Blockade of complement activation prevents local and pulmonary albumin leak after lower torso ischemia-reperfusion.

Lower torso ischemia and reperfusion leads to both local and remote tissue injuries. The purpose of this study was to assess the role of complement in mediating the local and remote microvascular permeability after bilateral hind limb tourniquet ischemia. Four hours of ischemia and 4 hours of reperfusion produced an increased skeletal muscle permeability index (muscle/blood 125I albumin ratio) of 2.

Soluble complement receptor type 1 ameliorates the local and remote organ injury after intestinal ischemia-reperfusion in the rat.

We examined the role of C activation in ischemia reperfusion injury by inhibiting C activation in a rat model of mesenteric arterial occlusion. In anesthetized rats, 60 min of mesenteric arterial occlusion was followed by 3 h of reperfusion. PBS alone or containing soluble C receptor 1 (3 or 6 mg) was administered i.

A Mac-1 antibody reduces liver and lung injury but not neutrophil sequestration after intestinal ischemia-reperfusion.

Background: Intestinal ischemia and reperfusion (I/R) result in leukosequestration and injury to the liver and lungs. The adherence-dependent oxidative burst of neutrophils requires cell adhesion through the Mac-1 integrin. Neutrophil-mediated tissue injury may depend on this specific cell adhesion event.

Role for tumor necrosis factor as mediator of lung injury following lower torso ischemia.

Ischemia and reperfusion of the ischemic lower torso lead to a neutrophil- (PMN) dependent lung injury characterized by PMN sequestration and permeability edema. This mimics the injury seen after infusion of tumor necrosis factor alpha (TNF), a potent activator of PMN and endothelium. This study tests whether TNF is a mediator of the lung injury after lower torso ischemia.

Ascending cholangitis: surgery versus endoscopic or percutaneous drainage.

A retrospective review of 61 patients with calculous cholangitis was carried out. There were 31 men and 30 women and their mean age was 75.8 years.

The effect of ischemia/reperfusion on adenine nucleotide metabolism and xanthine oxidase production in skeletal muscle.

Prolonged ischemia to skeletal muscle as occurs after an acute arterial occlusion results in alterations in adenine nucleotide metabolism. Adenosine triphosphate continues to be used for cellular functions, and an ischemia-induced degradation of phosphorylated adenine nucleotides is initiated. In this experiment we demonstrated the time-dependent aspect of adenine nucleotide depletion during ischemia and the production of large quantities of soluble precursors.

The rate and distribution of muscle blood flow after prolonged ischemia.

The magnitude and distribution of muscle blood flow in the lower extremity after relief of an acute arterial occlusion may influence the extent of the resulting necrosis. The object of this study was to document the distribution of blood flow in the resting state and after prolonged periods of complete ischemia, and to assess the relationship between the degree of reactive hyperemia and subsequent necrosis. The isolated bilateral canine gracilis muscle preparation that we have previously characterized was used for microsphere studies.

Free radical mediated damage in skeletal muscle.

Skeletal muscle subjected to prolonged ischemia will develop significant injury, however it can withstand periods of ischemia that would be irreversible in other tissues such as brain and heart. Reperfusion injury has been measured and suggested to occur secondary to oxygen free radicals. The increases in vascular permeability and resistance following ischemia/reperfusion can be blunted using free radical scavengers.

The impact of energy depletion on skeletal muscle.

Changes in the skeletal muscle adenine nucleotide pool during prolonged periods of normothermic ischemia, followed by reperfusion are a result of an exaggerated breakdown to lipid soluble precursors, the degree of reactive hyperemia, and activities of the salvage and direct pathways for resynthesis. We show that the degree of breakdown of ATP, ADP and AMP, is time dependent, and with restoration of circulation there is washout of these lipid soluble precursors, and no resynthesis of ATP. We demonstrated a relationship between the loss of energy during ischemia, and the degree of resultant necrosis, suggesting that a limit on the effectiveness of therapeutic interventions during reperfusion in reducing the extent of necrosis may exist.

Measurement of hydroxy-conjugated dienes after ischemia-reperfusion in canine skeletal muscle.

Recent studies have suggested that oxygen-derived free radicals are involved in the reperfusion injury of ischemic skeletal muscle. Although postischemic necrosis and increased vascular permeability have been attenuated with the addition of free radical scavengers, no unequivocal chemical evidence for free radical injury in skeletal muscle is available. The purpose of this study was to identify products of free radical-mediated membrane injury by isolation of lipid oxidation products (hydroxy-conjugated dienes) from postischemic skeletal muscle.

Quantitation of postischemic skeletal muscle necrosis: histochemical and radioisotope techniques.

Skeletal muscle necrosis will result from prolonged periods of ischemia. The purpose of this study was to develop a method to estimate the extent of necrosis using nitroblue tetrazolium staining and technetium scanning. The bilateral canine gracilis muscle preparation with total vascular isolation was exposed to 4 hr of complete normothermic ischemia followed by reperfusion.

The extent and distribution of skeletal muscle necrosis after graded periods of complete ischemia.

The management of an acutely ischemic extremity requires knowledge of the response of skeletal muscle (the largest component of the lower limb) to prolonged periods of complete normothermic ischemia. We have used the canine gracilis muscle model to evaluate the extent and distribution of ischemic necrosis after 3 and 5 hours of ischemia and 48 hours of reperfusion. Each muscle was cut into six slices, and the extent and distribution of postischemic necrosis identified by means of nitroblue tetrazolium staining and 99mTc pyrophosphate uptake.

Salvage of skeletal muscle with free radical scavengers.

Extensive skeletal muscle necrosis may occur after prolonged ischemia to the lower extremity, with serious consequences both locally and systemically. The extent of necrosis is a combination of cellular damage that occurs during both the period of ischemia and the period of reperfusion. The purpose of this study was to reduce the extent of reperfusion-induced muscle necrosis by therapeutic interventions administered only during the initial period of reperfusion.

Supplemental zinc restores antibody formation in cultures of aged spleen cells.

The in vitro production of antibody to T-dependent antigens is depressed as a function of age. The addition of supplemental zinc to cultures of cells from young adult, middle-aged, and immunodepressed-aged mice enhances antibody production. The responses of young mice are enhanced 30 to 40%, but the responses in cultures from aged mice are increased 5- to 12-fold and the maximum response achieved is often equivalent to that of young, fully competent mice.

Can Hypertensive Patients Tell When Their Blood Pressure is Elevated? A Cross-Sectional Study of 104 Patients.

A study was undertaken to see if a group of patients could estimate their blood pressure (BP). One hundred and thirteen hypertensive patients were asked whether they could tell when their BP was high, and if so, how. Patients were also asked to give a categorical and a numerical estimate of their current BP.

The preparation of stable phosphorylcholine-erythrocyte conjugates for use in plaque assays.

A method for the preparation of stable phosphorylcholine-conjugated erythrocytes is described. This method employs the formation of active esters of phosphorylcholine hydroxyphenylacetic acid (PC-HPA) and results in coupled red cells which are completely stable for 2-3 weeks. Using this procedure up to 80% of the activity was demonstrable after 6 weeks.