Effect of different classes of antibiotics on amniotic prostaglandin E release

Alcohol reinstatement after prolonged abstinence from alcohol drinking by female adolescent rats: Roles of cyclooxygenase-2 and the prostaglandin E2 receptor 1

BACKGROUND

Adolescent alcohol misuse is a global problem that can significantly increase the reinstatement of alcohol drinking during re-exposure after abstinence, but the mechanism that causes this increase is unknown. Female adolescents are an understudied population but they are particularly vulnerable to adolescent-onset alcohol abuse. We aimed to determine how adolescent-onset alcohol drinking affects pro-inflammatory mediators endothelin-1 (ET-1), cyclooxygenase-2 (COX-2), and prostaglandin E₂ (PGE₂) in the brain and the role of COX-2 and PGE₂ in EtOH reinstatement in adolescent females.

METHODS

Adolescent female rats were exposed to a 2-bottle choice paradigm of water vs 5% ethanol (EtOH) every other day over a 21 day period. ET-1 and COX-2 proteins were measured in the dorsal striatum (DS) after a 4 week abstinence from EtOH drinking. The COX-2 inhibitor nimesulide was then administered during abstinence prior to an EtOH reinstatement or sucrose preference or to measure PGE₂ content. The PGE₂ receptor 1 (EP₁) antagonist SC-51089 was then administered prior to EtOH reinstatement during which EtOH intake was measured.

RESULTS

EtOH drinking significantly increased ET-1 by 33.8 ± 8.9% and COX-2 by 71.4 ± 24.3% in the DS. Treatment with nimesulide during abstinence attenuated EtOH intake during reinstatement after prolonged abstinence by 40.3 ± 12.4% compared to saline controls. Adolescent EtOH drinking and abstinence increased PGE₂ 150.5 ± 30.9% in the DS and nimesulide attenuated this increase. SC-51089 treatment during abstinence attenuated EtOH reinstatement by 48.1 ± 8.4% compared to DMSO controls.

CONCLUSIONS

These experiments identified a prostaglandin-mediated mechanism that offers a putative pharmacological target to attenuate EtOH reinstatement after adolescent-onset EtOH drinking.

Vaginal Lactoferrin Modulates PGE2, MMP-9, MMP-2, and TIMP-1 Amniotic Fluid Concentrations

Inflammation plays an important role in pregnancy, and cytokine and matrix metalloproteases (MMPs) imbalance has been associated with premature rupture of membranes and increased risk of preterm delivery. Previous studies have demonstrated that lactoferrin (LF), an iron-binding protein with anti-inflammatory properties, is able to decrease amniotic fluid (AF) levels of IL-6. Therefore, we aimed to evaluate the effect of vaginal LF administration on amniotic fluid PGE₂ level and MMP-TIMP system in women undergoing genetic amniocentesis. One hundred and eleven women were randomly divided into controls (n = 57) or treated with LF 4 hours before amniocentesis (n = 54). Amniotic fluid PGE₂, active MMP-9 and MMP-2, and TIMP-1 and TIMP-2 concentrations were determined by commercially available assays and the values were normalized by AF creatinine concentration. PGE₂, active MMP-9, and its inhibitor TIMP-1 were lower in LF-treated group than in controls (p < 0.01, p < 0.005, and p < 0.001, resp.). Conversely, active MMP-2 (p < 0.0001) and MMP-2/TIMP-2 molar ratio (p < 0.001) were increased, whilst TIMP-2 was unchanged. Our data suggest that LF administration is able to modulate the inflammatory response following amniocentesis, which may counteract cytokine and prostanoid imbalance that leads to abortion. This trial is registered with Clinical Trial number NCT02695563.

Vaginal lactoferrin administration before genetic amniocentesis decreases amniotic interleukin-6 levels

AIM

To verify the eventual efficacy of lactoferrin (LF), an iron-binding glycoprotein, to decrease the amniotic concentration of interleukin-6 (IL-6).

METHODS

We prospectively enrolled 60 Caucasian patients at the 16th week of their singleton physiological gestation. A vaginal compound containing 300 mg of LF was administered randomly 4 or 12 h prior to amniocentesis, as to obtain 3 groups: A, 20 untreated patients; B, 20 treated 4 h before amniocentesis; C, 20 treated 12 h before amniocentesis.

RESULTS

A normal karyotype was registered in all cases. The comparison of the distribution of IL-6 among the 3 groups showed a highly significant difference (p = 0.001). The difference between mean values of group B and both groups C and A was shown to be highly significant (p = 0.006 and p = 0.03, respectively). In contrast, there was no significant difference between mean values of groups A and C.

CONCLUSION

Vaginal LF administration decreases amniotic IL-6 concentration. We therefore suggest that the glycoprotein may exert a protective role against ominous pregnancy complications linked to an increased level of the cytokine, such as abortion secondary to amniocentesis.

Mid-trimester amniocentesis and antibiotic prophylaxis

OBJECTIVES AND METHODS

Assuming that the rate of fetal loss after amniocentesis may be reduced in patients receiving antibiotic prophylaxis, we conducted a retrospective study on untreated versus treated patients receiving prophylactic antibiotics (amoxicillin/clavulanic-acid or azithromycin) and evaluated the fetal loss rate within the 22nd week of gestation, also with respect to the risk of spontaneous abortion, both preexisting and related to mid-trimester amniocentesis.

RESULTS

Spontaneous abortion occurred in 22 cases out of 1744 (1.26%). The incidence of spontaneous abortion was 1.3% among patients treated with antibiotic prophylaxis and 1.2% among untreated patients. Between patients with risk factors that predated amniocentesis, the spontaneous fetal loss rate was 9.2% in untreated patients versus 2.3% in patients treated (p = 0.10). In patients with procedure-related risk factors at amniocentesis, the spontaneous abortion rate was, respectively, 2.2 and 1.2% (p = 0.72).

CONCLUSION

Our data demonstrate that antibiotic prophylaxis does not reduce the risk of spontaneous abortion within the 22nd week of gestation. Compared with untreated patients, patients treated with amoxicillin showed the lower fetal loss rate (1.16 vs 0.31%), but the difference was not statistically significant (odds ratio (OR) = 3.68, p = 0.32). The same was true for patients with preexisting risks (OR = 4.25, p = 0.10).

Control of human trophoblast function

The trophoblast, i.e. the peripheral part of the human conceptus, exerts a crucial role in implantation and placentation. Both processes properly occur as a consequence of an intimate dialogue between fetal and maternal tissues, fulfilled by membrane ligands and receptors, as well as by hormone and local factor release. During blastocyst implantation, generation of distinct trophoblast cell types begins, namely the villous and the extravillous trophoblast, the former of which is devoted to fetal-maternal exchanges and the latter binds the placental body to the uterine wall. Physiological placentation is characterized by the invasion of the uterine spiral arteries by extravillous trophoblast cells arising from anchoring villi. Due to this invasion, the arterial structure is replaced by amorphous fibrinoid material and endovascular trophoblastic cells. This transformation establishes a low-resistance, high-capacity perfusion system from the radial arteries to the intervillous space, in which the villous tree is embedded. The physiology of pregnancy depends upon the orderly progress of structural and functional changes of villous and extravillous trophoblast, whereas a derangement of such processes can lead to different types of complications of varying degrees of gravity, including possible pregnancy loss and maternal life-threatening diseases. In this review we describe the mechanisms which regulate trophoblast differentiation, proliferation, migration and invasiveness, and the alterations in these mechanisms which lead to pathological conditions. Furthermore, based on the growing evidence that proper inflammatory changes and oxidative balance are needed for successful gestation, we explain the mechanisms by which agents able to influence such processes may be useful in the prevention and treatment of pregnancy disorders.

Renal effects of gentamicin in chronic bile duct ligated rats

Patients with advanced cirrhosis and rats with short-term bile duct ligation (BDL) are prone to develop nephrotoxicity from aminoglycosides. In this study, we characterized the renal response to gentamicin in rats with chronic BDL. BDL and sham-operated (SO) rats were given gentamicin (20 and 40 mg/kg/d) for 7 consecutive days, starting on the 18th postoperative day. Administration of gentamicin to SO group caused a decrease in cortical and medullary prostaglandin E(2)(PGE(2)) generation. However, mild reduction in creatinine clearance and an increase in fractional excretion of sodium occurred only in the BDL rats given the high gentamicin dose. This was accompanied by a reduction in cortical and medullary PGE(2) generation and a reduction in plasma nitric oxide production. In conclusion, gentamicin administration to rats with chronic BDL causes impairment of renal function. This happens only after the occurrence of simultaneous multiple insults to the renal protective mechanisms.

Effects of gentamicin sulfate on the contractility of myometrium isolated from non-pregnant cows

Gentamicin sulfate, an aminoglycoside antibiotic known to cause depression of neuromuscular function, is a drug of choice in intrauterine antibiotic treatment of bovine chronical or subclinical uterine infections but its effects on the contractility of the cow uterus have not been studied. The aim of this study was to characterize, in vitro, the effect of gentamicin sulfate on spontaneous as well as prostaglandin F2alpha (PGF2alpha) and oxytocin-induced contractility of the non-pregnant cow uterus. Myometrial strips were isolated from non-pregnant cows in follicular phase and suspended in a jacketed organ bath filled with Krebs solution at 37 degrees C (pH 7.4) continuously bubbled with 95% oxygen and 5% carbon dioxide and isometric contractions were recorded using isometric force displacement transducer. After manifestation of the spontaneous contractions during equilibration period the test substances PGF2alpha (1 microM), oxytocin (2.5 mIU/ml bath fluid) and gentamicin sulfate (150-600 microm) were added to the bath. The effects of gentamicin sulfate on amplitude (g) and frequency of spontaneous and the agonist-induced contractions were evaluated by 20 min intervals. Data were statistically analyzed using the Student's t-test and Wilcoxon signed-rank test where appropriate. P <0.05 was considered to be significant. Gentamicin sulfate inhibited spontaneous, as well as oxytocin or PGF2alpha-induced contractions in a dose-dependent manner. Although both the frequency and amplitude of contractions were significantly inhibited by gentamicin sulfate, the effect on the frequency of the spontaneous and agonist-induced contractions were more prominent than on the amplitude. The result from this in vitro study indicated that gentamicin sulfate inhibits spontaneous as well as oxytocin and PGF2alpha-induced contractions of myometrium isolated from non-pregnant cows. This may be of importance considering the potentially negative effect of gentamicin sulfate on uterine involution in cows with puerperal endometritis, resulting in impairment of fertility performance.

Inhibition of Amniotic Interleukin-6 and Prostaglandin E2 Release by Ampicillin

OBJECTIVE

To test the effect of ampicillin on amniotic interleukin-6 (IL-6) and prostaglandin E2 (PGE2) release.

METHODS

In an in vitro study, IL-6 and PGE2 release from amnion-like Wistar Institute Susan Hayflick cells was assayed under basal conditions, as well as after incubation with ampicillin. In an in vivo study, amniotic fluid IL-6 was assayed in a total of 212 patients submitted to genetic amniocentesis during the 17th week of their singleton physiological pregnancy. The study population was subdivided as follows: 92 patients sampled before ampicillin administration, 70 patients sampled 4 hours after administration of 1 g ampicillin, and 50 patients sampled 12 hours after administration of 1 g ampicillin.

RESULTS

At doses ranging from 10-7 to 10-4 M, ampicillin decreased IL-6 release from Wistar Institute Susan Hayflick cells. The drug effect was already statistically significant (-30%; P <.05) at the lowest concentration tested (10-7 M), reaching the maximum (-50%) at 10-6 M after 4 hours of incubation. Moreover, ampicillin concentrations ranging from 10-7 to 10-4 M decreased PGE2 release from Wistar Institute Susan Hayflick cells; maximal inhibition was reached at 10-6 M after 4 hours (-40%; P <.05). Finally, IL-6 levels measured in amniotic fluid of patients sampled 4 hours after ampicillin administration proved strongly and significantly reduced when compared with those sampled either before or 12 hours after treatment (P <.001).

CONCLUSION

The capacity of ampicillin to directly decrease amniotic IL-6 and PGE2 release should be considered in the management of bacterial and nonbacterial inflammatory complications of pregnancy mediated by the cytokine and prostanoid interaction.