Upregulated response to chemokines in oxidative metabolism of eosinophils in asthma and allergic rhinitis.

Reactive oxygen species (ROS) from eosinophils are known to cause tissue damage in allergic inflammation. CC chemokines, especially eotaxin and regulated on activation, normal T-cell expressed and secreted (RANTES), are involved not only in chemotaxis but also in eosinophil activation, such as ROS production. It has been shown that eosinophils from allergic patients are not functionally equivalent to those from normal subjects. In the present study, the characteristics of chemokine-primed ROS production in eosinophils from allergic patients and normal controls were compared. After pretreatment with chemokines, eosinophils were stimulated with calcium ionophore A23187. ROS production by eosinophils was measured using luminol-dependent chemiluminescence. Both RANTES and eotaxin exhibited a priming effect on calcium ionophore-induced ROS production from eosinophils. Despite there being no difference in expression of CC chemokine receptor 3, the priming effect of RANTES and eotaxin was significantly enhanced in eosinophils from the patients. Interleukin-5 further enhanced the priming effect of chemokines in eosinophils from normal subjects, but not those from allergic subjects. The present results suggest an upregulated response to chemokines in eosinophils from allergic patients, and that interleukin-5 can induce a similar phenotype to that found in vivo in allergic patients.

Possible involvement of C-C chemokines in functional augmentation of adhesion molecules in asthmatic patients.

Adhesion molecules and C-C chemokines play an important role in the accumulation of eosinophils in allergic inflammation. In the present study, the expression and function of adhesion molecules on eosinophils from asthmatic patients and involvement of RANTES and eotaxin were examined. Eosinophils isolated by the CD16 negative selection method were stimulated with or without RANTES or eotaxin. Expression of b integrins on eosinophils and the functional adherence to recombinant soluble intercellular adhesion molecule-1 (r-sICAM-1)-coated plates were examined. Compared with normal subjects, eosinophils from asthmatic patients showed increased expression of b2 integrins and functional adherence to r-sICAM-1-coated plates. RANTES and eotaxin augmented the functional adherence of eosinophils without a significant upregulation of b2 integrins. Anti-b2 integrin antibody inhibited the augmentative effect on eosinophil adherence of RANTES and eotaxin. Pertussis toxin, wortmannin, and genistein inhibited chemokine-induced adherence. RANTES and eotaxin are closely related to eosinophil accumulation not only as chemotactic agents but also as augmentative agents for eosinophil adherence through involvement in functional eosinophil adherence to ICAM-1 by a possible qualitative change of b2 integrins. Pertussis toxin-sensitive G proteins, PI3 kinase, and tyrosine kinase are involved in signal transduction leading to activation of b2 integrins on eosinophil following stimulation with RANTES and eotaxin.

Colchicine poisoning resulting from accidental ingestion of meadow saffron (Colchicum autumnale).

A rare case of colchicine poisoning resulting from accidental ingestion of meadow saffron (Colchicun Autumnale) is reported. The plant can frequently be found in the woods of the Northern Hemisphere (1), also in Japan. A 48-year-old male was admitted to hospital complaining of vomiting, nausea and diarrhea following ingestion of the plant and died in four days. The most striking histological findings were metaphasic mitotic figures in the mucosa of the large intestine and the liver. Colchicine was detected in the bile with high-performance liquid chromatography/sonicspray ionization mass spectrometry (HPLC/SSI-MS).

The functional role of rho and rho-associated coiled-coil forming protein kinase in eotaxin signaling of eosinophils.

The CC chemokine eotaxin plays a pivotal role in local accumulation of eosinophils. Very little is known about the eotaxin signaling in eosinophils except the activation of the mitogen-activated protein (MAP) kinase family. The p21 G protein Rho and its substrate Rho-associated coiled-coil forming protein kinase (ROCK) regulate the formation of stress fibers and focal adhesions. In the present study, we studied the functional relevance of Rho and ROCK in eosinophils using the ROCK inhibitor (Y-27632) and exoenzyme C3, a specific Rho inhibitor. Eotaxin stimulates activation of Rho A and ROCK II in eosinophils. Exoenzyme C3 almost completely inhibited the ROCK activity, indicating that ROCK is downstream of Rho. We then examined the role of Rho and ROCK in eosinophil chemotaxis. The eotaxin-induced eosinophil chemotaxis was significantly inhibited by exoenzyme C3 or Y-27632. Because extracellular signal-regulated kinase (ERK)1/2 and p38 MAP kinases are activated by eotaxin and are critical for eosinophil chemotaxis, we investigated whether Rho and ROCK are upstream of these MAP kinases. C3 partially inhibited eotaxin-induced phosphorylation of ERK1/2 but not p38. In contrast, neither ERK1/2 nor p38 phosphorylation was abrogated by Y-27632. Both C3 and Y-27632 reduced reactive oxygen species production from eosinophils. We conclude that both Rho and ROCK are important for eosinophil chemotaxis and reactive oxygen species production. There is a dichotomy of downstream signaling pathways of Rho, namely, Rho-ROCK and Rho-ERK pathways. Taken together, eosinophil chemotaxis is regulated by multiple signaling pathways that involve at least ROCK, ERK, and p38 MAP kinase.

Effect of roxithromycin on eotaxin-primed reactive oxygen species from eosinophils.

BACKGROUND: The CC chemokine eotaxin not only attracts eosinophils to inflamed sites but also promotes adhesion, degranulation and reactive oxygen species production of eosinophils. Reactive oxygen species released from eosinophils are believed to injure epithelial cells at inflamed sites, resulting in airway hyperresponsiveness. Roxithromycin has been reported to have antiasthmatic effects, although its mechanism of action is not thoroughly understood. Therefore, the effect of roxithromycin on eotaxin-primed reactive oxygen species production from eosinophils was studied. METHODS: Reactive oxygen species production by eosinophils cultured with or without roxithromycin was evaluated using luminol-dependent chemiluminescence. RESULTS: Roxithromycin inhibited the release of reactive oxygen species from eosinophils evoked with the calcium ionophore A23187, regardless of pretreatment with or without eotaxin. CONCLUSION: Roxithromycin may protect epithelial cells at inflamed sites, at least partly by inhibiting the release of reactive oxygen species from eosinophils.

Signaling through the beta2 integrin prolongs eosinophil survival.

BACKGROUND: Recently, adhesion molecules have been suggested to play an important role in allergic inflammatory diseases such as bronchial asthma. It is unclear whether eosinophil activation and paracrine or autocrine synthesis of eosinophilopoietic growth cytokines is mediated through signaling by intercellular adhesion molecule-1 (ICAM-1) and the beta2 integrin family. OBJECTIVE: We examined whether signaling by ICAM-1 and its ligands (beta2 integrins) could prolong eosinophil survival. METHODS: Eosinophils were isolated from patients with hypereosinophilia by modified CD16 negative selection. After culture with or without recombinant soluble ICAM-1, eosinophil viability was measured by trypan blue dye exclusion. RESULTS: Eosinophil survival was prolonged in cultures with recombinant soluble ICAM-1 compared with cultures without it (P <.01 on days 2, 4, and 6); this effect was dose-dependent. Eosinophil survival in cultures with recombinant soluble ICAM-1 was significantly inhibited by antibodies against ICAM-1 (P <.01), complement receptor 3 (P <.01), and lymphocyte function-associated antigen-1beta (P <.01). Anti-IL-3 showed no effect on eosinophil survival, whereas anti-IL-5 caused partial inhibition of survival. Interestingly, anti-granulocyte/macrophage colony-stimulating factor caused the complete inhibition of eosinophil survival in cultures with recombinant soluble ICAM-1. CONCLUSION: These results suggested the importance of the beta2 integrins in eosinophil-mediated allergic inflammation.

Death attributed to amobarbital and levomepromazine intoxication.

A 29-year-old man, possibly a schizophrenic patient, was found dead 9 h after admission to a hospital. Autopsy revealed neither significant injuries nor diseases except for congestion of all organs. Microscopic examination revealed severe edema in the lung and slight centrilobular necrosis in the liver. Since amobarbital and levomepromazine were detected by drug screening, the concentrations of these drugs in the victim's body fluids and tissues were determined using gas chromatography-mass spectrometry. The whole blood concentrations of amobarbital and levomepromazine were 9.02 microg/ml and 231 ng/ml, respectively. These levels exceeded therapeutic ranges, but are not so toxic or fatal. However, on the basis of the findings in the literature and of the severe lung edema and centrilobular necrosis in the liver, the cause of his death was judged to be amobarbital and levomepromazine intoxication.

An autopsy case of unusual massive gastrointestinal hemorrhaging.

An autopsy case is presented involving massive gastrointestinal hemorrhaging. A 58-year-old woman was found dead with bloody patches on her body. An autopsy revealed a lacerated wound to the mucosa of the stomach and a sharp fish bone was found among bloody contents within the stomach. The duodenum and small intestines contained abundant tarry contents, but the mucosa of the intestinal tract was intact. The cause of death was certified as hemorrhagic shock due to massive bleeding from a wound to the gastric mucosa inflicted by a sharp fish bone. Therefore the possibility that some foreign body has been swallowed must be considered when forensic pathologists investigate cases with bleeding of unknown origin from the alimentary tract.