No abstract

SUMMARY Accumulation of polymorphonuclear neutrophils during the acute inflammatory response may exacerbate tissue injury through the release of activated oxygen products or proteolytic enzymes or both. To assess the role of neutrophils in acute myocardial infarction, circulating neutrophil levels in dogs were reduced by 77 + 2% (mean SEM) by administering rabbit antiserum to dog neutrophils. Acute myocardial infarction was induced in open-chest anesthetized dogs by 90 minutes of left circumflex coronary artery occlusion followed by 6 hours of reperfusion. Dogs treated with neutrophil antiserum (n = 8) developed myocardial infarcts that were an average of 43% smaller' than infarcts in dogs treated with nonimmune rabbit serum (n = 7) (27.0 ± 4.5% vs 47.1% 7.5% of the area at risk, p < 0.05). In a salinetreated control group (n = 8), infarct size was 48.0 ± 4.7% of the area at risk, a value not significantly different from that of the nonimmune serum group but significantly greater than that in the neutrophil antiserum dogs (p < 0.05). There were no major hemodynamic differences between groups. Histopathologic examination revealed that infarcted myocardium from dogs given saline or treated with nonimmune serum had a substantial neutrophilic infiltrate, which was virtually absent in infarcted tissue from dogs treated with neutrophil, antiserum. These observations suggest that neutrophil accumulation in response to myocardial ischemia may be responsible for a substantial portion of the irreversible myocardial' injury resulting from temporary coronary artery occlusion.THE MIGRATION of polymorphonuclear neutrophils into recently infarcted myocardium represents the initial phase of a process that leads to demolition and subsequent organization of injured tissue and culminates in the replacement of necrotic myocardium with fibrous scar." 2 Infiltration of neutrophils into irreversibly injured myocardium facilitates the breakdown of necrotic myocardium, which promotes resorbtion or phagocytosis by macrophages.2 After the removal of tissue debris, capillaries and fibroblasts invade the infarcted area and lead to the formation of collagen-rich scar tissue, which replaces the necrotic area.2 During the early acute inflammatory response, polymorphonuclear neutrophils undergo a complex series of functional and biochemical alterations that promote tissue lysis. Although these events are important to the repair process, they may also result in the destruction of potentially viable tissue elements. Stimulated neutrophils release highly reactive and cytotoxic activated oxygen species such as superoxide anion, hydroxyl radical, hydrogen peroxide and singlet oxygen. These activated oxygen radicals degrade extracellular macromolecules, attack membrane phospholipids and, thus, promote cell injury or death. idonic acid, which is converted by specific lipoxygenases to potent chemotactic hydroxy-eicosatetraenoic acids (HETEs).6 These chemoattractant substances promote the further recruitment of neutrophils into the acute inflammatory re...

No abstract

The interactive seminar based on theories of self-regulation led to patient-physician encounters that were of shorter duration, had significant impact on the prescribing and communications behavior of physicians, led to more favorable patient responses to physicians' actions, and led to reductions in health care utilization.

No abstract

Four areas in Detroit were selected by factor analysis of all census tracts as varying widely in socio-ecological stressor conditions. High Stress areas were marked by rates of low socio-economic status, high crime, high density, high residential mobility, and high rates of marital breakup; Low Stress areas showed the converse conditions. All areas were racially segregated. The sample in each area provided about 125 married males, living with spouse, aged 25-60, with relatives in the city. Blood pressure levels were highest among Black High Stress males and showed no difference among Black Low Stress and White areas. Suppressed Hostility (keeping anger in when attacked and feeling guilt if one's anger is displayed when attacked) was related to high blood pressure levels and percent hypertensive for Black High Stress and White Low Stress males; Black Low Stress men with high pressures were associated with anger in but denying guilt. White High Stress high readings were most associated with guilt after anger. For Blacks, skin color was related positively to blood pressure and High Stress males had darker skin color than Black middle class males. Black High Stress men with dark skin color and suppressed hostility had the highest average blood pressure of all four race-area groups.

No abstract

Chronically elevated levels of glucocorticoids have deleterious effects on particular domains of cognition. Verbal learning and other verbal functions seem more vulnerable than nonverbal functions. The results suggest that both the neocortex and hippocampus are affected.