Diagnostic accuracy of 18F-FDG-PET in abdominal sepsis in rats

Abstract Purpose The objective of this study was to investigate the accuracy of 18F-FDG-PET in the diagnosis of multibacterial abdominal sepsis by cecum ligation and puncture (CLP) in rats. Methods Adult Wistar rats ( Rattus norvegicus ), weighing 227±35g, were allocated into a sepsis group by CLP (n=10) and sham group (n=10). 18F-FDG-PET using microPET was performed on all rats after 24 hours. Results All animals survived for postoperative 24h. The abdomen/liver ratio of the standardized uptake value (SUV) percentage was significantly higher in the sepsis group than in the sham (p=0.004). The ROC curve showed an accuracy of 18F-FDG-PET to detect abdominal sepsis of 88.9% (p=0.001), sensitivity of 90% and specificity of 88.9%. When a cut-off point of 79% of the ratio between the SUV on the abdominal region and liver was established, the sensitivity was 90%, specificity of 88.9%; positive and negative predictive values of 90.0% and 88.9%, respectively. Conclusions The diagnostic accuracy of 18F-FDG-PET in rats with abdominal sepsis was significantly high. It was also demonstrated the predictive ability of the abdomen/liver SUV ratio to diagnose abdominal sepsis. These findings may have implications for the clinical setting, locating septic foci with PETscan.

Effect of Arrabidaea chica extract against chemically induced breast cancer in animal model

Abstract Purpose: To examine the effects of Arrabidaa chica (Bignoniacea) extract, a native plant of the Amazon known as crajiru, on a 7,12-dimethyl-1,2-benzanthracene (DMBA)-induced breast cancer model in Wistar rats. Methods: We compared the response of breast cancer to the oral administration of A. chica extract (ACE) for 16 weeks, associated or not with vincristine. Groups: normal control; DMBA (50mg/kg v.o,) without treatment; DMBA+ACE (300 mg/kg); DMBA+vincristine. 500μg/kg injected i.p; DMBA+ACE+Vincristine 250μg/kg i.p. Imaging by microPET and fluorescence, biochemistry, oxidative stress, hematology and histopathology were used to validate the treatments. Results: All animals survived. A gradual weight gain in all groups was observed, with no significant difference (p>0.05). The oral administration of ACE and ACE+vincristine 50% significantly reduced breast tumors incidence examined with PET-18FDG and fluorescence (p<0.001). Significant reduction of serum transaminases, oxidative stress and hematological toxicity were observed in these groups. Antioxidant enzyme levels in breast tissue were significantly higher compared to the DMBA and DMBA+vincristine groups. Conclusion: These results demonstrate for the first time that ACE positively influences the treatment of DMBA-induced breast cancer in animal model, inducing a reduction in oxidative stress and chemotherapy toxicity, meaning that ACE may have clinical implication in further studies.

Oxacillin magnetically targeted for the treatment of Methicillin-Resistant S. aureus infection in rats

Abstract Purpose: To evaluate the effect of oxacillin bonded to magnetic nanoparticles in local infection model in rat. Methods: Twelve Wistar rats weighing 290±18g were randomly divided into four groups (n=6, each) and all rats had a magnet ring sutured on their right thighs. In the biodistribution group rats 0.1mL of 99mTc-magnetite (0.66 MBq) was injected i.v and after 30 minutes, biodistribution of 99mTc-magnetite was evaluated in right and left thighs. The other groups were inoculated with MRSA in each thigh muscles. Group 1 rats were injected i.v. with magnetite, group 2 with Magnetite + Oxacillin, group 3 with saline twice a day. After 24 hours samples of muscle secretion were harvested for microbiological analysis; muscle, lungs and kidneys for histology. Results: 99mTc-magnetite uptake was three-fold higher in right thigh muscles (with external magnet) than in the left. In magnetite and oxacillin-magnetite groups, bacterial/CFU was significantly lower in thigh muscles than in saline-controls. The inflammatory reaction in muscles and lungs was significantly lower in oxacillin-magnetite group-rats than in other groups (p<0.001) . Conclusion: This study confirms the potential antimicrobial activity of magnetic nanoparticles for Methicillin-Resistant S. aureus strains, which in addition to concentrate the antibiotic at the infection site, positively influenced the treatment.

Greater expression of the human leukocyte antigen-G (HLA-G) and interleukin-17 (IL-17) in cervical intraepithelial neoplasia: analytical cross-sectional study / Aumento da expressão do antígeno leucocitário humano-G (HLA-G) e interleucina-17 (IL-17) em neoplasia intraepitelial cervical: estudo transversal analítico

CONTEXT AND OBJECTIVE:Impaired local cell immunity seems to contribute towards the pathogenesis and progression of cervical intraepithelial neoplasia (CIN), but the underlying molecular mechanisms promoting its progression remain unclear. Identification of new molecular markers for prognosis and diagnosis of early-stage CIN may aid in decreasing the numbers of CIN cases. Several novel immunoregulatory molecules have been discovered over the past few years, including the human leukocyte antigen G (HLA-G), which through interaction with its receptors exerts important tolerogenic functions. Several lines of evidence suggest that T-helper interleukin-17 (IL-17)-producing cells (Th17 cells) may play a role in antitumor immunity. However, recent reports have implicated Th17 cells and their cytokines in both pro and anti-tumorigenic processes. The aim of the study was to evaluate the roles of HLA-G and Th17 in the immunopathogenesis of CIN I.DESIGN AND SETTING:Analytical cross-sectional study with a control group using 58 cervical specimens from the files of a public university hospital providing tertiary-level care.METHODS:We examined HLA-G and IL-17 expression in the cervical microenvironment by means of immunohistochemistry, and correlated these findings with clinical and pathological features.RESULTS:There was a greater tendency towards HLA-G and IL-17 expression in specimens that showed CIN I, thus suggesting that these molecules have a contribution towards cervical progression.CONCLUSION:These findings suggest that HLA-G and IL-17 expression may be an early marker for assessing the progression of cervical lesions.

CONTEXTO E OBJETIVO:A deficiência na imunidade celular localizada parece contribuir para a patogênese e progressão das neoplasias intraepiteliais cervicais (NIC), no entanto, ainda não está totalmente esclarecido o mecanismo molecular fundamental nesse processo de progressão. A identificação de novos marcadores moleculares de prognóstico e diagnóstico das NIC em estágios precoces pode ajudar a diminuir a quantidade de casos de NIC. Várias novas moléculas com função imunorregulatória foram descobertas nos últimos anos, inclusive o antígeno leucocitário humano G (HLA-G), que, através de interação com os receptores, tem importantes funções tolerogênicas. Diversas linhas de evidência sugerem que as células T-ajudantes produtoras de interleucina-17 (IL-17, células Th17), podem desempenhar um papel na imunidade antitumoral. Porém, recentes relatos implicaram as células Th17 e suas citocinas tanto em processos pro- quanto anti-tumorigênicos. O objetivo do estudo foi avaliar o papel do HLA-G e Th17 na imunopatogênese das NIC I.TIPO DE ESTUDO E LOCAL:Estudo transversal analítico com grupo controle em 58 espécimes cervicais dos arquivos de um hospital universitário público com assistência prestada no nível terciário.MÉTODOS:Avaliamos a expressão de HLA-G e IL-17 por imunoistoquímica no microambiente cervical, associando esses achados com as características clínico-patológicas.RESULTADOS:Houve tendência aumentada da expressão de HLA-G e IL-17 em espécimes que apresentaram NIC I, sugerindo que essas moléculas têm contribuição na progressão cervical.CONCLUSÃO:Estes resultados sugerem que a expressão do HLA-G e da IL-17 pode ser um marcador precoce para avaliar a progressão das lesões cervicais.

The ileum positively regulates hepatic regeneration in rats

To test the hypothesis that liver regeneration after partial hepatectomy can be influenced by the ileum. METHODS: Eighteen Wistar rats were distributed into groups of six animals: 1 - ileum resection+ hepatectomy 2/3; 2 - hepatectomy 2/3, and 3 - sham. Anesthesia with ketamine and xylazine i.p., aseptic technique, analgesia with meperidine (10mg/kg s.c.). On day 6, serum ALT, AST, alkaline phosphatase (AP) and albumin were measured. Liver regeneration and hepatocyte mitosis were quantified. Statistical analysis with ANOVA and Tukey tests, with significance p<0.05. RESULTS: In group hepatectomy+ileal resection, ALT, AST and AP were 180.6±24.9, 58.6±3.1 and 254.6±46.6 respectively. They were significantly higher than in the hepatectomy group, whose values were 126.0±16.5, 44.1±3.9 and 163.5±8.6, respectively (p<0.001). Albumin levels were not significantly different among groups. Liver regeneration in hepatectomy group (94.17%) was statistically higher (p<0.001) than in ileal resection+hepatectomy group (55.96%). In the latter group the mitosis of hepatocytes were significantly less frequent than in the hepatectomy group. CONCLUSION: The data confirm that the ileum positively influence on liver regeneration in rats undergoing hepatectomy.

The ileum as a determinant organ of the functional liver cell mass in rats

PURPOSE: To evaluate if the ileum resection changes the functioning liver cell mass, the hepatic metabolism and the biodistribution of radiopharmaceutical in rats. METHODS: Twelve Wistar rats weighing 285g±34g were randomly divided into the ileum resection group (n = 6) and sham group rats (n = 6). After 30 days, they were anesthetized and 0.1mL of 99m-Tc-phytate (0.66MBq) was injected via femoral vein. After 30 minutes, blood samples were collected for red blood cells radioactive labeling and serum ALT, AST and gammaGT. Liver samples were used for 99m-Tc-phytate percentage of radioactivity/gram of tissue and histopathology. Student 's t test was used with significance 0.05. RESULTS: There was a higher uptake of 99m-Tc-phytate in the liver of sham rats, compared to the ileum resection group (p<0.05). GammaGT, ALT and AST were increased in ileum resection rats compared to sham (p<0.05). The he patocytes count was significantly lower in ileum resection group than in sham (p<0.05). Liver: body mass ratio was lower in experimental animals than in sham group (p<0.05). CONCLUSION: These data support that the ileum has important role in liver function and liver mass regulation, and they have potential clinical implications regarding the pathogenesis of liver injury following lower bowel resection.

Repercussões do tempo operatório em pulmões de ratos idosos / Operative time repercussions in lungs of old-aged rats

A duração das operações pode representar um fator importante para uma série de complicações pós-operatórias, especialmente para os indivíduos idosos. Objetivo: estudar a repercussão nos pulmões, de operações de diferentes tempos de duração. Métodos: Vinte ratos idosos (18 meses) e 20 jovens (3 meses) foram separados aleatoriamente em grupos A e B respectivamente,=. os grupos foram divididos em A1, A2, A3, A4, B1, B2, B3 e B4, com cinco ratos cada. Os animais foram anestesiados com pentobarbital (20mg/Kg) intraperitoneal. No subgrupo A1 e B1 foi feita operação com duração de 30 minutos, nos grupos A2 e B2 60 minutos, em A3 e B3 a operação foi feita em 120 minutos e os animais A4 e B4 (controle) não foram operados. O procedimento constitui de laparotomia xifopubiana que foi aberta e fexada tantas vezes quanto necessário para atingir os tempos estipulados. Após o quinto dia pós-operatório os animais foram mortos com superdose de anestésico e biópsias de ambos os pulmões foram realizadas. Os achados histopatológicos foram transformados em escores. Resultados: os grupos de ratos jovens atingiram os escores A1=escore 6, A2=11; A3=28; A4=5. Os ratos idosos tiveram os escores: B1=12; B2=34; B3=51 e B4=6. A análise estatística revelou diferenças significantes entre os escores dos grupos A e B. Conclusões: O tempo prolongado nas operações realizadas em ratos idosos contribuiu para o aparecimento de alterações pulmonares de modo significante. Quanto maior o tempo operatório, mais intensas e mais frequentes as complicações pulmonares.

Translocaçäo de bactérias marcadas com Tc99 na icterícia obstrutiva em ratos / Bacterial translocation labeled with Tc99 in obstructive jaundice in rats

Estudo realizado com o objetivo de avaliar a translocaçäo bacteriana (TB) do tubo gastrointestinal para órgäos viscerais na icterícia obstrutiva. Quatro grupos de ratos foram estudados: grupo I (n=10) ligadura do colédoco, grupo II (n=10) controle ou "sham operation", grupo III (n=12) ligadura do colédoco e gavagem com 99mTc-Escherichia coli e grupo IV (n=5) controle ou "sham operation" e gavagem com 99mTc-E.coli. Usando técnica asséptica e sob anestesia com pentobarbital sódico (20mg/kg), os animais foram submetidos à laparotomia e nos ratos dos grupos I e III foi realizada ligadura do colédoco com fio de seda n§ 000. Nos ratos dos grupos II e IV foi feita apenas a manipulaçäo do colédoco com pinça de Adison. Após sete dias, os animais dos grupos I e II foram mortos e ressecados fígado, baço, linfonodos mesentéricos e pulmöes para exame microbiológico (meios Agar-sangue e Agar Mac Conkey) e exame histopatológico (coloraçäo H.E. e Tricrômico de Masson) por análise morfométrica. Nos animais dos grupos III e IV, após sete dias, foi administrada por via oral (gavagem) 99mTc-E.coli e após 24h, os ratos de ambos os grupos foram mortos e seus órgäos retirados para contagem da radioatividade em cintilador automático Gama, modelo ANSR (ABBOT). O nível médio de bilirrubina, nos grupos ictéricos, foi significantemente maior do que o do grupo controle. O estudo microbiológico revelou maior incidência de bactérias translocadas no grupo I, comparada ao controle (p< 0,05). Os resultados näo mostraram diferença significante na captaçäo da 99mTc-E.coli entre os dois grupos. Porém, a análise das interaçöes grupo x órgäo mostrou diferença entre os grupos ictérico e controle para os órgäos: fígado e pulmäo. Os dados permitem concluir que em ratos ictéricos por ligadura do colédoco ocorreu TB detectável por exame microbiológico. Näo ocorreu TB com 99mTc-E. coli no modelo proposto.