Paulo Roberto Carvalho de Almeida

Primeira descrição de um caso autopsiado de melioidose no Estado do Ceará

An autopsied case is reported concerning fulminant sepsis with predominantly pulmonary lesions, caused by Burkholderia pseudomallei, etiologic agent of melioidosis, originating from interior of Ceará State, Northeastern Brazil where there had been no previous cases reported. Autopsy findings and differential diagnosis are discussed.

The Adaptor Protein Myd88 Is a Key Signaling Molecule in the Pathogenesis of Irinotecan-Induced Intestinal Mucositis

Intestinal mucositis is a common side effect of irinotecan-based anticancer regimens. Mucositis causes cell damage, bacterial/endotoxin translocation and production of cytokines including IL–1 and IL–18. These molecules and toll-like receptors (TLRs) activate a common signaling pathway that involves the Myeloid Differentiation adaptor protein, MyD88, whose role in intestinal mucositis is unknown. Then, we evaluated the involvement of TLRs and MyD88 in the pathogenesis of irinotecan-induced intestinal mucositis. MyD88-, TLR2- or TLR9-knockout mice and C57BL/6 (WT) mice were given either saline or irinotecan (75 mg/kg, i.p. for 4 days). On day 7, animal survival, diarrhea and bacteremia were assessed, and following euthanasia, samples of the ileum were obtained for morphometric analysis, myeloperoxidase (MPO) assay and measurement of pro-inflammatory markers. Irinotecan reduced the animal survival (50%) and induced a pronounced diarrhea, increased bacteremia, neutrophil accumulation in the intestinal tissue, intestinal damage and more than twofold increased expression of MyD88 (200%), TLR9 (400%), TRAF6 (236%), IL–1β (405%), IL–18 (365%), COX–2 (2,777%) and NF-κB (245%) in the WT animals when compared with saline-injected group (P<0.05). Genetic deletion of MyD88, TLR2 or TLR9 effectively controlled the signs of intestinal injury when compared with irinotecan-administered WT controls (P<0.05). In contrast to the MyD88-/- and TLR2-/- mice, the irinotecan-injected TLR9-/- mice showed a reduced survival, a marked diarrhea and an enhanced expression of IL–18 versus irinotecan-injected WT controls. Additionally, the expression of MyD88 was reduced in the TLR2-/- or TLR9-/- mice. This study shows a critical role of the MyD88-mediated TLR2 and TLR9 signaling in the pathogenesis of irinotecan-induced intestinal mucositis.

Angiogenesis inhibition by green propolis and the angiogenic effect of L-lysine on bladder cancer in rats

PURPOSE To determine the effects of water-soluble derivative of green propolis in bladder cancer angiogenesis in rats given N-butyl-(-4-hydroxybutyl) nitrosamine (BBN). METHODS Nine groups were established, where six of them (Groups 1 to 6), the animals received 0.05% BBN in their drinking water for 14 weeks. From the 32nd to the 40th week, Groups 1, 2, 3 and 4 were treated respectively with water, L-lysine (300 mg/kg/day), celecoxib (30 mg/kg/day) and propolis (300 mg/kg/day). Groups 5 and 6 were given propolis and L-lysine from the 1st to the 40th week (150 mg/kg/day). Microvascular density was determined by histological sections stained for the marker CD-31 and analyzed with specific software. RESULTS The microvascular density in bladder carcinomas was lower (p<0.01) in rats receiving propolis than in controls given carcinogen only. On the other hand, the microvascular density of tumors in rats receiving carcinogen and L-lysine for 40 weeks from the beginning of carcinogen treatment was significantly higher (p<0.01) than in the corresponding controls. CONCLUSION Water-soluble derivative of propolis inhibits angiogenesis in BBN-induced rat bladder cancer, while L-lysine treatment stimulates angiogenesis if initiated concurrently with BBN.

Induction of COX-2 expression by acrolein in the rat model of hemorrhagic cystitis.

AIM Acrolein (ACR) is a urinary metabolite of cyclophosphamide (CPS) and ifosfamide (IFS), which has been demonstrated to be the causative agent of hemorrhagic cystitis (HC), induced by these compounds. In this study, we investigate the participation of cyclooxygenase-2 (COX-2) on ACR-induced HC. METHODS Male Wistar rats (150-200g; six rats per group) were treated with distilled water or intravesical ACR and analyzed by changes in bladder wet weight, macroscopic and microscopic parameters and COX-2 expression. RESULTS COX-2 immunohistochemical expression was significant 12h after ACR administration mainly in subepithelial cells. ACR injection also alters some macroscopic and microscopic parameters in bladder of rats analyzed by Grays criteria. CONCLUSIONS COX-2 participates in the pathogenesis of ACR-induced HC first seen 12h after initial contact between ACR and urothelium.

Chemoprevention with green propolis green propolis extracted in L-lysine versus carcinogenesis promotion with L-lysine in N-Butyl-N-[4-hydroxybutyl] nitrosamine (BBN) induced rat bladder cancer

PURPOSE To determine the effects of green propolis extracted in L-lysine (WSDP) and of L- lysine for 40 weeks on induced rat bladder carcinogenesis. METHODS The animals (groups I, II, III, IV, V and VI) received BBN during 14 weeks. Group I was treated with propolis 30 days prior received BBN, and then these animals were treated daily with propolis; Groups II and III was treated with subcutaneous and oral propolis (respectively) concurrently with BBN. The animals of Group IV were treated L-lysine; Group V received water subcutaneous; and Group VI received only to BBN. Among the animals not submitted to carcinogenesis induction, Group VII received propolis, Group VIII received L-lysine and Group IX received water. RESULTS The carcinoma incidence in Group I was lower than that of control (Group VI). The carcinoma multiplicity in Group IV was greater than in Group VI. All animals treated with L-lysine developed carcinomas, and they were also more invasive in Group IV than in controls. On the other hand, Group VIII showed no bladder lesions. CONCLUSION The WSDP is chemopreventive against rat bladder carcinogenesis, if administered 30 days prior to BBN , and that L-lysine causes promotion of bladder carcinogenesis.

ESTABELECIMENTO DE UM MODELO DE TUMOR EXPERIMENTAL PELA INOCULAÇÃO DO TUMOR DE WALKER EM ESTÔMAGO DE RATO

The spontaneous incidence of gastric cancer in rat is extremely low. Furthermore, the development of this type of cancer induced by chemical carcinogens, fundic resection, vagotomy or reflux is very low, erratic and takes several months. The present work developed a relatively easy and reliable method for topical implantation of a fast growth tumor in the rat gastric mucosa. Cells from Walker tumor were injected through a canula in the rat stomach previously injured by clamping the mucosa in three different gastric regions. The tumors were found 100% in the large curvature, 80% in the small curvature and 20% in the esophagogastric juction. The surviving time of the inoculated animals was 13,2±1,92 days. The neoplastic tissue showed a rapid and constant growth pattern and it has allowed to inoculate a large series of rats.

An adapted tissue microarray for the development of a matrix arrangement of tissue samples.

The arrangement of tissue samples in a matrix, known as the tissue microarray (TMA) method, is a well-recognized method worldwide. This technique makes it possible to assess the expression of molecular markers on a large scale with high yields in terms of time, costs, and archived material. Some researchers are trying to adapt the technique to expand the research possibilities. This study proposes an adaptive simplification of low-cost instruments for obtaining samples that will be used in the construction of the TMA. The use of a manual leather puncher, which has a very low cost and a long expected life and eliminates the need to use a press machine, is a simple and effective alternative to building blocks of tissue microarrays.

Dual effect of silymarin on experimental non-alcoholic steatohepatitis induced by irinotecan

ABSTRACT Irinotecan‐based regimens are commonly used for treatment of colorectal cancer, which is limited by mucositis and non‐alcoholic steatohepatitis (NASH). Silymarin (SIL) prevents fatty liver disease in the clinical setting and in models of liver damage induced chemically. This study investigated the possible effect of SIL on irinotecan (IRI)‐induced NASH. Swiss female mice were injected with saline (SAL 5 ml/kg i.p.), IRI (50 mg/kg i.p.), SIL (150 mg/kg p.o.) or IRI (50 mg/kg i.p.) + (SIL 1.5, 15 or 150 mg/kg p.o.) thrice/week/7 weeks. On the seventh week, blood samples were collected for transaminases assay and livers were collected for histopathology, measurement of the total lipids, malondyadehyde (MDA), non‐protein sulfhydryl groups (NPSH), cytokines (IL‐1&bgr;, IL 6 and IL‐10), 3‐nitrotyrosine (N‐Tyr) and toll‐like receptor 4 (TLR4) immunoexpression, quantification of NF‐kB, &agr;‐smooth muscle actin (&agr;‐SMA), and Escherichia coli 16S rRNA gene (RRS) expression. IRI increased liver transaminases, neutrophil infiltration, lipid accumulation, MDA, IL‐1&bgr; and IL‐6 levels, N‐Tyr and TLR4 immunostaining, NF‐kB, &agr;‐SMA expression and RRS versus the SAL group (p < 0.05). Additionally, SIL (1.5 mg/kg) improved these parameters (p < 0.05), except neutrophil infiltration and RSS versus the IRI group. Furthermore, the SIL (15 mg/kg) only improved the inflammatory parameters, the expression of &agr;‐SMA and RRS versus the IRI group (p < 0.05). The higher dose of SIL (150 mg/kg) was even more deleterious than the intermediate dose. Therefore, silymarin showed a dual effect on liver damage induced by IRI. Hepatoprotection seems to involve the inhibition of oxidative stress and protein nitrosylation, preventing activation of hepatic fibrosis mechanisms. Graphical abstract Figure. No caption available. HighlightsLow doses of silymarin attenuate irinotecan‐related liver damage.The protection involves the inhibition of inflammatory markers and oxidative stress.Silymarin also reduces bacterial accumulation in the liver and activation of TLR4.High doses of silymarin enhance irinotecan‐induced NASH and animal mortality.

Progressive loss of E-cadherin immunoexpression during cervical carcinogenesis

PURPOSE To investigate E-cadherin immunoexpression during cervical carcinogenesis. METHODS We assessed the immunohistochemical expression of E-cadherin in squamous intraepithelial lesions (SIL - 52 cases), squamous cell carcinoma (SCC) of the uterine cervix (23 cases) and also in eight cases of cervicitis. RESULTS The results show very different E-cadherin membrane expression levels when cervicitis (88%), SILs (73%) and SCC (17%) were compared. In SILs, higher E-cadherin loss was seen in less differentiated cells in the basal third of the epithelium. This study suggests that the absence of E-cadherin expression in the membrane is a molecular event that is observed more often in SCC of the uterine cervix than in SILs or cervicitis. CONCLUSIONS E-cadherin is an essential molecule during the process of cervical carcinogenesis and in this context exhibits a different expression pattern according to the epithelial thickness layer.

Modelo experimental do carcinossarcoma 256 de Walker em bexiga de ratos

PURPOSE: An animal model to study bladder tumor with Walker 256. METHODS: Bladders rats Wistar was catheterized via urethra and compression lesion of the wall bladder was realized with a little clamping after laparotomy. One total of the 0,3 ml suspension with 3 x 105 cels viable of the carcinossarcoma was instilled into each bladder. The animals were sacrificed after eight and 13 days. RESULTS: The index of tumor incidence was 100% and the average of surviving was 14,5 days. CONCLUSION: The model estudied was efficient and will can to take subsidy the study experiemental in treatment of local invasise bladder cancer.