The effect of the selective PAF antagonist CIS-19 on PAF- and antigen-induced bronchoconstriction, microvascular leakage and bronchial hyperreactivity in guinea-pigs

We investigated the effects of a novel platelet-activating factor (PAF) receptor antagonist, CIS-19 [cis-2-(3, 4-dimethoxyphenyl)-6-isopropoxy-7-methoxy-1-(N-methylformamido)-1, 2, 3, 4-tetrahydronaphthalene], on PAF-, histamine-, substance P- and antigen-induced bronchoconstriction and microvascular leakage, as well as PAF- and antigen-induced bronchial hyperreactivity to methacholine in urethane-anesthetized guinea-pigs. Administration of CIS-19 (0.5–5 mg/kg, i.v.) inhibited the increase in lung resistance induced by PAF (30 ng/kg, i.v.) in a dose-dependent manner, but failed to inhibit the increase induced by histamine (30 μg/kg, i.v.) or substance P (6.5 μg/kg, i.v.). CIS-19 (5 mg/kg, i.v.) did not inhibit the increase in lung resistance induced by ovalbumin (2 mg/kg, i.v.) in actively sensitized guinea-pigs. PAF (30 ng/kg, i.v.)-induced microvascular leakage, measured by the extravasation of Evans blue dye, was dose-dependently inhibited by CIS-19 (0.5–5 mg/kg, i.v.) in the trachea, main bronchi and intrapulmonary airways, but it did not affect histamine (30 μg/kg, i.v.)- or substance P (6.5 μg/kg, i.v.)-induced microvascular leakage at all airway levels. CIS-19 (2.5 and 5 mg/kg) did not affect ovalbumin (2 mg/kg, i.v.)-induced microvascular leakage in all airway levels in actively sensitized guinea-pigs. CIS-19 (2.5 and 5 mg/kg, i.v.) significantly inhibited PAF-induced enhancement of the bronchial response to methacholine, but had no effect on ovalbumin (0.05 mg/kg, i.v.)-induced bronchial hyperreactivity in actively sensitized guinea-pigs. It is concluded that CIS-19 is a potent PAF receptor antagonist which inhibits PAF- but not antigen-induced bronchoconstriction, microvascular leakage and bronchial hyperreactivity. These results suggest that PAF plays little or no role in early airway responses following antigen challenge. Received: 29 April 1996 / Accepted: 10 October 1996     

Sequence analysis of the gene encoding the Chlamydia pneumoniae DnaK protein homolog.

The antigen-coding region of a 4.2-kb PstI fragment of Chlamydia pneumoniae (pLC3), which encodes a 75-kDa immunoreactive protein recognized during human C. pneumoniae infection, was localized to a 2.0-kb EcoRI fragment. This subclone expressed an immunoreactive fusion protein of ca. 82 kDa. Nucleotide sequence analysis of the C. pneumoniae gene revealed that it consisted of a 1,980-base open reading frame with an inferred 71,550-Da protein of 660 amino acids. Putative Escherichia coli-like promoters and a ribosomal binding site were located in the 5' upstream region, and an 11-base dyad forming a stable stem-loop structure following two in-frame stop codons was identified. The C. pneumoniae 75-kDa protein is a member of the hsp70 family of heat shock proteins and has 87% amino acid similarity with the Chlamydia trachomatis protein.     

Postoperative deep vein thrombosis in the Taiwanese Chinese population

Reports of the incidence of postoperative deep vein thrombosis in the Chinese population of Taiwan are few in the literature. Over a 3 year period, the fibrinogen degradation products test, the pulse volume recorder, and venography were used to study 220 patients undergoing major operations at the Veterans General Hospital in Taipei, Taiwan. Deep vein thrombosis was found in 17 patients (7.7 percent). A comparison of the three diagnostic methods showed that the sensitivities of the fibrinogen degradation products test and the pulse volume recorder were 56.3 percent and 93.7 percent, respectively; the specificities, 97.4 percent and 95.7 percent, respectively; and the accuracies, 85.5 percent and 95.5 percent, respectively. These results support the combined use of the fibrinogen degradation products test and the pulse volume recorder for screening and diagnosing deep vein thrombosis.     

Concomitant translocation of Puralpha with its binding proteins (PurBPs) from nuclei to cytoplasm during neuronal development

Two Puralpha-binding proteins (PurBPs) were found in nuclear extract from mouse brain during P4-P10 by the overlay assay. At P14, they were decreased significantly in nuclear extract and increased in the S3 fraction, indicating their dynamic translocation during development. Western blot analysis also demonstrated concomitant translocation of Puralpha with the PurBPs during P7-P14, when neuronal circuit proceeds. Immunocytochemical study with cultured hippocampal neurons from rat E18 confirmed that nuclear Puralpha was translocated to cytoplasm after plating for 7-14 days. These results suggest that spatiotemporal translocation of Puralpha with the PurBPs from nuclei to cytoplasm has a crucial role in neuronal development.     

Inhibitory actions of serotonin on glutamate release in dorsal medulla suppress systemic arterial pressure of cats

The role of serotonin and glutamate release in dorsal medulla (DM) for regulation of systemic arterial pressure (SAP) was examined with microdialysis and high performance liquid chromatograph in anesthetized cats. KCl-perfusion in DM increased serotonin and glutamate concentrations in DM. Perfusion of serotonin resulted in decreases in glutamate concentration and SAP. Perfusion of alaproclate, a serotonin reuptake inhibitor that produced an increase in serotonin concentration in DM, had the same results as perfusion of serotonin. In conclusion, serotonin and glutamate appeared to be tonically and endogenously released from nerve terminals in DM, and the decrease in SAP could be attributed to the decreased glutamate release resulting from inhibitory action of serotonin in DM. The putative roles of serotonin and glutamate in DM may be important in SAP regulation.     

Alterations of plasma antioxidants and mitochondrial DNA mutation in hair follicles of smokers

The effects of long-term smoking on mitochondrial DNA (mtDNA) deletions in hair follicles were investigated in subjects with different antioxidant capacity. Twenty-two male smokers with a smoking index of greater than 5 pack-years and without any known systemic diseases were recruited for this study. Forty healthy nonsmoking males were included as controls. We found that the concentrations of ascorbate and alpha-tocopherol and the activities of glutathione S-transferase (GST) and glutathione peroxidase in blood plasma were significantly decreased in smokers. The levels of glutathione and protein thiols in whole blood and the incidence of a 4,977 bp deletion of mtDNA (dmtDNA) in hair follicles were significantly increased in smokers. A significantly higher incidence of the 4,977 bp dmtDNA was found in smokers with plasma GST activity less than 5.66 U/l (OR = 7.2, P = 0.020). Using multiple covariate ANOVA and logistic regression, we found that age and low plasma GST activity were the only two risk factors for the 4,977 bp dmtDNA. These results suggest that smoking depletes antioxidants and causes mtDNA deletions and that plasma GST may play an important role in the preservation of the mitochondrial genome in tissue cells of smokers.     

Synergistic antimicrobial effect of cefotaxime and minocycline on proinflammatory cytokine levels in a murine model of Vibrio vulnificus infection.

BACKGROUND AND PURPOSE: Vibrio vulnificus causes primary bacteremia and necrotizing wound infection, leading to high morbidity and mortality in humans. This study aimed to evaluate the antimicrobial effect of cefotaxime and minocycline on proinflammatory cytokine levels in a murine model of V. vulnificus infection. METHODS: We investigated the dynamics of proinflammatory cytokines and their modulation by antimicrobial agents using a murine model of V. vulnificus infection. The change in cytokine levels was followed over a time course to identify the antimicrobial activity of the drugs against V. vulnificus. BALB/c female mice were challenged with an intraperitoneal infection using a clinical invasive isolate of Vv05191, and their cytokine levels were assayed over various time points. RESULTS: Serum levels of tumor necrosis factor-alpha, interleukin (IL)-1 beta, and IL-6 post-infection were found to be inoculum dose-dependent and positively correlated to the subsequent fatality rate in the infected mice. With an inoculum of 6.6 x 10(6) colony-forming units and intraperitoneal administration of cefotaxime, minocycline, or both, the serum and peritoneal fluid cytokine levels increased and then declined gradually. Comparison of the 3 antimicrobial regimens revealed that the magnitude of reduction in cytokine levels was greatest in mice treated with cefotaxime-minocycline combination. Moreover, the peritoneal fluid cytokine level in the combination group was significantly lower than that in the groups treated with minocycline or cefotaxime alone. CONCLUSIONS: The current results support the superiority of the combination therapy in treating invasive V. vulnificus infections.     

Clinical features and risk factors for mortality in Aeromonas bacteremic adults with hematologic malignancies.

BACKGROUND AND PURPOSE: Aeromonas spp. often cause infections in immunocompromised patients. To specifically understand the clinical features of Aeromonas bacteremic adults with hematologic malignancies, we investigated the demographic, clinical and microbiologic characteristics of Aeromonas bacteremia in this patient population. METHODS: Retrospective study performed in a tertiary medical center in southern Taiwan, in which adults with hematologic malignancies suffered from Aeromonas bacteremia admitted between 1995 and 2003 were included for study. RESULTS: There were 45 episodes of Aeromonas bacteremia in 41 adults with hematologic malignancies. Episodes of Aeromonas bacteremia which occurred at least 2 months apart were counted as separate cases in the analysis. A total of 30 men and 15 women (mean age: 53.2 years), with 4 patients experiencing 2 episodes, was included. The 3 leading underlying hematologic malignancies were acute myelogenous leukemia (37.8%), myelodysplastic syndrome (26.7%) and non-Hodgkin's lymphoma (17.8%). No cluster of Aeromonas bacteremia was found during the study period. Twenty nine (64.4%) of the 31 patients with nosocomial Aeromonas bacteremia had received recent antineoplastic chemotherapy. The 3 leading clinical manifestations were fever (88.9%), septic shock (40%), and altered consciousness (26.7%). Eleven (24.4%) episodes of bacteremia were polymicrobial. Sixteen (35.6%) patients died within 14 days of onset of bacteremia. The mean duration from sampling blood for culture to death was 3.81 days. Altered consciousness (odds ratio, 8.999; 95% confidence interval, 1.787-45.33; p=0.008) was the only independent prognostic factor for mortality. High resistance rates (11.1% to piperacillin and 35.6% to imipenem) among Aeromonas isolates were also noted. CONCLUSION: In febrile patients with hematologic malignancies and suspected Aeromonas infections, particular attention to the development of alteration of consciousness is needed as it is an independent risk factor for mortality.