The effect of conglutinin on production of reactive oxygen species in bovine granulocytes

Conglutinin is a high molecular-weight lectin originally detected in bovine serum. It belongs to the family of collectins that bind sugar residues in a Ca(2+)-dependent manner and are effector molecules in innate immunity. Conglutinin appears to play an important role in immune defense mechanisms, showing antiviral and antibacterial activities when tested in vivo and in vitro. The present study evaluated the effect of conglutinin on the respiratory bursts in bovine peripheral phagocytes. Using nitroblue tetrazolium and hydrogen peroxide assays, we showed that sugar ligand-bound conglutinin stimulated the production of superoxide and H2O2 in granulocytes whereas the non-sugar-bound form of conglutinin inhibited these processes. These results indicate that both forms of conglutinin are able to interact with surface leukocyte receptors but have opposite effects on phagocytic activity. Our findings suggest that conglutinin bound to sugar residues on microbial surfaces can induce oxygen burst in phagocytes, and thereby mediates the elimination of pathogens and prevents the spread of infection.

Study of aerobic granulocyte functional activity in the presence of a radiosensitizer [metronidazole]

The in vitro effects of metronidazole on the production of reactive oxygen species by polymorphonuclear [PMN] cells were studied by means of nitroblue tetrazolium and luminol-dependent chemiluminescence. At therapeutic doses of metronidazole [4.98-24.86 microg/mL] significant inhibition of the production of reactive oxygen species was noted in both methods. The inhibitory effect was in a dose-dependent pattern. The data suggest a scavenging mechanism of metronidazole on reactive oxygen species generated by PMN

Impact of copper on haematological profile of freshwater fish, Channa punctatus.

The present study was to evaluate heavy metal toxicity stress symptoms in fish blood during long-term exposure of sublethal concentration of copper sulphate (CuSO4). The effects of copper on various heamatological parameters were evaluated exposing Indian fresh water fish, Channa punctatus to a sub-lethal concentration of copper sulphate (0.36 mg l(-1)) for different periods. Exposure of fish to copper showed a significant decrease in the haemoglobin (Hb) content from 10.73 to 6.60%, red blood cells (RBC) from 2.86 to 1.84 x 10(6)/mm3 and packed cell volume (PCV) from 31.00 to 23.33% at the end of 45th day as compared to control. Whereas the white blood cells (WBC) increased from 60.00 to 92.48 x10(3)/mm3, clotting time (CT) from 27.66 to 43.00 second, erythrocyte sedimentation rate from 5.0 to 13.66 mm/hr and mean corpuscular volume from 108.11 to 126.85 cmu, significantly, with increase in exposure periods. Although mean corpuscular haemoglobin concentration (MCHC) and mean corpuscular haemoglobin (MCH) values showed significant increase during 15 and 30 days exposures, both the values were found significantly increased at the end of the experimental period. The differential leucocytes count (DLC) showed a significant increase in the populations of lymphocytes and eosinophils, whereas neutrophils, monocytes and basophiles were found decreased after exposure to copper.

Resposta terapêutica e inflamatória de ratos com peritonite secundária submetidos ao uso tópico de ampicilina/sulbactam / Therapeutical and inflammatory response in rats with secondary peritonitis and topical use of ampicilin/sulbactam

OBJETIVOS: A peritonite aguda representa uma importante causa de sepsis e óbito nas unidades de terapia intensiva e cirurgia. Classicamente o seu tratamento deve incluir: a administração sistêmica de antibióticos, a remoção mecânica dos contaminantes e a restauração da integridade gastrintestinal. A utilização de antibióticos diretamente na cavidade peritoneal é controversa. Estudo com o objetivo de avaliar o uso terapêutico, intraperitoneal da ampicilina associada ao sulbactam. MÉTODOS: foram mensurados os níveis plasmáticos do óxido nítrico, bem como a contagem de eosinófilos, linfócitos, monócitos e neutrófilos no sangue e no lavado peritoneal, utilizando-se modelo de peritonite em ratos (ligadura-transfixação cecal). Vinte quatro ratos Wistar, machos, foram divididos em quatro grupos de seis animais, assim distribuídos: grupo A: método de indução de peritonite - soltura da ligadura + tratamento com soro fisiológico; grupo B: método de indução de peritonite + soltura da ligadura + tratamento com soro fisiológico acrescido de ampicilina / sulbactam; grupo C: método de indução de peritonite + soltura da ligadura-transfixação cecal; e grupo D: laparatomia para realização de lavado peritoneal mais coleta de sangue. A ligadura-transfixação do cecum permaneceu por 24 horas, antes do tratamento instaurado. Foi realizada uma relaparotomia nos 18 ratos com coleta de líquido de lavado peritoneal e sangue. Foram dosados os níveis plasmáticos de óxido nítrico e determinado o número de eosinófilos, linfócitos, monócitos e neutrófilos no sangue e no lavado peritoneal. RESULTADOS: Não ocorreu diferença estatisticamente significante (p > 0,05) nos níveis de óxido nítrico, bem como no número de eosinófilos, linfócitos, monócitos e neutrófilos no sangue e no lavado peritoneal, entre os grupos. CONCLUSÃO: Neste estudo, concluiu-se que: a utilização de ampicilina associada a sulbactam por via intraperitoneal nos ratos com peritonite fecal: não modificou a sobrevida; não alterou os níveis plasmáticos de óxido nítrico; não alterou a contagem de eosinófilos, linfócitos, monócitos e neutrófilos tanto no sangue como no lavado peritoneal.

Inhibition of luminol-dependent chemiluminescence of human granulocytes by low doses of inorganic mercury

HgCl2, added in vitro to human granulocytes in whole blood, caused a marked inhibitory effect on the luminol-dependent chemiluminescence induced by BaS04 crystals in suspension of these cells. The effect was both dose- and time-dependent when BaS04 was used to stimulate the oxidative burst in granulocytes. Incubation with the highest concentration of HgCl2 used [10 mmol/L], however, did not cause disruption of the membranes of granulocytes. The effect of HgCl2 on the granulocytes was irreversible following washing of the HgCl2-treated cells with phosphate buffered saline. HgCl2 did not affect chemiluminescence produced when luminol was excited by oxidative hydrogen peroxide in a cell-free medium. These results suggest that some of the toxicity of HgCl2 may be greater than mediated by an action on the phagocytic immune system

Effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on murine bone marrow and spleen erythropoiesis

100 mug/kg of recombinant human granulocyte colony - stimulating factor was injected twice daily into normal adult CF1 female mice for a period of 15 days. After that time was have observed a decrease (59)Fe marrow incorporation with a parallel increase in the spleen. During the first 9 days the marrow plus spleen erythroid cells number decreased to 60 percent of control approximately, but recovered thereafter and were not significantly different from normal values at 12 - 15 days. In addition, our studies demonstrate that the spleen erythropoiesis is quantitatively more important at the final time tham marrow erythropoiesis. For this reason, splenic compensatory erythropoiesis maintained the hematocrit values between normal ranges. Regarding the granulocytic compartment, 15 days of rhG-CSF treatment produce a marked increase in total count os splenic granulocytes (a 7.7 fold rise from control values). Marrow granulocytes shows a 2 - fold increment, but considering the absolute counts, bone marrow still was predominant as a granulopoieitc organ. Our results indicate that the spleen is a more important erythropoietic organ than marrow after 15 days of rhG-CSF treatment.

Leukocyte alkaline phosphatase activity and peripheral changes of granulocyte following administration of granulocyte colony-stimulating factor.

The rhG-CSF had specificity of stimulation proliferation and differentiation of the neutrophil lineage in which there was an increase of younger stages, the earliest was myelocyte, of granulocyte in circulation. The effect of it was demonstrated within 24 hours of administration and reduced immediately after withdrawal. LAP activity in this condition was normal. The pattern of hematologic change in this condition may mimic CML and leukemoid reaction. It differed clearly from CML, since LAP activity in CML was lower than normal, but LAP activity could not define it from leukemoid reaction. The detection of young cells in peripheral blood through automated measurement of nuclear density by TechniconH*1 was observed for the high sensitivity (100%) and low specificity (54.8%). Furthermore, the study of cell kinetic in bone marrow should be evaluated to complete the cell kinetic effect of rhG-CSF and give a better evaluation for the H*1 blast flag.