap on the antero-lateral aspect of a lower leg distal third. METHODS Direct gentiana violet injection into the interosseal perforator of ten fresh cadaveric lower legs with subsequent corrosion acrylic preparation was performed to reveal vascularization filed of the ascending branch of the PARP. Height, length, diameter and communication of perforating branch and its subsequent smaller ascending and descending branches were determined. The CAMIA software was used. RESULTS Our results show that the PARP is always present. Its origin from the peroneal artery is at the medial height of 66 mm when measured from the inferior border of the lateral malleolus. Medium length of ramus perforans is 51.7mm. After transition through the interosseous membrane, ramus perforans divides into ascending and descending branches. The diameter proximal to the level of bifurcation is 1.37 mm (variation 1.0-1.8 mm), and the diameter of the ascending branch distal to the level of bifurcation is 1 mm. Using CAMIA software, the medium length, width and area of the vascularization filed labeled with gentian violet were calculated to be 164 mm (variation 125-210 mm), 66 mm (57-77 mm), and 10,305 mm2 (6,385 mm2-14,341 mm2), respectively. CONCLUSION Our results support the use of fasciocutaneous distal flap, vascularized by the ascending branch of the PARP for reconstruction of soft tissue defects in the distal third of the lower limb, malleolar regions and dorsum.

Reliability of the CINtecTM p16INK4a immunocytochemical test in screening cervical precancerous lesions

BACKGROUND/AIM Overexpression of p16INK4a has been found to be linked with genomic integration of high-risk human papillomavirus (HPV) and the developement of precancerous cervical intraepithelial lesions. The aim of this study was to examine is there a higher positive level of correlation between grade of histological dysplasia and p16INK4a level of expression in cervical smear, compared to results of Papanicolaou test. We also examined the correlation between HPV type, p16INK4a expression and Papanicolau test results. METHODS A total of 48 women with precanceorous cervical lesions and HPV cervicitis and 10 healthy women were enrolled in the study. Papanicolaou test, CINtec p16INK4a cytological immunohistochemical test, polymerase chain reaction (PCR) HPV 16, 18, 31, 33 analysis and histopathology of the lesion were performed in all the patients. RESULTS Comparing the results of Papanicoulaou test and the grade of histological dysplasia, low-grade squamous intraepithelial lesion (LSIL) was confirmed in 38%, and high-grade squamous intraepithelial lesion (HSIL) in 69.2% of the patients (p > 0.05). Significant positive correlation was found between p16 overexpression and grade of histological dysplasia (p = 0.000). Overexpression p16 was found in 70% of LSIL and 94.4% of HSIL. Positive correlation was found between p16 overexpression and grade of dysplasia in Papanicolaou test (p = 0.011). In 38% of LSIL and 15% of HSIL cases p16 was not expressed. The most frequently found HPV type in PCR analysis was HPV16. Analysing the results of p16 test according to HPV status and Papanicolaou test rather heterogenous results were obtained. CONCLUSION In the patients with precancerous cervical lesions a higher level of correlation was found between the grade of histological dysplasia and p16INK4a level of expression in the cervical smear, compared to the results of Papanicolaou test.