Effect of dietary supplementation of prebiotics and probiotics on intestinal microarchitecture in broilers reared under cyclic heat stress.

This study was designed to evaluate the effect of dietary supplementation of prebiotics, mannanoligosaccharides (MOS) and/or probiotics (LBP) on intraepithelial lymphocytes (IEL) count, goblet cells (GC) count and differentiation and intestinal micro-architecture in broilers reared under cyclic heat stress. Day-old broilers (n = 250) were randomly divided into five groups. Fifty birds were reared within the thermoneutral zone (TNZ). Remaining birds were subjected to cyclic heat stress from day 21 to 42 (35° C, 75% RH, 8 h/d). The birds were fed corn-soy-based basal diet or the same diet supplemented with 0.5% MOS (HS-MOS), or 0.1% LBP (HS-LBP), or their combination (HS-SYN). The birds were slaughtered on day 42. Tissue samples were collected from mid-duodenum, jejunum and ileum, and stained with haematoxylin and eosin or combined Alcian blue and PAS technique. All differences were considered significant at p < 0.05. The IEL count increased in all intestinal segments of the HS group compared with the TNZ group and decreased in all supplemented groups compared with the HS group. Compared with the TNZ, heat stress reduced villus height, crypt depth and surface area in duodenum and ileum, and increased crypt depth in ileum. Villus width decreased in duodenum and jejunum compared with the TNZ group. Supplementation of LBP, MOS and SYN reversed all these changes in duodenum, while only increased villus height and surface area in ileum. In jejunum, the villus height and surface area increased with HS-LBP, and crypt depth increased with HS-MOS. The number of GC containing acid mucins (duodenum and ileum) and mixed mucins (ileum) were increased in the HS compared with the TNZ. Supplementation of MOS, LBP and SYN maintained the enhanced activity of goblet cells. In conclusion, dietary supplementation of MOS and/or LBP may be helpful in alleviating some of the detrimental effects of heat stress on microstructure of the broiler gut.

Relative roles of endothelial cell damage and platelet activation in primary Raynaud's phenomenon (RP) and RP secondary to systemic sclerosis.

OBJECTIVE: To evaluate the relative roles of endothelium and platelets in the pathogenesis of primary RP and RP secondary to SSc. METHODS: Endothelial derived ET-1, t-PA, PAI-1, and platelet derived beta-TG, PDGF, TGF-beta were measured in 36 patients with primary RP, 14 patients with RP secondary to SSc and 30 age and sex matched controls. RESULTS: A significative increase of ET-1, t-PA, PAI-1, TGF-beta, and beta-TG were the most relevant changes in patients with RP secondary to SSc with respect to the controls. Less relevant increases of t-PA, PAI-1, PDGF, and beta-TG levels were observed in patients with primary RP vs controls. CONCLUSIONS: These data seem to confirm the involvement of endothelial cells and platelets in the pathogenesis of RP, with mild changes in primary RP and more relevant changes in RP secondary to SSc.

Hypertrophic osteoarthropathy: endothelium and platelet function.

Hypertrophic osteoarthropathy (HOA) is characterized by finger clubbing, periostosis and arthritis. The pathogenesis of hypertrophic osteoarthropathy is still uncertain. Earlier studies have been focused on the potential role of platelet and endothelium in the pathogenesis of HOA. The aim of this study was to evaluate the circulating levels of endothelin-1 (ET-1), beta-thromboglobulin (beta-TG) and platelet-derived growth factor (PDGF) in 21 HOA patients. The circulating levels of ET-1, beta-TG were significantly higher in HOA patients vs healthy controls, but not vs controls with lung diseases. On the contrary, PDGF was significantly higher in HOA patients vs healthy controls and vs subjects with lung diseases. These findings suggest that "endothelium/platelet unit" may play a role in the pathogenesis of HOA, and PDGF could induce the changes observed in HOA.

Influence of nifedipine on plasma membrane fluidity and oxidative burst of polymorphonuclear leucocytes.

It has been demonstrated that the calcium antagonist nifedipine inhibits the reactive oxygen species (ROS) production by polymorphonuclear leucocytes (PMNLs) activated with phorbol myristate acetate (PMA), but the mechanism underlying this effect is still unknown. In the present study we investigated the influence of nifedipine on the PMNL plasma membrane using 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5,hexatriene (TMA-DPH) fluorescence polarization (P) and on PMA- and N-formyl-methionyl-leucyl-phenylalanine (FMLP)-induced ROS production, measured by luminol-dependent chemiluminescence (CL). The plasma membrane fluidity of untreated PMNLs, expressed as P, was 0.371 +/- 0.008. After preincubation of 15 min, nifedipine induced a significant change in P values only at a concentration of 10(-4) M (P = 0.00018). After preincubation of 60 min significant changes in P values were also observed at concentrations of 10(-6) M (P = 0.023) and 10(-7) M (P = 0.023). PMA-induced ROS production by PMNLs was markedly inhibited by nifedipine. Nifedipine also determined a striking change in the FMLP-induced CL response, characterized by both an overall inhibition of PMNL activity and a modification of the kinetics of the oxidative burst (rapid increase in ROS production followed by a pronounced drop in the PMNL response). Such a pattern was found at concentrations of 10(-4) M (preincubation time: 15 min), 10(-6) M and 10(-7) M (preincubation time: 60 min). These findings indicate that nifedipine directly interacts with the PMNLs by inducing a marked decrease in plasma membrane fluidity and an inhibition of the oxidative burst.

Influence of dichloromethylene diphosphonate on reactive oxygen species production by human neutrophils.

Biphosphonates suppress bone destruction in various diseases. Several studies have demonstrated the potential use of biphosphonate in arthritis. The results of these studies indicate that the effectiveness of the biphosphonates, for inhibiting the arthritic process, is related to their antiresorptive properties. It has been shown that the generation of reactive oxygen species is associated with the formation of new osteoclasts and enhanced bone resorption. We studied the effects of the dichloromethylene diphosphonate on the reactive oxygen species production by activated polymorphonuclear leucocytes, measured by chemiluminescence. Our results indicate a dose-dependent inhibitory effect of dichloromethylene diphosphonate on reactive oxygen species production by polymorphonuclear leucocytes stimulated with N-formil-methionyl-leucyl-phenylalanine, the calcium ionophore A23187 and phorbol myristate acetate. The mechanisms by which this biphosphonate inhibits the reactive oxygen species production by activated polymorphonuclear leucocytes are discussed.

Platelet release products modulate some aspects of polymorphonuclear leukocyte activation.

The aim of this research was to evaluate in vitro interactions between platelets and polymorphonuclear leukocytes. The effects of supernatant from thrombin-activated platelets and two platelet release products (adenosine triphosphate and beta-thromboglobulin) were tested on the following features of polymorphonuclear leukocytes activation: opsonized zymosan and phorbol myristate acetate stimulated chemiluminescence, release of membrane bound calcium, NADPH-oxidase activity, and membrane fluidity (fluorescent polarization). The results showed that the addition of platelet supernatant to polymorphonuclear leukocytes induces a significant activation of cells. On the other hand, after three hours of preincubation of polymorphonuclear leukocytes with platelet supernatant, a decreased response of polymorphonuclear leukocytes to stimulation with phorbol myristate acetate, a significant decrease in NADPH-oxidase activity, and a lowered membrane fluidity were observed. Adenosine triphosphate modulated only opsonized zymosan stimulated chemiluminescence, with and without preincubation with polymorphonuclear leukocytes. Beta-thromboglobulin caused a decrease of the chemiluminescent response of polymorphonuclear leukocytes, using both agonists, with and without preincubation with polymorphonuclear leukocytes. Moreover beta-thromboglobulin only caused a decrease of the polymorphonuclear leukocytes membrane fluidity without preincubation with the cells. These results support the thesis that platelets have a "time-related" modulating activity on polymorphonuclear leukocytes.

Stimulated chemiluminescence of polymorphonuclear leukocytes in rheumatoid arthritis: in vivo enhancement by auranofin.

The aim of the study was to investigate the interaction of opsonized zymosan with polymorphonuclear leukocytes (PMNLs) from 26 rheumatoid arthritis patients (six males and 20 females; mean age, 51.88 +/- 11.15 years; range, 33-72 years) and 11 control subjects (two males and nine females; mean age, 56.54 +/- 12.1 years; range, 33-75 years) using a luminol-amplified chemiluminescence (CL). The data obtained suggest that the opsonized zymosan stimulated CL is decreased in untreated rheumatoid patients compared with control subjects. The decreased stimulated CL may be the result of a physico-chemical alteration of the membrane (including decreased membrane fluidity and translocation of receptor sites) induced by free radicals of oxygen and/or by multiple exposures to chemotaxins. Auranofin enhances stimulated CL although the mechanism is not clear. Auranofin could interact with membrane lipids, induce changes in membrane surface charges and increase membrane fluidity. Our results are difficult to compare with those of previous studies, since different assays, and chemoattractants were applied. In addition, the disease activity and medication were also different.

[Chemiluminescence of oxygen radicals. A computerized method for its evaluation]. / La chemiluminescenza dei radicali dell'ossigeno. Un metodo computerizzato per la sua valutazione.

The measurement of oxygen free radicals (O2-) production after polymorphonuclear leukocytes (PMNLs) stimulation may be useful to elucidate the pathogenesis of rheumatic disorders and to assess the efficacy of anti-inflammatory and anti-rheumatoid drugs. The Authors describe a computerized method (with original specific analogic/digital converter and software) which allows a rapid and accurate determination of O2- production and a prompt storage of the data. The Authors, in disagreement with the current opinion, believe that PMNLs activity is more truly expressed by the total amount of emitted energy in a defined interval time than by the peak of emitted energy.