The effects of ethanol on beta2-integrin and l-selectin on the surface of leukocytes in human whole blood.

BACKGROUND: Acute alcohol intoxication is associated with increased susceptibility to infection. In host defense, the expression of adhesion molecules such as beta2-integrin and l-selectin on leukocytes is involved in leukocyte migration to inflamed organ tissue. To elucidate the mechanisms underlying the immunosuppressive effects of ethanol, we investigated whether ethanol pretreatment may influence the changes in adhesion molecule expression induced by lipopolysaccharide (LPS) or interleukin (IL)-8 in human whole blood. METHODS: Ethanol was added to samples of human whole blood (final concentration: 0%, 0.2%, 0.4%, and 0.8%). Samples were assigned to an unstimulated group and an LPS-stimulated group. In another set of experiments, stimulation was induced by IL-8. After fluorescence labeling of alphaM-subunit of beta2-integrin (CD11b) and l-selectin (CD62L), the expression of CD11b and CD62L were measured using flow cytometry. RESULTS: Stimulation with LPS significantly upregulated CD11b expression (5.9 +/- 0.9 to 16.3 +/- 1.8, p < 0.05). Ethanol inhibited this LPS-induced upregulation of CD11b (p < 0.001). Stimulation with IL-8 significantly upregulated CD11b expression (5.3 +/- 1.7 to 7.5 +/- 2.7, p < 0.01) and this IL-8-induced upregulation of CD11b was also inhibited by ethanol pretreatment (p < 0.001). In contrast, ethanol did not modify CD62L expression in either unstimulated or stimulated groups. CONCLUSION: The impairment of CD11b expression on leukocytes suggests that alcohol intake interferes with the migration of leukocytes to sites of inflammation, which may explain, in part, why alcohol intoxication increases susceptibility to infection.

N-acetyl-cysteine attenuates endotoxin-induced adhesion molecule expression in human whole blood.

Leukocyte adhesion to endothelial cells plays a pivotal role in the early stage of endotoxin shock. The attenuation of the leukocyte response to endotoxin may contribute to the prevention of further organ dysfunction. Recent evidence implies that N-acetyl-cysteine (NAC) attenuates endotoxin-induced pathophysiological changes. We investigated the effect of NAC on the expression of CD11b and CD62L in endotoxin-stimulated human whole blood. NAC (>10 mM) significantly inhibited the lipopolysaccharide (LPS)-induced upregulation of CD11b in a concentration-dependent manner. However, NAC did not affect the LPS-induced downregulation of CD62L. We also analyzed the effect of NAC on interleukin-8 (IL-8)-induced expression of CD11b in human whole blood. IL-8 (10 ng/mL) significantly upregulated the expression of CD11b, and the IL-8-induced upregulation was significantly attenuated by NAC (>10 mM) in a dose-dependent manner. We conclude that NAC attenuates the increased expression of CD11b in either LPS or IL-8-stimulated human whole blood.

A platelet activating factor receptor antagonist inhibits cytokine production in human whole blood by bacterial toxins and live bacteria.

UNLABELLED: We previously reported that a platelet-activating factor receptor (PAFR) antagonist (TCV-309) suppressed lipopolysaccharide (LPS)-induced mortality and tumor necrosis factor (TNF) production in mice. However, the effect of TCV-309 on cytokine production induced by Staphylococcus enterotoxin B (SEB) or live bacteria has not been reported. In this study we investigated the effect of TCV-309 on cytokine production in human whole blood induced by LPS, SEB, and both Gram-positive and -negative bacteria. Human whole blood diluted 5:1 (980 microL) was placed in the wells of a 24-well plate. Ten microliters of LPS, SEB, Escherichia coli O18 K(+), or Staphylococcus aureus were added to each well. After incubation at 37 degrees C for 6 h, TNF, interleukin (IL)-6, and IL-8 in the culture medium were measured. TCV-309 did not affect the growth of either E. coli or S. aureus bacteria in the culture medium for the 6 h incubation. LPS, SEB, and both E. coli and S. aureus induced TNF, IL-6, and IL-8 in human whole blood. TCV-309 significantly inhibited the production of TNF, IL-6, and IL-8 induced by LPS, SEB, and bacteria. A PAFR antagonist suppressed cytokine production induced by LPS, SEB, and both Gram-positive and -negative bacteria in human whole blood. A PAFR plays an important role of producing proinflammatory cytokines induced by both toxins and live bacteria. IMPLICATIONS: The platelet-activating factor receptor plays an important role in producing proinflammatory cytokines induced by bacterial toxins, such as lipopolysaccharide,Staphylococcus enterotoxin B, and live Gram-positive and Gram-negative bacteria.

The difference between intramural and arterial partial pressure of carbon dioxide increases significantly during laparoscopic cholecystectomy: the effect of thoracic epidural anesthesia.

UNLABELLED: We studied the effects of pneumoperitoneum on gastric submucosal perfusion metabolism during elective laparoscopic cholecystectomy (LASC) by measuring the PCO(2) gap, defined as the difference between intramucosal PCO(2) and arterial PCO(2), using gas tonometry in 20 patients. Furthermore, we examined whether thoracic epidural anesthesia (TEA) affects gastric submucosal perfusion metabolism during LASC. Patients were randomly allocated to receive general anesthesia (group G, n = 10) or general anesthesia combined with TEA (group E, n = 10). In both groups, the PCO(2) gap increased significantly during pneumoperitoneum and remained at this level until the end of surgery compared with the baseline value. There were no significant differences in PCO(2) gap values between the two groups at any time sampled. These results suggested that pneumoperitoneum significantly impaired gastric submucosal perfusion and metabolism and that TEA did not attenuate the impairment of gastric submucosal perfusion during or after pneumoperitoneum. IMPLICATIONS: We investigated the effect of pneumoperitoneum on gastric submucosal perfusion by measuring PCO(2) gap with the use of gas tonometry. PCO(2) gap significantly increased during and after the pneumoperitoneum compared with the control level. Thoracic epidural anesthesia did not attenuate this inhibition.

[Guidelines for revised cardiopulmonary resuscitation--basic life support].

Basic life support(BLS) does not require any special instruments or drugs, and its skills can be understood and performed easily by the lay person. The main goal of cardiopulmonary resuscitation(CPR) for the victims of cardiac pulmonary arrest(CPA) is not only restoration of cardiopulmonary function but also return to their previous life. An early bystander CPR plays a pivotal role to achieve this target. When encountering an unconscious person, emergency medical systems(EMS) such as calling 119 must be activated immediately. As the next step, cardiopulmonary condition status has to be determined after assurance of airway patency. When there are no signs of breathing or pulse, BLS consisting of artificial respiration and/or chest compression must be started immediately and continued until EMS staffs arrive. In this article, the details of the revised guidelines for BLS by the American Heart Association are described. Current CPR education for pre- or early post-graduate medical students in our institution is reported.

[The effect of formaldehyde exposure on cytokine production in murine alveolar macrophages].

The vapor of formaldehyde has been reported to represent a potential health hazard, resulting in respiratory dysfunction. To determine the potential role of alterations in the alveolar macrophages induced by inhalation of formaldehyde, we studied the cytokine production of murine alveolar macrophages. Mice were exposed at 0, 2.5, 5, 10 ppm of formaldehyde for 16 hrs daily, respectively. Durations of inhalation were 7, 14, 21 and 28 days. Immediately after the formaldehyde exposure, murine alveolar macrophages were harvested from the mice. 18 hrs after LPS stimulation, the cytokines (IL-4, IL-10, IFN-gamma, TNF-alpha) were measured in the supernatant of cultured murine alveolar macrophages using the ELISA method. No levels of formaldehyde exposure changed these cytokine productions. Either our dose or duration of formaldehyde exposure might not have been enough to produce significant changes of cytokine production of murine alveolar macrophages. Further experiments with low but longer formaldehyde exposure may be needed to understand the effect of formaldehyde on cytokine production.