Analysis of immunoglobulin A antibodies to Helicobacter pylori in serum and gastric juice in relation to mucosal inflammation

Helicobacter pylori is a major etiologic agent in gastroduodenal disorders. In this study, immunoglobulin A (IgA) antibodies to H. pylori antigens were evaluated in serum and gastric juice specimens obtained from patients with gastritis or peptic ulcers by utilizing antibody capture enzyme-linked immunosorbent assays (ACELISAs). Urease alpha subunit (UA), urease beta subunit (UB), the 66-kDa heat shock protein (HSP), and the 25-kDa protein (25K) were used as antigens for the ACELISAs. The antibody titers of the ACELISAs reflect the ratio of H. pylori-specific IgA to total IgA. The ratio is stable, although the antibody concentration fluctuates in gastric juice. By using ACELISAs it was possible to evaluate quantitatively not only serum IgA antibodies but also gastric juice secretory IgA (S-IgA) antibodies. In both serum IgA and gastric juice S-IgA ACELISAs, the titers of antibody to HSP and 25K were remarkably correlated with the histologic grade of gastritis, whereas those to UA and UB were not strongly correlated with histologic grade. Thus, it is useful for estimating the histologic grade of gastritis to quantify serum IgA and gastric juice S-IgA antibodies to HSP and 25K.

The effect of danaparoid sodium (danaparoid) on endotoxin-induced experimental disseminated intravascular coagulation (DIC) in rats

Danaparoid sodium (danaparoid) is a low molecular weight heparinoid with anticoagulation properties, which mainly consists of heparan sulfate. Compared with heparin sodium (heparin), danaparoid has a much higher anti-Xa/anti-thrombin ratio. We compared the effect of danaparoid on endotoxin-induced experimental disseminated intravascular coagulation (DIC) in rats with heparin. A bolus injection of endotoxin (10 mg/kg) induced gradual decreases in the platelet count, and the plasma fibrinogen, antithrombin III (AT-III) and heparin cofactor II levels, as well as an increase in the fibrinogen/fibrin degradation products level from 1 to 6 hours after the injection, indicating that both coagulation and fibrinolysis were activated. The intravenous administration of danaparoid or heparin 3 hours after the endotoxin injection inhibited the endotoxin-induced decreases in the platelet count and plasma fibrinogen level and also inhibited the endotoxin-induced increase in glomerular fibrin deposition in the kidney. Differences between danaparoid and heparin were observed in their effects on the plasma AT-III level and clotting time. Danaparoid significantly inhibited both the decrease in the plasma AT-III level and the prolongation of the prothrombin time induced by endotoxin, where as heparin showed no effect on those responses. Moreover, danaparoid enhanced the prolongation of the activated partial thromboplast in time induced by endotoxin to a lesser degree than heparin. These findings suggest that the effects of danaparoid on the endotoxin-induced decrease of the plasma AT-III level and the prolongation of the clotting time are more advantageous than those of heparin. The results may have been due to a higher anti-Xa/anti-thrombin ratio of danaparoid than that of heparin, indicating that danaparoid may be useful in the treatment of DIC.

Modification of Helicobacter pylori adhesion to human gastric epithelial cells by antiadhesion agents

Helicobacter pylori is a major etiological agent in gastroduodenal disorders. H. pylori adhesion to human gastric mucosa is the initial step of H. pylori colonization. Inhibition of H. pylori adhesion is thus a therapeutic target in preventing H. pylori infection. We have previously established a method using the enzyme-linked immunosorbent assay to analyze quantitatively H. pylori adhesion to gastric epithelial cells. This method is suitable for screening antiadhesion agents. Some mucoprotective agents are proved to have antiadhesion effects in vitro, and they may modify H. pylori adhesion. This evidence gives us a useful clue to analyze the molecular mechanism of H. pylori adhesion to mucosa. Furthermore, in clinical trials, these mucoprotective agents enhanced the eradication rate when administered with antibiotics. In conclusion, the antiadhesion agents may have potential as therapeutic regimens against H. pylori infection.

Development of obstructive hypertrophic cardiomyopathy from nonobstructive hypertrophic cardiomyopathy

A rare case of obstructive hypertrophic cardiomyopathy (HC) with mitral regurgitation (MR) is reported, which developed over 7 years from nonobstructive HC in an elderly woman. Systolic anterior motion of the anterior mitral leaflet was the most likely cause of the outflow obstruction and mitral valve replacement combined with septal myectomy resulted in complete abolition of the outflow tract gradient and MR.

Effect of rebamipide, a novel antiulcer agent, on Helicobacter pylori adhesion to gastric epithelial cells

Helicobacter pylori is a major etiological agent in gastroduodenal disorders. The adhesion of H. pylori to human gastric epithelial cells is the initial step of H. pylori infection. Inhibition of H. pylori adhesion is thus a therapeutic target in the prevention of H. pylori infection. Experiments were performed to evaluate the effect of rebamipide, a novel antiulcer agent, on H. pylori adhesion to gastric epithelial cells. MKN-28 and MKN-45 cells, derived from human gastric carcinomas, were used as target cells. Ten H. pylori strains isolated from patients with chronic gastritis and gastric ulcer were used in the study. We evaluated the effect of rebamipide on H. pylori adhesion to MKN-28 and MKN-45 cells quantitatively using our previously established enzyme-linked immunosorbent assay. The adhesion of H. pylori to MKN-28 and MKN-45 cells was significantly inhibited by pretreatment of these cells with 100 microg of rebamipide per ml. However, the adhesion was not affected by the pretreatment of H. pylori with rebamipide. On the other hand, the viabilities of H. pylori, MKN-28 cells, and MKN-45 cells were not affected by rebamipide. Our studies suggest that rebamipide inhibits the adhesion of H. pylori to gastric epithelial cells.

The association between serum levels of Th cytokines and rhinoconjunctivitis caused by methyltetrahydrophthalic anhydride

BACKGROUND

There are few epidemiologic studies on the association between serum levels of T helper (Th) cytokines and allergic symptoms caused by sensitizing agents.

METHODS

A population of 147 workers from two condenser plants using epoxy resin with methyltetrahydrophthalic anhydride (MTHPA) underwent a questionnaire survey and serologic investigations. Total and MTHPA-specific IgE levels were measured by the Pharmacia CAP System, and serum levels of interleukin (IL)-4, IL-13, and interferon-gamma (IFN-gamma) by enzyme immunoassay.

RESULTS

A significant association was found between work-related eye and nasal symptoms and a range of atopic characteristics, including the frequency of positive specific IgE, specific and total IgE levels, and IL-4 levels. A positive correlation was observed between levels of IL-4 and IL-13 (r=0.42). Furthermore, multiple logistic analysis revealed significant contributions of specific IgE and IL-13 to the work-related symptoms. A similar but nonsignificant association was also found for IL-4 (P=0.07). On the other hand, a multiple regression model with specific IgE levels as a dependent variable showed a significant association with total IgE, but not with IL-4, IL-13, and IFN-gamma.

CONCLUSIONS

These results suggest that work-related eye and nasal symptoms are closely related to specific IgE antibodies, and that allergic responses, mediated by IgE, to MTHPA may lead to a shift in the balance between Th1 and Th2 cells.

The significance of specific IgG4 antibodies to methyltetrahydrophthalic anhydride in occupationally exposed subjects

BACKGROUND

A definitive role for allergen-specific IgG4 as either an anaphylactic or a blocking antibody, or both, remains controversial.

OBJECTIVE

A population of 148 workers from two condenser plants (A and B) using epoxy resin with methyltetrahydrophthalic anhydride (MTHPA) was studied to evaluate the significance of MTHPA-specific IgG4 antibody.

METHODS

The workers were evaluated through questionnaire and serological investigations.

RESULTS

Ninety-seven (66%) of the currently exposed workers had positive MTHPA-specific IgE. IgE-sensitized workers in each plant had significantly more eye and nose complaints than unsensitized workers (P < 0.03). As the result of multiple logistic analysis, specific IgE antibodies was the most important predictor of work-related symptoms and its effect was greater than that of specific IgG4 (odds ratio 16.7 and 3.68, respectively). These indicate an IgE-mediated mechanism in most cases of work-related symptoms associated with MTHPA exposure. However, it cannot be denied that specific IgG4 is an anaphylactic antibody. Furthermore, IgE-sensitized workers in these plants displayed work-related symptoms despite the presence of specific IgG4. The frequency of positive specific IgG4 in continuously exposed workers was significantly (P < 0.02) higher in plant A than in plant B, reflecting the difference of the MTHPA levels between the two plants. In plant A, the frequency of positive specific IgG4 was significantly (P < 0.002) higher in continuously exposed workers than in intermittently exposed workers. Multiple regression analysis also confirmed that plant and exposure style contributed significantly (P < 0.01) to the determination of specific IgG4 levels.

CONCLUSION

These results suggest that work-related eye and nasal symptoms are likely to be IgE-mediated, and that specific IgG4 may reflect the intensity of MTHPA exposure and may not act as a blocking antibody.

Detection of Helicobacter pylori associated antigen and heat shock protein 60 on follicular dendritic cells in the germinal centres of low grade B cell lymphoma of gastric mucosa associated lymphoid tissue (MALT)

AIMS

To investigate the localisation of Helicobacter pylori antigens and the expression of human heat shock proteins (HSP) in stomachs affected by MALT lymphoma.

METHODS

Surgically resected stomachs from 24 patients with MALT lymphoma were immunostained with anti-H pylori rabbit antibodies (ORP-1 and ORP-2) and anti-human HSP60 mouse monoclonal antibodies (mAb) (LK-1 and LK-2).

RESULTS

Follicular dendritic cells of germinal centres in the stomachs affected by MALT lymphoma were immunostained with anti-H pylori polyclonal antibodies and with anti-human HSP60 mAb, as were the epithelial cells. None of the lymph node samples reacted.

CONCLUSIONS

Human HSP60, which cross reacts with anti-H pylori polyclonal antibodies, is often expressed on follicular dendritic cells in gastric MALT lymphoma tissues and may be aetiologically relevant to lymphomagenesis of MALT lymphoma.

[Quantitative analysis of telomerase activity in exfoliated urothelial cells for the diagnosis of bladder carcinoma]

Voided urine cytology is the most common non-invasive examination for the detection and monitoring of bladder cancer. However, the result is not satisfactory, especially for low grade tumors. Activity of telomerase can be detected in most tissues of bladder carcinoma using the telomeric repeat amplification protocol (TRAP) assay. We analyzed the quantitative telomerase activity in exfoliated urothelial cells, and evaluated the values for early diagnosis of bladder carcinoma. We performed a quantitative analysis using a hybridization protection assay (HPA) based on TRAP assay. Telomerase activity was significantly higher level in exfoliated urothelial cells from patients with bladder cancer than all of healthy cases and patients with benign disease (p < 0.0001). The cut off value was calculated as mean + 2SD of the telomerase activity level of the exfoliated urothelial cells from healthy cases. Using this cut off value, telomerase activity was positive in 26 of 41 in exfoliated urothelial cells from bladder cancer patients(63.4% sensitivity), and negative in 63 of 69 in exfoliated urothelial cells from healthy cases and patients with benign disease (91.3% specificity). The sensitivity of telomerase activity in exfoliated cells was higher than urinary cytology, especially in low grade tumors. Our results indicate that quantitative analysis of telomerase activity in exfoliated urothelial cells could become minimum invasive and useful method for detection of bladder carcinoma.

[Cough variant asthma among patients with chronic persistent cough and its clinical outcome]

Thirty-nine patients with chronic persistent cough continuing more than eight weeks were examined regarding to their airway responsiveness to methacholine challenge using the Astograph (TCK-6100H, Chest Corp. Japan). Of these, twenty-three individuals (59%) had airway hyperresponsiveness, leading to diagnose as having cough variant asthma (CVA). Patients with CVA had a higher percentage of eosinophils in peripheral blood and a lower forced expiratory volume in one second than those in non-CVA group. Furthermore, four patients (17%) developed the classic signs and symptoms of asthma, whereas 7 cases (30%) resolved their cough without further treatment and 12 cases (52%) continued to have CVA. These data suggested that a significant proportion of patients with chronic persistent cough had CVA and some of them may develop to classic wheezing asthma.

Prognostic values of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-2 expression in bladder cancer

BACKGROUND

Matrix metalloproteinase-2 (MMP-2), which degrades the extracellular matrix or the basement membrane, has an essential role in tumor invasion and metastasis. To evaluate the roles of MMP-2, its inhibitor (tissue inhibitor of metalloproteinase-2 [TIMP-2]), and its activator (membrane-type matrix metalloproteinase-1 [MT1-MMP]) in tumor invasion or as a prognostic factor in patients with bladder carcinoma, the authors investigated the expression of MMP-2, TIMP-2, and MT1-MMP in patients with bladder carcinoma.

METHODS

Tissues obtained from 41 patients with bladder carcinoma were used for analysis. Expression of MMP-2, TIMP-2, MT1-MMP, and glyceraldehyde-3-phosphate dehydrogenase was examined by reverse transcriptase-polymerase chain reaction analysis. Correlations between the levels of MMP-2, TIMP-2, and MT1-MMP expression and histologic findings or patient outcome were evaluated.

RESULTS

Expression of MMP-2 and TIMP-2 was significantly higher in muscle invasive pT2< or = bladder tumors than in pT1a tumors (MMP-2: P < 0.0005; TIMP-2: P < 0.005). Moreover, high levels of MMP-2 and TIMP-2, as well as MT1-MMP expression, all were strongly associated with decreased survival (MMP-2: P < 0.0001; TIMP-2: P < 0.0001; and MT1-MMP: P < 0.005). Even within the radically cystectomized muscle invasive pT2< or = tumor group, patients with a high expression of any of these three genes had a worse prognosis than those with low expression (MMP-2: P < 0.05; TIMP-2: P < 0.05; and MT1-MMP: P = 0.0641).

CONCLUSIONS

MMP-2 and TIMP-2 are believed to contribute to the invasive properties of bladder carcinoma. The authors report that expression of MMP-2, TIMP-2, and MT1-MMP are useful prognostic indicators in patients with bladder carcinoma and may be helpful in designing treatment protocols.

IgA protease produced by Streptococcus sanguis and antibody production against IgA protease in patients with Behçet's disease

The production of IgA protease in twelve strains of Streptococcus sanguis isolated from patients with Behcet's disease (BD) was examined. Protease activity was detected in 10 out of 12 strains. The protease was purified from one representative strain, S. sanguis 113-20, by employing Rotofor and DEAE-Sephacel chromatography. The molecular mass of the purified protease was approximately 100 kDa, and it cleaved the proline-threonine site of the IgA. Both IgG and IgA titers against the cells (113-20) and the purified IgA protease in the sera of BD patients and healthy controls, 36 each, were assayed. The IgG titers against the cells and protease were not significant in the BD patients or controls, but the IgA titers against the cells and protease in the BD patients were significantly higher than those of the controls. These data indicate that the BD patients are infected with IgA protease-producing S. sanguis strains, which cause an increase of IgA titer against these organisms and IgA protease antigen. Since the organisms can proliferate in BD patients for a long period of time (years), it seems that IgA antibodies cannot effectively eliminate the organisms.

Antibody and cytokine responses in Helicobacter pylori-infected various mouse strains

Helicobacter pylori (H. pylori) infection in the stomach is etiologically closely associated with chronic active gastritis, peptic ulcer, gastric cancer and gastric mucosa-associated lymphoid tissue lymphoma. In this study, we examined the antibody responses and cytokine profiles of three strains of mice (BALB/c, C3H/He, and C57BL/6) infected with H. pylori. Following this, correlations between host-immune reactions and intensity of inflammation were analyzed. H. pylori (ATCC43504) was intragastrically administered once a week to the mice from 4 weeks of age, and they were sacrificed at the ages of 4 and 7 months. In these mice, we examined the histology of the stomach, antibody titers against H. pylori, and serum levels of cytokines (IL-4, IL-10, TNF-alpha, IL-2 and Interferon-gamma). In BALB/c mice, inflammation of the stomach was minimal. Inflammation was observed in 63.6% of C57BL/6 mice and 33.3% of C3h/He mice. In C57BL/6 and C3H/He mice, all the cytokines tended to increase. In contrast, BALB/c mice were inactive in cytokine production except for IL-2. Two C3H/He mice developed severe inflammation with lymph follicles; one showed a response largely typical of Th-1, and the other showed a response largely typical of Th-2. Although a definite correlation was not shown between Th-1/Th-2 response evaluated by cytokine production and intensity of inflammation, it appears that in H. pylori-induced inflammation both cell-mediated (Th-1) and humoral (Th-2) immunity play a role in pathogenesis.

[Effectiveness of a health education class to increase fish intake evaluated by serum fatty acid compositions]

For prevention of cardiovascular disease, we recommended increased fish intake for 50 middle-aged women and men of 40-83 years old at a three-month community-based health education program in an inland farming community. The effectiveness of the education program was evaluated by examining changes in serum lipids and serum fatty acid compositions. For comparison, we selected 48 men and women of 38-82 years old did not participated in the program. Before education, there was no significant difference in the dietary frequency of fish, meat, egg and dishes prepared with oil, mean values of serum lipids or serum fatty acid compositions except for saturated fatty acid, gamma-linolenic acid, dihomo-gamma-linolenic acid and alpha-linolenic acid. After three months, the frequency of fish intake of one or more times per day increased from 33% to 43% in the education group while the frequency of fish intake did not change in the control group. In the education group, serum n3 polyunsaturated fatty acid composition increased from 8.8% to 10.6%. This fatty acid increase was primarily observed in eicosapentaenoic acid and docosahexaenoic acid. The n3/n6 ratio increased from 0.21 to 0.31. In the control group, no change was observed in n3 polyunsaturated fatty acids. This study suggests that the community-based dietary education increased fish intake and serum n3 polyunsaturated fatty acids in women and men of 40 years old or older.

Effect of ecabet sodium on Helicobacter pylori adhesion to gastric epithelial cells

Helicobacter pylori is a major etiological agent in gastroduodenal disorders, with the adhesion of H. pylori to gastric epithelial cells being the initial step of H. pylori infection. Inhibition of H. pylori adhesion is thus a therapeutic target in preventing H. pylori infection. We evaluated the effect of ecabet sodium, an antiulcer agent, on H. pylori adhesion to gastric epithelial cells, using our previously established enzyme-linked immunosorbent assay. The adhesion of H. pylori was significantly inhibited by ecabet sodium in a dose-dependent manner. Our studies suggest that ecabet sodium inhibits the adhesion of H. pylori to gastric epithelial cells.

Inhibitory effects of insulin on intracellular calcium and aggregatory response of platelets are impaired in hypertensive subjects with insulin resistance

To determine the effects of insulin on intracellular calcium and platelet aggregatory responses in hypertensive subjects with insulin resistance, we measured insulin sensitivity in terms of glucose disposal rate (GDR) by the hyperinsulinemic euglycemic clamp technique (GC) in 14 non-diabetic untreated hypertensive subjects, and determined basal ([Ca2+]i) and thrombin-stimulated (T-[Ca2+]i) platelet-free calcium concentrations and thrombin-stimulated platelet aggregatory response (AG) before (PRE[Ca2+]i, T-PRE[Ca2+]i, and PRE AG, respectively) and during (POST[Ca2+]i, T-POST[Ca2+]i, and POST AG, respectively) GC. As a control for GC, vehicle (normal saline) was infused on another day. No significant difference was observed between PRE[Ca2+]i and POST[Ca2+]i, T-PRE[Ca2+]i and T-POST[Ca2+]i, or PRE AG and POST AG, GDR inversely correlated with delta[Ca2+]i (POST [Ca2+]i-PRE[Ca2+]i, r = -0.75, p < 0.02), delta T-[Ca2+]i, (T-POST[Ca2+]i-T-PRE[Ca2+]i, r = -0.63, p < 0.02) and delta AG (POST AG-PRE AG, r = -0.67, p < 0.01). No significant changes were observed in these variables during vehicle infusion. [Ca2+]i, T-[Ca2+]i, and AG decreased during GC as compared with baseline in hypertensive subjects with normal insulin sensitivity, but were unchanged in those with insulin resistance, suggesting that the vasodilatory and anti-platelet aggregatory effects of insulin are impaired in patients with insulin-resistant hypertension.

Risk factors for sensitisation to methyltetrahydrophthalic anhydride

OBJECTIVES

To examine an association between specific IgE to methyltetrahydrophthalic anhydride (MTHPA) and exposure time, atopic history, smoking habits, and total IgE concentrations.

METHODS

A cross sectional survey was carried out on a population of 148 workers from two condenser plants using epoxy resin with MTHPA, an acid anhydride curing agent known to cause allergy.

RESULTS

Using a Pharmacia CAP system with a MTHPA human serum albumin conjugate, specific IgE antibody was detected in serum from 97 (66%) out of the 148 workers exposed to MTHPA. Stepwise multiple linear regression analysis showed a striking relation between log concentrations of specific and total IgE (P < 0.0001). Furthermore, when the workers were divided into two groups according to a cut-off point (100 IU/ml) between low and high total IgE, current smoking was significantly (P = 0.025) associated with specific IgE production only in the group with low total IgE (< 100 IU/ml).

CONCLUSIONS

Smoking is the most significant risk factor for raising specific IgE to MTHPA in the group with low total IgE concentrations.

Specific antibodies against methyltetrahydrophthalic anhydride and risk factors for sensitization in occupationally exposed subjects

OBJECTIVES

Occupational exposure to methyltetrahydrophthalic anhydride (MTHPA) from an epoxy resin was studied to evaluate the nature of reported ocular and nasal complaints and some risk factors for sensitization.

METHODS

Seventy-three current and 22 former workers underwent a questionnaire survey and serologic investigations. Total and MTHPA-specific immunoglobulin (Ig)E levels were measured by means of a Pharmacia CAP system, and MTHPA-specific immunoglobulin (Ig)E levels were measured by enzyme immunoassay.

RESULTS

Forty-six (63%) of the currently exposed workers has positive MTHPA-specific IgE, and no significant difference was found between those continuously or intermittently exposed (58% and 71%, respectively). Work-related ocular or nasal symptoms were significantly associated with specific IgE but not with specific IgG4. This finding indicates that there is an IgE-mediated mechanism in most cases of work-related symptoms associated with MTHPA exposure. The total IgE levels were significantly (P < 0.005) higher in the specific IgE-positive workers than in the specific IgE-negative workers (geometric mean 101 IU/ml and 44.8 IU/ml, respectively). Multiple logistic regression analysis also revealed that the group with high total IgE levels (> or = 80 IU/ml) had a significant relative risk (RR 4.7) of producing MTHPA-specific IgE as compared with the group with low total IgE levels (< 80 IU/ml).

CONCLUSIONS

These results show that MTHPA has a high sensitizing ability and that a high total IgE level is the most significant risk factor for workers exposed to MTHPA. However, to evaluate conclusively the effect of high total IgE levels on sensitization, further prospective studies are necessary.

A rapid and simple method to quantify Helicobacter pylori adhesion to human gastric MKN-28 cells

A rapid and simple method to quantitatively analyse Helicobacter pylori adhesion to human gastric epithelial cells was developed by using an enzyme-linked immunosorbent assay. This method made it possible to quantitatively evaluate the adhesion activities of many different H. pylori strains at a time. Our studies indicate that this method is well suited for the quantitative analysis of H. pylori adhesion to gastric epithelial cells.

[The role of serum soluble interleukin 2 receptor (sIL-2R) levels in patients with renal cell carcinoma]

PURPOSE

The correlation between the serum soluble interleukin-2 receptor (SIL-2R) levels and clinical stage is demonstrable in a variety of non-Hodgkin lymphomas. The prognostic significance of sIL-2R levels in the serum of patients with renal cell carcinoma (RCC) was investigated.

METHOD

sIL-2R were measured in patients with RCC (n=39) and normal control (n=6) by the enzyme immunoassay technique. Cases of RCC were classified according to the clinical stage, pathological grade and growth type. The IL-2R expression of RCC was evaluated by RT-PCR.

RESULT

The serum sIL-2R levels of patients with RCC showed significantly higher values than those of controls (p < 0.05). The serum sIL-2R levels in RCC were closely associated with the stage, grade and growth type of disease. The patients with high serum sIL-2R level (> = 1,000 U/L) exhibited a significantly poorer prognosis than those with low serum sIL-2R level (<1,000 U/L). The band of IL-R was detected only by using the template from the mRNA extracted from a resected tumor tissue of the RCC but not from the RCC cell lines.

CONCLUSION

It was suggested that the measurement of serum sIL-2R levels is useful for predicting the prognosis.

Molecular properties of the proteasome activator PA28 family proteins and gamma-interferon regulation

BACKGROUND

Recent cDNA cloning of two homologous proteasome activators, PA28 alpha and PA28 beta, indicated the presence of a structurally related third protein, Ki antigen, but a functional relationship between Ki antigen and the two PA28 proteins is unknown. Accumulating evidence has implicated an important role for PA28 in the major histocompatibility complex (MHC) class I-restricted antigen processing pathway. Recently, an immunomodulatory cytokine gamma-interferon (gamma-IFN) was found to increase greatly the messages for PA28 alpha and PA28 beta, but not Ki antigen, in human cells.

RESULTS

Ki antigen was co-immunoprecipitated with the 20S proteasome by anti-proteasome antibody, and associated reversibly with the 20S proteasome, as observed for PA28 alpha and PA28 beta. Therefore, Ki antigen was renamed PA28 gamma. Anti-PA28 gamma antibody, however, did not immunoprecipitate PA28 alpha and PA28 beta. gamma-IFN caused an almost complete loss of the PA28 gamma protein in cells without affecting its mRNA level, whereas the levels of both mRNA and protein for PA28 alpha and PA28 beta were coordinately upregulated by gamma-IFN. Finally we showed that the human chromosomal genes of PA28 alpha and PA28 gamma were located on 14q11.2 and 17q21.32-21.33, respectively.

CONCLUSION

PA28 gamma (equivalent to Ki antigen) is a new member of the PA28 family proteins. It exists as a unique homopolymer under non-denaturing conditions. gamma-IFN was found to induce the expression of PA28 alpha and PA28 beta, whereas it caused almost complete loss of the PA28 gamma protein in cells. The reciprocal expression of the PA28 family proteins may imply their involvement in distinct biological processes.

The mechanism of action of KBT-3022, a new antiplatelet agent

1. The mechanism of action of a new antiplatelet agent, KBT-3022 (ethyl 2-[4,5-bis(4-methoxyphenyl)thiazol-2-yl]pyrrol-1-ylacetate) and its active main metabolite, desethyl KBT-3022, was investigated. 2. KBT-3022 and desethyl KBT-3022 inhibited cyclooxygenase from ovine seminal gland with IC50 values of 0.69 and 0.43 microM, respectively. 3. At concentrations higher than those required for cyclooxygenase inhibition, desethyl KBT-3022 inhibited cAMP-phosphodiesterase, specific binding of U46619, and release of phosphatidic acid from thrombin-stimulated platelets. 4. Oral administration of KBT-3022 inhibited the production of thromboxane B2 during blood coagulation more potently than the production of 6-keto-prostaglandin F1 alpha from aortic strips in guinea pigs. 5. These findings suggest that KBT-3022 may inhibit platelet activation principally via the inhibition of cyclooxygenase by desethyl KBT-3022.

[The combination of amoxicillin-clavulanic acid and ofloxacin in the treatment of multidrug-resistant Mycobacterium tuberculosis]

A 67-year-old [correction of 53] man with multidrug resistant tuberculosis (MDR-TB) had been persistently positive for acid-fast bacilli (AFB) both on sputum smear and also on culture with the Ogawa egg medium for 30 years since 1951. The case had been treated previously with isoniazid, rifampin, streptomycin, ethambutol, kanamycin, ethionamide, paraaminosalicylate and cycloserine; however, M. tuberculosis strains isolated from this patient acquired a high resistance to all of these agents. Then, a new regimen of chemotherapy, INH combined with ofloxacin (OFLX) and amoxicillin-clavulanic acid (AMPC/ CVA), was applied to the case. He was successfully treated with this regimen, and a marked decrease in the amount of AFB on smear as well as on culture was observed during the course of chemotherapy. No adverse effects were seen meanwhile. These data suggest that it is worth while to try a regimen containing AMPC/CVA and OFLX in the treatment of MDR-TB.

Effect of estrogen replacement therapy on hepatic triglyceride lipase, lipoprotein lipase and lipids including apolipoprotein E in climacteric and elderly women

Estrogen provides beneficial effects on hyperlipidemia in climacteric and elderly women. In this study of 68 women (37 to 67 years old), hepatic triglyceride lipase (HTGL), lipoprotein lipase (LpL) serum lipids and apolipoproteins were analyzed to investigate the effects of estrogen replacement therapy (ERT). After menopause, LpL, total cholesterol, low-density lipoprotein (LDL)-cholesterol, and apolipoprotein B increased. But ERT suppressed total cholesterol, LDL-cholesterol, apolipoprotein B, and especially apolipoprotein E in menopausal women. The mechanism was thought that ERT significantly suppressed HTGL, but LpL was not affected. Estrogen also increases hepatic LDL receptors and accelerates transfer of serum LDL-C (and TC). It was said that HTGL accelerates conversion of intermediate-density lipoprotein (IDL) to LDL. The suppression of HTGL by the ERT may decrease conversion of IDL to LDL and lower LDL-C (and TC). These estrogen's beneficial effects on lipids, may prevent the atherosclerosis. In addition, apolipoprotein E increases senile plaques in senile dementia-Alzheimer's type. The decrease in apolipoprotein E with ERT may be related to cognitive functions of elderly women.

Identification of mRNA-rich keratinocytes in the basal/suprabasal layers of psoriatic skin

In this study, we examined the relative amounts of mRNA expressed in normal versus psoriatic epidermis, using in situ hybridization with a biotinylated oligonucleotide poly d(T) probe. The hybridization image was analyzed by Laser Scanning Confocal Microscopy (LSCM). In normal human skin, hybridization signals were detected homogeneously throughout the epidermis, mostly in nucleus. These signals disappeared following RNase T2 or RNase A treatment, indicating that the target for this probe is RNA; by implication, mRNA. In psoriatic lesions, the overall signal intensity was significantly elevated, especially in the basal/suprabasal layers. Moreover, those signals were most prominent in the cytoplasm, not in the nucleus. In contrast, the signals of uninvolved epidermis adjacent to the psoriatic lesions were indistinguishable from those of normal skin in both signal intensity and hybridization profile. Our data are consistent with the notion that one of the characteristic features of psoriasis is an elevated (or uncontrolled) synthesis of mRNA and proteins.

Gas chromatographic-mass spectrometric metabolic profiling of patients with fatal infantile mitochondrial myopathy with de Toni-Fanconi-Debré syndrome

The metabolic profiles of three patients with fatal infantile mitochondrial myopathy with de Toni-Fanconi-Debré syndrome were studied by simultaneous analysis, after urease treatment of urinary organic acids, carbohydrates, polyols and amino acids using gas chromatography/mass spectrometry (GC/MS). All three patients persistently showed lactic aciduria, phosphaturia, glucosuria and generalized amino aciduria. This abnormal urinary metabolic profile was observed before the onset of any clinical symptoms, indicating that chemical diagnosis may be done presymptomatically. In one patient, the concentration of lactate increased in parallel with the severity of the clinical condition, whereas the urinary levels of 3-hydroxybutyrate, amino acids and glucose fluctuated and showed only a general tendency to increase with the clinical course. The above results suggest that simultaneous GC/MS analyses, without fractionation, of urinary metabolites facilitate not only the early chemical diagnosis either before or after the first onset, but also follow-up studies, providing an important index for the evaluation of the severity and clinical course in patients with this disorder.

The enhancing effect of tumour necrosis factor-alpha on oxidative stress in endotoxemia

The enhancing effect of tumour necrosis factor-alpha (TNF-alpha) on oxidative stress with or without a sublethal dose of endotoxin was examined. The mortality of mice treated with recombinant human TNF-alpha (1 x 10(4) units/mouse, intravenously) and endotoxin (0.01-1 mg/kg, intraperitoneally) was dependent on the dose of endotoxin. The liver lipid peroxide level, superoxide anion generation and serum lactate dehydrogenase activity, especially serum lactate dehydrogenase-5 isozyme leakage, in mice 2-4 hr after administration of recombinant human TNF to endotoxin-pretreated mice (0.5 mg/kg, intraperitoneally) were markedly higher than in those without endotoxin, whereas the administration of recombinant human TNF significantly decreased the non-protein sulfhydryl level, superoxide dismutase and glutathione peroxide activities in the liver of endotoxin-injected mice compared with those in mice treated with recombinant human TNF or endotoxin alone. Furthermore, findings clearly demonstrated that J774A.1 cells stimulated with recombinant human TNF (1 x 10(4) units/ml) can effectively produce nitric oxide in the presence of endotoxin, and the production was dependent on the dose of endotoxin (0.01-10 micrograms/ml). The level of lipid peroxide in mice 4 hr after administration of recombinant human TNF and lead acetate (50 mg/kg, intravenously) was markedly higher than that in the mice treated with recombinant human TNF alone. By contrast, injection of polymyxin-B (20 mg/kg, intraperitoneally, an anti-endotoxin drug) markedly decreased the lipid peroxide level in the liver of the mice treated with recombinant human TNF and lead acetate. These findings suggest that the oxidative stress caused by TNF occurs as a enhancing effect of endotoxin or by bacterial translocation from the intestinal gut under reduction of reticuloendothelial system function in various disease states, and that the effect of TNF may cause a marked increase of toxicity of oxidative stress by endotoxin.

Effects of antitumor activity and protection of shock symptoms by a traditional Chinese medicine (sho-saiko-to) in recombinant human tumor necrosis factor administered mice

The effects of a traditional Chinese medicine Sho-saiko-to (Kampo prescription) were investigated on the various metabolic disorders and antitumor activity of recombinant human tumor necrosis factor (rhTNF) administered to mice. The glycogen level in liver of rhTNF (5 x 10(4) units/mouse, i.v.)-injected mice was markedly lower at 4 h post-intoxication than that in the control, whereas the administration of rhTNF to Sho-saiko-to (500 mg/kg/d, p.o.)-pretreated mice resulted in a greater level of glycogen than that in rhTNF alone-treated mice. In mice pretreated with Sho-saiko-to, the level of fibrinogen 4 h after rhTNF injection markedly increased as compared to that in mice treated with rhTNF alone. We also estimated the NO2 in murine macrophage cell line J774A.1 using mice serum after administration of Sho-saiko-to. Our results clearly demonstrated that J774A.1 cells stimulated with endotoxin (1 micrograms/ml) and rhTNF (1 x 10(4) units/ml) can effectively produce nitric oxide (NO), and ascertained the suppressive effect of Sho-saiko-to (500 mg/kg/d, p.o)-pretreated serum on NO generation by endotoxin/TNF-activated J774A.1 cells. When the cells were incubated with endotoxin/TNF and Sho-saiko-to pretreated serum (10-100 microliters), the NO level was significantly lower than that in control serum incubated with endotoxin/TNF alone. The effect of Sho-saiko-to (1 and 10 micrograms/ml) on in vitro cytotoxicity by rhTNF in Meth-A Sarcoma cells was observed to be in a dose dependent fashion. In addition, there was a remarkable enhancement of antitumor activity of rhTNF by Sho-saiko-to pretreatment in mice. These findings suggest that the Kampo prescription Sho-saiko-to may protect mice from severe shock syndrome by rhTNF, and that it may enhance rhTNF-induced activity.

Indonesian medicinal plants. XVII. Characterization of quassinoids from the stems of Quassia indica

Four new quassinoids named samaderines X (1), Y (2) and Z (3), and indaquassin X (5), and a new C19 quassinoid glycoside, 2-O-glucosylsamaderine C (10), together with five known quassinoids, samaderines B (7), C (8), and E (4), indaquassin C (6), and simarinolide (9), were isolated form the stems of Quassia indica (Simaroubaceae), an Indonesian medicinal plant. The chemical structures of these quassinoids have been elucidated on the bases of their chemical and physiochemical properties. Samaderines X (1), Z (3), E (4), and B (7) were shown to exhibit significant growth-inhibitory activity against the cultured malarial parasite Plasmodium falciparum (a chloroquine- resistant K1 strain), and 1--8 were shown to exhibit in vitro cytotoxicity (IC50: 0.04--100 micrograms/ml) against KB cells. Samaderines X (1), B (7) and C (8), as well s indaquassin X (5), exhibited inhibitory activity in the in vitro endothelial cell-neutrophil leukocyte adhesion assay, whereas samaderines X (1) and B (7) were found to exhibit significant anti-inflammatory activity.

Squamous cell carcinoma associated with verruciform xanthoma of the penis

We report a case of squamous cell carcinoma of the penis that seemed to arise within a verruciform xanthoma of this organ. A lesion in the prepuce was initially diagnosed as a verruciform xanthoma histopathologically and was removed in part. Six years later, the patient exhibited a well-differentiated squamous cell carcinoma of the penis that contained many clusters of xanthoma cells in the stroma. Although the retrospective examination of biopsy specimens of the initial lesion in this patient showed the features mainly of verruciform xanthoma, significant architectural and cytological atypia was also present in the overlying epidermis. Thus, we must be careful not to overlook the presence of a squamous cell carcinoma arising within a benign reactive lesion such as a verruciform xanthoma.

Binding assay of low density lipoprotein to Asp-hemolysin from Aspergillus fumigatus

Binding activity of Asp-hemolysin to low density lipoprotein (LDL) was measured. LDL binds to Asp-hemolysin with an affinity as high as the LDL receptor. The apparent Kd, determined by Scatchard plot analysis, was 8.9 x 10(-9) M [125I]LDL. Asp-hemolysin is thus identified as a novel LDL-binding protein.

Cytokine-mediated communication between dendritic epidermal T cells and Langerhans cells. In vitro studies using cell lines

Murine epidermis contains two leukocyte populations: Langerhans cells (LC), which are APC of dendritic cell (DC) lineage, and dendritic epidermal T cells (DETC), which are members of the tissue-type gamma delta T cell family. Despite close physical approximation in vivo, the extent to which LC and DETC affect each other's function has remained unknown. We addressed this question using the long term DC line XS52 and the gamma delta T cell line 7-17, both of which were established from mouse epidermis, and both of which retain important features of the resident populations from which they were derived. XS52 DC proliferated maximally when cocultured with gamma-irradiated 7-17 DETC. They also proliferated in response to culture supernatants collected from anti-CD3- or Con A-activated 7-17 DETC, but not from nonstimulated DETC. In both systems, DETC-induced XS52 DC growth was inhibited partially (up to 70%) by Abs against granulocyte/macrophage CSF (GM-CSF) or CD115 (CSF-1 receptor) and nearly completely (up to 90%) by both together. Among 28 tested cytokines, only GM-CSF, CSF-1, IL-4, and IL-13 promoted XS52 DC growth significantly. Anti-IL-4 failed to inhibit DETC-induced XS52 cell growth, and IL-4 was not detectable in DETC supernatants. Thus, we conclude that GM-CSF and CSF-1 (and perhaps IL-13) account for the DC growth-promoting activity secreted by DETC. These results suggest that during coculture, XS52 DC activate 7-17 DETC to secrete both GM-CSF and CSF-1. In fact, when cultured with XS52 DC, 7-17 DETC also elevated their expression of the gamma c receptor and acquired proliferative responsiveness to their own growth factor IL-15. We propose that LC and DETC in situ may interact with each other in a similar manner, thereby regulating their residence and function.

Cytokine-mediated communication between dendritic epidermal T cells and Langerhans cells. In vitro studies using cell lines

Murine epidermis contains two leukocyte populations: Langerhans cells (LC), which are APC of dendritic cell (DC) lineage, and dendritic epidermal T cells (DETC), which are members of the tissue-type gamma delta T cell family. Despite close physical approximation in vivo, the extent to which LC and DETC affect each other's function has remained unknown. We addressed this question using the long term DC line XS52 and the gamma delta T cell line 7-17, both of which were established from mouse epidermis, and both of which retain important features of the resident populations from which they were derived. XS52 DC proliferated maximally when cocultured with gamma-irradiated 7-17 DETC. They also proliferated in response to culture supernatants collected from anti-CD3- or Con A-activated 7-17 DETC, but not from nonstimulated DETC. In both systems, DETC-induced XS52 DC growth was inhibited partially (up to 70%) by Abs against granulocyte/macrophage CSF (GM-CSF) or CD115 (CSF-1 receptor) and nearly completely (up to 90%) by both together. Among 28 tested cytokines, only GM-CSF, CSF-1, IL-4, and IL-13 promoted XS52 DC growth significantly. Anti-IL-4 failed to inhibit DETC-induced XS52 cell growth, and IL-4 was not detectable in DETC supernatants. Thus, we conclude that GM-CSF and CSF-1 (and perhaps IL-13) account for the DC growth-promoting activity secreted by DETC. These results suggest that during coculture, XS52 DC activate 7-17 DETC to secrete both GM-CSF and CSF-1. In fact, when cultured with XS52 DC, 7-17 DETC also elevated their expression of the gamma c receptor and acquired proliferative responsiveness to their own growth factor IL-15. We propose that LC and DETC in situ may interact with each other in a similar manner, thereby regulating their residence and function.

Modification of cultured Madin-Darby canine kidney cells with dietary unsaturated fatty acids and regulation of arachidonate cascade reaction

Madin-Darby canine kidney (MDCK) cells were modified with dietary unsaturated fatty acids. The effects on the fatty acid composition in each phospholipid class and the formation of prostanoids upon stimulation were studied, from which the specificity of metabolism of individual unsaturated fatty acids and the regulation of arachidonate cascades in the modified cells were discussed. C18 unsaturated fatty acids were preferentially incorporated into phosphatidylcholine (PC) over phosphatidylethanolamine (PE), but arachidonic acid (20:4(n-6)) derived from gamma-linolenic acid (18:3(n-6)) was much more predominant in PE than PC. The fatty acid level in PE ranged from about 26-28% when the cells were modified with 20:4(n-6) or 5,8,11,14,17-eicosapentaenoic acid (20:5(n-3)), indicating the limitation of the storage of the eicosapolyenoic acids. The extra amounts appeared to be stored in PC. 18:3(n-6) was comparable to 20:4(n-6) to raise the level of 20:4(n-6) in PE, but not in PC which had half of 20:4(n-6) in PE. The supplementation of linoleic acid (18:2(n-6)). 18:3(n-6), and 20:4(n-6) caused significant increases in the synthesis of prostaglandin (PG)E2 up to almost the same levels when the modified cells were stimulated with 50 nM PMA and 100 nM A23187 for 24h. The cultured cells modified with eicosapolyenoic acids including 20:3(n-6), 20:4(n-6), and 20:5(n-3) were found to be inhibitory for the induction of PGE2 synthetic activity involving de nova synthesis of PG endoperoxide synthase, suggesting negative feedback regulation of the modified cells.

CDNA cloning of p112, the largest regulatory subunit of the human 26s proteasome, and functional analysis of its yeast homologue, sen3p

The 26S proteasome is a large multisubunit protease complex, the largest regulatory subunit of which is a component named p112. Molecular cloning of cDNA encoding human p112 revealed a polypeptide predicted to have 953 amino acid residues and a molecular mass of 105,865. The human p112 gene was mapped to the q37.1-q37.2 region of chromosome 2. Computer analysis showed that p112 has strong similarity to the Saccharomyces cerevisiae Sen3p, which has been listed in a gene bank as a factor affecting tRNA splicing endonuclease. The SEN3 also was identified in a synthetic lethal screen with the nin1-1 mutant, a temperature-sensitive mutant of NIN1. NIN1 encodes p31, another regulatory subunit of the 26S proteasome, which is necessary for activation of Cdc28p kinase. Disruption of the SEN3 did not affect cell viability, but led to temperature-sensitive growth. The human p112 cDNA suppressed the growth defect at high temperature in a SEN3 disruptant, indicating that p112 is a functional homologue of the yeast Sen3p. Maintenance of SEN3 disruptant cells at the restrictive temperature resulted in a variety of cellular dysfunctions, including defects in proteolysis mediated by the ubiquitin pathway, in the N-end rule system, in the stress response upon cadmium exposure, and in nuclear protein transportation. The functional abnormality induced by SEN3 disruption differs considerably from various phenotypes shown by the nin1-1 mutation, suggesting that these two regulatory subunits of the 26S proteasome play distinct roles in the various processes mediated by the 26S proteasome.

Electrocardiographic abnormalities in patients receiving hemodialysis

We assessed standard 12-lead and Holter electrocardiographic (ECG) abnormalities in maintenance hemodialysis (HD) patients. Of 221 outpatients receiving HD, 143 (65%) had ECG abnormalities. Rates were higher in male, elderly, hypertensive, and diabetic patients than in female, younger, normotensive, and nondiabetic patients. The prevalence of ECG changes correlated inversely with HD duration. Serial ECGs were compared in 87 patients whose average HD duration was 7.5 +/- 2.5 years. Thirty-four patients (39%) showed normal ECGs throughout, 27 (31%) relatively stable abnormalities, 22 (25%) worsening, and 4 (5%) reversion to normal. Age, hypertension, and diabetes are factors related to abnormal ECG findings. Among the 142 Holter recordings from 72 patients, 70 (97%) were basically in sinus rhythm, and 2 (3%) were in atrial fibrillation. The average frequency of supraventricular premature contractions (SVPCs) was 1597 +/- 9725 per 24 hours, and that of ventricular premature contractions (VPCs), 556 +/- 1415. VPCs were multifocal in 9%, in runs in 25%, and early in 1%. In 29 (40%) of recordings, VPCs appeared mainly during and for several hours after HD. ST-T changes were seen in 43 (60%). In 11, ST depression occurred during and a few hours after HD. Patients receiving HD showed diverse ECG abnormalities. Holter ECGs revealed a high incidence of arrhythmias and ST-T changes, which frequently appeared in relation to HD timing.

Auto-positive end-expiratory pressure during one-lung ventilation using a double-lumen endobronchial tube

The present study was undertaken to investigate the possible relationships between the magnitude of autopositive end-expiratory pressure (auto-PEEP) and measured PaO2 during one-lung ventilation (OLV). Forty-one adults received OLV anesthesia using a tidal volume of 8 mL/kg and a respiratory rate of 12 breaths/min. Auto-PEEP was quantified using an end-expiratory port occlusion method. During two-lung ventilation (2LV), auto-PEEP was observed in 18 of 41 patients and ranged from 0.5 to 2.5 cm H2O. During OLV, auto-PEEP was observed in 34 of 41 patients and ranged from 0.5 to 10 cm H2O. The mean (+/- SD) value of auto-PEEP was significantly higher during OLV than during 2LV (3.2 +/- 3.3 cm H2O versus 0.5 +/- 0.7 cm H2O, P < 0.0001). Auto-PEEP during OLV correlated inversely with preoperative forced expiratory volume in 1 s/forced vital capacity (y = 12.5 - 0.13x, r = -.05, P < 0.005). During OLV, there was no significant correlation between auto-PEEP and measured PaO2. These findings confirm that many patients do not exhale completely to functional residual capacity during OLV.

Lipid profile of Helicobacter spp.: presence of cholesteryl glucoside as a characteristic feature

The lipid and fatty acid profiles of eight Helicobacter spp. (H. nemestrinae, H. acinonyx, H. canis, Helicobacter sp. strain CLO-3, "H. rappini" [Flexispira rappini], H. pametensis, Helicobacter sp. strain Bird-B, and Helicobacter sp. strain Bird-C) and the fatty acid profiles of five additional species (H. pylori, H. felis, H. muridarum, H. mustelae, and H. fennelliae) were analyzed and compared. A heterologous fatty acid profile was observed among the Helicobacter spp., and on that basis the species could be divided into two groups. Group A had 19-carbon cyclopropane fatty acid (19:0cyc) and tetradecanoic acid (14:0) as the major fatty acids, and group B characteristically lacked the 19:0cyc and had hexadecanoic acid (16:0) and octadecenoic (18:1) acids as the major fatty acids. The species of group A are primarily gastric colonizers, and those of group B are primarily intestinal colonizers. Seven of the eight species studied showed the unusual and characteristic presence of cholesteryl glucosides (CGs), and most of these seven showed a very large amount (9.7 to 27.4% of the weight of total extractable lipid). The types of CGs and their distribution in different species were as follows: cholesteryl-6-O-acyl-alpha-D-glucopyranoside (cholesteryl-6-O-tetradecanoyl-alpha-D-glucopyranoside in H. nemestrinae and mainly cholesteryl-6-O-dodecanoyl-alpha-D-glucopyranoside in "H. rappini"), cholesteryl-alpha-D-glucopyranoside (H. nemestrinae, H. acinonyx, H. canis, Helicobacter sp. strain CLO-3, and "H. rappini"), and cholesteryl-6-O-phosphatidyl-alpha-D-glucopyranoside (H. nemestrinae, H. acinonyx, H. canis, and Helicobacter sp. strain CLO-3). Besides this, we could also detect cholesteryl acyl glucoside in H. acinonyx, cholesteryl glucoside in Helicobacter sp. strains Bird-B and -C, and cholesteryl phosphatidyl glucoside in "H. rappini" and Helicobacter sp. strain Bird-C. A selective accumulation of free cholesterol was observed in the neutral lipid fractions. On the basis of the detection of CGs in 11 of the 13 species studied so far, the presence of CGs appears to be a characteristic feature of the genus Helicobacter. In view of this and also because of a simple and rapid detection method described herein, the CGs can be used as a valuable chemotaxonomic marker.

Inhibitory effects of the new anti-platelet agent KBT-3022 and its metabolite on rabbit neutrophil function in vitro

The effects of the new anti-platelet agent KBT-3022, ethyl 2-[4,5-bis(4-methoxyphenyl)-thiazol-2-yl]pyrrol-1-ylacetate, and its metabolite desethyl KBT-3022 on rabbit neutrophil function were investigated in comparison with the effects of acetylsalicylic acid (ASA), ticlopidine hydrochloride (TP), cilostazol (CIL) and indomethacin (IM). The adhesion and migration of neutrophils induced by formyl-methionyl-leucyl-phenylalanine (fMLP) were inhibited by all the compounds tested, their rank order of potency being KBT-3022 = desethyl KBT-3022 > TP = CIL = IM > ASA. KBT-3022, desethyl KBT-3022, CIL and IM all suppressed fMLP-induced increases in the intracellular free Ca2+ concentration ([Ca2+]i) in neutrophils, their potencies correlating with their inhibitory effects on fMLP-induced adhesion and migration. KBT-3022 (1 microM), desethyl KBT-3022 (1-10 microM) and CIL (10 microM) but not IM significantly inhibited both neutrophil migration and the increase in [Ca2+]i induced by leukotriene B4 (LTB4). KBT-3022 (1 microM) and desethyl KBT-3022 (1 microM) suppressed the increase in [Ca2+]i induced by complement C5a. Although KBT-3022 and desethyl KBT-3022 did not influence [3H]LTB4 and [125I]C5a specific binding, [3H]fMLP specific binding was inhibited by desethyl KBT-3022 (IC50: 1.9 microM). Neutrophil adhesion and superoxide anion production stimulated by phorbol 12-myristate 13-acetate were partially inhibited by KBT-3022 (1 microM) and desethyl KBT-3022 (1-10 microM). These results suggest that KBT-3022 and desethyl KBT-3022 have a wider spectrum of action and are more potent inhibitors of neutrophil activation than ASA, TP, CIL and IM.