Phase lag entropy as a hypnotic depth indicator during propofol sedation

Phase lag entropy, an electro-encephalography-based hypnotic depth indicator, calculates diversity in temporal patterns of phase relationship. We compared the performance of phase lag entropy with the bispectral index™ in 30 patients scheduled for elective surgery. We initiated a target-controlled infusion of propofol using the Schnider model, and assessed sedation levels using the Modified Observer's Assessment of Alertness/Sedation scale every 30 s with each stepwise increase in the effect-site propofol concentration. Phase lag entropy and bispectral index values were recorded. The correlation coefficient and prediction probability between phase lag entropy or bispectral index and the sedation level or effect-site propofol concentration were analysed. We calculated baseline variabilities of phase lag entropy and bispectral index. In addition, we applied a non-linear mixed-effects model to obtain the pharmacodynamic relationships among the effect-site propofol concentration, phase lag entropy or bispectral index and sedation level. As sedation increased, phase lag entropy and bispectral index both decreased. The prediction probability values of phase lag entropy and bispectral index for sedation levels were 0.697 and 0.700 (p = 0.261) and for the effect-site concentration of propofol were 0.646 and 0.630 (p = 0.091), respectively. Baseline variability in phase lag entropy and bispectral index was 3.3 and 5.7, respectively. The predicted propofol concentrations, using the Schnider pharmacokinetic model, producing a 50% probability of moderate and deep sedation were 1.96 and 3.01 μg.ml^-1 , respectively. Phase lag entropy was found to be useful as a hypnotic depth indicator in patients receiving propofol sedation.

Development of a new analgesic index using nasal photoplethysmography

Although surrogate measures to quantify pain intensity have been commercialised, there is a need to develop a new index with improved accuracy. The aim of this study was to develop a new analgesic index using nasal photoplethysmography data. The specially designed sensor was placed between the columella and the nasal septum to acquire nasal photoplethysmography in surgical patients. Nasal photoplethysmography and Surgical Pleth Index^® (GE Healthcare) data were obtained for 14 min both in the absence (pre-operatively) or presence (postoperatively) of pain in a group of surgical patients, each patient acting as their own control. Various dynamic photoplethysmography variables were extracted to quantify pain intensity; the most accurate index was selected using logistic regression as a classifier. The area under the curve of the receiver-operating characteristic curve was measured to evaluate the accuracy of final model predictions. In total, 12,012 heart beats from 89 patients were used to develop a new Nasal Photoplethysmography Index for analgesic depth quantification. The two-variable model (a combination of diastolic peak point variation and heart beat interval variation) was most accurate in discriminating between the presence and absence of pain (numerical rating scale (NRS) ≥ 3). The accuracy and area under the curve of the receiver-operating characteristic curve for the Nasal Photoplethysmography Index were 75.3% and 0.8018, respectively, and 64.8% and 0.7034, respectively, for the Surgical Pleth Index. The Nasal Photoplethysmography Index clearly distinguished pain (NRS ≥ 3) in awake surgical patients with postoperative pain. The Nasal Photoplethysmography Index performed better than the Surgical Pleth Index. Further validation studies are needed to evaluate its feasibility to quantify pain intensity during general anaesthesia.

Machine learning methods applied to pharmacokinetic modelling of remifentanil in healthy volunteers: a multi-method comparison

This study compared the blood concentrations of remifentanil obtained in a previous clinical investigation with the predicted remifentanil concentrations produced by different pharmacokinetic models: a non-linear mixed effects model created by the software NONMEM; an artificial neural network (ANN) model; a support vector machine (SVM) model; and multi-method ensembles. The ensemble created from the mean of the ANN and the non-linear mixed effects model predictions achieved the smallest error and the highest correlation coefficient. The SVM model produced the highest error and the lowest correlation coefficient. Paired t-tests indicated that there was insufficient evidence that the predicted values of the ANN, SVM and two multi-method ensembles differed from the actual measured values at alpha = 0.05. The ensemble method combining the ANN and non-linear mixed effects model predictions outperformed either method alone. These results indicated a potential advantage of ensembles in improving the accuracy and reducing the variance of pharmacokinetic models.

Albumin versus normal saline for dehydrated term infants with metabolic acidosis due to acute diarrhea

To compare the efficacy of albumin to normal saline (NS) for initial hydration therapy for dehydrated term infants with severe metabolic acidosis due to acute diarrhea.

STUDY DESIGN

We randomized 33 infants presenting with moderate-to-severe dehydration and metabolic acidosis (pH <7.25 or base excess (BE) <-15) into two groups, an albumin group (n=15) and a NS group (n=18). For initial hydration treatment, the albumin group received 5% albumin (10 ml kg(-1)), whereas the NS group received NS (10 ml kg(-1)).

RESULT

After 3 h of treatment, both groups improved. However, the magnitude of improvement in the pH, BE and HCO(3)(-) levels were not different in comparisons between these two groups. In addition, there were no differences either in the body weight and weight gain 4 days after treatment or in the length of hospital stay.

CONCLUSION

Albumin was not more effective than NS for initial hydration treatment of dehydrated term infants with metabolic acidosis due to acute diarrhea.

Penta-O-galloyl-beta-D-glucose inhibits phorbol myristate acetate-induced interleukin-8 [correction of intereukin-8] gene expression in human monocytic U937 cells through its inactivation of nuclear factor-kappaB

We investigated the effects of the gallotannin penta-O-galloyl-beta-d-glucose (PGG) on interleukin (IL)-8 gene expression and nuclear factor (NF)-kappaB activation. PGG inhibited IL-8 production and gene expression in human monocytic U937 cells stimulated with phorbol myristate acetate (PMA), as measured by enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction analysis, respectively. PGG also inhibited PMA-mediated NF-kappaB activation, as measured by electromobility shift assay. Furthermore, PGG prevented PMA-mediated degradation of the NF-kappaB inhibitory protein I-kappaBalpha, as measured by Western blot analysis. PGG also inhibited both IL-8 production and NF-kappaB activation in the U937 cells stimulated with tumor necrosis factor-alpha. These results suggest that PGG, a major constituent of the root cortex of Paeonia suffruticosa ANDREWS, can inhibit IL-8 gene expression by a mechanism involving its inhibition of NF-kappaB activation, which is dependent on I-kappaBalpha degradation.

In Vitro Cytotoxicity of Mokko Lactone in Human Leukemia HL‐60 Cells: Induction of Apoptotic Cell Death by Mitochondrial Membrane Potential Collapse

We studied the effect of mokko lactone (ML) isolated from the roots of Saussurea lappa (Compositae), a plant that is used for medicinal purposes in Korea, on the induction of apoptosis in human leukemia HL-60 cells. ML was cytotoxic to HL-60 cells, and this cytotoxic effect of ML appears to be attributable to its induction of apoptotic cell death, as ML induced nuclear morphologic changes and internucleosomal DNA fragmentation and increased the proportion of Annexin V-positive cells and the activity of caspase-3. Further studies revealed that the induction of apoptosis by ML was associated with the loss of mitochondrial membrane potential. Collectively, our results suggest that apoptosis induced by ML in HL-60 cells was executed by a collapse of mitochondrial membrane potential followed by the activation of caspase-3. This is the first report on the mechanism of apoptosis-inducing effect of ML.

20(S)-Protopanaxatriol, one of ginsenoside metabolites, inhibits inducible nitric oxide synthase and cyclooxygenase-2 expressions through inactivation of nuclear factor-kappaB in RAW 264.7 macrophages stimulated with lipopolysaccharide

Ginsenosides from Panax ginseng are metabolized by human intestinal bacteria after oral administration of ginseng extract. 20(S)-Protopanaxatriol (PPT) is one of the major metabolites of ginsenosides. Inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) are important enzymes that mediate inflammatory processes. Improper up-regulation of iNOS and/or COX-2 has been associated with the pathogenesis of inflammatory diseases and certain types of human cancers. Here, we investigated whether PPT could modulate iNOS and COX-2 expressions in RAW 264.7 macrophages stimulated with the endotoxin lipopolysaccharide (LPS). We found that PPT blocked the increase in LPS-induced iNOS and COX-2 expressions through inactivation of nuclear factor-kappaB by preventing I-kappaBalpha phosphorylation and degradation. Thus, it may be possible to develop PPT as a useful agent for chemoprevention of cancer or inflammatory diseases.

Hepatoprotective effect of baicalin, a major flavone from Scutellaria radix, on acetaminophen-induced liver injury in mice

The protective effects of baicalin (BA), a major flavone from Scutellaria radix, on acetaminophen (AP)-induced hepatotoxicity and the possible mechanism(s) of its protective action were investigated in mice. Treatment with BA (300 mg/kg, p.o.) 0.5 h after AP administration significantly prevented an increase in plasma alanine aminotransferase and aspartate aminotransferase activities and AP-induced hepatic necrosis, and also reduced AP-induced mortality from 43% to 0%. In addition, oral treatment with BA significantly prevented AP-induced depletion of glutathione (GSH) contents. However, BA treatment, by itself, did not affect hepatic GSH contents. The effect of BA on the cytochrome P450 2E1 (CYP2E1), the major isozyme involved in AP bioactivation, was investigated. Oral treatment of mice with BA resulted in a significant decrease in AP-induced CYP2E1 activity together with its inhibition of AP-induced CYP2EI expression. These results show that the hepatoprotective effects of BA against AP overdose may be due to its ability to block the bioactivation of AP by inhibiting CYP2E1 expression.

Inhibitory effects of the stem bark of Catalpa ovata G. Don. (Bignoniaceae) on the productions of tumor necrosis factor-alpha and nitric oxide by the lipopolisaccharide-stimulated RAW 264.7 macrophages

In order to validate the use of the stem bark of Catalpa ovata G. Don. (Bignoniaceae) as an anti-inflammatory drug in the traditional Korean medicine, we have investigated the effects of the methanol extract of this folk medicine on the productions of tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) on RAW 264.7 macrophages activated with the endotoxin lipopolysaccharide. The extract inhibited the productions of TNF-alpha and NO with significant decreases in mRNA levels of TNF-alpha and inducible NO synthase, suggesting that the stem bark of Catalpa ovata may have therapeutic potential in the control of inflammatory disorders.

Induction of apoptosis by 4-acetyl-12,13-epoxyl-9-trichothecene-3,15-diol from Isaria japonica Yasuda through intracellular reactive oxygen species formation and caspase-3 activation in human leukemia HL-60 cells

Recently we have reported that the trichothecene mycotoxin 4-acetyl-12,13-epoxyl-9-trichothecene-3,15-diol (AETD) from the fruiting bodies of Isaria japonica Yasuda is a potent inducer of apoptosis in human promyelocytic HL-60 cells. The present study aims to characterize the molecular events leading to AETD-induced apoptosis in HL-60 cells. The percentage of apoptotic cells (annexin-V-positive cell population) increased dose- and time-dependently after AETD exposure. Apoptosis of HL-60 cells by AETD was associated with the formation of intracellular reactive oxygen species (ROS), the depletion of intracellular glutathione (GSH) and the activation of caspase-3. Pretreating the cells with the antioxidant N-acetyl-L-cystein (NAC) and the caspase-3 inhibitor Z-DEVD-fmk abrogated AETD-induced apoptosis and caspase-3 activation. NAC blocked intracellular ROS formation and GSH depletion, but Z-DEVD-fmk did not. These results indicate that AETD induces apoptosis in HL-60 cells by causing intracellular ROS formation and GSH depletion followed by the downstream event of caspase-3 activation.

Molsidomine ameliorates experimental allergic encephalomyelitis in Lewis rats

Experimental allergic encephalomyelitis (EAE) is an autoimmune CD4+ T cell-mediated disease of the central nervous system (CNS). Nitric oxide (NO) plays an important role in preventing the development of EAE. Molsidomine (Mol) is a drug used for the treatment of coronary artery disease. Its therapeutic effects are the consequences of NO formation. In this study, we investigated the effects of Mol on EAE development in myelin basic protein (MBP)-immunized Lewis rats. All rats immunized with MBP developed typical clinical signs of acute EAE. In the EAE rats receiving Mol, the severity of clinical signs and the infiltration of inflammatory cells in CNS were clearly reduced. Furthermore, Mol administration significantly reduced the production of interferon-gamma, a Th1 inflammatory cytokine, but increased the production of interleukin-10, a Th2 anti-inflammatory cytokine. Our findings suggest that the administration of the exogenous NO donor Mol is of considerable benefit in limiting the development of EAE and other Th1 cell-mediated inflammatory diseases.

Inhibitory effects of the root cortex of Paeonia suffruticosa on interleukin-8 and macrophage chemoattractant protein-1 secretions in U937 cells

In an effort to elucidate the mechanism of the anti-inflammatory effect of mudanpi, the root cortex of Paeonia suffruticosa Andrews (Ranunculaceae), we determined the effects of the methanolic extract of mudanpi (MEM) on the secretions of interleukin (IL)-8, a major mediator of acute neutrophil-mediated inflammation, and macrophage chemoattractant protein (MCP)-1, a major mediator of chronic macrophage-mediated inflammation, in human monocytic U937 cells stimulated with phorbol myristate acetate (PMA). MEM significantly inhibited PMA-induced secretions of IL-8 and MCP-1 proteins in a dose-dependent manner. The inhibition of these chemokines by MEM was due to its suppression of IL-8 and MCP-1 genes. In addition, 1,2,3,4,6-penta-O-galloyl-beta-D-glucose, one of major constituents isolated from MEM, inhibited PMA-induced secretions of IL-8 and MCP-1 proteins by its suppression of IL-8 and MCP-1 genes. Thus, one possible anti-inflammatory mechanism of mudanpi, an anti-inflammatory Chinese crude drug, may be to inhibit the secretions of inflammatory chemokines.

Inhibition of TNF-alpha, IL-1beta, and IL-6 productions and NF-kappa B activation in lipopolysaccharide-activated RAW 264.7 macrophages by catalposide, an iridoid glycoside isolated from Catalpa ovata G. Don (Bignoniaceae)

Catalposide, the major iridoid glycoside isolated from the stem bark of Catalpa ovata G. Don (Bignoniaceae), was found to inhibit the productions of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and interleukin-6 (IL-6), and the activation of nuclear factor kappaB (NF-kappaB) in RAW 264.7 macrophages activated with lipopolysaccharide (LPS). Catalposide also inhibited the expressions of TNF-alpha, IL-1beta, and IL-6 genes and the nuclear translocation of p65 subunit of NF-kappaB in LPS-activated RAW 264.7 cells. Flow cytometric analysis revealed that catalposide suppressed the binding of FITC-conjugated LPS to CD14 on the surface of cells, probably resulting in the inhibitory effects on TNF-alpha, IL-1beta, and IL-6 productions and NF-kappaB activation. These findings suggest that catalposide could be an attractive candidate for adjunctive therapy in gram-negative bacterial infections.

Effect of risperidone on serum cytokines

A variety of cytokines are dysregulated in schizophrenia, and some antipsychotic drugs effect cytokines. In order to examine the effect of risperidone on plasma cytokines, we measured the serum level of IL-1b, IL-2, IL-6, IL-12, and INF-g during acute states of illness, and after 4 weeks of treatment with risperidone in 19 schizophrenic patients. The patients' psychopathology was assessed by PANSS. Plasma IL-12 levels increased significantly after 4 weeks of treatment (p = .002). Plasma IL-b, IL-2, IL-6, and INF-g levels were not significantly different before and after treatment. There were no significant correlations between the changes in cytokine levels and the changes in PANSS scores. Increased IL-12 may contribute to activation of immune responses during treatment with risperidone. IL-12 may play an important role in immune responses related to neuropsychiatry.

Nitric oxide as a bioregulator of apoptosis

Nitric oxide (NO), synthesized from l-arginine by NO synthases, is a small, diffusible, highly reactive molecule with dichotomous regulatory roles under physiological and pathological conditions. NO can promote apoptosis (proapoptosis) in some cells, whereas it inhibits apoptosis (antiapoptosis) in other cells. This complexity is a consequence of the rate of NO production and the interaction with biological molecules such as iron, thiols, proteins, and reactive oxygen species. Long-lasting production of NO acts as a proapoptotic modulator by activating caspase family proteases through the release of mitochondrial cytochrome c into the cytosol, upregulation of p53 expression, activation of JNK/SAPK, and altering the expression of apoptosis-associated proteins including Bcl-2 family proteins. However, low or physiological concentrations of NO prevent cells from apoptosis induced by trophic factor withdrawal, Fas, TNFalpha, and lipopolysaccharide. The antiapoptotic mechanism can be understood via expression of protective genes such as heat shock proteins, Bcl-2 as well as direct inhibition of the apoptotic caspase family proteases by S-nitrosylation of the cysteine thiol. Our current understanding of the mechanisms by which NO exerts both pro- and antiapoptotic actions is discussed in this review article.

Transplacental transfer and age-related levels of serum IgG antibodies to the capsular polysaccharides of Streptococcus pneumoniae types 14 and 19 in Korea

Little is known about the prevalence of naturally acquired IgG antibodies to the capsular polysaccharides of Streptococcus pneumoniae (pneumococcal IgG) in Korea. In the present study, we investigated transplacental transfer and age-related levels of pneumococcal IgG to provide background seroepidemiologic data for S. pneumoniae in Korea. One hundred thirty eight sera were assayed by ELISA for IgG to pneumococcal polysaccharide capsular serotypes 14 and 19, the predominant serotypes for under 15 yr of age in Korea. The subjects were divided into 7 subgroups according to age. The cord/maternal geometric mean titer of pneumococcal were 4.47+/-5.88/5.21 +/- 5.88 for serotype 14, and 4.68 +/- 5.55/6.55 +/- 6.92 for serotype 1 9 (mean +/- standard deviation, microg/mL). After birth, the geometric mean titers of pneumococcal IgG for serotypes 14 and 19 expressed in microg/mL were 1.18+/-2.12 and 1.41+/-2.17 in the 0-6 months group, 0.27+/-0.19 and 0.69+/-0.93 in 7-12 months, 0.21+/-0.22 and 0.64+/-1.32 in 1-2 yr, 0.69+/-0.78 and 2.65+/-2.46 in 3-6 yr, 2.52+/-2.72 and 8.29+/-4.24 in 7-10 yr, respectively. In conclusion, reduced transplacental transfer and very low serum concentrations of pneumococcal IgG may contribute to the susceptibility of neonates, infants, and young children to S. pneumoniae infection.

Cyclic adenosine monophosphate inhibits ursolic acid-induced apoptosis via activation of protein kinase A in human leukaemic HL-60 cells

This study was designed to investigate the effect of cAMP on ursolic acid-induced apoptosis of HL-60 cells. Ursolic acid decreased the viability of the cells in a dose-dependent manner, which was revealed as an apototic process characterized by ladder-pattern DNA fragmentation in agarose gel electrophoresis and segmented nuclei in DAPI-sulpharhodamin 101 staining. Ursolic acid-induced apoptosis of the cells was markedly inhibited by the addition of cAMP-elevating agents including DB-cAMP, CPT-cAMP, 8-Br-cAMP and forskolin. These results were further evidenced by the fact that inhibitors of cAMP-dependent protein kinase including H89 and KT5720 completely inhibited the cAMP-mediated rescue of HL-60 cells from ursolic acid-induced apoptosis. In addition, differentiating agents of the cells such as dimethyl sulfoxide and retinoic acid did not affect the ursolic acid-induced apoptosis of HL-60 cells. These results suggest that signaling pathway of cAMP-dependent activation of protein kinase A may affect the responsiveness of tumor cells upon ursolic acid.

Ionizing radiation potentiates the induction of nitric oxide synthase by interferon-gamma (Ifn-gamma) or Ifn-gamma and lipopolysaccharide in bnl cl.2 murine embryonic liver cells: role of hydrogen peroxide

The effects of ionizing irradiation on the nitric oxide (NO) production in murine embryonic liver cell line, BNL CL.2 cells, were investigated. Various doses (5-40 Gy) of radiation made BNL CL.2 cells responsive to interferon-gamma alone for the production of NO in a dose-dependent manner. Small amounts of lipopolysaccharide (LPS) or tumor necrosis factor-alpha (TNF-alpha) synergized with IFN-gamma in the production of NO from irradiated BNL CL.2 cells, even though LPS or TNF-alpha alone did not induce NO production from the same cells. Immunoblots showed parallel induction of inducible nitric oxide synthase (iNOS). NO production in irradiated BNL CL.2 cells by IFN-gamma or IFN-gamma plus LPS was decreased by the addition of catalase, suggesting that H(2)O(2) produced by ionizing irradiation primed the cells to trigger NO production in response to IFN-gamma or IFN-gamma plus LPS. Furthermore, the treatment of nongamma-irradiated BNL CL.2 cells with H(2)O(2) made the cells responsive to IFN-gamma or IFN-gamma plus LPS for the production of NO. This study shows that ionizing irradiation has the ability to induce iNOS gene expression in responsive to IFN-gamma via the formation of H(2)O(2) in BNL CL.2 murine embryonic liver cells.

12-O-tetradecanoyl phorbol 13-acetate, protein kinase C (PKC) activator, protects human leukemia HL-60 cells from taxol-induced apoptosis: possible role for extracellular signal-regulated kinase

The purpose of this study was to evaluate whether the mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK) signaling pathway contributes to 12-O-tertadecanoyl phorbol 13-acetate (TPA)-mediated protection from taxol-induced apoptosis of human leukemia HL-60 cells. Treatment of cells with taxol for 12 h resulted in apoptosis of HL-60 cells. TPA was protective against taxol-induced apoptosis and this anti-apoptotic effect was reversible when TPA was used in conjunction with staurosporine and H-7, PKC inhibitors, suggesting that TPA may protect HL-60 cells against taxol-induced apoptosis via the PKC-dependent pathway. Since TPA stimulates MEK signal transduction pathway in HL-60 cells, we postulated that MEK pathway may be playing a role in the ability of TPA to inhibit taxol-induced apoptosis. PD098059, a specific MEK kinase inhibitor, abolished the ability of TPA to inhibit taxol-induced apoptosis. These results suggest that activation of PKC in HL-60 cells confers protection against taxol-induced apoptosis and that MEK mediates anti-apoptotic signaling of PKC.

Apoptotic cell death induced by taxol is inhibited by nitric oxide in human leukemia HL-60 cells

Taxol, an antineoplastic drug, increases the fraction of cells in G2/M phases of cell cycle, induces apoptosis of leukemic cells, and activates macrophages to produce nitric oxide (NO) in response to interferon-gamma. NO has been found to play roles as pro-apoptotic or anti-apoptotic effector molecules. In this study, we investigate effects of NO on taxol-induced apoptosis in human myeloid leukemia cell, HL-60. Incubation of the cells with taxol for 24 hr induced marked DNA fragmentation of HL-60 cells. Treatment of the cells with S-nitrosogluthathione (GSNO), a NO-generating agent, protected the cells against taxol-induced apoptosis. Cell cycle analysis showed that treatment of the cells with 100 nM taxol for 12 hr rendered the cells to be accumulated in G2/M phase, but the cotreatment of the cells with taxol and 0.1 mM GSNO decreased the accumulation of the cell in G2/M phases, suggesting that NO might interfere entering of taxol-treated cells into G2/M phases. Deferoxamine or mimosine, which can arrest cells mainly at G1/S phases, also decreased taxol-induced apoptosis and reduced the number of the taxol-treated cells arresting in G2/M phases. Thus, we conclude that a protective effect of NO on taxol-treated cells from apoptosis may be partially caused by interfering entering of the taxol-treated cells into G2/M phases.

Indomethacin treatment decreases renal blood flow velocity in human neonates

This study was designed to evaluate the effect of indomethacin (ID) on renal perfusion in 13 neonates with symptomatic patent ductus arteriosus (PDA). Serial blood flow velocity in the left renal artery was measured just before and at 10, 30, 45, 60, 75 and 90 min after ID administration. Serum creatinine (Cr), sodium (Na), and osmolarity were measured just before, at 12 and 24 h, and at 3 days after ID administration. Timed urine also was collected for measurement of amount, fractional excretion of Na (FE(Na)), and creatinine clearance (C(Cr)). ID decreased end-diastolic flow velocity of renal artery and increased Pourcelot's index, starting at 10 min and lasting for 75 min (p < 0.05). Serum Cr significantly increased at 12 h, and hourly urine output and C(Cr) decreased for 24 h. Serum Na and osmolarity decreased for a period of at least 3 days (p < 0.05). FE(Na) decreased at 12-24 h (p < 0.05). We conclude that ID treatment can induce significant renal dysfunction due to diminution of renal perfusion in human neonates.

In vitro inducible nitric oxide synthesis inhibitors from Alismatis Rhizoma

Bioassay-guided fractionation of an aqueous extract of Alismatis Rhizoma has furnished two inducible nitric oxide synthase (iNOS) inhibitory compounds, alismol (1) and alisol B monoacetate (2), together with an inactive triterpene, alisol C monoacetate (3). Compounds 1 and 2 inhibited nitric oxide (NO) synthesis in a dose-dependent manner in murine macrophage-like RAW 264.7 cells stimulated with interferon-gamma (IFN-gamma) plus lipopolysaccharide (LPS). The inhibitory effects of 1 and 2 on NO synthesis were partly due to suppression of iNOS mRNA expression as determined by Northern blotting.

In vitro inducible nitric oxide synthesis inhibitory active constituents from Fraxinus rhynchophylla

Bioassay-guided fractionation of an H2O extract of the barks of Fraxinus rhynchophylla has furnished two inducible nitric oxide synthase (iNOS) inhibitory compounds, ferulaldehyde (1) and scopoletin (3) together with a coumarin, fraxidin (2). Compounds 1 and 3 showed inhibition of nitric oxide (NO) synthesis in a dose-dependent manner by murine macrophage-like RAW 264.7 cells stimulated with interferon-gamma (IFN-gamma) plus lipopolysaccharide (LPS). The inhibition of NO synthesis of 1 was reflected in the decreased amount of iNOS protein, as determined by Western blotting.

Chloroquine inhibits inducible nitric oxide synthase expression in murine peritoneal macrophages

Induction of inducible nitric oxide synthase in vivo or in vitro in response to stimuli is only temporary. However, chronic localized expression of inducible nitric oxide synthase in certain organs has been associated with the development of autoimmune diseases or chronic inflammatory diseases. Chloroquine is being used as an antiinflammatory drug, and its inhibitory effect on the synthesis of pro-inflammatory cytokines, such as tumour necrosis factor-alpha and interferon-gamma, has been reported. In this study, we examined whether chloroquine could inhibit nitric oxide synthesis in murine peritoneal macrophages stimulated with interferon-gamma and lipopolysaccharide. Although prolonged incubation of cells with high concentrations of chloroquine showed some cytotoxicity, the drug itself was not cytotoxic when macrophages were preincubated with chloroquine for 2 hr, washed and stimulated with interferon-gamma and lipopolysaccharide in the absence of chloroquine for another 48 hr. The nitric oxide production from stimulated macrophages was markedly reduced by chloroquine in a dose-dependent manner and induction of inducible nitric oxide synthase mRNA was also suppressed by chloroquine pretreatment. These results show that chloroquine inhibits the induction of inducible nitric oxide synthase from interferon-gamma and lipopolysaccharide-stimulated macrophages, thereby reducing nitric oxide synthesis.

Protective effects of glucocorticoids on taxol-induced cytotoxicity in human leukemia HL-60 cells

Although the therapeutic actions of glucocorticoids are largely attributed to anti-inflammatory and immunosuppressive effects, they have been implicated in enhancing tissue and cellular protections. In this study, we examined whether glucocorticoids including dexamethasone (Dex) and hydroxycortisone could diminish the cytotoxic effects of anti-microtubule agents including taxol (paclitaxel), microtubule stabilizing agent, and colchicine, microtubule disrupting agent, on human leukemia HL-60 cells. Taxol or colchicine decreased the viability of HL-60 cells in a dose-dependent manner. However, micromolar concentrations of glucocorticoids rendered HL-60 cells resistant against the cytotoxic activity of anti-microtubule agents. Pretreatments of the glucocorticoids were more effective than simultaneous treatments with antimicrotuble agents. The fact that actinomycin D or cycloheximide reversed the cytoprotective effects of glucocorticoids on cytotoxicities in HL-60 cells induced by antimicrotuble agents suggests glucocorticoids cytoprotection might be mediated via newly synthesized protein. Collectively, these data showed that micromolar concentrations of dexamethasone or hydrocortisone could attenuate the cytotoxic effects of taxol or colchicine on human leukemia HL-60 cells via protein synthesis.

Scopoletin: an inducible nitric oxide synthesis inhibitory active constituent from Artemisia feddei

Bioassay-guided fractionation of an H2O extract of Artemisia feddei has furnished an inducible nitric oxide synthase (iNOS) inhibitory coumarin, scopoletin (1) and one of the inactive sesquiterpenes, achillin (2). Compound 1 showed inhibition of nitric oxide (NO) synthesis in a dose-dependent manner in murine macrophage-like RAW 264.7 cells stimulated with interferon-gamma (IFN-gamma) plus lipopolysaccharide (LPS). The inhibition of NO synthesis of 1 was due to suppression of iNOS mRNA and iNOS protein, as determined by Northern and Western blotting, respectively.

Modulation of nitric oxide-induced apoptotic death of HL-60 cells by protein kinase C and protein kinase A through mitogen-activated protein kinases and CPP32-like protease pathways

To define the signaling pathways during NO-induced apoptotic events and their possible modulation by two protein kinase systems, we explored the involvement of three structurally related mitogen-activated protein kinase subfamilies. Exposure of HL-60 cells to sodium nitroprusside (SNP) strongly activated p38 kinase, but did not activate c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK). In addition, SNP-induced apoptosis was markedly blocked by the selective p38 kinase inhibitor (SB203580) but not by MEK1 kinase inhibitor (PD098059), indicating that p38 kinase serves as a mediator of NO-induced apoptosis. In contrast, treatment of cells with phorbol 12-myristate 13-acetate (PMA) strongly activated not only JNK but also ERK, while not affecting p38 kinase. However, although SNP by itself weakly activated CPP32-like protease, SNP in combination with PMA markedly increased the extent of CPP32-like protease activation. Interestingly, N6,O2-dibutylyl cAMP (DB-cAMP) significantly blocked SNP- or SNP plus PMA-induced activation of CPP32-like protease and the resulting induction of apoptosis. DB-cAMP also blocked PMA-induced JNK activation. Collectively, these findings demonstrate the presence of specific up- or down-modulatory mechanisms of cell death pathway by NO in which (1) p38 kinase serves as a mediator of NO-induced apoptosis, (2) PKC acts at the point and/or upstream of JNK and provides signals to potentiate NO-induced CPP32-like protease activation, and (3) PKA lies upstream of either JNK or CPP32-like protease to protect NO- or NO plus PMA-induced apoptotic cell death in HL-60 cells.

Increased intracellular cAMP renders HL-60 cells resistant to cytotoxicity of taxol

The treatment of advanced cancers with paclitaxel (taxol) is hindered by the development of drug resistance. Resistance to taxol is known to be associated with multidrug resistance (MDR) and a mutation affecting either the alpha- or beta-subunit of tubulin. In this study, we demonstrated that an intracellular cAMP level may also play an important role in resistance to taxol in HL-60, acute promyelocytic leukemia cells. Exposure of HL-60 cells to various doses of taxol for 18 hr resulted in cell death. However, pretreatment of the cells with cAMP analogs such as N6:O2-dibutyl cAMP (Db-cAMP), 8-(4-chlorophenylthio) cAMP (CPT-cAMP) and 8-bromo-cAMP (8-Br-cAMP) or an intracellular cAMP elevating agent such as forskolin apparently rendered HL-60 cells more resistant to taxol, but not with dimethyl sulfoxide (DMSO) or retinoic acid (RA), well known differentiating agents. To investigate whether protein kinase A (PKA) activated by an increase in intracellular cAMP level could be involved in increased taxol resistance of the cells, we examined the effects of PKA inhibitors, including H-89 and KT5720, on taxol resistance induced by Db-cAMP. The PKA inhibitors significantly abolished Db-cAMP-induced taxol resistance. These results suggest that cAMP analogs may render tumor cells more resistant to taxol via PKA activation.

Overexpression of protein kinase C isoforms protects RAW 264.7 macrophages from nitric oxide-induced apoptosis: involvement of c-Jun N-terminal kinase/stress-activated protein kinase, p38 kinase, and CPP-32 protease pathways

Nitric oxide (NO) induces apoptotic cell death in murine RAW 264.7 macrophages. To elucidate the inhibitory effects of protein kinase C (PKC) on NO-induced apoptosis, we generated clones of RAW 264.7 cells that overexpress one of the PKC isoforms and explored the possible interactions between PKC and three structurally related mitogen-activated protein (MAP) kinases in NO actions. Treatment of RAW 264.7 cells with sodium nitroprusside (SNP), a NO-generating agent, activated both c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) and p38 kinase, but did not activate extracellular signal-regulated kinase (ERK)-1 and ERK-2. In addition, SNP-induced apoptosis was slightly blocked by the selective p38 kinase inhibitor (SB203580) but not by the MAP/ERK1 kinase inhibitor (PD098059). PKC transfectants (PKC-beta II, -delta, and -eta) showed substantial protection from cell death induced by the exposure to NO donors such as SNP and S-nitrosoglutathione (GSNO). In contrast, in RAW 264.7 parent or in empty vector-transformed cells, these NO donors induced internucleosomal DNA cleavage. Moreover, overexpression of PKC isoforms significantly suppressed SNP-induced JNK/SAPK and p38 kinase activation, but did not affect ERK-1 and -2. We also explored the involvement of CPP32-like protease in the NO-induced apoptosis. Inhibition of CPP32-like protease prevented apoptosis in RAW 264.7 parent cells. In addition, SNP dramatically activated CPP32 in the parent or in empty vector-transformed cells, while slightly activated CPP32 in PKC transfectants. Therefore, we conclude that PKC protects NO-induced apoptotic cell death, presumably nullifying the NO-mediated activation of JNK/SAPK, p38 kinase, and CPP32-like protease in RAW 264.7 macrophages.

Interferon-gamma alone triggers the production of nitric oxide from serum-starved BNL CL.2, murine embryonic liver cells

A previous study has demonstrated that both interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS) were needed to induce the production of nitric oxide (NO) in BNL CL.2 cells, murine embryonic liver cells. We here demonstrate that when BNL CL.2 cells were cultured with serum-free medium, they were induced to produce NO by the stimulation of IFN-gamma alone. BNL CL.2 cells were cultured with serum-free or serum-containing medium for 1-3 days and then stimulated to synthesize NO by IFN-gamma. Surprisingly, only serum-starved cells showed significant amount of nitrite accumulation and iNOS protein expression in response to IFN-gamma in dose- and time-dependent manners, but serum-supplied cells did not. When the cells were stimulated with IFN-gamma, tumor necrosis factor-alpha (TNF-alpha), or LPS in combinations, only the combination of IFN-gamma and LPS produced more NO than that produced by IFN-gamma alone. The production of NO by the cells stimulated with IFN-gamma or IFN-gamma plus LPS was blocked by the addition of N(G)-monomethyl-L-arginine (N(G)MMA), a NO synthesis inhibitor. To address the intracellular signal pathway responsible for the production of NO by the cells stimulated with IFN-gamma aloneor IFN-gamma plus LPS, we examined the effects of several protein kinase inhibitors on the production of NO from the cells. The production of NO was significantly inhibited by protein tyrosine kinase (PTK) inhibitors, genistein and herbimycin A, but not by protein kinase A or C inhibitors. These results suggest that the deprivation of serum from BNL CL.2 cell culture medium might prime the cells to induce NO synthesis when the cells are triggered by IFN-gamma and the involvement of PTK signal transduction pathway in the expression of inducible NO synthase gene in murine hepatoma cells.

Inhibition of nitric oxide synthesis by butanol fraction of the methanol extract of Ulmus davidiana in murine macrophages

Since there is increasing evidence that nitric oxide (NO) plays a crucial role in the pathogenesis of inflammatory diseases, this study was undertaken to address whether the methanol (MeOH) extract and its fractions of the bark of Ulmus davidiana Planch (Ulmaceae) could modulate the expression of inducible NO synthase (iNOS) in thioglycollate-elicited murine peritoneal macrophages and murine macrophage cell line, RAW264.7 cells. Stimulation of the peritoneal macrophages and RAW264.7 cells with interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS) resulted in increased production of NO in the medium. However, the butanol (BuOH) fraction of the MeOH extract of U. davidiana barks showed marked inhibition of NO synthesis in a dose-dependent manner. The inhibition of NO synthesis was reflected in the decreased amount of iNOS protein, as determined by Western blotting. The BuOH fraction did not affect the viability of RAW264.7 cells, as assessed by methylthiazol-2-yl-2, 5-diphenyl tetrazolium bromide (MTT) assay; rather, it reduced endogenous NO-induced apoptotic cell death via inhibition of NO synthesis in RAW264.7 cells. On the other hand, the BuOH fraction showed no inhibitory effect on the synthesis of NO by RAW264.7 cells, when iNOS was already expressed by the stimulation with IFN-gamma and LPS. Collectively, these results demonstrate that the BuOH fraction inhibits NO synthesis by inhibition of the induction of iNOS in murine macrophages.

The role of inducible 70-kDa heat shock protein in cell cycle control, differentiation, and apoptotic cell death of the human myeloid leukemic HL-60 cells

Several studies have suggested a role for heat shock proteins (hsps) during development and differentiation. However, relatively little is known about the role of hsp70 in controlling human hematopoietic cell differentiation and death. Here, we show that constitutive expression of human inducible 70-kDa heat shock protein (hsp70) promotes differentiation of HL-60 cells and prevents apoptosis that occurred after terminal differentiation or directly by apoptotic agents. After treatment with phorbol 12-myristate 13-acetate (PMA), hsp70-overexpressing cells (HL-60/hsp70) underwent rapid growth arrest and plastic adherence and expressed more CD14 than parental HL-60 or empty vector-transformed cells (HL-60/puro). HL-60/hsp70 cells also rapidly differentiated into granulocytes by addition of all-trans-retinoic acid, as assessed by phenotypic changes after staining with Wright-Giemsa. After differentiation into monocyte/macrophage-like cells or granulocytes, hsp70-overexpressing cells showed little evidence for apoptosis and had a prolonged survival, indicating that the survival-enhancing properties of hsp70 counteract programmed cell death that accompanies terminal differentiation. HL-60/hsp70 cells also showed more resistance than parental cells against apoptotic agents such as sodium nitroprusside, a NO-generating agent, or Taxol, a microtubule stabilizing agent. Further, heat shock of parental HL-60 cells at 42 degrees C for 3 h increased hsp70 levels, promoted plastic adherence (< 6 h) of the cells in respond to PMA, and protected cells from SNP or Taxol. Taken together, these studies demonstrate that hsp70 plays a crucial role in the differentiation of myeloid cells, participating in cell cycle controls and phenotypic changes, with protecting effects on apoptosis induced by different pathways.

Potentiation of the activity of nitric oxide by the protein kinase C activator phorbol ester in human myeloid leukemic HL-60 cells: association with enhanced fragmentation of mature genomic DNA

Nitric oxide (NO) has been known to induce programmed cell death or apoptosis in murine macrophages, mouse splenocytes, and thymocytes. We demonstrate here that phorbol ester, a protein kinase C (PKC) activator, synergistically augments the antileukemic actions of the NO in HL-60 human promyelocytic leukemia cells. Exposure of cells to sodium nitro-prusside (SNP; 0.5 to 2 mM), a NO-generating agent, induced time- and concentration-related increases in morphological changes, including condensation of nuclear chromatin, nuclear fragmentation, and the apoptotic peak of propidium iodide-stained nuclei by flow cytometry. Phorbol ester alone had a small effect on inducing DNA damage, whereas SNP in combination with phorbol ester at all concentrations tested markedly increased the extent of fragmentation. Maximal potentiation of fragmentation (e.g., four- to fivefold greater than that obtained with 0.5 mM SNP alone) was observed with simultaneous treatment of phorbol ester. Similar results were obtained with another commonly used NO donor agents such as SNAP (0.5 mM) and GSNO (0.5 mM). DNA fragmentation of HL-60 cells was also augmented by 100 U/ml human recombinant interferon-gamma but not by 1.5% (v/v) DMSO or 1 microM retinoic acid. The stage-2 tumor promotor mezerein also mimicked the effect of phorbol ester to induce NO-induced apoptosis. In contrast, PKC inhibitors such as staurosporine and 1-(5-isoquinolinesulfonyl)-2-methyl-piperazine partially blocked high concentration of SNP (2-3 mM)-induced apoptosis, suggesting that activation of PKC closely relates to the potentiation of the activity of NO on HL-60 cell apoptosis. Under the same conditions, SNP in combination with phorbol ester caused apoptosis in another transformed cell line, U-937 cells, but was ineffective at inducing apoptosis in normal peripheral blood mononuclear cells. Taken together, these findings suggest that exposure of HL-60 cells to phorbol ester renders them more susceptible to NO-induced DNA damage and that this phenomenon contributes to the cytotoxic effects of the NO-PKC combination in myeloid leukemia cells.

Stem cell factor protects bone marrow-derived cultured mast cells (BMCMC) from cytocidal effect of nitric oxide secreted by fibroblasts in murine BMCMC-fibroblast coculture

The survival of mast cells are dependent on two kinds of growth factors, one derived from T cells (IL-3) and another derived from fibroblasts (stem cell factor [SCF]). The 3T3 fibroblast cell line derived from WCB6F(1-)+/+ mouse embryos (+/+ 3T3 fibroblasts) supported the proliferation of bone marrow-derived cultured mast cells (BMCMC) in the PWM-stimulated spleen cell conditioned medium (PWM-SCM), whereas the 3T3 fibroblast cell line from WCB6F1-Sl/Sld mouse embryos (Sl/Sld 3T3 fibroblasts) did not. To study the role of nitric oxide (NO) on the growth of mast cells in BMCMC-fibroblast coculture, we used a NO synthase inhibitor, NG-monomethyl-L-arginine (NGMMA). NGMMA recovered survival and maintained proliferation of mast cells in BMCMC-Sl/Sld 3T3 fibroblasts coculture. Sl/Sld 3T3 fibroblasts as well as 3T3 fibroblasts from NIH(-)+/+, BALB(-)+/+ or Swiss(-)+/+ mouse embryos secreted NO in PWM-SCM, but not in alpha-MEM. SCF protected BMCMC from cytotoxicity of exogenous NO in IL-3-supplemented alpha-MEM. We concluded that SCF might protect BMCMC from cytocidal effect of NO in BMCMC-fibroblasts coculture.

Control of scarring in adult wounds using antisense transforming growth factor-beta 1 oligodeoxynucleotides

Adult wounds heal with scar formation, whereas fetal wounds heal without scarring and with a lesser inflammatory and cytokine response. We reasoned that a strategy employing antisense oligodeoxynucleotides (ODN) complementary to transforming growth factor (TGF)-beta-1 mRNA might decrease the scarring of dermal wounds in the mouse. To evaluate this concept, we tested the effects of antisense ODN targeted to TGF-beta 1 mRNA by topical application of the ODN on the skin wound. Phosphorothioation of ODN to retard their degradation. When antisense TGF-beta 1 ODN were applied on the wound site, there was marked reduction of scarring compared with a control wound site. This effect of antisense TGF-beta 1 ODN on scar formation was associated with decreased expression of the TGF-B1 gene. However, sense TGF-beta 1 ODN had no effect on the expression of the TGF-beta 1 gene. In addition, control wounds healed with excessive fibrosis compared with the antisense-treated wounds. In conclusion, our results indicate that antisense TGF-beta 1 ODN could be used for ameliorating scar formation during wound healing.

Expression of protein kinase C delta gene in germ cells

PURPOSE

To investigate the biological functions of protein kinase C delta (PKC delta) in spermatogenesis.

MATERIALS AND METHODS

We examined PKC delta transcript in mouse testis by means of in situ hybridization and Northern blotting.

RESULTS

In testes of normal mice, signals of PKC delta gene expression were detected specifically at the spermatid stage. The PKC delta gene was weakly expressed in 8-week-old mice and highly expressed by 12 weeks. However, the expression was not detected in testes of germ cell-deficient W/Wv mice even at 12 weeks.

CONCLUSIONS

Protein kinase C delta gene expression may be controlled by specific developmental processes and PKC delta may play a role in spermatogenesis.

Involvement of protein kinase C during taxol-induced activation of murine peritoneal macrophages

Taxol has been known to block cell division by stabilizing microtubules with promising anticancer activity. However, taxol has distinct cell cycle-independent effects. Recently, this novel drug has been shown to provide a second signal for murine macrophage activation to tumoricidal activity via L-arginine-dependent nitric oxide (NO) synthesis. To investigate the mechanism of taxol-induced NO synthesis, we evaluated the ability of protein kinase C (PKC) inhibitors such as staurosporine (STSN) or polymyxin B to block taxol-induced effects. Taxol alone had only a small effect, whereas taxol in combination with rIFN-gamma markedly increased NO synthesis in a dose-dependent manner. STSN and polymyxin B decreased NO synthesis, which had been induced by rIFN-gamma plus taxol. Furthermore, prolonged incubation of the cells with phorbol ester, which down-regulates PKC activity, abolished synergistic cooperative effect of taxol with rIFN-gamma on NO synthesis. Synergy between IFN-gamma and taxol was mainly dependent on taxol-induced TNF-alpha secretion because not only the increase of inducible NO synthase (iNOS) gene expression by rIFN-gamma plus taxol was associated with the increased expression of TNF-alpha gene but also taxol-induced NO production was decreased by the treatment of anti-murine TNF-alpha neutralizing Abs. STSN and polymyxin B potently inhibited taxol-induced TNF-alpha secretion and TNF-alpha gene expression as well as iNOS gene expression by rIFN-gamma plus taxol. However, rIFN-gamma plus TNF-alpha-induced NO synthesis was not blocked by STSN or polymyxin B. This result indicates that TNF-alpha-induced signaling for induction of NO synthesis is not dependent on PKC activation, and further suggests that the point at which TNF-alpha acts on the NO synthesis from rIFN-gamma-primed macrophages lies next to the point of PKC activation. In conclusion, the present results strongly suggest that the capacity of taxol to increase NO synthesis from rIFN-gamma-primed macrophages is the result of taxol-induced TNF-alpha secretion via the signal transduction pathway of PKC activation.

Involvement of protein kinase C during taxol-induced activation of murine peritoneal macrophages

Taxol has been known to block cell division by stabilizing microtubules with promising anticancer activity. However, taxol has distinct cell cycle-independent effects. Recently, this novel drug has been shown to provide a second signal for murine macrophage activation to tumoricidal activity via L-arginine-dependent nitric oxide (NO) synthesis. To investigate the mechanism of taxol-induced NO synthesis, we evaluated the ability of protein kinase C (PKC) inhibitors such as staurosporine (STSN) or polymyxin B to block taxol-induced effects. Taxol alone had only a small effect, whereas taxol in combination with rIFN-gamma markedly increased NO synthesis in a dose-dependent manner. STSN and polymyxin B decreased NO synthesis, which had been induced by rIFN-gamma plus taxol. Furthermore, prolonged incubation of the cells with phorbol ester, which down-regulates PKC activity, abolished synergistic cooperative effect of taxol with rIFN-gamma on NO synthesis. Synergy between IFN-gamma and taxol was mainly dependent on taxol-induced TNF-alpha secretion because not only the increase of inducible NO synthase (iNOS) gene expression by rIFN-gamma plus taxol was associated with the increased expression of TNF-alpha gene but also taxol-induced NO production was decreased by the treatment of anti-murine TNF-alpha neutralizing Abs. STSN and polymyxin B potently inhibited taxol-induced TNF-alpha secretion and TNF-alpha gene expression as well as iNOS gene expression by rIFN-gamma plus taxol. However, rIFN-gamma plus TNF-alpha-induced NO synthesis was not blocked by STSN or polymyxin B. This result indicates that TNF-alpha-induced signaling for induction of NO synthesis is not dependent on PKC activation, and further suggests that the point at which TNF-alpha acts on the NO synthesis from rIFN-gamma-primed macrophages lies next to the point of PKC activation. In conclusion, the present results strongly suggest that the capacity of taxol to increase NO synthesis from rIFN-gamma-primed macrophages is the result of taxol-induced TNF-alpha secretion via the signal transduction pathway of PKC activation.

Administration of dehydroepiandrosterone reverses the immune suppression induced by high dose antigen in mice

Several factors including antigen concentration, the route of antigen administration, hormones and cytokines have shown to affect T cells to produce the distinct patterns of lymphokines which exert regulatory and effector functions of immune response. In this study, we asked whether administration of dehydroepiandrosterone (DHEA) to mice which were tolerized by high dose of antigen could modulate T cell functions to restore the suppressed cellular immune response and to produce the distinct lymphokines. An intravenous injection of high dose of sheep red blood cells induced suppression of delayed type hypersensitivity (DTH) and a single subcutaneous injection of the tolerant mice with DHEA restored the suppressed DTH response. Furthermore, in vitro treatment of spleen cells from tolerant mice with DHEA abolished the transfer of tolerance to naive recipients. Lymphocytes from the DHEA-treated tolerant mice produced more IFN-gamma and less IL-4 and IL-6 than the cells from tolerant animals without DHEA treatment. These findings indicate that DHEA could recover antigen-specific immune suppression by differentially affecting T cells to produce the distinct lymphokines.

Down-regulation of transforming growth factor-beta gene expression by antisense oligodeoxynucleotides increases recombinant interferon-gamma-induced nitric oxide synthesis in murine peritoneal macrophages

Increasing evidence indicates that the production of nitric oxide (NO) by inducible NO synthase (iNOS) is tightly regulated. Transforming growth factor-beta (TGF-beta) is a family of multifunctional peptides secreted during macrophage activation, but several lines of evidence suggest that TGF-beta is selectively suppressive for macrophage NO production. We therefore reasoned that a strategy employing oligodeoxynucleotides (ODN) complementary to TGF-beta mRNA (antisense ODN) might increase NO production in interferon-gamma (IFN-gamma) treated murine peritoneal macrophages. To evaluate this concept, we tested the effects of antisense ODN targeted to TGF-beta mRNA (25-mer ODN complementary to TGF-beta mRNA sequences) by introducing them into the medium of cultured macrophages. Phosphorothioation of ODN was employed to retard their degradation. Antisense ODN had no effect on NO production by itself, whereas IFN-gamma alone had a modest effect. When antisense ODN were used in combination with IFN-gamma, there was a marked cooperative induction of NO production. These effects of antisense ODN were associated with decreased TGF-beta expression in activated macrophages. However, sense ODN had no effect. Adding anti-TGF-beta antibodies to the IFN-gamma-treated macrophages mimicked the positive effect of antisense ODN on NO production. In addition, the effects of either antisense ODN or anti-TGF-beta antibodies were blocked by adding exogenous TGF-beta in cultured macrophages. These results indicate that the generation of TGF-beta by activated macrophages provides a self-regulating mechanism by which the temporal and perhaps spatial production of NO, a reactive and potentially toxic mediator, can be finely regulated.

Effect of qigong training on proportions of T lymphocyte subsets in human peripheral blood

The effect of Qigong training on proportions of T lymphocyte subsets was investigated in human peripheral blood. We observed that the ratio of CD4+/CD8+ T lymphocytes was increased as much as 50% in a trainee group who practiced Qigong training more than 5 months compared to a normal healthy group who did not practice. The absolute number of CD4+ T lymphocytes was also elevated in trainee group with 100 cells/mm3 more than in normal healthy group. The positive correlation between the ratio of CD4+/CD8+ T lymphocytes and the ratio of CD4+45RA-/CD4+CD45RA+ T lymphocytes was shown in the trainee group. In contrast, there was a negative correlation between the ratio of CD4+/CD8+ T lymphocytes and the ratio of CD8+CD57+/CD8+CD57- T lymphocytes in the trainee group. The data indicate that Qigong training affects the profile of lymphocyte subsets in human peripheral blood, especially the proportion of CD4+ T lymphocytes.

Delayed cutaneous hypersensitivity reactions in Qigong (chun do sun bup) trainees by multitest cell mediated immunity

To determine the difference of cellular immunity between a Qigong trainee group and a normal healthy group, skin tests for delayed cutaneous hypersensitivity (DCH) were carried out with ubiquitous seven antigens. The maximal antigen response time was faster in Qigong trainee group (24 hr) and the response antigen number was also higher in the Qigong trainee group (6 antigens) than in normal healthy person (48 hr and 4 antigens). Qigong trainee also had a larger induration diameter (5.14 mm) than normal healthy person (3.79 mm) at 24 hr. Our results represent the difference in cell mediated immunity (CMI) between Qigong trainees and normal healthy subjects.

Synergistic cooperation between phorbol ester and IFN-gamma for induction of nitric oxide synthesis in murine peritoneal macrophages

The role of protein kinase C (PKC) in the induction of nitric oxide (NO) synthesis in murine peritoneal macrophages was examined. Phorbol ester, a PKC activator, had no effect on NO synthesis by itself, whereas IFN-gamma alone had modest activity. When phorbol ester was used in combination with IFN-gamma, there was a marked cooperative induction of NO synthesis in a dose-dependent manner. This increase in NO synthesis was reflected as increased amount of inducible NO synthase (iNOS) mRNA, as determined by Northern blotting. The optimal effect of phorbol ester was shown at 6 h after treatment with IFN-gamma. Phorbol ester also induced the release of NO to the incubation medium by bacillus Calmette-Guerin-infected peritoneal macrophages. Prolonged incubation of cells with phorbol ester, which down-regulates PKC activity, abolished the synergistic cooperative effect on NO production with IFN-gamma. In addition, such PKC inhibitors as staurosporin or polymyxin B reduced NO production induced by IFN-gamma plus phorbol ester. When the cells were treated with both actinomycin D and phorbol ester after IFN-gamma stimulation, more NO was produced and more iNOS mRNA was expressed than in the cells treated with actinomycin D alone. On the basis of these observations, we conclude that PKC might not be directly involved in the expression of NO synthase, but, instead, might be involved in the stabilization of the iNOS mRNA already expressed by the treatment of IFN-gamma.

Synergistic cooperation between phorbol ester and IFN-gamma for induction of nitric oxide synthesis in murine peritoneal macrophages

The role of protein kinase C (PKC) in the induction of nitric oxide (NO) synthesis in murine peritoneal macrophages was examined. Phorbol ester, a PKC activator, had no effect on NO synthesis by itself, whereas IFN-gamma alone had modest activity. When phorbol ester was used in combination with IFN-gamma, there was a marked cooperative induction of NO synthesis in a dose-dependent manner. This increase in NO synthesis was reflected as increased amount of inducible NO synthase (iNOS) mRNA, as determined by Northern blotting. The optimal effect of phorbol ester was shown at 6 h after treatment with IFN-gamma. Phorbol ester also induced the release of NO to the incubation medium by bacillus Calmette-Guerin-infected peritoneal macrophages. Prolonged incubation of cells with phorbol ester, which down-regulates PKC activity, abolished the synergistic cooperative effect on NO production with IFN-gamma. In addition, such PKC inhibitors as staurosporin or polymyxin B reduced NO production induced by IFN-gamma plus phorbol ester. When the cells were treated with both actinomycin D and phorbol ester after IFN-gamma stimulation, more NO was produced and more iNOS mRNA was expressed than in the cells treated with actinomycin D alone. On the basis of these observations, we conclude that PKC might not be directly involved in the expression of NO synthase, but, instead, might be involved in the stabilization of the iNOS mRNA already expressed by the treatment of IFN-gamma.

Nitric oxide inhibits the expression of protein kinase C delta gene in the murine peritoneal macrophages

Since there is increasing evidence that protein kinase C (PKC) has a crucial role in the production of nitric oxide (NO) from activated macrophages, this study was undertaken to address whether NO could regulate the expression of the gene of this enzyme. Stimulation of the cells with lipopolysaccharide (LPS) or phorbol 12-myristate 13-acetate (PMA) after treatment with recombinant interferon-gamma (rIFN-gamma) resulted in the increased production of NO in the medium. rIFN-gamma in combination with either LPS or PMA showed marked inhibition of the expression of PKC delta gene, whereas rIFN-gamma alone showed modest inhibition. The inhibition of gene expression was correlated with the amount of NO produced by activated macrophages. The inhibitory effect of NO on the expression of PKC delta gene is mimicked by the treatment of NO generating agent, sodium nitroprusside (SNP). On the other hand, a specific inhibitor for NO synthase, NG-monomethyl-L-arginine (NGMMA), blocked the inhibition of the expression of PKC delta gene by blocking the NO production in the rIFN-gamma and LPS-stimulated cells. However, production of NO did not affect the expression of both TNF-alpha and TGF-beta gene which were induced by the stimulation of macrophages, as well as beta-actin gene, which was constitutively expressed in the macrophages. In conclusion, these findings show that NO has a regulatory role for the expression of the gene of PKC delta which is crucially involved in the process of NO synthesis.

Generation of nitric oxide inhibits formation of superoxide in macrophages during activation

We have studied the production of nitric oxide (NO) and superoxide by murine peritoneal macrophages during activation. The production of NO was induced by activation of cells with recombinant interferon-gamma (rIFN-gamma) and lipopolysaccharide (LPS). Phorbol 12-myristate 13-acetate (PMA)-induced formation of superoxide also increased during activation. However, NO released by the activated macrophages exerted the inhibitory effect on the superoxide formation in the same cells. This fact is supported by the increased production of superoxide when the cells were treated with NG-monomethyl-L-arginine (NGMMA) in addition to stimulation with rIFN-gamma and LPS. The production of superoxide was also inhibited by treatment with sodium nitroprusside (SPN), which spontaneously released nitric oxide in vitro, and at the same time there was increased adenosine diphosphate (ADP)-ribosylation of 37 kDa proteins of the cytoplasm. The 3-aminobenzamide (3-AB) treatment, which decreased ADP-ribosylation, partially reversed SNP-induced inhibition of superoxide generation in macrophages. The above data provide evidence that NO decreases superoxide formation possibly via ADP-ribosylation.

Mianserin-induced restless legs syndrome

Restless legs syndrome was observed in three patients receiving mianserin. The symptoms resolved when the treatment was discontinued or reduced.