Anesthesiologist/Pediatric Critical Care, currently transitioning to retirement. 35-year history in academic medicine, achieving clinical but not scientific, success.
The organic peroxide tert-butyl hydroperoxide (t-bu-OOH) induces pulmonary vasoconstriction by st... more The organic peroxide tert-butyl hydroperoxide (t-bu-OOH) induces pulmonary vasoconstriction by stimulating production of thromboxane in the rabbit lung, possibly by activating phospholipase A2. t-bu-OOH-induced vasoconstriction and thromboxane production is augmented by inhalational anesthetic agents, perhaps due to an effect of anesthetic agents on membrane lipids. To further investigate the mechanism of thromboxane generation, we studied the influence of the phospholipase A2 inhibitor, mepacrine, in a dose known to inhibit the enzyme in other systems, on t-bu-OOH-induced pulmonary arterial vasoconstriction. We found that 10(-4) M mepacrine completely inhibited t-bu-OOH-induced vasoconstriction. We also found that mepacrine inhibited arachidonic acid-induced pulmonary vasoconstriction but did not inhibit thromboxane productions. We also investigated the effect of mepacrine on two other pulmonary vasoconstrictors, angiotensin II (ANG II) and KCl, which do not act through arachidonic acid metabolites in the rabbit lung. Mepacrine inhibited both ANG-II and KCl-induced vasoconstriction. The inhibition by mepacrine of pulmonary vasoconstriction is reversible if the drug is washed out of the lung. This effect of mepacrine cannot be explained by phospholipase inhibition alone and is consistent with prevention of smooth muscle contraction.
Human dermal fibroblasts failed to proliferate when cultured in medium containing 0.15 mmol/l (mi... more Human dermal fibroblasts failed to proliferate when cultured in medium containing 0.15 mmol/l (millimolar) Ca2+ (keratinocyte growth medium [KGM]) but did when the external Ca2+ concentration was raised to 1.4 mmol/l. All-trans retinoic acid (retinoic acid) stimulated proliferation in KGM but did not further stimulate growth in Ca2(+)-supplemented KGM. The ability of retinoic acid to stimulate proliferation was inhibited in KGM prepared without Ca2+ or prepared with 0.03 mmol/l Ca2+ and in KGM treated with 1 mmol/l ethylene-glycol-bis-(beta-aminoethyl ether)N,N'-tetra acetic acid. Using 45Ca2+ to measure Ca2+ influx and efflux, it was found that retinoic acid minimally increased Ca2+ uptake into fibroblasts. In contrast, retinoic acid treatment of fibroblasts that had been pre-equilibrated for 1 day with 45Ca2+ inhibited release of intracellular Ca2+ into the extracellular fluid. Retinoic acid also stimulated 35S-methionine incorporation into trichloroacetic acid-precipitable material but in contrast to its effect on proliferation, stimulation of 35S-methionine incorporation occurred in both high-Ca2+ and low-Ca2+ medium. These data indicate that retinoic acid stimulation of proliferation, but not protein synthesis, is dependent on the concentration of Ca2+ in the extracellular environment.
The authors measured the peripheral blood pro-inflammatory cytokine responses (tumor necrosis fac... more The authors measured the peripheral blood pro-inflammatory cytokine responses (tumor necrosis factor-alpha [TNF-alpha] and interleukin-6 [IL-6]) and related end organ responses ti intraperitoneal zymosan-saline suspension over 5 days in CD-1 mice. Other indicators of local and systemic inflammation included wet:dry weight ratios of lung, liver, kidneys, spleen, and bowel; peripheral blood hematocrit, white blood cell count, and platelet count; lung myeloperoxidase activity; lung protein leak; and bacterial translocation to liver, spleen, and mesenteric lymph nodes. The initial event in responses to zymosan A injection was a sharp rise in the peripheral blood TNF-alpha level, which crested within 1 h of injection. This response was followed by a peripheral blood leukocytosis also within 1 h, and a peak lung myeloperoxidase activity within 1-2 h of injection. The maximum lung permeability index occurred 8 h after injection (zymosan, .398 +/- .019 [n = 10]; saline vehicle, .266 +/- .007 [n = 10], p < .001) followed by the maximum lung wet:dry weight ratio, which occurred 18 h after injection. The peak wet:dry weight ratios for the other organs occurred between 12 and 24 h after injection as well. Peripheral blood IL-6 maxima followed TNF-a maxima after lags of several hours. The release of pre-formed TNF-a is likely the most proximal event following injection of zymosan, and may set in motion the processes that result in end-organ injury and secondary multiple organ dysfunction, particularly activation of leukocytes. The precise roles of TNF-alpha and IL-6 in the pathogenesis of end-organ injury, however, are not addressed.
First passage human umbilical vein endothelial cells (HUVECs) were sensitive to killing by activa... more First passage human umbilical vein endothelial cells (HUVECs) were sensitive to killing by activated neutrophils and reagent hydrogen peroxide (H2O2). Catalase and deferoxamine prevented killing whereas soybean trypsin inhibitor and superoxide dismutase did not. In these regards, HUVECs are similar to previously characterized endothelial cells from bovine and rat. Although first passage HUVECs were killed by activated neutrophils, sensitivity fell off rapidly as the cells were maintained in culture. At passage 2 (four population doublings), and beyond, HUVECs were highly resistant. The cells also became resistant to killing by reagent H2O2. The acquisition of resistance to killing was not accompanied by a failure to up-regulate neutrophil adhesion molecules or to support neutrophil adhesion. Levels of intracellular anti-oxidants (total thiols, though not glutathione, glutathione peroxidase or catalase activity) increased as a function of passage in culture. However, levels of glutathione and total thiols in late passage (resistant) HUVECs were similar to levels in late passage rat pulmonary artery endothelial cells, that were sensitive to killing by activated neutrophils. Cell-associated iron in HUVECs fell as a function of time in culture. By passage 2, the amount of total iron measurable with the Ferrozine reagent was only about 30% of the amount recovered from first passage HUVECs. The loss of iron from the cells may underlie much of the concomitant resistance to killing because when the cells were pretreated with iron under conditions in which it could be taken up, sensitivity to killing by activated neutrophils and by H2O2 was restored.
Volatile anesthetics inhibit phagocytic cell function, yet little is known about their effects on... more Volatile anesthetics inhibit phagocytic cell function, yet little is known about their effects on target tissues or on the target tissue response to stimulated phagocytes. Experiments were performed to determine how exposure to halothane and isoflurane changes rat pulmonary artery endothelial cell (RPAEC) viability in response to the toxic oxygen metabolites produced by stimulated phagocytic cells. RPAECs were grown in monolayer culture. The monolayers were treated with phorbol myristate acetate (PMA) -stimulated human neutrophils at an effector-to-target ratio of 20:1 after equilibration with 0.4% or 1.7% halothane or 0.7% or 2.8% isoflurane. As measured by percent-specific release of incorporated 51Cr label (mean +/- SE), cytotoxicity in the presence of 1.7% halothane (75.3 +/- 3.4%) was significantly greater (P less than 0.02) than cytotoxicity in 5% CO2 in air (44.7 +/- 3.3%) and in 0.4% halothane (57.3 +/- 4.7%). Also, cytotoxicity in 1.7% halothane was significantly greater than in 0.4% halothane (P less than 0.02). The authors found that RPAECs incubated in isoflurane exhibited significantly greater release of 51Cr than cells incubated in the MAC equivalent concentrations of halothane: 78.2 +/- 2.6% in 0.7% isoflurane (P = 0.0004) and 83.8 +/- 1% in 2.8% isoflurane (P = 0.005). Because early neutrophil cytotoxicity has been found to be mediated primarily by hydroxyl radical (HO.) and hydrogen peroxide (H2O2), the authors measured H2O2 production by similar numbers of PMA-stimulated neutrophils under similar exposure conditions. In carrier gas, PMA-stimulated neutrophils produced 20.5 +/- 1.3 nmol H2O2.10(6) cells-1.h-1. At the higher concentrations of halothane, H2O2 production actually was inhibited in comparison with carrier gas (15.4 +/- 1.4 nmol H2O2.10(6) cells-1.h-1 in 1.7% halothane and 16.8 +/- 0.8 in 2.8% halothane), but the degree of inhibition did not reach statistical significance. In isoflurane, however, H2O2 production was not different from that seen in carrier gas. In other experiments, the monolayers were treated with 0, 200, 500, and 1,000 microM H2O2 after equilibration with 0.4%, 1.7%, and 2.8% halothane or 0.7%, 2.8%, and 5% isoflurane in 5% CO2 in air. Efficiency of replating was used to measure degree of injury. Both halothane and isoflurane enhance the sensitivity of the RPAEC monolayers to injury by H2O2. The sensitizing effect of halothane was reversed by removing the anesthetic. Halothane and isoflurane thus enhance RPAEC sensitivity to injury by both H2O2 and PMA-stimulated neutrophils. In increasing RPAEC sensitivity to injury by oxygen metabolites, halothane and isoflurane may be inhibiting processes involved in intracellular antioxidant defenses.(ABSTRACT TRUNCATED AT 400 WORDS)
FASEB Journal (Federation of American Societies for Experimental Biology); (United States), Mar 11, 1991
The isolated perfused rabbit lung model is used in studies of pulmonary hemodynamics, structure, ... more The isolated perfused rabbit lung model is used in studies of pulmonary hemodynamics, structure, and function under conditions closely resembling those which occur in living animals. The purpose of this study is to observe changes in P{sub pa} in response to differing concentrations of COâ over time. After rapid exsanguination a tracheostomy was performed. Cannulas were secured in the main
Responses to the nondepolarizing muscle relaxant, metocurine, were studied in eight hemiplegic an... more Responses to the nondepolarizing muscle relaxant, metocurine, were studied in eight hemiplegic and eight unmatched patients with normal motor strength during the general anesthetic given for various neurosurgical operations. Metocurine, 0.3 mglkg, was administered intravenously, and indirectly evoked thumb twitch tensions were measured on both sides in the hemiplegic patients, and on one side in the normal patients. Arterial blood samples were obtained as twitch tension was recovering, and serum metocurine concentrations were determined using a specific radioimmunoassay. Percentage of paralysis was plotted as a function of log [metocurinel and the data were compared by analysis of covariance. For the normal motor strength patients, r = 0.84; for the unaffected arm of the hemiplegic patients, r = 0.69; and for the affected arm ofthe hemiplegic patients, r = 0.86, all significant at P < 0.001. The mean plasma metocurine concentrations at 20, 25, 50, 75, and 80% paralysis were significantly different for all groups (P < 0.001). The regression lines, in turn, did not overlap and were sign$cantly different, each from the other (P < 0.005). We were, howmer, unable to detect any significant deviation from parallelism among the three regression lines. We also measured time to 50% return of single twitch height for each data group as follows (mean ? SEM: for NMS patients, 242 2 73 min;for the unaffected arm of hemiplegic patients, 116 2 60 min; and for the affected arm of hemiplegic patients, 59 f 36 min. By ANOVA and the Bonferroni test, each value was different from the other at P 5 0.01. We conclude that both the affected arm and the unaffected arm of hemiplegic patients exhibit decreased sensitivity to metocurine, and that the effect of stroke is, even in the long term, global. Thus thumb twitch monitoring in patients with hemiplegia may underestimate the degree of blockade of the muscles of respiration, no matter which side is monitored.
The organic peroxide tert-butyl hydroperoxide (t-bu-OOH) induces pulmonary vasoconstriction by st... more The organic peroxide tert-butyl hydroperoxide (t-bu-OOH) induces pulmonary vasoconstriction by stimulating production of thromboxane in the rabbit lung, possibly by activating phospholipase A2. t-bu-OOH-induced vasoconstriction and thromboxane production is augmented by inhalational anesthetic agents, perhaps due to an effect of anesthetic agents on membrane lipids. To further investigate the mechanism of thromboxane generation, we studied the influence of the phospholipase A2 inhibitor, mepacrine, in a dose known to inhibit the enzyme in other systems, on t-bu-OOH-induced pulmonary arterial vasoconstriction. We found that 10(-4) M mepacrine completely inhibited t-bu-OOH-induced vasoconstriction. We also found that mepacrine inhibited arachidonic acid-induced pulmonary vasoconstriction but did not inhibit thromboxane productions. We also investigated the effect of mepacrine on two other pulmonary vasoconstrictors, angiotensin II (ANG II) and KCl, which do not act through arachidonic acid metabolites in the rabbit lung. Mepacrine inhibited both ANG-II and KCl-induced vasoconstriction. The inhibition by mepacrine of pulmonary vasoconstriction is reversible if the drug is washed out of the lung. This effect of mepacrine cannot be explained by phospholipase inhibition alone and is consistent with prevention of smooth muscle contraction.
Human dermal fibroblasts failed to proliferate when cultured in medium containing 0.15 mmol/l (mi... more Human dermal fibroblasts failed to proliferate when cultured in medium containing 0.15 mmol/l (millimolar) Ca2+ (keratinocyte growth medium [KGM]) but did when the external Ca2+ concentration was raised to 1.4 mmol/l. All-trans retinoic acid (retinoic acid) stimulated proliferation in KGM but did not further stimulate growth in Ca2(+)-supplemented KGM. The ability of retinoic acid to stimulate proliferation was inhibited in KGM prepared without Ca2+ or prepared with 0.03 mmol/l Ca2+ and in KGM treated with 1 mmol/l ethylene-glycol-bis-(beta-aminoethyl ether)N,N'-tetra acetic acid. Using 45Ca2+ to measure Ca2+ influx and efflux, it was found that retinoic acid minimally increased Ca2+ uptake into fibroblasts. In contrast, retinoic acid treatment of fibroblasts that had been pre-equilibrated for 1 day with 45Ca2+ inhibited release of intracellular Ca2+ into the extracellular fluid. Retinoic acid also stimulated 35S-methionine incorporation into trichloroacetic acid-precipitable material but in contrast to its effect on proliferation, stimulation of 35S-methionine incorporation occurred in both high-Ca2+ and low-Ca2+ medium. These data indicate that retinoic acid stimulation of proliferation, but not protein synthesis, is dependent on the concentration of Ca2+ in the extracellular environment.
The authors measured the peripheral blood pro-inflammatory cytokine responses (tumor necrosis fac... more The authors measured the peripheral blood pro-inflammatory cytokine responses (tumor necrosis factor-alpha [TNF-alpha] and interleukin-6 [IL-6]) and related end organ responses ti intraperitoneal zymosan-saline suspension over 5 days in CD-1 mice. Other indicators of local and systemic inflammation included wet:dry weight ratios of lung, liver, kidneys, spleen, and bowel; peripheral blood hematocrit, white blood cell count, and platelet count; lung myeloperoxidase activity; lung protein leak; and bacterial translocation to liver, spleen, and mesenteric lymph nodes. The initial event in responses to zymosan A injection was a sharp rise in the peripheral blood TNF-alpha level, which crested within 1 h of injection. This response was followed by a peripheral blood leukocytosis also within 1 h, and a peak lung myeloperoxidase activity within 1-2 h of injection. The maximum lung permeability index occurred 8 h after injection (zymosan, .398 +/- .019 [n = 10]; saline vehicle, .266 +/- .007 [n = 10], p < .001) followed by the maximum lung wet:dry weight ratio, which occurred 18 h after injection. The peak wet:dry weight ratios for the other organs occurred between 12 and 24 h after injection as well. Peripheral blood IL-6 maxima followed TNF-a maxima after lags of several hours. The release of pre-formed TNF-a is likely the most proximal event following injection of zymosan, and may set in motion the processes that result in end-organ injury and secondary multiple organ dysfunction, particularly activation of leukocytes. The precise roles of TNF-alpha and IL-6 in the pathogenesis of end-organ injury, however, are not addressed.
First passage human umbilical vein endothelial cells (HUVECs) were sensitive to killing by activa... more First passage human umbilical vein endothelial cells (HUVECs) were sensitive to killing by activated neutrophils and reagent hydrogen peroxide (H2O2). Catalase and deferoxamine prevented killing whereas soybean trypsin inhibitor and superoxide dismutase did not. In these regards, HUVECs are similar to previously characterized endothelial cells from bovine and rat. Although first passage HUVECs were killed by activated neutrophils, sensitivity fell off rapidly as the cells were maintained in culture. At passage 2 (four population doublings), and beyond, HUVECs were highly resistant. The cells also became resistant to killing by reagent H2O2. The acquisition of resistance to killing was not accompanied by a failure to up-regulate neutrophil adhesion molecules or to support neutrophil adhesion. Levels of intracellular anti-oxidants (total thiols, though not glutathione, glutathione peroxidase or catalase activity) increased as a function of passage in culture. However, levels of glutathione and total thiols in late passage (resistant) HUVECs were similar to levels in late passage rat pulmonary artery endothelial cells, that were sensitive to killing by activated neutrophils. Cell-associated iron in HUVECs fell as a function of time in culture. By passage 2, the amount of total iron measurable with the Ferrozine reagent was only about 30% of the amount recovered from first passage HUVECs. The loss of iron from the cells may underlie much of the concomitant resistance to killing because when the cells were pretreated with iron under conditions in which it could be taken up, sensitivity to killing by activated neutrophils and by H2O2 was restored.
Volatile anesthetics inhibit phagocytic cell function, yet little is known about their effects on... more Volatile anesthetics inhibit phagocytic cell function, yet little is known about their effects on target tissues or on the target tissue response to stimulated phagocytes. Experiments were performed to determine how exposure to halothane and isoflurane changes rat pulmonary artery endothelial cell (RPAEC) viability in response to the toxic oxygen metabolites produced by stimulated phagocytic cells. RPAECs were grown in monolayer culture. The monolayers were treated with phorbol myristate acetate (PMA) -stimulated human neutrophils at an effector-to-target ratio of 20:1 after equilibration with 0.4% or 1.7% halothane or 0.7% or 2.8% isoflurane. As measured by percent-specific release of incorporated 51Cr label (mean +/- SE), cytotoxicity in the presence of 1.7% halothane (75.3 +/- 3.4%) was significantly greater (P less than 0.02) than cytotoxicity in 5% CO2 in air (44.7 +/- 3.3%) and in 0.4% halothane (57.3 +/- 4.7%). Also, cytotoxicity in 1.7% halothane was significantly greater than in 0.4% halothane (P less than 0.02). The authors found that RPAECs incubated in isoflurane exhibited significantly greater release of 51Cr than cells incubated in the MAC equivalent concentrations of halothane: 78.2 +/- 2.6% in 0.7% isoflurane (P = 0.0004) and 83.8 +/- 1% in 2.8% isoflurane (P = 0.005). Because early neutrophil cytotoxicity has been found to be mediated primarily by hydroxyl radical (HO.) and hydrogen peroxide (H2O2), the authors measured H2O2 production by similar numbers of PMA-stimulated neutrophils under similar exposure conditions. In carrier gas, PMA-stimulated neutrophils produced 20.5 +/- 1.3 nmol H2O2.10(6) cells-1.h-1. At the higher concentrations of halothane, H2O2 production actually was inhibited in comparison with carrier gas (15.4 +/- 1.4 nmol H2O2.10(6) cells-1.h-1 in 1.7% halothane and 16.8 +/- 0.8 in 2.8% halothane), but the degree of inhibition did not reach statistical significance. In isoflurane, however, H2O2 production was not different from that seen in carrier gas. In other experiments, the monolayers were treated with 0, 200, 500, and 1,000 microM H2O2 after equilibration with 0.4%, 1.7%, and 2.8% halothane or 0.7%, 2.8%, and 5% isoflurane in 5% CO2 in air. Efficiency of replating was used to measure degree of injury. Both halothane and isoflurane enhance the sensitivity of the RPAEC monolayers to injury by H2O2. The sensitizing effect of halothane was reversed by removing the anesthetic. Halothane and isoflurane thus enhance RPAEC sensitivity to injury by both H2O2 and PMA-stimulated neutrophils. In increasing RPAEC sensitivity to injury by oxygen metabolites, halothane and isoflurane may be inhibiting processes involved in intracellular antioxidant defenses.(ABSTRACT TRUNCATED AT 400 WORDS)
FASEB Journal (Federation of American Societies for Experimental Biology); (United States), Mar 11, 1991
The isolated perfused rabbit lung model is used in studies of pulmonary hemodynamics, structure, ... more The isolated perfused rabbit lung model is used in studies of pulmonary hemodynamics, structure, and function under conditions closely resembling those which occur in living animals. The purpose of this study is to observe changes in P{sub pa} in response to differing concentrations of COâ over time. After rapid exsanguination a tracheostomy was performed. Cannulas were secured in the main
Responses to the nondepolarizing muscle relaxant, metocurine, were studied in eight hemiplegic an... more Responses to the nondepolarizing muscle relaxant, metocurine, were studied in eight hemiplegic and eight unmatched patients with normal motor strength during the general anesthetic given for various neurosurgical operations. Metocurine, 0.3 mglkg, was administered intravenously, and indirectly evoked thumb twitch tensions were measured on both sides in the hemiplegic patients, and on one side in the normal patients. Arterial blood samples were obtained as twitch tension was recovering, and serum metocurine concentrations were determined using a specific radioimmunoassay. Percentage of paralysis was plotted as a function of log [metocurinel and the data were compared by analysis of covariance. For the normal motor strength patients, r = 0.84; for the unaffected arm of the hemiplegic patients, r = 0.69; and for the affected arm ofthe hemiplegic patients, r = 0.86, all significant at P < 0.001. The mean plasma metocurine concentrations at 20, 25, 50, 75, and 80% paralysis were significantly different for all groups (P < 0.001). The regression lines, in turn, did not overlap and were sign$cantly different, each from the other (P < 0.005). We were, howmer, unable to detect any significant deviation from parallelism among the three regression lines. We also measured time to 50% return of single twitch height for each data group as follows (mean ? SEM: for NMS patients, 242 2 73 min;for the unaffected arm of hemiplegic patients, 116 2 60 min; and for the affected arm of hemiplegic patients, 59 f 36 min. By ANOVA and the Bonferroni test, each value was different from the other at P 5 0.01. We conclude that both the affected arm and the unaffected arm of hemiplegic patients exhibit decreased sensitivity to metocurine, and that the effect of stroke is, even in the long term, global. Thus thumb twitch monitoring in patients with hemiplegia may underestimate the degree of blockade of the muscles of respiration, no matter which side is monitored.
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Papers by Jay Shayevitz