Gender influences volume regulation via several mechanisms; whether these include microvascular exchange, especially in the heart, is not known. In response to adenosine (Ado), permeability (P s )to protein of coronary arterioles of female pigs decreases acutely. Whether Ado induces similar P s changes in arterioles from males or whether equivalent responses occur in coronary venules of either sex has not been determined. Hypotheses that 1) basal P s properties and 2) P s responses to vasoactive stimuli are sex independent were evaluated from measures of P s to two hydrophilic proteins, α-lactalbumin and porcine serum albumin (PSA), in arterioles and venules isolated from hearts of adult male and female pigs. Consistent with hypothesis 1, basal P s values of both microvessel types were independent of sex. Contrary to hypothesis 2, P s responses to Ado varied with sex, protein, and vessel type. Confirming earlier studies, Ado induced a ~20% decrease in P s to both proteins in coronary arterioles from females. In arterioles from males, Ado did not change P s for α-lactalbumin ( , 3 ± 13%) whereas P s for PSA ( ) decreased by 27 ± 8% (P < 0.005). In venules from females, Ado elevated by 44 ± 20% (P < 0.05), whereas in those from males, Ado reduced by 24 ± 5% (P < 0.05). The variety of outcomes is consistent with transvascular protein and protein-carried solute flux being regulated by multiple sex-dependent mechanisms in the heart and provides evidence of differences in exchange homeostasis of males and females in health and, likely, disease.
Objective-To assess the role of adenosine receptors in the regulation of coronary microvascular permeability to porcine serum albumin ( ).Methods-Solute flux was measured in single perfused arterioles and venules isolated from pig hearts using fluorescent dye-labeled probes by microspectro-fluorometry. Messenger RNA, protein, and cellular distribution of adenosine receptors in arterioles and venules were analyzed by RT-PCR, immunoblot, and immunofluorescence.Results-Control venule (10.7 ± 4.8 × 10 −7 cm s −1 ) was greater than that of arterioles (6.4 ± 2.8 × 10 −7 cm · s −1 ; p <.05). Arteriolar decreased ( p <.05) with adenosine suffusion over the range from 10 −8 to 10 −5 M, while venular did not change. The nonselective A 1 and A 2 receptor antagonist, 8-(p-sulfophenyl) theophylline, blocked the adenosine-induced decrease in arteriolar . Messenger RNA for adenosine A 1 ,A 2A ,A 2B , and A 3 receptors was expressed in arterioles and venules. Protein for A 1 , A 2A , and A 2B , but not A 3 , was detected in both microvessel types and was further demonstrated on vascular endothelial cells. Conclusion-Arteriolardecreases with adenosine suffusion but not venular . Adenosine A 1 , A 2A , and A 2B receptors are expressed in both arterioles and venules. Selective receptor-linked cellular signaling mechanisms underlying the regulation of permeability remain to be determined. Keywords adenosine receptor; arteriole; heart; permeability; swine; venule In the heart the vasculature is critical for maintaining cardiac function via delivery of O 2 and nutrients, including free fatty acids carried on albumin, to the interstitial spaces around the myocardial cells and transport of metabolic by-products and hormones such as the natriuretic peptides away from the myocytes. Coronary exchange capacity depends on the surface area and permeability of all vessels available for exchange. Adenosine (ADO), a NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript metabolite of adenine nucleotides, is increased dramatically when an imbalance between oxygen supply and consumption exists under a variety of conditions including hypoxia, ischemia/reperfusion, and inflammation (4,61,62). Subsequently, ADO plays a myriad of important cardioprotective roles, including vasodilatation. Conventionally, it is assumed that permeability properties are either unchanged or affected insignificantly when coronary exchange capacity is assessed under the condition of constant surface area during ADOinduced maximal vasodilatation (37). However, evidence from studies with cultured endothelium (15,54,65), as well as conduit and microvascular vessels (5,12,35) showed that ADO influenced exchange, eliciting predominantly a decrease in permeability. It has been argued that findings from in vivo studies result primarily from a direct response of the endothelium to ADO combined with secondary effects of ADO on exchange mediated by hemodynamics, platelet, neutrophil, and/or mast cell functions.Recently, we modified the techniques for asse...
Background: Constant interruptions and continual data flow result in information overload for clinicians and become barriers to identification and extraction of relevant patient data and its correct interpretation. The aim of the study was to describe the types, frequencies, and impact of intensive care unit (ICU) interruptions on patient safety event occurrences and electronic health records (EHR) use. Methods:We conducted a live observational study for 6 weeks, observing critical care physicians' and other providers' communication while recording interruptions, patient safety events, and EHR use.Results: Across 55 hours, the researchers observed 7515 ICU tasks, 15.7% of which were interrupted. We found that technological interruptions directly influences the occurrence of patient safety events: an increase in technological interruptions directly contributes to patient safety event occurrence (P = 0.004). Technological interruptions had a direct effect on human interruptions, as the frequency of technological interruptions increase, human interruptions also increase (P = 0.02). Conclusions:A prospective, observational study was conducted to understand the relationship between interruptions and patient safety events and EHR use, in a time-sensitive, activity-based study in a large academic medical center with a certified EHR system. We found that technological interruptions were statistically correlated to the occurrence of patient safety events, and human interruptions significantly affected the level of EHR use. This study recommends that ICUs adopt a safety culture that promotes minimizing unnecessary interruptions, such as side conversations during rounds, for improved quality of care.
Measurement of fluorescently labeled albumin leakage from mesenteric venules depends on the dye used to label the albumin and requires an assessment of losses from the extravascular measuring region.
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