Induction of neutrophil infiltration by rat chemotactic cytokine (CINC) and its inhibition by dexamethasone in rats

In vivo effects of cytokine-induced neutrophil chemotactic factor (CINC) derived from rats on neutrophil infiltration were investigated using an air-pouch-type inflammation model in rats, and effects of dexamethasone on neutrophil infiltration induced by CINC was also examined in order to gain further insight into the mechanism of antiinflammutory activity of glucocorticoids. Injection of CINC into the air pouch made on the dorsum of rats induced a marked infiltration of neutrophils into the pouch fluid but not mononuclear cells and eosinophils during a 30-min interval after the injection. Maximum effect was induced at a dose of 1.4g/pouch. Treatment with dexamethasone 3 h before the injection of CINC suppressed the neutrophil infiltration in a dose-dependent manner, but no complete inhibition was observed. CINC injection into the air pouch of rats that had been sacrificed by bleeding in order to minimize neutroph il infiltration from blood stream also stimulated neutrophil infiltration into the pouch fluid when the carcass was incubated at 37C for 30 min, but the number of infiltrated neutrophils was about 35% of CINC-induced neutrophil infiltration in intact ruts. CINC-induced neutrophil infiltration in the carcass, which is supposed to be a reflection of neutrophil migration from extravascular space in subcutaneous tissues to pouch fluid, was not inhibited by dexamethasone treatment. Therefore, the inhibition of neutrophil infiltration by dexamethasone might be due to inhibition of the extravasation of peripheral neutrophils but not due to inhibition of neutrophil chemotaxis from subcutaneous extravascular space to pouch fluid. These findings suggest that clinical effects of steroidal antiinflammatory drugs on neutrophil infiltration in inflammatory disease is partly due to inhibition of neutrophil extravasation induced by preformed neutrophil chemotactic factors in the inflammatory site.     

Apparent genotype–phenotype correlation in childhood,adolescent, and adult Chediak‐Higashi syndrome

Chediak‐Higashi syndrome (CHS) is a rare autosomal recessive disorder characterized by severe immunologic defects, reduced pigmentation, bleeding tendency, and progressive neurological dysfunction. Most patients present in early childhood and die unless treated by bone marrow transplantation. About 10–15% of patients exhibit a much milder clinical phenotype and survive to adulthood, but develop progressive and often fatal neurological dysfunction. Very rare patients exhibit an intermediate adolescent CHS phenotype, presenting with severe infections in early childhood, but a milder course by adolescence, with no accelerated phase. Here, we describe the organization and genomic DNA sequence of the CHS1 gene and mutation analysis of 21 unrelated patients with the childhood, adolescent, and adult forms of CHS. In patients with severe childhood CHS, we found only functionally null mutant CHS1 alleles, whereas in patients with the adolescent and adult forms of CHS we also found missense mutant alleles that likely encode CHS1 polypeptides with partial function. Together, these results suggest an allelic genotype–phenotype relationship among the various clinical forms of CHS. © 2002 Wiley‐Liss, Inc.     

Changes in the incidence and duration of ventricular fibrillation in dependence on the extraneuronal accumulation of isoprenaline in the perfused rat heart

Summary The relationship between the accumulation of isoprenaline and the incidence and duration of ventricular fibrillation was investigated in the perfused rat heart. Isolated rat hearts were perfused with ³H-isoprenaline (1 mol/l) for 30 min at a constant flow rate of 6.5 ml/min at a temperature between 40 and 41° C. Electrocardiograms were recorded during the perfusion period and the isoprenaline content of the tissue was measured after the perfusion. The accumulation of isoprenaline was significantly increased and the duration of ventricular fibrillation was significantly prolonged by the presence of tropolone (100 mol/l). When extraneuronal uptake inhibitors such as normetanephrine (100 mol/l), 3-O-methylisoprenaline (100 mol/l) or phenoxybenzamine (1 mol/l) were added to the perfusion fluid containing ³H-isoprenaline (1 mol/l) and tropolone (100 mol/l), the accumulation of isoprenaline was sifnificantly decreased, the incidence of ventricular fibrillation was significantly reduced and the duration of ventricular fibrillation was significantly shortened. There was a significant correlation for dependence of duration of ventricular fibrillation on the isoprenaline content of rat hearts perfused with various extraneuronal uptake inhibitors in the presence of tropolone (correlation coefficient [r]=0.62, P<0.001).These results indicate that the accumulation of isoprenaline in perfused rat hearts relates to the occurrence and duration of ventricular fibrillation.This study was supported in part by a Grant-in-Aid for Scientific Research (59570980) from the Ministry of Education, Science and Culture, Japan     

A case of pseudolymphoma of the liver

A case of pseudolymphoma (reactive lymphoid hyperplasia) of the liver in a 66 year old female is presented. A tumor-like lesion was incidentally discovered in the liver during clinical follow up of diabetes mellitus. The hepatic lesion was resected because malignant lymphoma was suspected after a needle biopsy. Grossly, the lesion was well-deflned and measured 1.0 × 1.5 × 1.0 cm. Microscoplcally, the lesion consisted of hyperplastic lymphoid follicles with distinctive germinal centers and interfollicular areas consisting of mature lymphocytes and plasma cells. An immunohistologlcal study revealed that the lymphoid cells of the lesion were polyclonal in immunophenotypes. These histological and immunohistochemical findings strongly suggested a pseudolymphoma and not hepatic inflammatory pseudotumor. Thls case was diagnosed as pseudolymphoma of liver. Only a few cases of hepatic pseudolymphoma have so far been reported In the English literature.     

Evidence for feeding elicited through antihistaminergic effects of tricyclic antidepressants in the rat hypothalamus

We studied central mechanisms of antidepressants that affect feeding behavior in rats. The tricyclic compounds amitriptyline, doxepin and imipramine significantly induced feeding after their infusion into the third cerebral ventricle in the light phase, but the tricyclic, desipramine, and the dicyclic zimelidine, did not. Drinking was not affected by any compound tested. The relative order of potency in eliciting feeding was: amitriptyline and doxepin > imipramine > desipramine and zimelidine. To clarify the involvement of neuronal histamine in antidepressant-induced feeding, alpha-fluoromethylhistidine (FMH), a suicide inhibitor of histidine decarboxylase, was intraperitoneally administered before infusion of amitriptyline. FMH attenuated the amitriptyline's effect. Bilateral microinfusion of amitriptyline into the ventromedial hypothalamus or the paraventricular nucleus verified that these are loci for the modulation of feeding by amitriptyline. In the lateral hypothalamus, amitriptyline was less effective. These findings indicate that tricyclic antidepressants directly facilitate feeding, which is, at least in part, mediated by histamine in the hypothalamus.     

Are bladder washing samples suitable for investigation of HPV infection in urinary bladder? Comparison in HPV prevalence between urine and washing samples

Although urine and bladder washing samples are commonly used for the cytological evaluation of the bladder mucosa, it has been unknown whether these samples are likely suitable to investigate human papillomavirus (HPV) prevalence in the urinary bladder. The present study aimed to elucidate the appropriateness of spontaneously voided urine or bladder washing in screening HPV infection in the urinary bladder. Urine and bladder washing samples were obtained from 201 patients who underwent transurethral bladder tumor resection. After extracting DNA from both samples, HPV-DNA was examined using a nested polymerase chain reaction with GP5+/6+ and MY09/11 primers. HPV genotyping was performed in the HPV-positive samples. In situ hybridization (ISH) was performed to observe the HPV-DNA localization in urothelial cells among cytological samples and paraffin-embedded tumor tissues in HPV-positive washing samples. HPV prevalence in urine and washing samples were 9.5% and 7.0%, respectively. High-risk HPV prevalence in urine and washing samples was 7.5% and 4.0%, respectively. The most common HPV type was HPV 16, followed by HPV 52 and HPV 18 in both samples. HPV type distribution in both samples was not in agreement (κ = −0.431). The ISH analysis revealed that HPV-DNA signal was observed in urothelial cells of five (55.7%) of nine detectable HPV-positive cytological samples. Six (66.7%) of nine HPV-positive cases had HPV-DNA signals in tumor tissue. The use of washing samples was likely applicable for investigating HPV prevalence in the urinary bladder. HPV-DNA detected in washing samples might be frequently derived from the urinary bladder.     

Interaction of ketamine with μ2 opioid receptors in SH-SY5Y human neuroblastoma cells

Purpose. Ketamine is known to interact with opioid receptors. However, because this agent does not produce opioid-like respiratory depression, it might not interact with μ₂ opioid receptors. Therefore, we have studied the interaction of ketamine with μ₂ opioid receptors expressed in SH-SY5Y cells. Methods. SH-SY5Y cells (passage 70–80) were used to obtain ketamine dose-response curves for inhibition of 0.4 nM [³H][d-Ala²,MePhe⁴,Gly(ol)⁵] enkephalin (DAMGO) binding to μ₂ opioid receptors and of forskolin (1 μM)-stimulated cyclic AMP (cAMP) formation. Results. Ketamine displaced [³H]DAMGO binding in SH-SY5Y cells with a K _i of 12.1 μM. However, this concentrations did not inhibit forskolin-stimulated cAMP formation, although at supraclinical concentrations, significant inhibition was observed with an estimated IC₅₀ of 700 μM. Conclusion. The present study indicates that a clinically relevant concentration of ketamine interacts with μ₂ opioid receptors. However, no agonist activity was observed. Received for publication on September 10, 1998; accepted on January 5, 1999     

Droperidol inhibits tracheal contraction induced by serotonin,histamine or carbachol in guinea pigs

Purpose

Droperidol (D) is effective in the treatment of patients with status asthmaticus. It has been reported that D inhibits the bronchoconstriction induced by serotonin (5-HT) but not that by histamine (H) or acetylcholine. However, haloperidol, another butyrophenone, is known to interact with and inhibit calmodulin, an intracellular Ca⁺⁺-binding protein which is important in the contraction of smooth muscles. The present study was designed to investigate the effects of D on tracheal contractions induced by 5-HT, H or carbachol (C) and to determine the contribution of α-adrenoceptors to the relaxant effect of D in vitro.

Methods

Tracheas of female guinea pigs were cut spirally into strips and mounted in water-jacketed organ baths in Tyrode’s solution, aerated with a mixture of 95% O₂ and 5% CO₂ at 37°C. The changes in isometric tension induced by each spasmogen in the strips were measured with a transducer and a polygraph.

Results

We found that D inhibited the tracheal contractions induced by 5-HT, H or C in a concentration-dependent manner. At 1.25 × 10^?6 M D blocked the effect of 10^?4 M 5-HT by 44.1 ± 4.3% and at 2.5 × 10^?6 M by 63.8 ± 3.8%. Similarly, at 5.0 × 10^?6 M concentration, D blocked the effect of 10^?5 M H by 27.7 ± 5.3% and at 10^?5 M by 56.2 ± 2.6%. Furthermore, 5 ×10^?6 M of D reduced the contractions produced by 10^?7 M C by 37.1 ± 3.0% and 70^?5 M of D by 76.1 ± 3.2%. The inhibiting effect of D was strongest on contractions induced by 5-HT. Prazosin (70^?6 M) affected neither 5-HT-induced contractions nor the inhibition by D.

Conclusion

Our data indicate that D partially blocks the contractile responses not only to 5-HT, an effect which would be mediated through a blockade of the 5-HT receptors, but also to H or C, probably through inhibition of calmodulin. Our data support previous reports indicating that droperidol may be an important therapeutic agent in the treatment of patients with hyperreactive airways.