Experimental evidence and model explanation for cell population characteristics modification when applying sequential photodynamic therapy

We present experimental evidence of the existence of cell variability in terms of threshold light dose for Hep G2 (liver cancer cells) cultured. Using a theoretical model to describe the effects caused by successive photodynamic therapy (PDT) sessions, and based on the consequences of a partial response we introduce the threshold dose distribution concept within a tumor. The experimental model consists in a stack of flasks, and simulates subsequent layers of a tissue exposed to PDT application. The result indicates that cells from the same culture could respond in different ways to similar PDT induced-damages. Moreover, the consequence is a partial killing of the cells submitted to PDT, and the death fraction decreased at each in vitro PDT session. To demonstrate the occurrence of cell population modification as a response to PDT, we constructed a simple theoretical model and assumed that the threshold dose distribution for a cell population of a tumor is represented by a modified Gaussian distribution.

HPV16 Tumor Associated Macrophages Suppress Antitumor T Cell Responses

Purpose: High-risk human papillomavirus (HPV) is the main etiologic factor for cervical cancer. The severity of HPV-associated cervical lesions has been correlated to the number of infiltrating macrophages. The objective of this work is to characterize the role of tumor-associated macrophages (TAM) on the immune cellular response against the tumor. Experimental Design: We used the HPV16 E6- and E7-expressing TC-1 mouse tumor model to study the effect of TAM on T-cell function in vitro, and depleted TAM, using clodronate-containing liposomes, to characterize its role in vivo. Results: TAM, characterized by the positive expression of CD45, F4/80, and CD11b, formed the major population of infiltrating tumor cells. TAM displayed high basal Arginase I activity, producing interleukin-10 (IL-10); they were resistant to iNOSll activity induction, therefore reversion to M1 phenotype, when stimulated in vitro with lipopolysaccharide/IFN gamma, indicating an M2 phentoype. In cultures of isolated TAM, TAM induced regulatory phenotype, characterized by IL-10 and Foxp3 expression, and inhibited proliferation of CD8 lymphocytes. In vivo, depletion of TAM inhibited tumor growth and stimulated the infiltration of tumors by HPV16 E7(49-57)-specific CD8 lymphocytes, whereas depletion of Gr1(+) tumor-associated cells had no effect. Conclusions: M2-like macrophages infiltrate HPV16-associated tumors causing suppression of antitumor T-cell response, thus facilitating tumor growth. Depletion or phenotype alteration of this population should be considered in immunotherapy strategies.

Association of soluble tumor necrosis factor receptors 1 and 2 with nephropathy, cardiovascular events, and total mortality in type 2 diabetes

AIMS/HYPOTHESIS: Soluble tumor necrosis factor receptors 1 and 2 (sTNFR1 and sTNFR2) contribute to experimental diabetic kidney disease, a condition with substantially increased cardiovascular risk when present in patients. Therefore, we aimed to explore the levels of sTNFRs, and their association with prevalent kidney disease, incident cardiovascular disease, and risk of mortality independently of baseline kidney function and microalbuminuria in a cohort of patients with type 2 diabetes. In pre-defined secondary analyses we also investigated whether the sTNFRs predict adverse outcome in the absence of diabetic kidney disease. METHODS: The CARDIPP study, a cohort study of 607 diabetes patients [mean age 61 years, 44 % women, 45 cardiovascular events (fatal/non-fatal myocardial infarction or stroke) and 44 deaths during follow-up (mean 7.6 years)] was used. RESULTS: Higher sTNFR1 and sTNFR2 were associated with higher odds of prevalent kidney disease [odd ratio (OR) per standard deviation (SD) increase 1.60, 95 % confidence interval (CI) 1.32-1.93, p < 0.001 and OR 1.54, 95 % CI 1.21-1.97, p = 0.001, respectively]. In Cox regression models adjusting for age, sex, glomerular filtration rate and urinary albumin/creatinine ratio, higher sTNFR1 and sTNFR2 predicted incident cardiovascular events [hazard ratio (HR) per SD increase, 1.66, 95 % CI 1.29-2.174, p < 0.001 and HR 1.47, 95 % CI 1.13-1.91, p = 0.004, respectively]. Results were similar in separate models with adjustments for inflammatory markers, HbA1c, or established cardiovascular risk factors, or when participants with diabetic kidney disease at baseline were excluded (p < 0.01 for all). Both sTNFRs were associated with mortality. CONCLUSIONS/INTERPRETATIONS: Higher circulating sTNFR1 and sTNFR2 are associated with diabetic kidney disease, and predicts incident cardiovascular disease and mortality independently of microalbuminuria and kidney function, even in those without kidney disease. Our findings support the clinical utility of sTNFRs as prognostic markers in type 2 diabetes.

O envolvimento do marcador inflamatório Heme Oxigenêse-1 na carciinogênese experimental de esôfago

Sabe-se que o refluxo crônico pode induzir lesão mucosa, estimular a proliferação de células e promover tumorigênese no esôfago distal. Ainda não é sabido por que apenas uma parcela dos pacientes com refluxo esofágico progrediram para uma metaplasia intestinal (Esôfago de Barrett) e adenocarcinoma. O estresse oxidativo parece exercer um papel importante nessa progressão . Assim sendo, examinamos o padrão de expressão da enzima Heme Oxigenase-1 (HO-1), enzima indutora do estresse oxidativo, em peças de esôfago obtidos de um estudo experimental com ratos que avaliou o papel do refluxo gástrico e duodenoesofágico na carcinogênese esofágica. Métodos: Uma amostra de três (3) peças de esôfago de cada grupo de ratos submetidos a tratamentos diferentes tiveram a expressão da enzima Heme Oxigenase-1 avaliada através de imunohistoquímica. Os ratos foram divididos nos seguintes grupos: (1) cardioplastia para induzir refluxo predominantemente gástrico, (2) anastomose esofagoduodenal para induzir refluxo duodenal, (3) sem tratamento, (4) cardioplastia+dietilnitrosamina (DEN), (5) anastomose esofagoduodenal +DEN, (6) DEN. Resultados: Não houve desenvolvimento de câncer ou metaplasia intestinal nos animais que não foram expostos ao refluxo de conteúdo duodenal. A expressão de HO-1 foi observada apenas em ratos submetidos à anastomose esofagoduodenal (Grupos 2 e 5) e a análise da média de intensidade de fluorescência demonstrou uma diferença significante de expressão de HO-1 (4,8 e 4,6 vezes respectivamente) comparando-se ao controle (Grupo 3) (p<0,05). O alvo principal para expressão da HO-1 foram as células inflamatórias dentro do tumor ou em áreas subepiteleiais. Os ratos expostos ao refluxo gástrico não desenvolveram tumores ou expressaram a HO-1. Conclusões: A esofagite de refluxo induzida por refluxo esofágico com conteúdo duodenal provocou estresse oxidativo considerável e pode desempenhar um papel importante na carcinogênese esofágica. O refluxo gástrico não foi suficiente para induzir estresse oxidativo neste modelo experimental.

Avaliação do potencial anti-inflamatório de composto tipo heparina (cCTH) extraído do caranguejo Goniopsis cruentata em modelo experimental de peritonite

Heparin, a sulfated polysaccharide, was the first compound used as an anticoagulant and antithrombotic agent. Due to their structural characteristics, also has great potential anti-inflammatory, though such use is limited in inflammation because of their marked effects on coagulation. The occurrence of heparin-like compounds that exhibit anticoagulant activity decreased in aquatic invertebrates, such as crab Goniopsis cruentata, sparked interest for the study of such compounds as anti-inflammatory drugs. Therefore, the objective of this study was to evaluate the potential modulator of heparin-like compound extracted from Goniopsis cruentata in inflammatory events, coagulation, and to evaluate some aspects of its structure. The heparin-type compound had a high degree of N-sulphation in its structure, being able to reduce leukocyte migration into the peritoneal cavity at lower doses compared to heparin and diclofenac sodium (anti-inflammatory commercial). Furthermore, it was also able to inhibit the production of nitric oxide and tumor necrosis factor alpha by activated macrophages, inhibited the activation of the enzyme neutrophil elastase in low concentrations and showed a lower anticoagulant effect in high doses as compared to porcine mucosal heparin. Because of these observations, the compound extracted from crab Goniopsis cruentata can be used as a structural model for future anti-inflammatory agents

Abordagem inicial de lesões mamárias por biopsia helicóide: estudo experimental

OBJECTIVE: Evaluating the kit-Bh performance in carrying out of breast biopsies. METHODS: They were randomly selected a sample of 30 patients with breast cancer undergoing mastectomy, based on the results of a pilot study from February 2008 to April 2010. They were excluded women with had not palpable, stone-hard consistency tumors, previous surgical manipulation or that contains liquid. Using the helicoid biopsy Kit (kit Bh) and an equipment Core biopsy with cannula and needle and 14 gauge respectively, it was collected a fragment of sound equipment in the area and in tumors in each specimen, totaling 120 fragments for histological study. For data analysis, it was defined a 95% confidence level and used the SPSS-13 version, the Kappa index and the parametric Student t test. RESULTS: Mean age of patients was 51.6 years (± 11.1 years). The infiltrating ductal carcinoma showed a higher incidence, 26 cases (86.7%). The Core biopsy had a sensitivity of 93.3%, specificity of 100% and accuracy 96.7%, while the helicoid biopsy had a sensitivity of 96.7%, specificity of 100% and accuracy 98.3%. By comparing the histology of tumors and the fragments of biopsies, there was high degree of agreement in diagnoses (kappa of 0.93 with p <0.05) CONCLUSION: Both devices provided the histological diagnosis of lesions with high accuracy. Results of this study showed that the helicoid biopsy is a reliable alternative in 22 the preoperative diagnosis of breast lesions. Further studies in vivo better will define the role of Kit Bh in the diagnosis of these lesions

Experimental murine mycobacteriosis: evaluation of the functional activity of alveolar macrophages in thalidomide- treated mice

Thalidomide is a selective inhibitor of tumor necrosis factor-alpha (TNF-alpha), a cytokine involved in mycobacterial death mechanisms. We investigated the role of this drug in the functional activity of alveolar macrophages in the presence of infection induced by intranasal inoculation of Mycobacterium avium in thalidomide-treated and untreated adult Swiss mice. Sixty animals were inoculated with 5 x 10(6) M. avium by the respiratory route. Thirty animals received daily thalidomide (30 mg/kg mouse) and 30 received water by gavage up to sacrifice. Ten non-inoculated mice were used as a control group. Lots of animals from each group were evaluated until 6 weeks after inoculation. Infection resulted in an increased total number of inflammatory cells as well as increased activity of pulmonary macrophages. Histologically, intranasal inoculation of bacilli resulted in small mononuclear infiltrates located at the periphery of the organ. Culture of lung fragments revealed the presence of bacilli only at the beginning and at the end of the experimental period. Thalidomide administration did not affect the microbiological or histological features of the infection. Thalidomide-treated and untreated animals showed the same amount of M. avium colonies 3 weeks after infection. Although it did not affect bacillary clearance, thalidomide administration resulted in a decreased percent of spread cells and release of hydrogen peroxide, suggesting that factors other than TNF-alpha play a role in the killing of mycobacteria by alveolar macrophages. Thalidomide administration also reduced the number of spread cells among resident macrophages, suggesting a direct effect of the drug on this phenomenon.

Human breast tumor slices as an alternative approach to cell lines to individualize research for each patient

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hepatoprotective and anti-inflammatory effects of silibinin on experimental preeclampsia induced by 1-NAME in rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Subpopulations of mononuclear leukocytes associated with inhibition of Ehrlich ascites tumor growth by treatment with Bothrops jararaca venom

Snake venoms have been used as antineoplastic substances in several experimental models. We demonstrated in previous studies that Bothrops jararaca venom (BjV) induces inhibition of Ehrlich ascites tumor ( EAT) growth accompanied by an increase of mononuclear (MN) leukocytes in all groups inoculated with EAT and/or venom. The objective of the present study was to characterize the subpopulations of MN leukocytes involved in the inhibition of EAT growth by treatment with BjV. Swiss mice were inoculated with 1.0 x 10(3) EAT cells by the intraperitoneal route and treated with 0.4 mg/kg of BjV by the same route ( Group TV). Treatment was started 24 h after tumor cell inoculation and consisted of five intraperitoneal injections performed at 72 h intervals. After 2, 8 and 14 days, groups of animals were sacrificed and the number of B, TCD4 and TCD8 lymphocytes, macrophages and natural killer cells present in the peritoneal cavity was determined by flow cytometry. The control group consisted of animals inoculated with EAT and treated with 0.1 ml of saline under the same conditions as the experimental group ( Group T). Two additional control groups consisted of animals not inoculated with EAT and treated with saline or venom. Data were analyzed statistically by the Kruskal - Wallis nonparametric test for independent samples. on the 2nd and 8th day we observed a difference between groups T and TV ( group T > group TV) for all cell types, except natural killer cells, that only differed on the 2nd day. However, on the 14th day there was no difference in MN cells among groups. These data suggest that the inhibition of EAT is related to the toxic action of BjV on tumor cells and/or to the proteolytic effect of the venom on the mediators produced by the cells for growth modulation.

Analysis of the expression of toll-like receptors 2 and 4 and cytokine production during experimental Leishmania chagasi infection

Toll-like receptors (TLRs) recognise pathogen-derived molecules and influence immunity to control parasite infections. This study aimed to evaluate the mRNA expression of TLRs 2 and 4, the expression and production of the cytokines interleukin (IL)-12, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-17, IL-10 and transforming growth factor (TGF)-β and the production of nitric oxide (NO) in the spleen of mice infected with Leishmania chagasi. It also aimed to evaluate any correlations between mRNA expression TLR2 and 4 and cytokines and NO production. Infection resulted in increased TLR2-4, IL-17, TNF-α and TGF-β mRNA expression during early infection, with decreased expression during late infection correlating with parasite load. IFN-γ and IL-12 mRNA expression decreased at the peak of parasitism. IL-10 mRNA expression increased throughout the entire time period analysed. Although TGF-β, TNF-α and IL-17 were highly produced during the initial phase of infection, IFN-γ and IL-12 exhibited high production during the final phase of infection. IL-10 and NO showed increased production throughout the evaluated time period. In the acute phase of infection, there was a positive correlation between TLR2-4, TNF-α, IL-17, NO, IL-10 and TGF-β expression and parasite load. During the chronic phase of infection, there was a positive correlation between TLR2-4, TNF-α, IL-17 and TGF-β expression and parasite load. Our data suggest that infection by L. chagasi resulted in modulation of TLRs 2 and 4 and cytokines.

Effects of Lidocaine Infusion during Experimental Endotoxemia in Horses

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of Antiplatelet Drugs in the Pathogenesis of Experimental Periodontitis and Periodontal Repair in Rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Experimental paracoccidioidomycosis of the Syrian hamster: fungicidal activity and production of inflammatory cytokines by macrophages

Phagocytic cells play an important role in nonspecific resistance to fungal infection by mediating an inflammatory response and by a direct fungicidal action. In this study, the functional activity of peritoneal macrophages obtained from hamsters experimentally infected with strain Pb18 of Paracoccidioides brasiliensis was evaluated during 16 weeks of infection. The results showed that macrophages had a higher spreading ability associated with increased production of tumor necrosis factor alpha (TNF-alpha) and enhanced fungicidal activity during the early periods of infection. TNF-alpha levels remained elevated during all periods studied, while low levels of interleukin-1 beta (IL-1 beta) were produced during the infection. A necrotic area with dead fungi was observed at the inoculation site and the infection disseminated only to liver and lymph nodes in a few animals. These results suggest that during the early stages of infection with P. brasiliensis, macrophage activation by the high levels of TNF-alpha limited fungal dissemination. In contrast, in the later stages of infection, high levels of TNF-alpha were observed while the fungicidal activity of macrophages was lower and the animals presented loss of vitality resulting in their death. These observations suggest a complex role of TNF-alpha in experimental paracoccidioidomycosis of Syrian hamsters, involving not only resistance but also pathogenesis.

Decreased production of TNF-alpha by lymph node cells indicates experimental autoimmune encephalomyelitis remission in Lewis rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)