Angiotensin-converting enzyme inhibition and angiotensin II type 1 receptor blockade prevent cardiac remodeling in pigs after myocardial infarction: role of tissue angiotensin II

BACKGROUND: The mechanisms behind the beneficial effects of renin-angiotensin system blockade after myocardial infarction (MI) are not fully elucidated but may include interference with tissue angiotensin II (Ang II). METHODS AND RESULTS: Forty-nine pigs underwent coronary artery ligation or sham operation and were studied up to 6 weeks. To determine coronary angiotensin I (Ang I) to Ang II conversion and to distinguish plasma-derived Ang II from locally synthesized Ang II, (125)I-labeled and endogenous Ang I and II were measured in plasma and in infarcted and noninfarcted left ventricle (LV) during (125)I-Ang I infusion. Ang II type 1 (AT(1)) receptor-mediated uptake of circulating (125)I-Ang II was increased at 1 and 3 weeks in noninfarcted LV, and this uptake was the main cause of the transient elevation in Ang II levels in the noninfarcted LV at 1 week. Ang II levels and AT(1) receptor-mediated uptake of circulating Ang II were reduced in the infarct area at all time points. Coronary Ang I to Ang II conversion was unaffected by MI. Captopril and the AT(1) receptor antagonist eprosartan attenuated postinfarct remodeling, although both drugs increased cardiac Ang II production. Captopril blocked coronary conversion by >80% and normalized Ang II uptake in the noninfarcted LV. Eprosartan did not affect coronary conversion and blocked cardiac Ang II uptake by >90%. CONCLUSIONS: Both circulating and locally generated Ang II contribute to remodeling after MI. The rise in tissue Ang II production during angiotensin-converting enzyme inhibition and AT(1) receptor blockade suggests that the antihypertrophic effects of these drugs result not only from diminished AT(1) receptor stimulation but also from increased stimulation of growth-inhibitory Ang II type 2 receptors

Changing perspectives on the internationalization of R&D and innovation by multinational enterprises: a review of the literature

Internationalization of R&D and innovation by Multinational Enterprises (MNEs) has undergone a gradual and comprehensive change in perspective over the past 50 years. From sporadic works in the late 1950s and in the 1960s, it became a systematically analysed topic in the 1970s, starting with pioneering reports and “foundation texts”. Our review unfolds the theoretical and empirical evolution of the literature from dyadic interpretations of centralization versus decentralization of R&D by MNEs to more comprehensive frameworks, wherein established MNEs from Advanced Economies still play a pivotal role, but new players and places also emerge in the global generation and diffusion of knowledge. Hence views of R&D internationalization increasingly rely on concepts, ideas and methods from IB and other related disciplines such as industrial organization, international economics and economic geography. Two main findings are highlighted. First, scholarly research pays an increasing attention to the network-like characteristics of international R&D activities. Second, different streams of literature have emphasized the role of location- specific factors in R&D internationalization. The increasing emphasis on these aspects has created new research opportunities in some key areas, including inter alia: cross-border knowledge sourcing strategies, changes in the geography of R&D and innovation, and the international fragmentation of production and R&D activities

Minimally Invasive Strip Craniectomy Simplifies Anesthesia Practice in Patients With Isolated Sagittal Synostosis

Background: Traditional open corrective surgery for isolated sagittal synostosis entails significant blood loss, transfusion rates, morbidity, and a lengthy hospitalization. Minimally invasive strip craniectomy (MISC) was introduced to avoid the disadvantages of open techniques. Objectives: The aim of the study was, first, to compare the anesthesia practice in MISC and open extended strip craniectomy (OESC), and, second, to evaluate the incidence of perioperative complications in both surgical procedures. Methods: A retrospective analysis was conducted for all consecutive patients receiving either OESC or MISC for nonsyndromic isolated sagittal synostosis between January 2006 and February 2014. The primary endpoints were the volume of blood loss, the volume of infused blood products, the duration of surgery, the anesthesia time, the intubation time, and the length of admission to high care units and the hospital. Results: In MISC, the median duration of surgery (90 versus 178 min.), anesthesia time (178 versus 291 min), and intubation time (153 versus 294 min) were all significantly (P < 0.001) shorter than in OESC. Intraoperative blood loss was less in MISC than in OESC (3.8 versus 29.7 mL/kg, P < 0.001), requiring less crystalloids (33.3 versus 76.9 mL/kg, P < 0.001) as well as less erythrocyte transfusions (0.0 versus 19.7 mL/kg, P < 0.001) in a smaller number of patients (2/20 versus 13/15). The improved hemodynamic stability in MISC allowed for placement of less arterial and central venous catheters. After OESC all 15 patients were admitted to high care units, compared with 9 of 20 in MISC. The overall median hospital stay was shorter in MISC than in OESC (4 versus 6 d, P < 0.001). Although the incidence of technical complications was similar in both techniques, patients in MISC were less affected by perioperative electrolyte and acid-base disturbances and postoperative pyrexia. Conclusions: Minimally invasive strip craniectomy simplifies anesthesia practice relative to OESC with shorter operative times, decreased needs for replacement fluids and blood products, lessened requirements for invasive monitoring, and reduced demands for postoperative high care beds