Irreversible Injury and CO2Production from Cells of Nitella flexilis

1929 ◽  
Vol 87 (5) ◽  
pp. 660-664
Author(s):  
P. A. Davies
Keyword(s):  
Irreversible Injury ◽  
Nitella Flexilis

Patterns and predictors of serious surf-related injuries in Hawaii

Trauma ◽  
2021 ◽  
pp. 146040862098362
Author(s):  
Ashley Marumoto ◽  
Adam Guzman ◽  
William B. Harris ◽  
John Vossler ◽  
Sidney Johnson
Keyword(s):  
Risk Factors ◽  
Public Awareness ◽  
Leisure Activity ◽  
Severe Injury ◽  
Spine Injury ◽  
Inherent Risk ◽  
Risk Of Injury ◽  
Safety Interventions ◽  
Associated Risk Factors ◽  
Irreversible Injury

Introduction Surfing is a popular leisure activity with inherent risk of injury that many participants fail to mitigate. There is a paucity of literature reporting severe surf-related trauma and associated risk factors. Methods A retrospective observational study of registry data from Honolulu’s main trauma center assessing surf-related injuries and risk factors for severe injury was performed between January 1, 2014 and December 31, 2018. Results Spine (35.1%), face (17.5%), and head (12.3%) injuries were the most common injuries identified in this cohort. A number of predictors for severe injury as well as serious spine injury were identified. Major risk factors for severe injury and serious spine injury included location of injury on Maui (Severe injury: OR 6.79, 95%CI 1.43–40.35, p = 0.0217; serious spine injury: OR 7.27, 95%CI 1.39–58.24, p = 0.0308) and being from one of the 48 contiguous states (severe injury: OR 3.33, 95%CI 1.10–10.98, p = 0.0388; serious spine injury: OR 2.95, 95%CI 1.08–8.46, p = 0.0379). Conclusion Understanding the nature of surf-related injuries and who is at risk can help to inform safety interventions that may prevent severe, sometimes irreversible injury. Efforts should be made to increase public awareness to the potential risk of surf-related activities.

scholarly journals Enhancing Recovery after Stroke with Noradrenergic Pharmacotherapy: A New Frontier?

2000 ◽  
Vol 27 (2) ◽  
pp. 97-105 ◽  
Author(s):  
David J. Gladstone ◽  
Sandra E. Black
Keyword(s):  
Animal Studies ◽  
Recovery Of Function ◽  
Recovery Process ◽  
Stroke Recovery ◽  
Therapeutic Interventions ◽  
New Frontier ◽  
Focal Brain Injury ◽  
Completed Stroke ◽  
Scientific Attention ◽  
Irreversible Injury

ABSTRACT:Despite much progress in stroke prevention and acute intervention, recovery and rehabilitation have traditionally received relatively little scientific attention. There is now increasing interest in the development of stroke recovery drugs and innovative rehabilitation techniques to promote functional recovery after completed stroke. Experimental work over the past two decades indicates that pharmacologic intervention to enhance recovery may be possible in the subacute stage, days to weeks poststroke, after irreversible injury has occurred. This paper discusses the concept of “rehabilitation pharmacology” and reviews the growing literature from animal studies and pilot clinical trials on noradrenergic pharmacotherapy, a new experimental strategy in stroke rehabilitation. Amphetamine, a monoamine agonist that increases brain norepinephrine levels, is the most extensively studied drug shown to promote recovery of function in animal models of focal brain injury. Further research is needed to investigate the mechanisms and clinical efficacy of amphetamine and other novel therapeutic interventions on the recovery process.

Abstract 16939: Reversible Myocardial Ischemia Sufficient to Produce Transient Stunning Leads to Delayed Cardiac Troponin I Release That Reflects Focal Myocyte Apoptosis in the Absence of Pathological Infarction

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Brian R Weil ◽  
Rebeccah F Young ◽  
Xiaomeng Shen ◽  
Gen Suzuki ◽  
Jun Qu ◽  
...  
Keyword(s):  
Cardiac Troponin ◽  
Coronary Occlusion ◽  
Troponin I ◽  
Myocardial Necrosis ◽  
Heart Tissue ◽  
Cardiac Troponin I ◽  
Wall Thickening ◽  
Reversible Ischemia ◽  
Myocyte Apoptosis ◽  
Irreversible Injury

Introduction: The release of cardiac troponin I (cTnI) after reversible ischemia is controversial. It has been hypothesized that elevations in serum cTnI in this scenario reflect selective release from an exchangeable pool rather than cellular necrosis since irreversible injury with sarcolemmal membrane disruption does not begin until ischemia exceeds 15 minutes following a total coronary occlusion. Objective: To determine whether cTnI release occurs after a brief coronary occlusion when the duration of ischemia is insufficient to induce myocyte necrosis. Methods: Closed-chest propofol-anesthetized swine (n=10) were subjected to a 10 minute LAD occlusion. Blood sampling was performed to measure serum cTnI concentrations before, during and after ischemia. Myocardial tissue was collected either 1 hour (n=5) or 24 hours (n=5) after reperfusion for pathological assessment of infarction (TTC) and apoptosis (TUNEL). Results: Regional LAD wall thickening was 60 ± 4% at baseline and became dyskinetic during coronary occlusion (-4 ± 2%, p<0.05). One hour after reperfusion, wall thickening improved but remained depressed relative to baseline, indicative of myocardial stunning (37 ± 4%, p<0.05). It returned to normal after 24 hours (59 ± 2%). Serum cTnI was 0.01 ± 0.01 ng/mL at baseline and remained unchanged at the end of ischemia. A slight increase in cTnI was observed 1 hour after reperfusion (0.06 ± 0.02 ng/mL, p<0.05 vs. baseline), followed by a marked elevation at 24 hours (1.02 ± 0.57 ng/mL, p<0.05 vs. baseline). TTC staining demonstrated no evidence of infarction. Heart tissue collected 1 hour after reperfusion demonstrated a regional increase in apoptotic myocytes (LAD: 17.7 ± 3.7 myocytes/cm 2 vs. Remote: 3.1 ± 2.0 myocytes/cm 2 , p<0.05). Myocyte apoptosis normalized 24 hours after reperfusion (LAD: 5.2 ± 2.3 myocytes/cm 2 vs. Remote: 3.6 ± 1.5 myocytes/cm 2 ) when serum cTnI remained elevated. Conclusion: A duration of reversible ischemia compatible with angina can lead to cTnI release that is similar in magnitude to that occurring with myocardial infarction. Rather than infarction or release from an exchangeable cTnI pool, the rise in serum cTnI is delayed and appears to reflect focal programmed myocyte death from apoptosis rather than myocardial necrosis.

Determination of transport constants of isolated Nitella cell walls

1968 ◽  
Vol 46 (4) ◽  
pp. 317-327 ◽  
Author(s):  
M. T. Tyree
Keyword(s):  
Activation Energy ◽  
Cell Wall ◽  
Diffusion Coefficient ◽  
Cell Walls ◽  
Transport Coefficients ◽  
Irreversible Thermodynamics ◽  
Kcal Mole ◽  
Limiting Value ◽  
Nitella Flexilis

Transport coefficients LPP, LPE, LEP, and LEE for electrokinetic equations according to irreversible thermodynamics, the Onsager coefficients, were measured for isolated Nitella flexilis cell walls in KCl solutions ranging from 10−4 to 100 normal. LPP and LPE (= LEP) were found to be independent of KCl concentration and equal to 1.4 × 10−6 cm3 sec−1 cm−2 (joule cm−3)−1 cm and 6 × 10−5 cm3 sec−1 cm−2 volt−1 cm respectively. LEE was a function of the salt concentration, reaching a limiting value of about 1.2 × 10−3 mho cm−1 in 10−4 N KCl. The activation energy for movement of KCl in cell walls was found to be 4.33 Kcal mole−1; the diffusion coefficient for KCl in cell walls was calculated by two methods to be 8 × 10−6 cm2 sec−1; and the concentration of the fixed ions in Nitella cell walls from the above data was estimated at greater than 0.04 equivalent per liter of cell wall. Electroosmosis in Nitella membranes is re-examined in the light of the measured transport coefficients and it is concluded that under proper conditions the cell wall of Nitella can contribute significantly (~20% or more) to the observed electroosmosis of living Nitella cells.

Cellular electrophysiological marker of irreversible ischemic myocardial injury

1978 ◽  
Vol 235 (5) ◽  
pp. H559-H568
Author(s):  
J. McGee ◽  
D. H. Singer ◽  
R. E. Eick ◽  
R. Kloner ◽  
N. Belic ◽  
...  
Keyword(s):  
Ischemic Injury ◽  
Resting Potential ◽  
Morphological Evidence ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Coronary Ligation ◽  
Microscopic Studies ◽  
Anesthetized Dogs ◽  
Definition Of ◽  
Irreversible Injury

Glass microelectrode studies on posterior papillary muscle (PPM) slice preparations from 20 pentobarbital-anesthetized dogs (15 subjected to prior circumflex coronary artery ligation, 5 to sham ligation) have resulted in the definition of an electrophysiological marker of irreversible ischemic injury, namely, findings of areas composed of cells unable to generate a significant resting potential (less than -25) mV), designated "electrically inactive areas." Electrically inactive areas were essentially confined to PPM from dogs with circumflex coronary ligation; the incidence and distribution of the areas was related to duration of ischemia. Correlative phase- and light-microscopic studies demonstrated close correspondence between such areas and morphological evidence of irreversible ischemic injury. Analysis of frequency and distribution of electrically inactive areas permits quantitative assessment of the extent and spatial distribution of irreversible injury. This method has been used to quantitate injury in PPM from dogs that had been subjected to ligation for varying time periods. The potential utility of this method for evaluation of interventions designed to protect against ischemic injury and to assess electrical properties of surviving cells is considered.

scholarly journals Differentiation of Acute Myocarditis and Acute Myocardial Infarction by the Regional Distribution of Myocardial Irreversible Injury Using Cardiovascular Magnetic Resonance Imaging

Medicina ◽  
2012 ◽  
Vol 48 (3) ◽  
pp. 18 ◽  
Author(s):  
Nomeda Valevičienė ◽  
Žaneta Petrulionienė ◽  
Birutė Petrauskienė ◽  
Gediminas Lauraitis ◽  
Sigita Glaveckaitė ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Cardiovascular Magnetic Resonance ◽  
Magnetic Resonance ◽  
Acute Myocarditis ◽  
Regional Distribution ◽  
Final Diagnosis ◽  
Resonance Imaging ◽  
Gadolinium Enhancement ◽  
Irreversible Injury

Background and Objective. In this study, we have sought for differences between cardiovascular magnetic resonance patterns of acute myocarditis and acute myocardial infarction. Material and Methods. A prospective analysis of 110 consecutive patients was performed. The presence, precise location, and pattern of late gadolinium enhancement (LGE) by cardiovascular magnetic resonance were investigated. Results. The subendocardial LGE pattern was much more frequent in the myocardial infarction group (76.7%) than myocarditis group (10.0%) (P<0.001). Meanwhile, midmyocardial LGE was much more typical of myocarditis (65.0%) than acute myocardial infarction (1.1%) (P<0.001), and epicardial LGE was also much more typical of myocarditis (55.0%) than acute myocardial infarction (0.0%) (P<0.001). Midmyocardial and epicardial LGE patterns were defined as a nonischemic LGE pattern more typical of myocarditis. Logistic regression analysis revealed that the subendocardial and midmyocardial LGE locations played the greatest role in differentiation between acute myocarditis and acute myocardial infarction. A statistical model based on midmyocardial LGE distribution and age showed a sensitivity of 90% and a specificity of 93.3% in differentiating between acute myocarditis and acute myocardial infarction. Conclusion. Our findings suggest that in clinical practice, differentiation between acute myocardial infarction and acute myocarditis can be done based on the subendocardial and midmyocardial LGE location. The presence of subendocardial LGE was found to be strongly associated with acute myocardial infarction; meanwhile, the presence of midmyocardial LGE indicated acute myocarditis. However, other clinical factors should also be taken into account when making the final diagnosis.

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