Lanthanum staining of coronary microvascular endothelium: Effects of ischemia reperfusion, propranolol, and atenolol

Cat isolated hearts were perfused via the aorta with normothermic arterial blood from donor cats. After 1 hr of equilibration, dl-propranolol (1.9 mg/kg), atenolol (1.65 mg/kg), or physiological saline solution was infused via the aortic cannula. The hearts were made globally ischemic for 1 hr and reperfused for 1 hr. Hearts given saline but not made ischemic, and hearts from blood-donor cats served as controls. The hearts were flushed with physiological saline for 2 min, then perfused with cacodylate-buffered glutaraldehyde containing 1% LaCl3. Samples of left ventricle were postfixed in osmium and prepared for electron microscopy. Microvessels in nonischemic tissues had heavy La3+ staining on luminal surfaces of endothelial cells. Many plasmalemmal vesicles along luminal surfaces of endothelial cells were filled with La3+. Several vesicles appeared to open onto both surfaces thus forming channels through the endothelium. Lanthanum penetrated into, and occasionally through, interendothelial junctions. Endothelial cells lining vessels in ischemic myocardium were swollen, had pale cytoplasm, and showed little La3+ on the luminal surfaces. Few plasmalemmal vesicles were present and the mitochondria contained deposits of La3+. Extravascular spaces were distended but interendothelial junctions seemed to be intact. Lanthanum staining and morphology of endothelial cells in hearts treated with propranolol or atenolol were very similar to nonischemic myocardium. The data suggest that the [beta]-blocking agents, propranolol and atenolol, maintain the integrity of coronary vascular endothelium during ischemia.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24387/1/0000657.pd

Time-dependent changes in canine cardiac mitochondrial function and ultrastructure resulting from coronary occlusion and reperfusion

Time-dependent changes in mitochondrial function and structure resulting from 1 hr of left circumflex coronary artery occlusion followed by 2 to 24 hrs of reperfusion were examined. These changes were correlated with changes in myocardial ultrastructure, tissue water content, infarct size and mitochondrial calcium content. The heart was removed after different periods of reperfusion, and mitochondria were isolated from ischemic and nonischemic regions of the left ventricle. Tissue samples from ischemic and nonischemic myocardium also were taken for electron microscopy and tissue water content determinations. Infarct size was measured by the nitroblue tetrazolium staining method. Oxygen consumption by mitochondria isolated from ischemic and nonischemic myocardium was measured in vitro . Mitochondria from ischemic myocardium showed time-dependent decreases in rates of oxygen consumption and tightness of coupling. Electron microscopy revealed progressive ultrastructural deterioration in ischemic myocardium, including accumulation of calcium deposits within mitochondria, a finding corroborated by elevated concentrations of calcium in mitochondria isolated from the same area. Tissue wet-to-dry weight ratios were increased significantly in ischemic myocardium. A small, but significant, decrease in respiratory function was observed in mitochondria isolated from nonischemic myocardium several hrs after reperfusion; however, nomal respiration was observed 24 hrs after release of occlusion. This latter observation indicates that the nonischemic zone also is affected by regional ischemia. The results obtained indicate that temporary left circumflex artery occlusion and reperfusion result in progressively decreasing mitochondrial function and structure within the ischemic myocardium, and that these changes are accompanied by cellular electrolyte alterations. Untersucht wurden zeitabhängige Veränderungen in Struktur und Funktion der Mitochondrien, die durch einstündigen Verschluß und 2- bis 24stündige Reperfusion des Ramus circumflexus der linken Koronararterie erzeugt wurden. Diese Veränderungen wurden mit Veränderungen der myokardialen Ultrastruktur, dem Wassergehalt des Gewebes, der Infarktgröße und dem mitochondrialen Calciumgehalt korreliert. Das Herz wurde nach verschiedenen Reperfusionszeiten entnommen und die Mitochondrien aus ischämischen und nichtischämischen Gebieten des linken Ventrikels isoliert. Ebenso wurden Gewebeproben von ischämischem und nichtischämischem Myokard für Elektronenmikroskopie und Bestimmung des Wassergehaltes des Gewebes entnommen. Die Infarktgröße wurde durch die Anfärbung mit Nitroblau-Tetrazolium bestimmt. Der Sauerstoffverbrauch der Mitochondrien aus ischämischem und nichtischämischem Myokard wurde in vitro gemessen. Mitochondrien aus ischämischem Myokard zeigten eine zeitabhängige Abnahme des Sauerstoffverbrauchs und seiner Bindung an die Phosphorylierung von ADP. Die Elektronenmikroskopie zeigte eine fortschreitende Zerstörung der Ultrastruktur im ischämischen Myokard, einschließlich einer Zunahme der Calciumablagerungen in Mitochondrien, was mit erhöhten Calciumkonzentrationen in Mitochondrien aus dem gleichen Gebiet übereinstimmte. Im ischämischen Myokard war die Relation Feuchtgewicht/Trockengewicht signifikant erhöht. Eine geringe, aber signifikante Abnahme der Atmung wurde in Mitochondrien, die nach einigen Stunden Reperfusion aus nichtischämischem Myokard isoliert worden waren, beobachtet; aber nach 24 h Reperfusion fand sich normale Atmung. Letzteres weist darauf hin, daß auch das nichtischämische Gebiet von der regionalen Ischämie betroffen ist. Die Ergebnisse zeigen, daß vorübergehender Verschluß des Ramus circumflexus der linken Koronararterie und Reperfusion zu fortschreitender Zerstörung mitochondrialer Funktion und Struktur führen und daß diese Veränderungen von Änderungen des Electrolytstatus der Zelle begleitet werden.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41744/1/395_2005_Article_BF01907837.pd

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

Protective effects of [beta]-adrenergic blockade in isolated ischemic hearts

The protective effects of the [beta]-adrenergic blocking drugs, propranolol and atenolol, were tested in a model of global ischemia and assessed electron microscopically. Cat isolated hearts were perfused retrogradely with arterial blood drawn from donor cats. After a period of equilibration, isolated hearts rendered globally ischemic for 1 h and subsequently reperfused for another hour. Hearts were then flushed with physiological salt solution followed by perfusion-fixation with cacodylate-buffered glutaraldehyde, containing ionic lanthanum. Lanthanum was included as a probe of myocardial membrane integrity. Left ventricular subendocardial samples were processed and examined electron microscopically. Nontreated hearts, which underwent normothermic ischemic and reperfusion, displayed extensive ultrastructural damage. Nonischemic and donor cat control myocardial tissue appeared normal in all respects. Hearts that received either propranolol or atenol maintained their ultrastructural integrity, resembling controls. Ionic lanthanum proved to be reliable as a marker of membrane integrity and permeability, as nontreated hearts displayed intracellular deposition of the marker, indicating that deteriorations of membrane integrity occurred. The results suggest that [beta]-adrenergic blockade may be valuable in preserving myocardium subjected to ischemia and reperfusion.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23120/1/0000044.pd

How are the dietary needs of pregnant incarcerated women being met? A scoping review and thematic analysis

Introduction: The number of incarcerated pregnant women is increasing globally. With many having complex health and social backgrounds, incarceration provides opportunities for health interventions, including the chance to have their nutritional needs met. Despite the additional nutritional requirements of pregnancy being well documented, how these are being met within the correctional setting is currently poorly understood. Methods: A scoping review of the literature was conducted to identify the literature published between January 2010 and April 2023 related to the provision of nutrition for pregnant women in the international prison systems. Sixteen papers met the criteria for inclusion in the review. The relevant key findings were charted and thematically analysed. Results: Two themes were identified: ‘the inconsistent reality of food provision’ and ‘choice, autonomy and food’. There is a clear disparity in the way in which diet is prioritised and provided to pregnant incarcerated women across several countries. Discussion: The findings highlight the need for a consistent approach to diet on a macro, global level to ensure the health of women and their infants in context

Cerium chloride as a histochemical marker of hydrogen peroxide in reperfused ischemic hearts

Hydrogen peroxide (H2O2) has been implicated in cardiac damage due to ischemia and reperfusion. We adapted an electron microscopic, histochemical method for demonstrating H2O2 produced by isolated cells to isolated, buffer-perfused rabbit hearts. The method involves formation of an electron-dense precipitate when H2O2 reacts with cerium chloride (CeCl3). We perfused hearts retrograde via the aorta with well-oxygenated bicarbonate-buffered solution, followed by one in which bicarbonate was replaced with imidazole (IPSS) to prevent precipitation of bicarbonate and CeCl3. Some hearts were made globally ischemic (30 min, 37[deg]C), reperfused 5 min with well-oxygenated IPSS containing 1 m CeCl3, then processed for electron microscopy. Others were perfused with IPSS containing catalase (300 U/ml) or albumin before ischemia and upon reperfusion, followed by CeCl3 administration. Nonischemic control hearts perfused with IPSS (+/- catalase) were also studied. Electron micrographs were assessed visually and by computer for precipitate localization and amount. There was abundant precipitate on the luminal face of the coronary vascular endothelium in ischemic-reperfused, cerium-treated hearts, including those treated with albumin. There was significantly less in reperfused catalase-treated or nonischemic control hearts. X-ray microbeam analysis of the endothelial precipitate indicated the presence of Ce. This appears to be the first visual demonstration of a CeCl3-H2O2-dependent reaction product in intact isolated ischemic hearts. The data indicate that at the time of reperfusion some H2O2 is accessible to the vascular space, and that its amount can be reduced by perfused catalase. Further modifications this technique may be useful for assessing the sites and pathways by which H2O2 is generated by hearts or other buffer-perfused organs subjected to stresses such as ischemia or hypoxia.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28797/1/0000631.pd

[beta]-Hydroxybutyrate and response to hypoxia in the ground squirrel, Spermophilus tridecimlineatus

1. 1. Previous studies have suggested that elevated ketone levels are associated with increased survival time in rodents exposed to hypoxia. In this study the association between whole blood BHB ([beta]-hydroxybutyrate) and hypoxic surivaval time was investigated in hibernating and non-hibernating ground squirrels and in rats.2. 2. Non-hibernating ground squirrels and rats were exposed to hypoxia (4.5% O2). One hundred per cent of ground squirrels survived 1 hr of hypoxia vs 20% of rats.3. 3. Ketone levels were significantly higher in ground squirrels than rats during hypoxia, and rats surviving the longest had the highest ketone levels. 4. When hibernation was induced in ground squirrels there was a significant increase in [beta]-hydroxybutyrate from 0.45 to 1.6 mM (P = 0.0005).4. 5. Ground squirrel heart mitochondrial respiratory control ratios and ATP synthesis rates indicated no preferential ketone utilization which might suggest a possible extramitochondrial role of BHB during hypoxia.5. 6. We conclude that elevated blood BHB levels are associated with increased hypoxic survival and they may have evolved in response to life-threatening hypoxia as experienced during hibernation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28833/1/0000668.pd