Luciana Corrêa

Photodynamic therapy mediated by methylene blue dye in wound healing.

OBJECTIVE We sought to investigate the wound-healing process after photodynamic therapy (PDT) mediated by methylene blue dye (MB). BACKGROUND DATA Few scientific studies show the PDT roles in wound healing. MATERIALS AND METHODS One hundred rats were given a circular wound on the back, inflicted with a 6-mm-diameter punch. The animals were divided into four groups: control (no treatment); dye (topical application of MB); laser (InGaAlP, 117.85 J/cm(2), 100 mW, 660 nm, single point); and PDT (topical application of MB followed by laser irradiation). After 1, 3, 5, 7, and 14 days, the cutaneous wounds were photographed and assessed with histopathologic examination by using light microscope. Changes seen in edema, necrosis, inflammation, granulation tissue, re-epithelialization, and number of young fibroblasts were semiquantitatively evaluated. The wound-area changes were measured with special software and submitted to statistical analysis. RESULTS The laser group demonstrated the smallest wound area at 14 days after the surgical procedure (p < 0.01). Concerning complete re-epithelialization, the laser group showed it at 5-7 days after surgery, whereas the PDT and the other groups showed it at 14 days. CONCLUSIONS Laser interaction with tissue is somehow changed when exposed to the MB. PDT mediated by MB was not prejudicial to wound healing, as no delay occurred compared with the control group.

Immunohistochemical aspects of basal cell adenoma and canalicular adenoma of salivary glands

Basal cell adenoma is a benign epithelial neoplasm with a uniform histologic appearance dominated by basaloid cells. Those cells may be distributed in various arrangements as solid, trabecular, tubular and membranous. Canalicular adenoma is also a benign neoplasm composed by columnar cells arranged in branching and interconnecting cords of single or double cell thick rows. There is some disagreement among investigators about whether canalicular adenoma should be included within the basal cell adenoma histologic spectrum. In the present study we compared the expression of cytokeratins (CK), vimentin and muscle-specific actin, utilizing immunohistochemical technique, in three cases diagnosed as basal cell adenomas predominantly of the solid type, and three cases of canalicular adenomas. The results obtained showed a distinct immunoprofile for both neoplasms. Solid areas of basal cell adenomas did not stain for any of the tested antibodies; only when there was tubular differentiation, those structures expressed CKs 7, 8, 14, and 19 in luminal cells and vimentin in non-luminal cells. On the other hand, canalicular adenomas strongly expressed CKs 7 and 13. The panel of antibodies utilized supports the separation of the two entities.

Low-level laser therapy can produce increased aggressiveness of dysplastic and oral cancer cell lines by modulation of Akt/mTOR signaling pathway

Low-level laser therapy (LLLT) is a non-thermal phototherapy used in several medical applications, including wound healing, reduction of pain and amelioration of oral mucositis. Nevertheless, the effects of LLLT upon cancer or dysplastic cells have been so far poorly studied. Head and neck cancer patients receiving LLLT for oral mucositis, for example, might have remaining tumor cells that could be stimulated by LLLT. This study demonstrated that LLLT (GaAlAs--660 nm or 780 nm, 40 mW, 2.05, 3.07 or 6.15 J/cm²) can modify oral dysplastic cells (DOK) and oral cancer cells (SCC9 and SCC25) growth by modulating the Akt/mTOR/CyclinD1 signaling pathway; LLLT significantly modified the expression of proteins related to progression and invasion in all the cell lines, and could aggravate oral cancer cellular behavior, increasing the expression of pAkt, pS6 and Cyclin D1 proteins and producing an aggressive Hsp90 isoform. Apoptosis was detected for SCC25 and was related to pAkt levels.

Immunohistochemical Localization of Tenascin, Fibronectin, and Type III Collagen in Human Dental Pulp

The distribution of tenascin (TN), fibronectin (FN), and type III collagen (col III) in the extracellular matrix of the connective tissue of normal, inflamed, and hyalinized human dental pulp was studied by immunohistochemical staining with monoclonal antibodies against these molecules. TN, FN, and col III were present in all normal tissues studied. In areas of hyalinization only col III was observed. None of the molecules studied were seen in areas of inflammatory exudate. Strong staining for TN and FN was found in the periphery of all specimens analyzed next to the odontoblastic layer. We therefore conclude that TN, FN, and col III are present in the extracellular matrix of normal human dental pulp. TN, FN, and col III distribution in inflammatory and degenerative processes is different from that observed in normal human dental pulp.

Cost-effectiveness of the introduction of specialized oral care with laser therapy in hematopoietic stem cell transplantation

Oral mucositis (OM) is one of the side effects of hematopoietic stem cell transplantation (HSCT), resulting in major morbidity. The aim of this study was to determine the cost‐effectiveness of the introduction of a specialized oral care program including laser therapy in the care of patients receiving HSCT with regard to morbidity associated with OM. Clinical information was gathered on 167 patients undergoing HSCT and divided according to the presence (n = 91) or absence (n = 76) of laser therapy and oral care. Cost analysis included daily hospital fees, parenteral nutrition (PN) and prescription of opioids. It was observed that the group without laser therapy (group II) showed a higher frequency of severe degrees of OM (relative risk = 16.8, 95% confidence interval −5.8 to 48.9, p < 0.001), with a significant association between this severity and the use of PN (p = 0.001), prescription of opioids (p < 0.001), pain in the oral cavity (p = 0.003) and fever > 37.8°C (p = 0.005). Hospitalization costs in this group were up to 30% higher. The introduction of oral care by a multidisciplinary staff including laser therapy helps reduce morbidity resulting from OM and, consequently, helps minimize hospitalization costs associated with HSCT, even considering therapy costs. Copyright

Oral mucositis in pediatric patients undergoing hematopoietic stem cell transplantation: Clinical outcomes in a context of specialized oral care using low‐level laser therapy

OM is a painful inflammatory condition of the oral mucosa, derived from the toxic effects of chemotherapy and radiotherapy. High OM severity is frequently present in HSCT pediatric patients, who exhibit multiple painful ulcers that limit their mastication and swallowing, leading to poor nutritional status. Few studies have demonstrated OM clinical outcomes in young patients undergoing HSCT. Feasibility of oral care and LLLT on OM prophylaxis and treatment is also poorly discussed. The aim of this study was to describe a specialized oral care protocol that included LLLT for pediatric patients undergoing transplantation and to demonstrate the clinical outcomes after OM prevention and treatment. Data from OM‐related morbidity were collected from 51 HSCT pediatric patients treated daily with LLLT, followed by standard oral care protocols. All the patients, even infants and young children, accepted the daily oral care and LLLT well. The majority (80.0%) only exhibited erythema in the oral mucosa, and the maximum OM degree was WHO II. Patients who had undergone autologous and HLA‐haploidentical transplants showed OM with the lowest severity. The frequency of total body irradiation and methotrexate prescriptions was higher in adolescents when compared with infants (p = 0.044), and adolescents also exhibited OM more severely than infants and young children. We found that good clinical outcomes were obtained using this therapy, mainly in regard to the control of OM severity and pain reduction in the oral cavity. Specialized oral care, including LLLT, is feasible and affordable for HSCT pediatric patients, although some adaptation in the patients oral hygiene routine must be adopted with help from parents/companions and clinical staff.

Oral leukoplakia manifests differently in smokers and non-smokers

Oral leukoplakias (OL) are potentially malignant lesions that are typically white in color. Smoking is considered a risk factor for developing OL, and dysplastic lesions are more prone to malignant transformation. The aim of this study was to describe the clinical features observed in dysplastic and non-dysplastic OL in both smokers and non-smokers. A total of 315 cases of OL were retrieved and separated into either dysplastic or non-dysplastic lesions, and these cases were further categorized as originating in either smokers or non-smokers. Frequencies of the type of OL lesion, with respect to whether the patients smoked, were established. The results demonstrated that 131 cases of OL were dysplastic (74 smokers and 57 non-smokers), and 184 were non-dysplastic (96 smokers and 88 non-smokers). For OL cases in smokers for which information about alcohol consumption was also available (84 cases), the results revealed no significant difference in the amount of dysplastic and non-dysplastic lesions. Dysplastic lesions were more frequent in male smokers and in non-smoking females. The median age of smokers with cases of OL was significantly lower than in non-smokers; the lowest median ages were observed for female smokers with dysplastic OL. The most frequent anatomical sites of dysplastic lesions were the floor of the mouth in smokers and the tongue in non-smokers. Dysplastic lesions in smokers were significantly smaller than non-dysplastic lesions in non-smokers. Being a male smoker, being female, being younger, and having smaller lesions were associated with dysplastic features in OL. These clinical data may be important for predicting OL malignant transformation.

Oral Exfoliative Cytology in the Diagnosis of Paracoccidioidomycosis

OBJECTIVE To assess the efficacy of conventional oral exfoliative cytology as a diagnostic tool in paracoccidioidomycosis. STUDY DESIGN Cytologic smears and incisional biopsies were obtained from 10 patients with a clinical suspicion and oral manifestations of paracoccidioidomycosis. Cytologic smears and sections of the incisional biopsy underwent methenamine silver staining for fungi according to the Gomori-Grocott method. The dry glass slides were examined at 400 or 1,000 x magnification, and the presence and shape of yeasts of Paracoccidioides brasiliensis were investigated. RESULTS Yeasts of the fungus P brasiliensis were clearly identified in cytologic smears and sections from incisional biopsies in all cases analyzed (100.0%). CONCLUSION Cytology of oral samples proved an effective diagnostic method for the detection of paracoccidioidomycosis in humans.

ATR-FTIR spectroscopy for the assessment of biochemical changes in skin due to cutaneous squamous cell carcinoma.

Nonmelanoma skin cancers represent 95% of cutaneous neoplasms. Among them, squamous cell carcinoma (SCC) is the more aggressive form and shows a pattern of possible metastatic profile. In this work, we used Fourier transform infrared spectroscopy (FTIR) spectroscopy to assess the biochemical changes in normal skin caused by squamous cell carcinoma induced by multi-stage chemical carcinogenesis in mice. Changes in the absorption intensities and shifts were observed in the vibrational modes associated to proteins, indicating changes in secondary conformation in the neoplastic tissue. Hierarchical cluster analysis was performed to evaluate the potential of the technique to differentiate the spectra of neoplastic and normal skin tissue, so that the accuracy obtained for this classification was 86.4%. In this sense, attenuated total reflection (ATR)-FTIR spectroscopy provides a useful tool to complement histopathological analysis in the clinical routine for the diagnosis of cutaneous squamous cell carcinoma.

Photodynamic therapy has antifungal effect and reduces inflammatory signals in Candida albicans-induced murine vaginitis

BACKGROUND Vaginal candidiasis (VC) is a disease that affects thousands of women of childbearing age, mainly caused by Candida albicans fungus. Photodynamic therapy (PDT) uses photosensitizing substances that are nontoxic in the dark, but able to produce reactive oxygen species when they are subjected to a light source. In this work our purpose was to investigate PDT effects on fungal burden and inflammatory cells in a murine model of C. albicans-induced vaginal candidiasis. METHODS Female BALB/c mice 6-10 weeks were estrogenized and maintained in this state during all experiment. After 72h, mices were inoculated intravaginally (IV) with 20μL of 2×10(5)C. albicans cells suspension. Mice were separated into 5 groups after five days: H (healthy), PBS (control), laser, MB (methylene blue) and PDT. PDT and MB groups received IV 20μL solution with 1mM of MB, others received PBS. PDT and laser groups were irradiated with a red laser (100mW, 660nm) in one (36J, 6min) or two sessions (18J, 3min). After the end of treatment, mice were submitted to microbiological and histomorphometric analysis with ImageJ software. Data were plotted by mean values and standard deviations of CFU/mL and percentage of inflammatory cells area. ANOVA and Bonferroni post-test were used and data were considered significant when p<0.05. RESULTS PDT significantly reduced C. albicans after the two tested protocols, however, percentage area of inflammatory cells was significantly reduced just with two sessions of PDT. CONCLUSIONS PDT with MB and red laser is a promising therapy for VC. It is able to reduce fungal infection in biofilm and inflammatory signals associated with VC in a murine model of vaginitis.