Search

In late 2016, a collaborative between the HSE Integrated Care Programme for Patient Flow, National Clinical Programme for Anaesthesia (NCPA), National Clinical Programme in Surgery (NCPS), supported by the HSE Quality Improvement division and the RCSI’s Quality & Process Improvement Centre (QPIC) was established to oversee a sustainable theatre quality improvement programme.Building on the learning from the experience of introducing The Productive Operating Theatre (TPOT) in Ireland, TQIP aims to support hospitals and multidisciplinary perioperative teams who are committed to quality and process improvement to deliver sustainable improvements in: patient experience and outcomes; safety, quality & reliability of care; improved team effectiveness and staff wellbeing; value and improved efficiency; organisational Quality Improvement (QI) capability, enabling a culture of continuous improvement.Implementation of the programme at scale will improve patient flow and value for money through improved theatre efficiency (e.g. reduction in delays in start times, improved utilisation, reduced over runs and inventory costs), increased capability in the application of quality improvement tools with perioperative teams in the selected sites and increased uptake in other hospitals through demonstrated improvements in waiting lists and performance metrics. Furthermore a central repository and QI knowledge sharing network for perioperative teams will be developed including HSE Perioperative Teams certified in QI methodologies following an accredited programme.The Programme Governance and team have been established and agreement reached on a programme plan. The programme includes a QI training programme for perioperative teams in selected sites and on-going support from the QPIC Quality Improvement Advisors and Nurse Leads. Site selection is based on agreed readiness assessment criteria. Outcome measures will be specific to projects in sites but a target of 10% theatre efficiency improvement is expected by the end of year 1. Two sites, one of which has already begun introducing TPOT, and a new site have been identified as pioneers for the new programme. Specific projects in both sites will be agreed and commenced in early 2017. Early results are expected in the next 6-12 months.

Mammalian oocytes undergo significant growth during oogenesis and experience extensive cytoplasmic and nuclear modifications immediately before ovulation in a process commonly referred to as oocyte maturation. These changes are intended to maximize the developmental success after fertilization. Entry of a spermatozoon into the oocyte, which occurs a few hours after ovulation, initiates long-lasting oscillations in the free intracellular calcium ([Ca(2+)](i)) that are responsible for all events of oocyte activation and the initiation of the developmental programme that often culminates in the birth of young. Nevertheless, the cellular and molecular changes that occur during maturation to optimize development are transient, and exhibit rapid deterioration. Moreover, fertilization of oocytes after an extended residence in the oviduct (or in culture) initiates a different developmental programme, one that is characterized by fragmentation, programmed cell death, and abnormal development. Inasmuch as [Ca(2+)](i) oscillations can trigger both developmental programmes in mammalian oocytes, this review addresses one of the mechanism(s) possibly used by spermatozoa to initiate these persistent [Ca(2+)](i) responses, and the cellular and molecular changes that may underlie the postovulatory cellular fragmentation of ageing mammalian oocytes.

Injection of a porcine cytosolic sperm factor (SF) or of a porcine testicular extract into mammalian eggs triggers oscillations of intracellular free calcium ([Ca2+]i) similar to those initiated by fertilization. To elucidate whether SF activates the phosphoinositide (PI) pathway, mouse eggs or SF were incubated with U73122, an inhibitor of events leading to phospholipase C (PLC) activation and/or of PLC itself. In both cases, U73122 blocked the ability of SF to induce [Ca2+]i oscillations, although it did not inhibit Ca2+ release caused by injection of inositol 1,4,5-triphosphate (IP3). The inactive analogue, U73343, had no effect on SF-induced Ca2+ responses. To determine at the single cell level whether SF triggers IP3 production concomitantly with a [Ca2+]i rise, SF was injected into Xenopus oocytes and IP3 concentration was determined using a biological detector cell combined with capillary electrophoresis. Injection of SF induced a significant increase in [Ca2+]i and IP3 production in these...

Sperm entry in mammalian eggs initiates oscillations in the concentration of free calcium ([Ca(2+)](i)). In mouse eggs, oscillations start at metaphase II (MII) and conclude as the zygotes progress into interphase and commence pronuclear (PN) formation. The inositol 1,4,5-trisphosphate receptor (IP(3)R-1), which underlies the oscillations, undergoes degradation during this transition, suggesting that one or more of the eggs' Ca(2+)-releasing machinery components may be regulated in a cell cycle-dependent manner, thereby coordinating [Ca(2+)](i) responses with the cell cycle. To ascertain the site(s) of interaction, we initiated oscillations at different stages of the cell cycle in zygotes with different IP(3)R-1 mass. In addition to sperm, we used two other agonists: porcine sperm factor (pSF), which stimulates production of IP(3), and adenophostin A, a non-hydrolyzable analogue of IP(3). None of the agonists tested induced oscillations at interphase, suggesting that neither decreased IP(3)R-1 mass nor lack of production or excessive IP(3) degradation can account for the insensitivity to IP(3) at this stage. Moreover, the releasable Ca(2+) content of the stores did not change by interphase, but it did decrease by first mitosis. More importantly, experiments revealed that IP(3)R-1 sensitivity and possibly IP(3) binding were altered at interphase, and our data demonstrate stage-specific IP(3)R-1 phosphorylation by M-phase kinases. Accordingly, increasing the activity of M-phase kinases restored the oscillatory-permissive state in zygotes. We therefore propose that the restriction of oscillations in mouse zygotes to the metaphase stage may be coordinated at the level of IP(3)R-1 and that this involves cell cycle stage-specific receptor phosphorylation.

KN-93, a Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) inhibitor, concentration-dependently and reversibly inhibited inositol 1,4,5-trisphosphate receptor (IP(3)R)-mediated [Ca(2+)](i) signaling in mouse eggs and permeabilized A7r5 smooth muscle cells, two cell types predominantly expressing type-1 IP(3)R (IP(3)R-1). KN-92, an inactive analog, was ineffective. The inhibitory action of KN-93 on Ca(2+) signaling depended neither on effects on IP(3) metabolism nor on the filling grade of Ca(2+) stores, suggesting a direct action on the IP(3)R. Inhibition was independent of CaMKII, since in identical conditions other CaMKII inhibitors (KN-62, peptide 281-309, and autocamtide-related inhibitory peptide) were ineffective and since CaMKII activation was precluded in permeabilized cells. Moreover, KN-93 was most effective in the absence of Ca(2+). Analysis of Ca(2+) release in A7r5 cells at varying [IP(3)], of IP(3)R-1 degradation in eggs, and of [(3)H]IP(3) binding in Sf9 microsomes all indicated that KN-93 did not affect IP(3) binding. Comparison of the inhibition of Ca(2+) release and of [(3)H]IP(3) binding by KN-93 and calmodulin (CaM), either separately or combined, was compatible with a specific interaction of KN-93 with a CaM-binding site on IP(3)R-1. This was also consistent with the much smaller effect of KN-93 in permeabilized 16HBE14o(-) cells that predominantly express type 3 IP(3)R, which lacks the high affinity CaM-binding site. These findings indicate that KN-93 inhibits IP(3)R-1 directly and may therefore be a useful tool in the study of IP(3)R functional regulation.

Publisher Summary Mammalian oocytes are ovulated arrested at the metaphasic stage of the second meiotic division (MII), from which they initiate the embryonic development if fertilized in a timely manner. Prior to the MII arrest, the oocytes undergo maturation, during which they progress from the G2/M stage of the first meiotic division to MII. During this process, the oocytes undergo significant reorganization and redistribution of organelles and acquire a full complement of signaling molecules. These changes render the mammalian oocytes competent to exit meiosis and initiate embryonic development. Exit from the MII arrest is accomplished by fertilization, and is commonly referred to as “oocyte activation.” Oocyte activation comprises a sequence of cellular changes, all of which have to be completed to assure the development to the term. Oocyte activation is triggered by Ca2+ release, and in mammalian oocytes, multiple [Ca2+]i oscillations are required to achieve full activation. This chapter focuses on the Ca2+ requirements of mammalian oocytes necessary to initiate activation and development, and compares the mechanisms of action of the various parthenogenetic procedures. The probable pathway(s) by which the sperm may initiate Ca2+ release and the mechanism(s) that may control the persistence and termination of oscillations are also reviewed. The cellular and molecular events required for a pronuclear assembly as well as the likely differences in the assembly and composition of nuclear envelope membranes formed following the transfer of a somatic nucleus and their impact on the embryo development are discussed. Finally, recent evidence suggesting a role for [Ca2+]i oscillations as an apoptotic-inducing agent, rather than an activating agent, is examined.