Biomedical subjects

Karen Cherubini

Publications and source records attributed to Karen Cherubini.

5 recordsLinked to original sources

PubMed2006

Histologic evaluation of effect of thiocyanate topical application on hamster cheek pouch.

The present study was conducted to investigate the effect of topical thiocyanate (SCN(-)) application on hamster cheek pouch mucosa. Sixty-six hamsters were divided into two groups. The test substance containing potassium thiocyanate was applied on the hamsters' cheek pouches at 55 mg/kg dosages. Cheek pouches were grossly examined after 12 weeks. Histometric evaluation included height measurements from the epithelium without stratum corneum, stratum corneum, and full epithelium. Clear cells frequency was compared between groups. Results were analyzed using Student's t test. The experimental group showed a lower height of the stratum corneum (p=0.035) and higher frequency of clear cells (p<0.001). There was no height difference for the epithelium without stratum corneum (p=0.677) and full epithelium (p=0.904) between groups. SCN(-) promotes no gross alterations on hamsters' cheek pouch and does not induce dysplastic features at the epithelium or inflammation at the connective tissue. The ion promotes histologic alterations on mucosa that need to be investigated in further studies.

Administration, Topical↗

PubMed2006

Squamous cell carcinoma of the tongue after bone marrow transplantation in a patient with Fanconi anemia.

Fanconi anemia (FA) is an autosomal recessive disorder that might cause a variety of congenital and developmental abnormalities. The most important features of FA are progressive bone marrow failure and development of malignancies, particularly acute myeloid leukemia and solid tumors. This paper reports the case of a 12-year-old patient with FA assisted at the Stomatology and Bucomaxillofacial Cancer Prevention Service of São Lucas Hospital, Brazil, who had been submitted to bone marrow transplantation (BMT) at the age of 5 and exhibited oral lesions characteristic of chronic graft versus host disease (GVHD). The patient was treated and followed-up for the oral lesions. Eleven years after the BMT, he developed squamous cell carcinoma of the tongue with an aggressive behavior, which was considered an untreatable condition. The patient died few months later from asphyxia at the age of 16. The reasons for development of these malignant conditions are unknown. However, chromosomal instability typically observed in FA cases, BMT factors and GVHD have been considered. Systematic follow-up of these patients allows early and less invasive therapeutic approaches.

Adolescent↗

PubMed2006

Comparison between semi-automated segmentation and manual point-counting methods for quantitative analysis of histological sections.

The aim of the present study was to compare results obtained using the manual point-counting method with results obtained using the semi-automated segmentation method, in the quantitative evaluation of histological sections by light microscopy. The tongues of 40 rats (Ratus norvergicus) were processed using the paraffin technique, in which a 5-mum-thick tissue slice cut from each tongue is stained with picrosirius and methyl green. Three digital images were captured randomly from each section, which were later converted to black-and-white. The collagen fibers shown in each image were quantified using the semi-automated segmentation method and the manual point-counting method. The results obtained using the 2 different quantification methods were compared using the paired t-test and Pearson's correlation test, with statistical analysis using the methods of Bland and Altman. The t-test indicated that there was no significant difference in results between the 2 different quan-tification methods. Pearson's correlation test indicated a strong correlation (r = 0.987), and a comparison of the methods using the Bland and Altman plot indicated no significant error. These findings indicate that both quantification methods can be reliably used to evaluate tissue sections, without discrepancies between the 2 methods.

Animals↗

PubMed2006

Association between recurrent aphthous stomatitis and salivary thiocyanate levels.

The aim of this work was to investigate the association between recurrent aphthous stomatitis (RAS) and salivary thiocyanate levels. The sample comprised men and women of age ranging from 15 to 55 years, who were allocated to four groups: 28 patients in RAS active phase (group 1); 28 patients in RAS remission phase (group 2); 29 smokers (group 3); 26 non-smokers without RAS (group 4). Samples of whole saliva mechanically stimulated were collected, and thiocyanate levels were measured. The results were analyzed by ANOVA and paired t-test. Mean salivary thiocyanate values were 0.55 mM, 0.64 mM, 2.36 mM and 0.96 mM in groups 1 (active RAS), 2 (remission RAS), 3 (smokers) and 4 (control), respectively. There was no significant difference in thiocyanate levels when groups 1 and 2 were compared with group 4. Group 3 showed a significantly higher thiocyanate concentration when compared with groups 1, 2 and 4 (P < 0.05). There was no significant difference in thiocyanate levels between groups 1 and 2 (P > 0.05). It is therefore suggested that there is no association between RAS and salivary thiocyanate levels.

Adolescent↗

PubMed2004

Characterization of p53 gene mutations in a Brazilian population with oral squamous cell carcinomas.

Mutations in the p53 tumor suppressor gene are present in approximately 50% of all human cancers. We sought to determine the frequency and type of p53 mutations in squamous cell carcinomas (SCC) of the oral cavity in a Brazilian population. To identify p53 mutations we used PCR-SSCP in tumor tissue microdissected from paraffin- embedded and from fresh-frozen sections followed by direct sequencing of SSCP bands with altered electrophoretic mobility. We identified p53 mutations in 40% of the human SCC analyzed. The mutations were of a broad spectrum, with a preponderance of G --> A and A --> G transitions with an apparent hotspot at the CpG dinucleotide at codon 290. Patient samples were stratified according to tobacco and alcohol consumption as well as by anatomic location of the tumor, and although trends did emerge, no statistically significant associations were obtained between the occurance of TP53 mutations and these lifestyle habits. We conclude that p53 mutations are common among oral cavity cancers in this population, and stress the significance of this study since it is the first analysis of p53 mutation in oral cancer in a southern Brazilian population.

Adult↗