Lysophosphatidylglycerol inhibits formyl peptide receptor like-1-stimulated chemotactic migration and IL-1beta production from human phagocytes

In this study, we observed that lysophosphatidylglycerol (LPG) completely inhibited a formyl peptide receptor like-1 (FPRL1) agonist (MMK-1)-stimulated chemotactic migration in human phagocytes, such as neutrophils and monocytes. LPG also dramatically inhibited IL-1beta production by another FPRL1 agonist serum amyloid A (SAA) in human phagocytes. However, LPG itself induced intracellular calcium increase and superoxide anion production in human phagocytes. Keeping in mind that phagocytes migration and IL-1beta production by FPRL1 are important for the induction of inflammatory response, our data suggest that LPG can be regarded as a useful material for the modulation of inflammatory response induced by FPRL1 activation.

Evaluation of the effectiveness of peracetic acid in the sterilization of dental equipment.

PURPOSE: To evaluate the effectiveness of peracetic acid in the microbiological sterilisation of dental materials. METHODS: Peracetic acid solution was evaluated at concentrations of 800, 1500 and 2500 ppm. At these concentrations, it was determined whether peracetic acid caused corrosion to dental instruments and induced cellular mutagenicity and cytotoxicity. In addition, the minimum inhibitory concentration (MIC), the minimum bactericidal concentration (MBC), agar diffusion and diffusion by well method, were also verified. RESULTS: The corrosion rate, calculated from potentiodynamic assays was 10(-6) cm/year, indicating that the product does not damage equipment. The sterilisation capacity of peracetic acid at 2500 ppm was the best. The comet assay indicated genotoxic activity at 2500 ppm. CONCLUSIONS: This study demonstrated the effectiveness of peracetic acid for sterilizing dental equipment, providing another alternative for the prevention of infections in clinics.

Mechanism of Immune Response During Immunotherapy

Tumor immunology embraces an extensive array of biological phenomena that include interactions between neoplastic cells and the innate and adaptive immune response. Among immune cells, T cells have taken the center stage because they can be easily demonstrated to specifically recognize autologous cancer cells. However, their role is limited and other components of the immune response are likely necessary for the completion of cancer rejection. Metastatic melanoma and renal cell carcinoma (RCC) are malignancies strongly predisposed to regress in response to the systemic administration of high-dose interleukin (IL)-2. Several clinical Studies in extensive cohorts of patients have shown that this treatment can induce complete or partial clinical regressions of metastatic disease in 15 to 20% of patients who receive this treatment.1-6 Although IL-2 has direct pluri-potent effects on cells with immune and inflammatory function, it remains unexplained which cell subset is implicated in mediating tumor regression. In a quest to characterize the mechanism of action of IL-2 during the course of immunotherapy, we have investigated the early changes in transcriptional profiles of circulating mononuclear cells and microenvironment of melanoma metastases following high dose IL-2 administration (720,000 IU/kg) by serial sampling of blood cells and tumors in the form of fine needle aspirate (FNA).7 Furthermore, studies are currently ongoing to characterize the proteomic profiling of RCC patients undergoing the same treatment using protein arrays (manuscript in preparation). The predominant activation of genes related to inflammation and activation of mononuclear phagocytes lead us to further characterize this cell subset in the context of stimulation with a panel of soluble factors potentially present in the circulation and tumor microenvironment.

Immunopharmacological activity of polysaccharide from the pericarb of mangosteen garcinia: phagocytic intracellular killing activities.

Polysaccharides from the pericarbs of mangosteen, Garcinia mangostana Linn., was obtained by treating the dried ground pericarbs with hot water followed by ethanol precipitation (M fraction). The extract was fractionated by anion exchange chromatography on a DEAE-cellulose column as MDE1-5 fractions. The fractions of MDE3 and MDE4 composed of mainly D-galacturonic acid and a small amount of neutral sugar (L-arabinose as the major one and L-rhamnose and D-galactose as the minor ones) were studied for immunopharmacological activities by phagocytic test to intracellular bacteria (Salmonella enteritidis) and nitroblue tetrazolium (NBT) and superoxide generation tests. The results showed that the number of S. enteritidis in cultured monocyte with extract of pericarb of mangosteen (MDE3) was killed. Activating score (mean +/- SD) of NBT test of 100 polymorphonuclear phagocytic cells were 145 +/- 78, 338 +/- 58, 222 +/- 73, 209 +/- 77, 211 +/- 63, 372 +/- 19, 369 +/- 20, 355 +/- 34 in normal saline control, phorbol myristate acetate (PMA), MDE3, MDE4, indomethacin (I), PMA + MDE3, PMA + MDE4 and PMA + I, respectively. Superoxide generation test was also done by color reduction of cytochrome c. Both MDE3 and MDE4 stimulate superoxide production. The number of S. enteritidis in cultured monocyte with extract of pericarb of mangosteen was killed. This paper suggests that polysaccharides in the extract can stimulate phagocytic cells and kill intracellular bacteria (S. enteritidis).

Efeito da heparina sobre o sistema mononuclear fagocitário / Effects of heparin on the phagocytic mononuclear system

Apesar de a heparina ser amplamente utilizada como agente anticoagulante, suas funçoes biológicas permanecem incertas. Além do papel na coagulaçao, esse sacarídeo parece modular respostas imunológicas e inflamatórias. Com o objetivo de avaliar-se o efeito da heparina sobre o sistema mononuclear fagocitário, realizou-se este trabalho em nível experimental. Foram utilizadas 24 ratas divididas em dois grupos: Grupo I - administraçao de soluçao salina a O,9 por cento e Grupo II - administraçao de heparina sódica. Os animais foram acompanhados durante 26 dias. Decorrido esse prazo, administrou-se soluçâo de enxofre coloidal marcado com 99 mTc, por via venosa. Após trinta minutos, foram retirados segmentos do figado, baço e pulmao, além de um coágulo sangüíneo, que foram analisados através de cintilografia. Houve maior captaçao do radiofármaco pelos baços de ambos os grupos. Nao houve diferença entre os registros cintilográficos dos dois grupos, porém a depuraçao sangüínea do colóide foi menor em presença de heparina. Concluindo, a heparina parece interferir com a depuraçao sangüínea de colóide e tende a mudar o padrao de captaçao do sistema mononuclear fagocitário.