111 research outputs found
Effects of dimethyl sulfoxide on the globally ischemic heart: Possible general relevance to hypothermic organ preservation
Isolated perfused rabbit hearts were made globally ischemic for 2 hr, then reperfused. For 5 min before and after ischemia hearts were perfused with hypothermic (20 or 27 [deg]C), hypoxic, substrate-free cardioplegic solutions, some of which contained 70 mM dimethyl sulfoxide. Postischemic ventricular pressure development, spontaneous heart rate, coronary flow, lactate dehydrogenase release, tissue Ca2+ content, and in vitro mitochondrial oxidative phosphorylation were used to evaluate the protective effects of the various solutions. Aside from the expected observations that cold cardioplegia lessens ischemic damage, we found that dimethyl sulfoxide gave no indication that it exacerbated ischemic damage or lessened the protection afforded by cardioplegia. We also found that, compared to values measured in comparable drug-free treated hearts, dimethyl sulfoxide significantly improved mitochondrial State 3 respiratory rates, respiratory control, and oxidative phosphorylation rates, and essentially prevented mitochondrial changes due to ischemia and reperfusion. We propose that dimethyl sulfoxide may act as a "scavenger" of cytotoxic free radicals, many of which are known to be generated by mitochondria during reoxygenation. Since hypoxia, ischemia, and reoxygenation are common accompaniments of most organ preservation protocols, we suggest that low concentrations of dimethyl sulfoxide might serve as a useful adjunct to organ preservation in the nonfrozen state, when cryoprotective concentrations are not needed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24063/1/0000315.pd
Absence of detectable xanthine oxidase in human myocardium
The enzyme xanthine oxidase has been implicated as a generator of toxic oxygen metabolites that contribute to ischemic injury. Because substantial species variability has been demonstrated and because there are minimal human data available, the relevance of xanthine oxidase to human heart damage has been in doubt. We report the absence of xanthine oxidase activity in nine human heart biopsy specimens obtained during cardiac surgery, and in two larger samples obtained during heart transplantation. A sensitive radiochemical assay was used to assess enzyme activity. Our findings imply that oxygen free radicals generated by xanthine oxidase are not relevent in terms of human myocardial injury.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28034/1/0000473.pd
Absence of xanthine oxidase or xanthine dehydrogenase in the rabbit myocardium
We directly measured the activity of the enzymes xanthine oxidase and xanthine dehydrogenase in rabbit and rat hearts, using a sensitive radio-chemical assay. Neither xanthine oxidase activity nor xanthine dehydrogenase activity was detected in the rabbit heart. In the rat heart, xanthine oxidase activity was 9.1 [plus-or-minus sign] 0.5 mIU per gram wet weight and xanthine dehydrogenase activity was 53.0 [plus-or-minus sign] 1.9 mIU per gram wet weight. These results argue against the involvement of the xanthine oxidase/xanthine dehydrogenase system as a mechanism of tissue injury in the rabbit heart, and suggest that the ability of allopurinol to protect the rabbit heart against hypoxic or ischemic damage must be due to a mechanism other than inhibition of these enzymes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25939/1/0000001.pd
The oxygen consumption paradox of “stunned myocardium” in dogs
The contractile state of the heart is a major determinant of myocardial oxygen consumption. Since regional myocardial contractility can be severely impaired following a transient coronary occlusion, post-ischemic myocardium is frequently assumed to consume less oxygen. To test this assumption, regional myocardial function and oxygen consumption were studied in ancsthetized dogs during 2 h of myocardial reperfusion following either a 15-min (Group I) or 4-h (Group II) left anterior descending coronary artery occlusion. Both groups developed similar post-ischemic regional dysfunction characterized by paradoxical motion (negative shortening). Measured as a percent of baseline segment shortening, anterior wall function in Group I (n=8) and Group II (n=5) at 30 min of reperfusion was −33±11% and −34±16% (p=NS) and at 120 min was −23±9% and −40±16% (p=NS). However, the two groups showed a marked difference in regional myocardial oxygen consumption during reperfusion. Despite the abnormal wall motion, regional oxygen consumption in Group I at 30 and 120 min of reperfusion was unchanged from pre-ischemic levels as measured as a percent of bascline: 104±20% (p=NS) and 111±21% (p=NS). In contrast, regional oxygen consumption in Group II was markedly depressed from bascline at 30 and 120 min of reperfusion: 42±7% (p<.01) and 40±8% (p<.01). To determine whether the dissociation between regional myocardial oxygen consumption and function in Group I was related to mitochondrial uncoupling, six additional dogs were studied. Tissue samples were obtained from post-ischemic myocardium after 120 min of reperfusion following a 15-min coronary artery occlusion, and compared to non-ischemic myocardium. There were no differences in the in vitro mitochondrial respiratory rates or oxidative phosphorylation capacity between the post-ischemic and non-ischemic myocardium. Therefore, in the post-ischemic myocardium, significant depressions in regional contractility may not be associated with falls in oxygen consumption. Following a 15-min coronary artery occlusion, the injured myocardium maintains a paradoxically high oxygen consumption with normal mitochondrial function despite decreased contractility and abnormal wall motion.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41748/1/395_2005_Article_BF01906965.pd
The structure of the psychological adaptation in patients with schizophrenia depending on duratioh of a disease
То study the structure of psychological adaptation in patients with schizophrenia in comparative aspect depending on duration of a disease 140 persons were examined. 97 schizophrenia patients with the first psychotic episode are the basic group (average age 31,88 + 8,06 years), 43 schizophrenia patients (average age 40,37 + 9,55 years) with more than 5 years duration of process are in the comparison group. Methods of investigation: clinical-psychopathological, pathopsychological (Heim’s questionnaire - coping diagnostics, life style index* questionnaire, ‘Self-stigmatization’ questionnaire), statistical (Student T-criterion). It has been established along schizophrenia chronisation psychological defence structure protection gains the most disadaptive and pathoprotective content. On schizophrenia patients with the First Psychotical Episode (FPE) 'negation', 'compensation', 'reactive formation' dominates. In the comparison group "negation", 'regression', 'replacement 'reactive formations' are the leading factors, and the level of intensity considerably increasing. The level of self-stigmatization increases, its dominating form changes: rate shift of autopsychotic and socioreversive form of self-stigmatization to the compensatory and socioreversive forms. The use frequency of adaptive coping-mechanisms in behavioral and cognitive spheres by schizophrenia patients with the FPE is more than the use level of relatively adaptive and no adaptive coping-strategies. In emotional sphere relatively adaptive coping-strategies dominate. On duration of the disease (more than 5 years) relatively adaptive and (or) no adaptive copings become dominative in the coping structure of all three spheres, but the use level of adaptive coping-strategies considerably decreases.С целью изучения структуры психологической адаптации у больных шизофренией в сравнительном аспекте в зависимости от продолжительности течения заболевания обследовано 140 человек. 97 больных шизофренией с первым психотическим эпизодом (ППЗ) составили основную группу (средний возраст 31,88 ± 8,06 лет), 43 больных шизофренией (средний возраст 40,37 ± 9,55 лет) с длительностью процесса более 5 лет - группу сравнения. Методы исследования: клинико-психопатологический, патопсихологический (методика Хейма, опросник «Индекс жизненного стиля», опросник «Самостигматизация»), статистический (t-критерий Стьюдента). Установлено, что по мере хронизации шизофрении структура психологической защиты (ПЗ) приобретает наиболее дезадаптивное патопротекторное содержание. У больных шизофренией с ППЗ доминируют «отрицание», «компенсация», «реактивные образования». В группе сравнения ведущими являются «отрицание», «регрессия», «замещение», «реактивные образования», причем уровень их напряженности значительно возрастает. Возрастает уровень самостигматизации (CC), изменяется её доминирующая форма: сдвиг частоты аутопсихотической и социореверсивной форм CC в сторону компенсаторной и социореверсивной форм. Частота использования адаптивных копинг - механизмов в поведенческой и когнитивной сферах больными шизофренией с ППЗ превышает уровень использования относительно адаптивных и неадаптивных копингов. В эмоциональной сфере доминируют относительно адаптивные копинг - стратегии. При длительном течении заболевания (более 5 лет) в структуре копинга во всех трех сферах доминирующими становятся относительно адаптивные и (или) неадаптивные копинги, а уровень использования адаптивных копингов значительно снижается
Pregnant Behind Bars: Meeting the Nutrition Needs of Incarcerated Pregnant Women
The number of women involved in the criminal justice system has increased dramatically over the past 20 years. Due to their marginalized background, incarcerated women have a complex set of health-related needs. This is especially true of those who are pregnant, a particularly vulnerable, high-risk group. Although guidelines have been developed that recommend pregnancy screening, provision of dietary supplements, regular nutritious meals, and nutritional counseling for incarcerated pregnant women, jail policies and health care protocols often fail to heed these recommendations. In this chapter, we discuss the nutritional needs of pregnant incarcerated women as well as breastfeeding in the context of the criminal justice system and consider some of the challenges in developing programming and policies to address these health-related needs. We also present findings from the William & Mary Healthy Beginnings Project, a nutrition intervention program developed for pregnant incarcerated women in Southeastern Virginia. Assessment of this program suggests that through the development of protocols and polices that consider the health-related needs of pregnant women, correctional facilities could play a pivotal role in helping incarcerated women develop healthier habits to better care for themselves and their newborns.https://scholarworks.wm.edu/asbookchapters/1106/thumbnail.jp
Mitochondrial function after global cardiac ischemia and reperfusion: Influences of organelle isolation protocols
Dog hearts were made globally ischemic for 1 hr at normothermia, at 28°C, or at normothermia after perfusion with a hyperkalemic cardioplegia solution. After 1 hr of reperfusion mitochondria were isolated from each heart using three protocols involving: processing (homogenization and centrifugation) exclusively in KCl, Tris-EDTA plus albumin (KEA) solution; homogenizing in KEA but washing mitochondria in EDTA-depleted media (KA); or processing exclusively in EDTA-free medium.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41745/1/395_2005_Article_BF01907770.pd
Failure of superoxide dismutase and catalase to alter size of infarction in conscious dogs after 3 hours of occlusion followed by reperfusion.
Reduction in experimental infarct size by recombinant human superoxide dismutase: insights into the pathophysiology of reperfusion injury.
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