The role of resident cells during the lipopolysaccharide (LPS)-induced neutrophil recruitment into rat air pouches was investigated. In this model, LPS (Escherichia coli, O55: B5 strain; 2–2000 ng) induced a dose– and time-dependent neutrophil recruitment accompanied by the generation of a tumour necrosis factor-α (TNFα)-like activity. Dexamethasone (0.05–5 mug) and cycloheximide (6 ng), injected 2 h before LPS into the pouches, inhibited the neutrophil recruitment and the generation of the TNFα-like activity, while the H1-receptor antagonist mepyramine (1 and 4 mg/kg, i.p., 0.5 h before LPS) and the PAF-receptor antagonist WEB 2170 (0.05 and 1 mg/kg, i.p., 0.5 h before LPS) had no effect. Purified alveolar macrophages (AM) were used to replenish the pouches of cycloheximide-treated recipient rats. AM provided by PBS-treated animals led to the recovery of the LPS-induced neutrophil recruitment and of the TNFα-like formation contrasting with those from cycloheximide-treated animals (1 mg/kg, i.p.). When delivered in situ, liposome-encapsulated clodronate, a macrophage depletor, significantly impaired both the LPSinduced neutrophil recruitment and the TNFα-like activity. An anti-murine TNFα polyclonal antibody (0.5 h before LPS) was also effective. These results emphasize the pivotal role of macrophages for LPS-induced neutrophil recruitment via the formation of TNFα.

Objective: The objective of this work is to develop a simple, efficient, and reproducible spectrophotometric method for the quantitative estimation of sugammadex sodium, apremilast, riociguat and vorapaxar sulfate drugs in its active pharmaceutical ingredient (API) form. Methods:The developed ultraviolet-visible spectrophotometric method for the quantitative estimation of drugs -Sugammadex sodium, apremilast, riociguat and vorapaxar sulfate is based on measurement of absorption at a wavelength maximum (λ max ) of 210, 230, 323, and 271 nm using water and methanol as diluents. Results:The method was validated in terms of specificity, precision, linearity, accuracy, and robustness as per the ICH guidelines. The method was found to be linear in the range of 33-167% for sugammadex sodium and apremilast drug substances; 50-150% for riociguat and vorapaxar sulfate drug substances. The percentage recovery values were in the range of 99.7-100.9% for sugammadex sodium, 99.3-100.3% for apremilast, 99.7-100.3% for riociguat, and in the range of 99.5-100.3% for vorapaxar sulfate at different concentration levels. Relative standard deviation for precision and intermediate precision results were found to be <2%. The correlation coefficient value observed for sugammadex sodium, apremilast, riociguat and vorapaxar sulfate drug substances was not <0.99 for their respective drugs. Results obtained from the validation experiments prove that the developed method is quantified for the estimation of assay of sugammadex sodium, apremilast, riociguat and vorapaxar sulfate drug substances. Conclusion:The developed method can be successfully applied for routine analysis, quality control analysis and also suitable for stability analysis of assay of sugammadex sodium, apremilast, riociguat and vorapaxar sulfate in API form as per the regulatory requirements.

We used a variety of techniques to evaluate the effects of airway allergen exposure in mice on the responses of hemopoietic cells to cytokines and drugs in vitro and in vivo. Initial studies have shown that allergen exposure of sensitized mice leads to release of circulating mediators, that induce rapid upregulation of bone-marrow responses to IL-5 and GM-CSF. This may be related to glucocorticoids, because exogenous dexamethasone has similar effects on cultured murine bone-marrow, and because stress-induced glucocorticoids, in naïve or sensitized mice, have effects indistinguishable from those of allergen challenge in sensitized animals. Upregulation of eosinophil production is associated with an increased expression of alpha4 integrins, which may contribute to retention of these cells in the bone-marrow. Glucocorticoids regulate the adhesiveness, maturation and survival of eosinophils in murine bone-marrow culture, partly by counteracting the actions of Prostaglandin E2 and possibly other prostanoids. Allergen exposure of sensitized mice leads to accumulation of hemopoietic progenitors in the lungs, which differ from those in bone-marrow in growth properties and sensitivity to glucocorticoids. Lung transplantation has been used to demonstrate that the lung acts as a source of endocrine factors that promote hemopoietic cell accumulation, independently of damage caused by local allergic inflammation.

No abstract

No abstract