Progesterone modulates extracellular heat-shock proteins and interlukin-1ß in human choriodecidual after Escherichia coli infection.

INTRODUCTION: Chorioamnionitis is an adverse condition in human pregnancy caused by many bacterial pathogens including Escherichia coli (E. coli); which has been associated with higher risk of preterm birth. We recently reported that human maternal decidua (MDec) tissue responds to E. coli infection by secreting extracellular heat-shock proteins (eHsp)-60, -70 and interlukin-1ß (IL-1ß). Previous studies have shown that progesterone (P4) regulates the immune response, but it is unknown whether P4 inhibits the secretion of eHsp. The aim of this investigation was to determine the role of P4 on the secretion of eHsp-27, -60, -70 and IL-1ß in MDec after 3, 6, and 24 h of E. coli infection. METHODS: Nine human feto-maternal interface (HFMi) tissues were included and mounted in the Transwell culture system. Only the maternal decidua (MDec) was stimulated for 3, 6 and 24 h with E. coli alone or in combination with progesterone and RU486. After each treatment, the HFMi tissue was recovered to determine histological changes and the culture medium recovered to evaluate the levels of eHsp-27, -60, -70 and IL-1ß by ELISA and mRNA expression by RT-PCR. RESULTS: No structural changes were observed in the HFMi tissue treated with P4 and RU486. However, stimulation with E. coli produces diffuse inflammation and ischemic necrosis. E. coli induced infection decreases, in time- and dose-dependent manner, eHsp-27 and increases eHsp-60, eHsp-70 and IL-1ß levels. In contrast, incubation of HFMi tissue with E. coli + P4 reversed eHsp and IL-1ß secretion levels relative to E. coli stimulation group but not relative to the control group. The same profile was observed on the expression of eHsp-27 and eHsp-60. DISCUSSION: we found that progesterone modulates the anti-inflammatory (eHsp-27) and pro-inflammatory (eHsp-60 and eHsp-70) levels of eHsp induced by E. coli infection in human choriodecidual tissue. eHsp-60 and eHsp-70 levels were not completely reversed; maintaining the secretion of IL-1ß, which has been associated with adverse events during pregnancy.

Pharmacological characterization of mechanisms involved in the vasorelaxation produced by rosuvastatin in aortic rings from rats with a cafeteria-style diet.

The present study aimed to investigate the possible influence of several inhibitors and blockers on the vascular effect produced by the acute in vitro application of rosuvastatin to phenylephrine-precontracted aortic rings from rats with a semi-solid, cafeteria-style (CAF) diet. It also aimed to examine the effects of rosuvastatin on the expression of endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase, constitutive cyclooxygenase, and inducible cyclooxygenase in aortic rings from rats with a CAF diet. From comparisons of the effect on phenylephrine-precontracted aortic rings extracted from rats with two different diets (a standard and a CAF diet), it was found that 10(-9) -10(-5) -mol/L rosuvastatin produced lower concentration-dependent vasorelaxation on rings from the CAF diet group. The vasorelaxant effect was unaffected by the vehicle, but it was significantly attenuated by 10(-5) -mol/L N(G) -nitro-l-arginine methyl ester, 10(-2) -mol/L tetraethylammonium, 10(-3) -mol/L 4-aminopyridine, 10(-7) -mol/L apamin plus 10(-7) -mol/L charybdotoxin, 10(-5) -mol/L indomethacin, or 10(-5) -mol/L cycloheximide. Moreover, in aortic rings from rats with a CAF diet, rosuvastatin enhanced the expression of eNOS, inducible nitric oxide synthase, constitutive cyclooxygenase, and inducible cyclooxygenase. The acute in vitro application of rosuvastatin to phenylephrine-precontracted aortic rings from rats with a CAF diet had a vasorelaxant effect. Overall, the present results suggest that the stimulation of eNOS, the opening of Ca(2+) -activated and voltage-activated K(+) channels, the stimulation of prostaglandin synthesis and enhanced protein levels of eNOS, inducible nitric oxide synthase, constitutive cyclooxygenase, and inducible cyclooxygenase are involved in this relaxant effect.

Rapid and sensitive determination of levofloxacin in microsamples of human plasma by high-performance liquid chromatography and its application in a pharmacokinetic study.

A rapid, sensitive and simple high-performance liquid chromatographic assay with ultraviolet detection was developed for the quantification of levofloxacin in microsamples (100 µL) of human plasma. The extraction procedure included a protein precipitation technique and a short chromatographic running time (4.5 min). Analyses were carried out on a Symmetry C18 column using a mixture of acetonitrile and 0.01 m potassium dihydrogen aqueous solution (pH 3.4; 14:86 v/v) as mobile phase. The method provided specificity and was linear (r ≥ 0.9992) over the concentration range 0.1-12 µg/mL. The average absolute recovery was 93.59%. The intra- and inter-day coefficients of variation were <6%. Additionally, levofloxacin was stable in all evaluations. The usefulness of this method was demonstrated in a pharmacokinetic study of levofloxacin in healthy adult volunteers. The present method offers two main advantages: (a) the use of microsamples reduces the total volume of blood to be collected from patients; and (b) it provides a good cost-effectiveness ratio. It is concluded that the method is rapid, simple, sensitive, economical and suitable for the determination of levofloxacin in human plasma using a small volume of sample.

Relationship between blood levels and the anti-hyperalgesic effect of ketoprofen in the rat.

The relationship between blood levels of ketoprofen and its anti-hyperalgesic effects was examined in rat using the carrageenan-evoked thermal hyperalgesia model. Female adult Wistar rats were injected with carrageenan into the plantar surface of the right hind paw. Immediately after, rats were administered with ketoprofen po and hindpaw withdrawal latency measured and micro-whole blood samples were obtained over six hours via a cannula inserted in the caudal artery. Ketoprofen levels were measured by HPLC. Ketoprofen concentration increased in a dose-dependent manner and was reflected in dose-dependent anti-hyperalgesic effect. The pharmacokinetic and pharmacodynamic parameters expressed as mean ± s.e.m. following administration of 1, 3.2, and 10 mg/kg ketoprofen were: Cmax 1.27 ± 0.08, 3.44 ± 0.20 and 11.76 ± 0.81 µg/mL; AUClast 4.16 ± 0.17, 11.63 ± 0.65 and 28.15 ± 1.32 µg h/mL; and Emax observed (AUCE ): 65.41 ± 7.79, 92.06 ± 6.46 and 98.42 ± 7.53%. A direct relationship between blood concentrations and the anti-hyperalgesic effect of ketoprofen followed a maximum effect model equation. The results indicate that the anti-hyperalgesic effect of ketoprofen in the carrageenan pain model can be predicted by the pharmacokinetic properties of ketoprofen.

Further evidence for interethnic differences in the oral pharmacokinetics of meloxicam.

INTRODUCTION: Meloxicam is a nonsteroidal anti-inflammatory agent used widely in therapeutics. It is mainly metabolised by the cytochrome P450 enzyme (CYP) 2C9, with minor involvement of CYP3A4. So far, no information on the oral pharmacokinetics of this drug in adult Mexicans is available. The purpose of this study was to evaluate the oral pharmacokinetics of meloxicam in Mexican subjects. METHODS: Twenty-four healthy male subjects received an oral dose of meloxicam 7.5mg after fasting for 10 hours. Blood samples were drawn from a suitable forearm vein and plasma obtained. The meloxicam concentration was evaluated by a high-performance liquid chromatographic method and pharmacokinetic parameters were obtained by non-compartmental techniques. Pharmacokinetic parameters obtained in this study were compared with those reported under similar conditions in other populations in order to establish if interethnic differences in the pharmacokinetics of meloxicam exist. RESULTS: After administration of meloxicam, plasma levels increased to a maximum concentration (C(max)) of 0.702 +/- 0.027 (mean +/- SEM) microg/mL with a time to reach C(max) of 4.77 +/- 0.65h. The area under the plasma concentration versus time curve was 24.82 +/- 1.23 microg . h/mL. The clearance was about 4.8 mL/min and the volume of distribution 9.8 +/- 0.36L. When these parameters were compared with those reported in German and Indian subjects, a reduced clearance and volume of distribution were evident in Mexicans. However, clearance and volume of distribution obtained in this study were very similar to those reported in Chinese subjects. CONCLUSIONS: The oral pharmacokinetic parameters of meloxicam in healthy Mexican subjects compared with historic controls reported in other populations showed a reduced clearance and volume of distribution when compared with German subjects, whereas no differences between Mexican and Chinese subjects were observed. These results suggest that there are interethnic differences in the pharmacokinetics of meloxicam.