Secretor status and ABH antigens expression in patients with oral lesions

Objectives: The aim of this work was to investigate the secretor status of patients with oral pre-cancerous and cancerous lesions and ABH antigens expression in fixed tissue sections of these patients. Study design: To reveal A, B and H antigens in tissue sections of patients with precancerous and cancerous oral lesions (n= 54) we used a modified specific red cell adherence technique (SRCA-test). Normal endothelial cells expressed ABH antigens, the presence of indicator erythrocytes at the lumen of the blood vessels served as a built in positive control. The test results were graded from negative adherence to very strongly positive adherence. Negative adherence was defined as a complete absence of adhered indicator erythrocytes. A strongly positive reaction was defined as a sheet of indicator erythrocytes adhered to the epithelia cells. Results: In 31 of the 54 samples analyzed the test showed slightly positive results on atypical areas, and there was a complete antigen deletion in areas histologically affected by neoplasia. Sixteen samples showed a total absence of ABH antigens in both histologically normal and pathological areas. As a working hypothesis, we propose that areas of SRCA-test negative epithelium are closely related to invasive carcinomas and may be their precursor lesions. Further it is suggested that areas of blood group isoantigen negative epithelium showing atypia, or in some instances near normal histology, may give rise to relatively low grade carcinomas. Conclusions: Considering these results we suggest the use of this method to monitor probable preneoplastic lesions in risk population, specially in those with no secretor status

Transient Receptor Potential Vanilloid 1 Expression and Functionality in MCF-7 Cells: A Preliminary Investigation

PURPOSE: Transient receptor potential vanilloid 1 (TRPV1) is a nonselective cation channel belonging to the transient receptor potential family, and it is expressed in different neoplastic tissues. Its activation is associated with regulation of cancer growth and progression. The aim of this research was to study the expression and pharmacological characteristics of TRPV1 in cells derived from human breast cancer MCF-7 cells. METHODS: TRPV1 presence was assessed by binding studies and Western blotting. Receptor binding characteristics were evaluated through competition assays, while 3-(4,5-dimethylthiazol-2-yl)-2,5,-dipheyltetrazolium bromide reduction assays were performed to confirm an early hypothesis regarding the modulation of cancer cell proliferation. The functionality of TRPV1 was evaluated by measuring Ca(2+) uptake in the presence of increasing concentrations of TRPV1 agonists and antagonists. RESULTS: Binding studies identified a single class of TRPV1 (B(max) 1,492±192 fmol/mg protein), and Western blot showed a signal at 100 kDa corresponding to the molecular weight of human TRPV1. Among the different tested agonists and antagonists, anandamide (Ki: 2.8×10(-11) M) and 5-iodoresiniferatoxin (5-I-RTX) (Ki: 5.6×10(-11) M) showed the highest degrees of affinity for TRPV1, respectively. All tested TRPV1 agonists and antagonists caused a significant (p<0.05) decrease in cell growth rate in MCF-7 cells. For agonists and antagonists, the efficacy of tested compounds displayed the following rank order: resiniferatoxin>anandamide>capsaicin and 5-I-RTX=capsazepine, respectively. CONCLUSION: These data indicate that both TRPV1 agonists and antagonists induce significant inhibition of MCF-7 cell growth. Even though the mechanisms involved in the antiproliferative effects of TRPV1 agonists and antagonists should be further investigated, it has been suggested that agonists cause desensitization of the receptor, leading to alteration in Ca(2+)-influx regulation. By contrast, antagonists cause a functional block of the receptor with consequent fatal dysregulation of cell homeostasis

Experimental model for the study of the effects of platelet-rich plasma on the early phases of muscle healing

BACKGROUND: There is abundant evidence suggesting that growth factors may play a key role in the healing process, especially in the early stages of inflammation. Despite the reported clinical successes with the use of growth factors there is still a lack of knowledge on the biological mechanism underlying the activity of platelet-rich plasma during the process of muscle healing. The aim of this study was to analyse the early effects of platelet- rich plasma in an easily reproducible animal model. MATERIALS AND METHODS: Wistar male adult rats (n =102) were used in this study. The muscle lesion was created with a scalpel in the flexor sublimis muscles. Platelet-rich plasma was applied immediately after surgery. Treated, untreated and contralateral muscles were analysed by morphological evaluation and western blot assay. RESULTS: Leucocyte infiltration was significantly greater in muscles treated with platelet-rich plasma than in both untreated and contralateral muscles. The latter showed greater leucocyte infiltration when compared to the untreated muscles. Platelet-rich plasma treatment also modified the cellular composition of the leucocyte infiltration leading to increased expression of CD3, CD8, CD19 and CD68 and to decreased CD4 antigen expression in both platelet-rich plasma treated and contralateral muscles. Blood vessel density and blood vessel diameters were not statistically significantly different between the three groups analysed. DISCUSSION: The results of this study showed that treatment with platelet-rich plasma magnified the physiological early inflammatory response following a muscle injury, modifying the pattern of cellular recruitment. Local platelet-rich plasma treatment may exert a direct or, more plausibly, indirect systemic effect on healing processes, at least in the earliest inflammatory phase