Experimental biology and medicine
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Exp. Biol. Med. (Maywood) · Apr 2010
Model-derived assessment of cerebrovascular resistance and cerebral blood flow following traumatic brain injury.
The published guidelines point out the need for the development of methods that individualize patient cerebral perfusion management and minimize secondary ischemic complications associated with traumatic brain injury. A laboratory method has been developed to determine model-derived assessments of cerebrovascular resistance (mCVR) and cerebral blood flow (mCBF) from cerebrovascular pressure transmission, and the dynamic relationship between arterial blood pressure (ABP) and intracranial pressure (ICP). The aim of this two-fold study is to (1) evaluate relative changes in the model-derived parameters of mCVR and mCBF with the corresponding changes in the pial arteriolar vascular parameters of pial arteriolar resistance (PAR) and relative pial arteriolar blood flow (rPABF); and (2) examine the efficacy of the proposed modeling methodology for continuous assessment of the state of cerebrovascular regulation by evaluating relative changes in the model-derived parameters of CBF and cerebrovascular resistance in relation to changes of cerebral perfusion pressure prior to and following fluid percussion brain injury. ⋯ Following fluid percussion, hypertensive challenge resulted in a significant decrease of PAR and mCVR and consistent with impaired cerebrovascular regulation. Hypertensive challenge significantly increased both rPABF and mCBF, which approximately doubled with increased CPP with correlation values of r = 0.96 (P < 0.01) and r = 0.97 (P
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Exp. Biol. Med. (Maywood) · Jan 2010
Prediction of outcome in patients with acute respiratory distress syndrome by bronchoalveolar lavage inflammatory mediators.
Acute respiratory distress syndrome (ARDS) is characterized by overwhelming lung inflammation. This study explored the inflammatory mediators in bronchoalveolar lavage fluid (BALF) for prognostic relevance in patients with infection-induced ARDS. Thirty-nine patients with infection-induced ARDS (28 pneumonia and 11 extrapulmonary sepsis) and two patients with cardiogenic lung edema as the control were included. ⋯ In conclusion, we show the expression profiles of inflammatory mediators in BALF of infection-induced ARDS. Among the mediators, IL-8 is the most significant predictor for mortality, and several mediators are correlated with clinical severity. However, potential selection bias due to limited control subjects and lack of serum inflammatory mediator data suggest a necessity of further studies to confirm our findings.
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Exp. Biol. Med. (Maywood) · Nov 2009
Interaction between pre- and postconditioning in the in vivo rat heart.
Patients with an impending myocardial infarction may be preconditioned by pre-infarct angina. Hence, it is important to establish whether ischemic postconditioning is still effective in preconditioned hearts. We therefore studied in anesthetized rats the effect of postconditioning after coronary artery occlusions (CAO) of 60 min in control hearts, hearts preconditioned by a single 15-min CAO (1IPC15) or a triple 3-min CAO (3IPC3). ⋯ Lack of additional protection may be related to the observation that postconditioning and preconditioning are both mediated via NO synthase. In contrast, the increase in infarct size by postconditioning following a 30-min CAO is abolished by either IPC stimulus. These findings indicate that the interaction between preconditioning and postconditioning is highly dependent on the duration of index ischemia, but independent of the preconditioning stimulus.
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Exp. Biol. Med. (Maywood) · Oct 2009
Propensity of human embryonic stem cell lines during early stage of lineage specification controls their terminal differentiation into mature cell types.
Human embryonic stem cells (hESCs) are able to stably maintain their characteristics for an unlimited period; nevertheless, substantial differences among cell lines in gene and protein expression not manifested during the undifferentiated state may appear when cells differentiate. It is widely accepted that developing an efficient protocol to control the differentiation of hESCs will enable us to produce adequate numbers of desired cell types with relative ease for diverse applications ranging from basic research to cell therapy and drug screening. Hence of late, there has been considerable interest in understanding whether and how hESC lines are equivalent or different to each other in their in vitro developmental tendencies. ⋯ Upon further differentiation, HUES-9 generated largely neural cells (neurons, oligodendrocytes, astrocytes and gangliosides) whereas HUES-7 formed mesendodermal derivatives, including cardiomyocytes, skeletal myocytes, endothelial cells, hepatocytes and pancreatic cells. Overall, our findings endorse the hypothesis that independently-derived hESCs biologically differ among themselves, thereby displaying varying differentiation propensity. These subtle differences not only highlight the importance of screening and deriving lines for lineage-specific differentiation but also indicate that individual lines may possess a repertoire of capabilities that is unique.
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Exp. Biol. Med. (Maywood) · Oct 2009
Comparative StudyComparison of isoflurane-, sevoflurane-, and desflurane-induced pre- and postconditioning against myocardial infarction in mice in vivo.
The murine in vivo model of acute myocardial infarction is increasingly used to investigate anesthetic-induced preconditioning (APC) and postconditioning (APOST). However, in mice the potency of different volatile anesthetics to reduce myocardial infarct size (IS) has never been investigated systematically nor in a head to head comparison with regard to ischemic preconditioning (IPC) and postconditioning (IPOST). Male C57BL/6 mice were subjected to 45 min of coronary artery occlusion (CAO) and 180 min of reperfusion. ⋯ ISO APC significantly reduced IS compared to control when administered 30 min (33 +/- 4%*), but not when administered 15 min (48 +/- 6%). DES APC significantly reduced IS compared to control and to SEVO APC (7 +/- 1%*). Within the paradigm of preconditioning, the potency of volatile anesthetics to reduce myocardial infarct size in mice significantly increases from ISO over SEVO to DES, whereas within the paradigm of postconditioning the potency of these volatile anesthetics to reduce myocardial infarct size in mice is similar.