Regulation by endogenous opioids of suckling-induced prolactin secretion in pregnant and lactating rats: Role of ovarian steroids

Evidence suggests that endogenous opioid peptides are implicated in the suckling-induced prolactin rise. We explored the role of the opioid system and the participation of ovarian hormones in the regulation of prolactin induced by the suckling stimulus at the end of pregnancy in rats with developed maternal behavior, and during lactation. Suckling for 24 h induced a significant increase in serum prolactin on day 19 of pregnancy, which was increased more than three times when naloxone (2 mg/kg s.c.) or mifepristone (2 mg/kg) was administered. The combination of naloxone and mifepristone did not increase serum prolactin more than either compound alone. Administration of tamoxifen (500 μg/kg orally) on days 14 and 15 of pregnancy completely abolished the effect of naloxone, indicating a role for estrogens in establishing this inhibitory role of opioids. To examine the participation of the opioid system during lactation, we used groups of rats on days 1, 3, 5, 12 and 19 postpartum either (i) isolated from the pups for 4 h, or (ii) isolated from the pups for 3.5 h and reunited with them and suckled for 30 min. Naloxone, given just before replacing the pups, prevented the increase in serum prolactin levels observed in the suckled group of rats but had no effect on the basal levels of the isolated rats. To examine whether the participation of the opioid system in the release of prolactin is dependent on the variation of progesterone levels, rats on day 20 of pregnancy were implanted with two cannulae containing progesterone (that blocked postpartum ovulation) or cholesterol, and cesarean surgery was performed on day 21. To maintain lactation, pups (1-3 days old) were replaced every 24 h, and 4 days after the cesarean eight pups were placed in the cage at 1800 h to maintain a strong suckling stimulus during the following 24 h. Naloxone administration significantly reduced serum prolactin levels in control (cholesterol) rats but progesterone implants prevented the inhibitory effect of naloxone and this effect was not modified by treatment with estrogen. These results indicate that the opioid system modulates suckling-induced prolactin secretion, passing from an inhibitory action before delivery to a stimulatory action during lactation. This regulatory shift seems to be dependent on the fall in progesterone concentration at the end of pregnancy and the subsequent increase after the postpartum ovulation and luteal phase.Fil: Soaje, Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: de Di Nasso, E. G.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Deis, Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentin

Proactive risk assessment through failure mode and effect analysis (FMEA) for perioperative management model of oral anticoagulant therapy. A pilot project

Introduction: Correct perioperative management of anticoagulant therapy is essential to prevent thromboembolic events and reduce the risk of bleeding. The lack of universally accepted guidelines makes perioperative anticoagulant therapy management difficult. The present study aims to identify the perioperative risks of oral anticoagulant therapy and to reduce adverse events through Failure Mode and Effect Analysis (FMEA). Materials and Methods: A multidisciplinary working group was set up, and four main phases of the process were identified. Each of these phases was divided into micro-activities to identify the related possible failure modes and their potential consequences. The Risk Priority Number was calculated for each failure mode. Results and Discussion: Seventeen failure modes were identified in the entire perioperative period; those with a higher priority of intervention concern the incorrect timing between therapy suspension and surgery, and the incorrect assessment of the bleeding risk related to the invasive procedure. Conclusion: The FMEA method can help identify anticoagulant therapy perioperative failures and implement the management and patient safety of surgical procedures

Minimally invasive aortic valve surgery

Aortic valve disease is a prevalent disorder that affects approximately 2% of the general adult population. Surgical aortic valve replacement is the gold standard treatment for symptomatic patients. This treatment has demonstrably proven to be both safe and effective. Over the last few decades, in an attempt to reduce surgical trauma, different minimally invasive approaches for aortic valve replacement have been developed and are now being increasingly utilized. A narrative review of the literature was carried out to describe the surgical techniques for minimally invasive aortic valve surgery and report the results from different experienced centers. Minimally invasive aortic valve replacement is associated with low perioperative morbidity, mortality and a low conversion rate to full sternotomy. Long-term survival appears to be at least comparable to that reported for conventional full sternotomy. Minimally invasive aortic valve surgery, either with a partial upper sternotomy or a right anterior minithoracotomy provides early- and long-term benefits. Given these benefits, it may be considered the standard of care for isolated aortic valve disease

Suitability of switchgrass (Panicum virgatum L.) as a forage crop in the Mediterranean area

In Mediterranean rainfed cropping systems, drought-resistant crops can increase yield and availability of forage during the summer period. In North America, switchgrass (Panicum virgatum L.) has been used for decades as pasture and fodder. In Europe, switchgrass has been investigated mainly for its potential as an energy crop. e overall aim of the present study was to analyse the suitability of switchgrass as a forage crop in a Mediterranean environment. A eld trial was carried out in Central Italy (Pisa) to evaluate the productivity and nutritive value in mature stands of two switchgrass varieties (Alamo and Blackwell). Alamo reached the maturity for hay harvest (boot stage) in August, about one-month delay with respect to Blackwell. At this stage, the biomass was 13.3 and 7.5 t ha-1 of dry matter (DM) in Alamo and Blackwell, respectively. Both varieties produced a summer regrowth harvested in autumn. Nutritive value declined during the growing season due to the increase of bre and the reduction of protein content. Saponin content signi cantly di ered between varieties and according to the growth stage, ranging from 1.8 to 4.5 mg g-1 DM. is study provides useful knowledge to favour the introduction of perennial grasses as forage crops in the Mediterranean, leading to several environmental bene ts when compared with the annual species that currently cover half of the forage cropland in Tuscany

Non-sutureless minimally invasive aortic valve replacement: mini-sternotomy versus mini-thoracotomy: a series of 1130 patients

OBJECTIVES: Aortic valve replacement through conventional sternotomy still represents the gold-standard surgical approach for aortic valve disease. However, given the increasing number of patients with comorbidities, strategies that can improve operative results are always sought. Minimally invasive aortic valve surgery, although related to a steep learning curve, might be associated with improved post- operative outcomes. The main aim of this study was to assess whether significant differences exist in terms of operative and early results between a mini-sternotomy and a right mini-thoracotomy approach for isolated aortic valve replacement without sutureless technologies. METHODS: This is an observational retrospective multicentre study from nine Italian cardiac centres that analyses prospectively collected data of patients who underwent isolated minimally invasive aortic valve replacement between January 2010 and December 2014. Two approaches are considered (mini-sternotomy and mini-thoracotomy) and compared in terms of operative and early outcomes. RESULTS: After interrogation of the centralized database, a total of 1130 patients were retrieved (854 mini-sternotomy and 276 mini-thoracotomy). Patients in the mini-sternotomy group had a higher risk profile. There was no difference in terms of early mortality; cardiopulmonary bypass and cross-clamp time did not differ significantly between the groups; and a significantly higher number of reoperations for bleeding was observed in the right mini-thoracotomy group. CONCLUSIONS: Both mini-sternotomy and mini-thoracotomy could be performed safely, with low mortality and postoperative morbidity. The mini-thoracotomy approach was associated with a significantly higher rate of reoperation for bleeding. Uptake among cardiac centres was low. Sutureless technologies could potentially increase surgical volume by simplifying the mini-thoracotomy procedure

Hypernatural Numbers as Ultrafilters

In this paper we present a use of nonstandard methods in the theory of ultrafilters and in related applications to combinatorics of numbers