Hypocapnic alkalosis enhances oxidant-induced apoptosis of human alveolar epithelial type II cells.

Apoptosis of alveolar epithelial type II (AEC-II) cells induced by reactive oxygen species (ROS) contributes to extensive alveolar damage during acute lung injury. Hypercapnic acidosis and hypocapnic alkalosis are known to modulate ROS-mediated lung damage. This study assessed the effects of acid-base balance disturbances on hydrogen peroxide (H2O2)-induced apoptosis of the AEC-II-like human cell line A549, which was cultured under different conditions of pH and CO2 tension (normal pH and CO2, hypercapnic acidosis, metabolic acidosis, hypocapnic alkalosis and metabolic alkalosis). H2O2-induced apoptosis was assessed by a dye-uptake bioassay and induction of caspase activity, which were quantified using analytical digital photomicroscopy. Acidosis or alkalosis of the culture medium alone did not induce A549 cell apoptosis. Hypocapnic alkalosis significantly increased H2O2-induced apoptosis and caspase activation of A549 cells. Metabolic alkalosis non-significantly increased H2O2-induced A549 cell apoptosis and caspase activation. These data suggest that hypocapnic alkalosis intensifies oxidative-induced apoptosis of alveolar epithelial cells.

Glycaemic control boosts glucosylated nanocarrier crossing the BBB into the brain.

Recently, nanocarriers that transport bioactive substances to a target site in the body have attracted considerable attention and undergone rapid progression in terms of the state of the art. However, few nanocarriers can enter the brain via a systemic route through the blood-brain barrier (BBB) to efficiently reach neurons. Here we prepare a self-assembled supramolecular nanocarrier with a surface featuring properly configured glucose. The BBB crossing and brain accumulation of this nanocarrier are boosted by the rapid glycaemic increase after fasting and by the putative phenomenon of the highly expressed glucose transporter-1 (GLUT1) in brain capillary endothelial cells migrating from the luminal to the abluminal plasma membrane. The precisely controlled glucose density on the surface of the nanocarrier enables the regulation of its distribution within the brain, and thus is successfully optimized to increase the number of nanocarriers accumulating in neurons.There are only a few examples of nanocarriers that can transport bioactive substances across the blood-brain barrier. Here the authors show that by rapid glycaemic increase the accumulation of a glucosylated nanocarrier in the brain can be controlled.

Improvement of gas exchange following endobronchial instillation of an exogenous surfactant in an infant with respiratory failure by postoperative pulmonary haemorrhage.

We administered surfactant to a 5-month-old infant with respiratory failure due to right pulmonary haemorrhage accompanied by oedema following abdominal surgery. These pathological conditions were probably precipitated by disseminated intravascular coagulation and intra-operative excessive administration of fluids, respectively. Endobronchial instillation of the exogenous surfactant (120 mg) after selective intubation of the right bronchus produced a dramatic improvement of gas exchange 30 min after treatment and of chest X-ray findings at 6 h post-treatment. This case on an infant indicates that administration of surfactant may be one of promising therapeutic approaches to respiratory failure due to pulmonary haemorrhage.

Inhibitory effect of prostaglandin E1 on human neutrophil function.

Neutrophils accumulated in the lung are thought to play a pivotal role in the pathogenesis of host auto-injury such as adult respiratory distress syndrome (ARDS). We investigated the effect of prostaglandin E1 (PGE1) on several aspects of human neutrophil function. PGE1 significantly decreased reactive oxygen species (ROS), (O2-, H2O2, OH.) generation by neutrophils as well as neutrophil phagocytosis and chemotaxis. In contrast, the drug did not affect the levels of ROS generated by a cell-free ROS generating system. In addition, intracellular calcium concentrations ([Ca2+]i) in neutrophils stimulated by f-Met-Leu-Phe were decreased in the presence of PGE1. These data suggest that the reduction in ROS production and neutrophil phagocytosis and chemotaxis by PGE1 may contribute to the effectiveness of the drug in host auto-injury including ARDS. The suppression of the increase in [Ca2+]i may at least be responsible for inhibition of these neutrophil functions by PGE1.

Effect of methylprednisolone on phospholipase A(2) activity and lung surfactant degradation in acute lung injury in rabbits.

Glucocorticoids are the most potent and widely used anti-inflammatory agents, but they are not particularly effective against early phase of acute respiratory distress syndrome. We investigated whether methylprednisolone, a synthetic glucocorticoid, could inhibit increase of phospholipase A(2) activity in the lung and lead to protection against a model of acute respiratory distress syndrome in rabbits. Infusion of oleic acid (0.1 ml/kg/h, i.v. for 2 h) provoked pulmonary hemorrhage and edema, protein leakage and massive neutrophil infiltration, resulted in severe hypoxemia and impaired lung compliance, accompanying the increase of phospholipase A(2) activity and interleukin-8, and degradation of surfactant in the bronchoalveolar lavage fluid. Infusion of methylprednisolone (60 mg/kg/h, i.v. for 30 min before the oleic acid and then 0.5 mg/kg/h, i.v. for 6 h) did not improve the above described lung injury induced by oleic acid, nor did it suppress phospholipase A(2) activity and degradation of surfactant in bronchoalveolar lavage fluid, while it strongly reduced interleukin-8 levels in both plasma and bronchoalveolar lavage fluid. We conclude that methylprednisolone did not attenuate oleic acid-induced acute lung injury and this can be explained partly by its failure to reduce the increase of phospholipase A(2) activity and the surfactant degradation in the lung, which might also account for its clinical ineffectiveness against early acute respiratory distress syndrome.

The effects of sarpogrelate on superoxide production by human neutrophils.

BACKGROUND AND OBJECTIVES: Superoxide anion (O2-) released from neutrophils plays an important role in antibacterial host defense system and tissue auto-injury. Sarpogrelate, a serotonin-receptor antagonist, has been successfully used for management of chronic pain caused by arterial occlusive or ischemic vascular diseases, or by microcirculation disturbances. Suppression of O2- generation may be detrimental to infection or contribute to the therapeutic approach to these diseases, the pathogenesis of which probably includes neutrophil activation. No data regarding the effects of sarpogrelate on neutrophil functions are available despite the possible clinical concern. The purpose of this study was to determine whether sarpogrelate reduces O2- production by human neutrophils using an in vitro system. In addition, we examined changes in concentrations of the intracellular calcium ion ([Ca2+]i), which is responsible for one of the mechanisms of the neutrophils' O2- production. METHODS: The O2- production by human neutrophils or the xanthine-xanthine oxidase system and [Ca2+]i were measured in the absence and the presence (at clinically relevant concentrations: 0.1x, 10x, and 100x these concentrations) of sarpogrelate. RESULTS: Sarpogrelate inhibited O2- production of neutrophils in a dose-dependent manner. The drug at a clinically relevant concentration suppressed this neutrophil function. In contrast, sarpogrelate failed to inhibit O2-generation by the cell-free (xanthine-xanthine oxidase) system. Elevation of [Ca2+]i in neutrophils stimulated by a chemotactic factor was dose-dependently attenuated with sarpogrelate. CONCLUSIONS: These findings suggest that sarpogrelate (even at clinically relevant concentrations) is able to inhibit O2- production by neutrophils. However, the drug failed to quench an excessive amount of O2- (similar to the level produced by neutrophils). There is a possibility that the inhibitory effect of the drug on [Ca2+]i response in neutrophils may contribute to impairment of the neutrophils' O2- production. Further studies using in vivo systems are required to elucidate the inhibitory effects of sarpogrelate on O2- in clinical settings.

Alpha-fetoprotein producing clones derived from ascites hepatoma AH70B culture.

The establishment of permanent cell line that can produce an alpha-fetoprotein has made tissue culture a powerful tool for the study of alpha-fetoprotein. For this reason, the hepatoma cells of rat ascites hepatoma AH70B were cultured in vitro and some biological characters of the isolated six clones examined. The cultured cells were morphologically epithelial and the mode of chromosome number in hypotetraploid range, and possessed tumorigenicity. The cells secreted alpha-fetoprotein at the high level and a few components of serum proteins in the culture medium for more than one year. Alpha-Fetoprotein was also detected in cytoplasm by fluorescent antibody technique. The examined character was little different among the six colonial clones. From the present cloning procedure, it was suggested that the cultured cells derived from a single cell were secreting alpha-fetoprotein and several components of serum proteins together.

Effect of anti-alpha-fetoprotein serum on growth and plating efficiency of alpha-fetoprotein-producing hepatoma cells in vitro.

The effect of a specific rabbit antiserum to rat alpha-fetoprotein (AFP) was examined on the growth and the plating efficiency of AFP-producing rat hepatoma cells (AH70Btc Clone 10-5) in cultures. The addition of anti-AFP serum to the culture medium inhibited cell growth moderately and inhibited plating efficiency markedly, although no inhibitory effect of complexes of AFP and antibody to AFP was observed on cell growth. Anti-AFP globulin in the immune serum was demonstrated on the cell surface by fluorescent antibody technique. Several clones producing low levels of AFP were obtained by long-term treatment of the original Clone 10-5 cells with anti-AFP serum. These treated clones showed characteristics that differed from the untreated original clone 10-5 cells: The relative plating efficiency of the treated clones on agar plates containing 5% anti-AFP serum was higher than the original Clone 10-15 cells and the amount of AFP secreted by the treated clones was lower.

Effect of superoxide dismutase on endothelium-dependent relaxation of aorta from endotoxin-treated rabbits.

To assess the protective effect of superoxide dismutase (SOD) on the endothelium of aorta in endotoxaemia, we investigated the production of endothelium-derived relaxing factor in aorta obtained from endotoxin-treated rabbits concomitantly receiving SOD or not. Thirty-two male Japanese white rabbits were randomly divided into four groups (n = 8 for each group): one group receiving saline as a placebo, a second receiving 5 mg/kg endotoxin intravenously, a third receiving 5 mg/kg endotoxin intravenously plus SOD, and a fourth receiving SOD alone. SOD was injected intravenously at a dose of 10,000 U/kg before the endotoxin and was infused continuously at a rate of 15,000 units/kg/h throughout the experiment. The tension of the aorta was recorded in vitro 6 h after the start of in vivo treatment with endotoxin or saline. In the aorta of rabbits receiving endotoxin alone, acetylcholine-induced relaxation was reduced by 50%. The SOD fully restored the reduction of acetylcholine-induced relaxation by endotoxin. Histological studies using photomicroscopy revealed endothelial damage in the endotoxin-treated aorta, which was attenuated in the SOD-treated group. These data suggest that intravenous SOD may be an effective treatment for unstable haemodynamics in endotoxaemia.

Use of prostaglandin E1 to treat peri-anaesthetic pulmonary hypertension associated with mitral valve disease.

Severe pulmonary hypertension (PH) can be a critical problem during and after cardiac surgery, since it increases right ventricular afterload resulting in decreased cardiac output. A case of pulmonary hypertension associated with mitral valve disease and resistant to glyceryl trinitrate therapy during surgery is reported. The case was treated successfully with prostaglandin E1 (PGE1), indicating that PGE1 can be used peri-operatively in a patient with refractory PH resistant to glyceryl trinitrate treatment.

Acceleration of phagocytosis in human neutrophils incubated with gabexate mesilate.

It has recently been shown that gabexate mesilate inhibited human neutrophil functions including chemotaxis and reactive oxygen species production. In the present study, the effects of gabexate mesilate on phagocytosis by human neutrophils in vitro were investigated. Gabexate mesilate significantly enhanced neutrophil phagocytosis in a dose-dependent manner. This characteristic of gabexate mesilate may facilitate protection against infecting micro-organisms, although the inhibition of reactive oxygen species production by neutrophils may be a disadvantage for host-defense against infection.

Inhibitory effect of gabexate mesilate on human neutrophil function.

Neutrophils accumulated in the lung are thought to play a key role in the pathogenesis of adult respiratory distress syndrome and interstitial pneumonia following bone-marrow transplantation. The effects of gabexate mesilate on several aspects of human neutrophil function have been investigated. Gabexate mesilate significantly decreased both the generation of reactive oxygen species (O2-, H2O2, OH.) by neutrophils and neutrophil chemotaxis. In contrast, the drug did not affect the levels of reactive oxygen species generated by a cell-free reactive-oxygen-species generating system. Intracellular calcium concentrations in neutrophils stimulated by f-Met-Leu-Phe were decreased in the presence of gabexate mesilate. These data suggest that the reduction in reactive-oxygen-species production and neutrophil chemotaxis by gabexate mesilate may contribute to the effectiveness of the drug in adult respiratory distress syndrome and interstitial pneumonia after bone-marrow transplantation. The suppression of the increase in intracellular calcium concentration may at least be responsible for the inhibition of these neutrophil functions by gabexate mesilate.

Prostaglandin E1 and tracheal intubation: relationship between the cardiovascular responses and plasma catecholamine concentrations.

A study was carried out on 30 normotensive patients (American Society of Anesthesiologists physical status 1) to investigate whether or not a suppressive effect of 0.3 or 0.6 microgram/kg prostaglandin E1 on the hypertensive response to tracheal intubation was due to inhibition of the increase in plasma catecholamine concentrations following the stressful stimulation. A total of 30 patients in three groups underwent elective surgery. Anaesthesia was induced with 5 mg/kg sodium thiopentone given intravenously and tracheal intubation was facilitated by 0.2 mg/kg vecuronium. Either saline (group A) or 0.3 (group B) or 0.6 micrograms/kg (group C) prostaglandin E1 was administered intravenously 15 s before direct laryngoscopy (lasting 30 s) which was attempted 2 min after administering thiopentone and vecuronium. All groups exhibited significant (P less than 0.05) increases in mean arterial pressure, heart rate, rate-pressure product and plasma noradrenaline concentrations following tracheal intubation, but the increases in mean arterial blood pressure and rate - pressure product were significantly (P less than 0.05) less in groups B and C than in group A. Prostaglandin E1, however, enhanced the increase in plasma noradrenaline concentrations following intubation. Data suggest that attenuation of the pressor response to intubation by prostaglandin E1 may not be due to inhibition of the noradrenaline release stimulated by intubation but to inhibition of noradrenaline-induced vasoconstriction.

Effects of mexiletine on the haemodynamic responses to tracheal intubation.

The efficacy of intravenous mexiletine in attenuating the cardiovascular responses to laryngoscopy and tracheal intubation was studied in 30 normotensive patients undergoing elective surgery. The patients were randomly allocated to one of three treatment groups: saline (n = 10); 2 mg/kg mexiletine (n = 10); and 3 mg/kg mexiletine (n = 10). The placebo/mexiletine was administered immediately before induction of anaesthesia using 5 mg/kg thiopentone and tracheal intubation was facilitated with 0.2 mg/kg vecuronium; laryngoscopy lasting 30 s was attempted 2 min after induction of anaesthesia. All groups showed a significant (P less than 0.05) increase in mean arterial pressure and heart rate associated with tracheal intubation. The increase in mean arterial pressure was significantly (P less than 0.05) smaller in patients receiving 3 mg/kg mexiletine compared with those receiving either saline or 2 mg/kg mexiletine. There was no significant attenuation in heart rate in either of the mexiletine treatment groups compared with the saline group. It is concluded that 3 mg/kg mexiletine given intravenously provides a simple and effective method for attenuating the pressor response to laryngoscopy and tracheal intubation.

The efficacy of guanfacine in reducing perioperative hemodynamic changes and volatile anesthetic requirement.

STUDY OBJECTIVE: To evaluate the efficacy of guanfacine, an alpha 2-adrenergic agonist, for attenuating hemodynamic changes associated with tracheal intubation or extubation, providing intraoperative hemodynamic stability, and reducing inhalation anesthetic requirement in patients undergoing gynecologic surgery. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Inpatient gynecology at a university hospital. PATIENTS: 45 women (ASA I) undergoing elective abdominal hysterectomy. INTERVENTIONS: Guanfacine and placebo supplementation. Oral guanfacine at 0.5 or 1 mg or a placebo (control) 3 hours before induction of anesthesia. Anesthesia was induced with thiamylal 5 mg/kg and vecuronium 0.2 mg/kg, and maintained with isoflurane and 50% nitrous oxide (N2O) in oxygen. The inspired isoflurane concentration was maintained at 1% during the first 5 minutes following induction of anesthesia and titrated to the concentration required to maintain hemodynamic stability [defined as +/- 10% of systolic blood pressure (SBP)]. The end-tidal concentration of isoflurane was monitored throughout anesthesia. On completion of surgery, N2O and isoflurane were discontinued. Following confirmation of recovery from anesthesia and muscle relaxation, the endotracheal tube was removed. MEASUREMENTS AND MAIN RESULTS: Patients in the control group showed significant increases in SBP and diastolic blood pressure (DBP) and heart rate (HR) associated with tracheal intubation 50 +/- 5, 57 +/- 6.3, and 45 +/- 4.6 (%, mean +/- SEM, p < 0.05 for any variables), respectively. Plasma norepinephrine and epinephrine concentrations increased to 382 +/- 40 pg/ml and 49 +/- 4.2 pg/ml, respectively (p < 0.05 compared with basal values). These changes were attenuated in patients receiving 1 mg of guanfacine (29 +/- 4.2, 33 +/- 4.5, 25 +/- 3.2, 210 +/- 32, and 22 +/- 3.5, respectively (p < 0.05 for any variables compared with placebo group). Higher inspired concentrations of isoflurane (%) were required in the control and 0.5 mg guanfacine-treated groups (1.2 +/- 0.05 and 1.0 +/- 0.04, respectively) than in the 1 mg guanfacine-treated group (0.62 +/- 0.03) for hemodynamic stability (p < 0.05). Coefficient of variation in HR changes during surgery was 17.2, 13.9, and 8.8 in the placebo, guanfacine 0.5 mg, and guanfacine 1 mg treated groups, respectively. Compared with placebo, guanfacine 1 mg reduced the maximum changes (mean +/- SEM) in SBP (7 +/- 1.2 vs. 18 +/- 2.2) and in HR (23 +/- 2.1 vs. 44 +/- 3.6) occurring during tracheal extubation. The incidence of perioperative complications was similar among the three groups. CONCLUSION: Guanfacine 1 mg administered orally proved to be an effective premedicant for providing intraoperative hemodynamic stability, attenuating the increase in BP and HR associated with tracheal intubation and extubation, and reducing anesthetic requirements without increasing the incidence of perioperative complications.

Partial attenuation of the cardiovascular responses to tracheal intubation with oral nisoldipine.

STUDY OBJECTIVE: To evaluate the efficacy and safety of nisoldipine given orally in attenuating the cardiovascular responses to laryngoscopy and tracheal intubation. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Induction of anesthesia for elective surgery at a university hospital. PATIENTS: Thirty normotensive patients (ASA physical status I) undergoing elective surgery were assigned to one of three groups; placebo, nisoldipine 5 mg, or nisoldipine 10 mg. Each group consisted of ten patients. INTERVENTIONS: Either 5 mg of nisoldipine, 10 mg of nisoldipine, or a placebo was administered orally 2 hours before induction of anesthesia. Anesthesia was induced with thiopental sodium 5 mg/kg intravenously, and tracheal intubation was facilitated with vecuronium 0.2 mg/kg. During anesthesia, ventilation was assisted or controlled with 1% enflurane and 50% nitrous oxide in oxygen. Laryngoscopy lasting 30 seconds was attempted 2 minutes after administration of thiopental sodium and vecuronium. MEASUREMENTS AND MAIN RESULTS: Patients receiving the placebo showed a significant increase in mean arterial pressure associated with tracheal intubation. These increases following tracheal intubation were significantly reduced in patients receiving nisoldipine 10 mg compared with patients receiving the placebo (p less than 0.05). CONCLUSIONS: Oral administration of nisoldipine before induction of anesthesia is a simple, practical, and safe method for attenuating pressor response to laryngoscopy and tracheal intubation.

[Nitric oxide and the lung].

Many studies on nitric oxide (NO) as a messenger for biosignal transduction have recently been published. Endogenous NO is thought to play a pivotal role in homeostasis of the respiratory system and pulmonary circulation. As exhaled NO levels increase in patients with asthma or bronchiectasia, NO seems to be related to some pathological states in the respiratory organ. NO inhalation has been shown to be effective in attenuating pulmonary hypertension and desaturation in acute respiratory failure. Recent findings concerning NO in the lung were described in this review article.

[Transcranial Doppler monitor in the case of selective cerebral perfusion].

Six patients underwent ascending aorta and aortic arch replacement for aneurysmal disease between 1991.12-1992.2 using the cardiopulmonary bypass technique with selective cerebral perfusion from right axillary artery. For four patients, intraoperative transcranial Doppler monitorings of left MCA flow velocity were done. We added left carotid artery perfusion for 5 patients because of old age; 1, intraoperative finding of anisocoria; 1 and low left MCA flow velocity on the TCD monitor; 3. After the addition of left side perfusion, the left MCA flow velocity on the TCD monitor recovered to normal level in the 3 patients. TCD reflected the cerebral perfusion state every minutes and seemed to be very useful monitor in selective cerebral perfusion. It also suggested that unilateral cerebral perfusion does not supply enough blood flow in contralateral side of brain in many cases. To another patient who also underwent aortic arch replacement, we examined preoperatively left MCA flow velocity on the TCD monitor under left carotid artery compression. This "carotid artery compression test" was thought to suggest the degree of right to left intracranial collateral blood flow via Willis's circle. TCD image, when the left carotid artery was clamped, was compared with the result of preoperative "carotid artery compression test". But we can't evaluate the results quantitatively now.