FGF-2 isoforms of 18 and 22.5 kDa differentially modulate t-PA and PAI-1 expressions on the pancreatic carcinoma cells AR4-2J: consequences on cell spreading and invasion

Pancreatic tumors overexpress FGF-2 and t-PA, but the implication of the growth factor in t-PA synthesis and t-PA-dependent tumor invasion remains unknown. FGF-2 is present in different isoforms: The 18 kDa FGF-2 is secreted, while the 22.5 kDa one is nuclearized and exerts intracrine regulations bypassing cell-surface FGF receptors. Rat pancreatic carcinoma AR4-2J cells producing either the 18 or the 22.5 kDa FGF-2 after transfection with FGF-2 cDNAs have been used to analyze the role of FGF-2 in t-PA expression and t-PA-related cell spreading. The 22.5 kDa FGF-2 reduced t-PA and PAI-1 synthesis 2-fold. Addition of recombinant 18 kDa FGF-2 (rFGF-2) to cell cultures resulted in increased t-PA and decreased PAI-1 expression. By contrast, rFGF-2 did not significantly modify t-PA synthesis in cells producing the 22.5 kDa FGF-2. Cell spreading was t-PA-dependent. Furthermore, cells producing the 22.5 kDa FGF-2 migrated less than control cells and cells producing the 18 kDa FGF-2. Overall, our data show that secretory FGF-2 is involved in t-PA synthesis by pancreatic cancer cells and facilitates cell spreading. The 22.5 kDa FGF-2 exerts opposite effects by decreasing t-PA expression in basal conditions and during rFGF-2 stimulation. Since the expression of the 22.5 kDa FGF-2 is under specific controls, its up-regulation might have the potential to reduce spreading of pancreatic cancer cells.

Fas-induced death of a murine pulmonary epithelial cell line: modulation by inflammatory cytokines

Here we report that a murine pulmonary epithelial cell line (LA-4) expresses Fas (CD95) under resting conditions. Exposure of untreated cells to an anti-Fas monoclonal antibody induces apoptosis in a time- and dose-dependent fashion as revealed by cell viability and by propidium iodide staining followed by FACS analysis. Fas surface expression was increased, in a time-dependent fashion, by the inflammatory cytokines IL-1beta and TNF-alpha. Other inflammatory mediators such as IFN-gamma or endothelin-1 were without any effect. This increase in Fas expression was associated with an increase in sensitivity to anti-Fas-induced apoptosis of LA-4 cells. IL-4, which is known to induce CD95 resistance in other cell types, did not protect LA-4 cells against anti-CD95-induced cell death. These results suggest that Fas-induced apoptosis of epithelial cells may contribute to the epithelial shedding observed in asthmatic airways.

Regulation of Escherichia coli cell division genes ftsA and ftsZ by the two-component system rcsC-rcsB

Genes rcsC and rcsB form a two-component system in which rcsC encodes the sensor element and rcsB the regulator. In Escherichia coli, the system positively regulates the expression of the capsule operon, cps, and of the cell division gene ftsZ. We report the identification of the promoter and of the sequences required for rcsB-dependent stimulation of ftsZ expression. The promoter, ftsA1p, located in the ftsQ coding sequence, co-regulates ftsA and ftsZ. The sequences required for rcsB activity are immediately adjacent to this promoter.

Malassezia spp carriage in patients with seborrheic dermatitis

The role of Malassezia spp in seborrheic dermatitis (SD) is controversial. To compare the cutaneous density and the cultural characteristics of Malassezia in persons with or without SD, quantitative cultures were obtained by stripping the forehead with a tape placed on Leeming and Notman medium. Plates were incubated at 37 degrees C in a plastic bag, and colonies were counted after 14 days. High yeast density was defined as > 100 colony forming units (CFU)/tape. Volunteers were divided into four groups depending on their HIV serology [HIV (+) versus HIV (-) or unknown] and their clinical status (with or without SD). 126/129 cultures were positive (97.7%). Malassezia spp density was low on clinically normal skin in all HIV (-) persons (40/40) but was high in 8/34 (24%) HIV (+) persons without SD (p < 0.001). In SD patients, high densities were found in 10/22 (45%) HIV (+) and in 17/33 (52%) HIV (-) persons. The strains could be divided into three basic groups on the basis of their cultural characteristics. Colony morphology type A predominated on normal skin (72%), and morphology type C predominated on persons with SD (78%). High yeast density can be present without skin symptoms. The pathogenicity of Malassezia seems more likely to be determined by the subtype present on the skin rather than by its density.

Anti-apoptotic activity of p53 maps to the COOH-terminal domain and is retained in a highly oncogenic natural mutant

The tumour suppressor p53 plays a complex role in the regulation of apoptosis. High levels of wild type p53 potentiate the apoptotic response, while physiological range, low levels of the protein have an anti-apoptotic activity in serum starved immortalized fibroblasts. Here we report that primary fibroblast-like cells that show normal growth control are also efficiently protected from apoptosis by the endogenous p53 activity. The capacity to inhibit apoptosis is not restricted to the wild type protein: the R-->H175 p53 mutant fully retains the anti-apoptotic activity of the wild type p53, providing a possible explanation for its high oncogenicity. Using a series of point and deletion mutants of p53 under the control of tetracycline-regulated promoter we show that certain mutants, like the wild type, protect cells at low levels but lead to apoptosis when overexpressed. This latter effect is lost upon deletion of a proline-rich domain in the NH2 part of the protein. The anti-apoptotic activity can be mapped to the extreme carboxy-terminal part of the protein and is therefore independent of other well characterized p53 activities. Our results add a new level of complexity to the network of interactions mediated by p53 in normal physiology and pathology.

Systematic use of total vascular exclusion in 14 elective hepatic resections

Between March 1992 and May 1995, 14 hepatic resections under total vascular exclusion were performed (10 major resections and 4 minor resections involving central segments). Mean age was 64 years (SD +/- 12). During hepatic resection, 4 patients required blood transfusion. The reason was a too low level of haemoglobin (< 10 gr/100 ml) to undergo Hepatic Vascular Exclusion (HVE) (1 patient), an unacceptable decrease in blood pressure following HVE leading to insertion of venovenous bypass (1 patient), or an extensive bleeding following removal of the clamps (2 patients). The 10 remaining patients did not need peroperative blood transfusion. Two patients were transfused after the 6th postoperative day. Complications usually described during HVE were not encountered except for one pleural effusion needing thoracocentesis.

Reactivities to serotonin and histamine in umbilical and placental vessels during the third trimester after normotensive pregnancies and pregnancies complicated by preeclampsia

OBJECTIVE

The aim of the study was to evaluate responses of umbilical and placental arteries and veins to serotonin and histamine after normotensive pregnancies and pregnancies complicated by preeclampsia.

STUDY DESIGN

Each pair of placentas from a normotensive woman and a woman with preeclampsia was matched for gestational age. Rings of these vessels were prepared and mounted in tissue baths under their respective optimal passive tension. Cumulative concentration-response curves to serotonin and histamine were measured.

RESULTS

Responses to serotonin were decreased in umbilical vessels from the preeclampsia group with respect to the normotensive group. This is reflected by reduced maximum responses and sensitivity (negative logarithm of the 50% effective concentration) to serotonin. Maximum response to serotonin was significantly decreased in placental vein rings from the preeclampsia group. We recorded a decreased maximal response to histamine in placental vein rings from pregnancies complicated by preeclampsia with respect to those from normal pregnancies. Among normotensive women there was a significant positive linear relationship between neonatal weight and sensitivity to serotonin in umbilical and placental veins. This relationship was totally absent in preeclampsia. Sensitivity to histamine was linearly related to neonatal weight in umbilical vessels of the pooled results of both experimental groups.

CONCLUSION

The vasoconstrictive effects of serotonin, but not those of histamine, are decreased in umbilical and placental vessels after preeclampsia. Sensitivities to serotonin and histamine change in umbilicoplacental vessels during the third trimester. Altered reactivity to serotonin may play a significant role in the reduction of umbilicoplacental blood flow in preeclampsia.

Functional anatomy of the avian centrifugal visual system

Although first described over a century ago, the centrifugal visual system (CVS) projecting to the retina still remains somewhat of an enigma with regard to its functional role in visually-guided behavior. The highly developed avian CVS has been the most extensively investigated and the anatomical organization of its two component centrifugal structures, the n. isthmo-opticus (NIO) and ectopic neurons (EN), including its afferent brainstem projections is reviewed. The results of double-labeling studies combining axonal tracing techniques and immunohistofluorescence have demonstrated GABA immunoreactivity (-ir) of interneurons within the neuropilar zone of the NIO, choline acetyltransferase (ChAT)-ir and nitric oxide synthase (NOS)-ir in the centrifugal cells of the NIO and EN as well as in the afferent projection neurons of layers 9/10 of the optic tectum. The data are discussed in terms of neurochemical and excitatory/inhibitory mechanisms within the different components of the avian CVS in relation to hypotheses which have implicated this system in visual attention and ground-feeding behavior.

Modulation of ET-1-induced contraction of human bronchi by airway epithelium-dependent nitric oxide release via ET(A) receptor activation

1. The purpose of this work was to investigate whether endothelin-1 (ET-1) was able to induce the release of an inhibitory factor from the airway epithelium in isolated human bronchi and to identify this mediator as well as the endothelin receptor involved in this phenomenon. 2. In intact bronchi, ET-1 induced a concentration-dependent contraction (-logEC50 = 7.92+/-0.09, n = 18) which was potentiated by epithelium removal (-logEC50 = 8.65+/-0.11, n = 17). BQ-123 , an ET(A) receptor antagonist, induced a significant leftward shift of the ET-1 concentration-response curve (CRC). This leftward shift was abolished after epithelium removal. 3. L-NAME (3 x 10(-3) M), an inhibitor of nitric oxide (NO) synthase, induced a significant leftward shift of the ET-1 CRC, and abolished the potentiation by BQ-123 (10(-8) M) of ET-1-induced contraction. 4. In intact preparations, the ET(B) receptor antagonist BQ-788 induced only at 10(-5) M a slight rightward shift of the ET-1 CRC. In contrast, in epithelium-denuded bronchi or in intact preparations in the presence of L-NAME, BQ-788 displayed a non-competitive antagonism toward ET-1-induced contraction. 5. IRL 1620, a selective ET(B) receptor agonist, induced a contraction of the isolated bronchus (-logEC50=7.94+/-0.11, n= 19). This effect was not modified by epithelium removal or by BQ-123. BQ-788 exerted a competitive antagonism against IRL 1620 which was similar in the presence or absence of epithelium. 6. These results show that ET-1 exerts two opposite effects on the human airway smooth muscle. One is contractile via ETB-receptor activation, the other is inhibitory and responsible of NO release which counteracts via ETA-receptor activation the contraction.

[Analysis of hematopoietic growth factor prescriptions in 19 french cancer centers]

Medical prescription of hematopoietic growth factors (HGF) was analysed in 19 anticancer french centers during 2 months. About 4% of anticancer chemotherapeutic cycles prescribed during this period were supported by HGF prescription. The mean duration of treatment was 8 days. Among the 755 collected prescriptions, two tumor localizations represented about 50% of the prescriptions: malignant non Hodgkin lymphomas and breast cancer. The other main localizations concerned adult or pediatric soft tissue sarcomas (18%), testicular cancer (7%) and gynecologic tumors (6%). The prescription for primary prophylaxis for febrile neutropenia remains the main use of HGF (44%). The respect of the guidelines established by the F|d|ration nationale des centres de lutte contre le cancer was analyzed. Overall, 66% of the prescriptions were in adequation with these guidelines. Whereas the consommation of HGF decreased in the 19 considered institutions, it did not reach a plateau and could decrease in institutions which are awaked to the international and national recommendations.

Characterization of the endothelin receptor subtype mediating epithelium-derived relaxant nitric oxide release from guinea-pig trachea

1. The endothelin (ET) receptor subtype that mediates niric oxide (NO)-dependent airway relaxation in tracheal tube preparations precontracted with carbachol and pretreated with indomethacin was investigated. The release of NO induced by ET from guinea-pig trachea using a recently developed porphyrinic microsensor was also measured. 2. ET-1 (1 pM-100 nM) contracted tracheal tube preparations pretreated with the NO-synthase inhibitor, L-NMMA, and relaxed, in an epithelium-dependent manner, preparations pretreated with the inactive enantiomer D-NMMA. The effect of L-NMMA was reversed by L-Arg, but not by D-Arg. 3. The selective ET(B) receptor agonists, IRL 1620 or sarafotoxin S6c, both (1 pM-100 nM) contracted tracheal tube preparations in a similar manner either after treatment with D-NMMA or with L-NMMA. In the presence of the ET(A) receptor antagonist, FR139317 (10 microM), ET-1 administration resulted in a contraction that was similar after either L-NMMA or D-NMMA. In the presence of the ET(B) receptor antagonist, BQ788 (1 microM), ET-1 relaxed and contracted tracheas pretreated with D-NMMA and L-NMMA, respectively. 4. Exposure of tracheal segments to ET-1 (1-1000 nM) caused a concentration-dependent increase in NO release that was reduced by L-NMMA. IRL1620 (1 microM) did not cause any significant NO release. FR139317 (10 microM), but not, BQ788 (1 microM), inhibited the NO release induced by ET-1. 5. These results demonstrate that in the isolated guinea-pig trachea activation of ET(B) receptors results in a contractile response, whereas activation of ET(A) receptors cause both a contraction, and an epithelium-dependent relaxation that is mediated by NO release.

An outbreak of Serratia marcescens infections related to contaminated chlorhexidine

An outbreak of Serratia marcescens infections occurred in a university tertiary-care hospital. Alcohol-free chlorhexidine solutions were contaminated with S marcescens. The majority of patient and chlorhexidine strains had similar pulsed field-gel electrophoresis banding patterns. Chlorhexidine was recalled, and the rate of S marcescens isolation returned to baseline. Chlorhexidine without alcohol should not be used as an antiseptic.

[Tracheal intubation in prehospital resuscitation: importance of rapid-sequence induction anesthesia]

OBJECTIVE

To investigate complications of emergency endotracheal intubation (EEI), possibly facilitated by rapid-sequence induction, in the prehospital critical care setting: 1) the difficulty of intubation; 2) the cardiorespiratory consequences of intubation; 3) the relationship between the occurrence of complications and prognosis.

STUDY DESIGN

Prospective non randomized, open study.

PATIENTS

All patients treated over a 5-month period by a physician-manned ambulance service and requiring EEI.

METHODS

Patients were allocated either in with cardiac arrest (CA) group or a group with maintained spontaneous circulation (SC). Difficulty of intubation was assessed by the number of attempts.

RESULTS

Two hundred and twenty-four consecutive EEI were carried out by physicians (46%) and residents (38%) not trained in anaesthesia, anaesthetists (8%), or nurse anaesthetists (7%). Trachea was intubated after a maximum of three attempts in all patients. Success rate at the first attempt was 91%. It was 92% in CA patients (n = 76) and 90% in SC patients (P = 0.59). Anaesthetic induction, with (n = 112) or without (n = 12) succinylcholine, was used to facilitate 84% of intubations in SC patients. Complications occurred in 30 patients (20%). There was no relationship between the latter and hospital mortality, duration of ventilatory support, duration of stay in the intensive care unit.

CONCLUSION

In this study, EEI in SC patients was frequently facilitated by rapid sequence induction and was associated with a high success rate at the first attempt, as in CA patients. Morbidity was low. All physicians involved in emergency airway management should be skilled in this technique.

An immunohistochemical study of putative neuromodulators and transmitters in the centrifugal visual system of the quail (Coturnix japonica)

The aim of the present study was to analyze the neurochemical properties of the centrifugal visual system (CVS) of the quail using an immunohistochemical approach by testing 16 neuropeptides (angiotensin: ANG, bradykinin: BK, cholecystokinin, dynorphin, L and M-enkephalin, beta-endorphin: beta-END, galanin, alpha-neoendorphin, neurokinin A, neuropeptide Y (NPY), ocytocin, somatostatin, substance P, vasopressin, vasoactive intestinal polypeptide) and three neurotransmitters or their synthetic enzymes (choline acetyltransferase: ChAT, tyrosine hydroxylase: TH, serotonin: 5-HT and nitric oxide synthase: NOS, including the histochemical nicotinamide adenine dinucleotide phosphate diaphorase technique). For each substance, the somatic and afferent fiber and terminal labeling was analyzed within the nucleus isthmo-opticus (NIO) and the ectopic area (EA) and compared with that of retinopetal cell bodies labeled retrogradely with RITC following its intraocular injection (double-labeling procedure). The results showed that none of the centrifugal neurons were reactive to any of the substances tested. In contrast, all with the exception of ANG, BK and beta-END, labeled fibers and terminals within the EA and only four (ChAT, 5-HT, NPY and NOS) within the NIO. Possible sources of these immunoreactive fibers terminating in the NIO and EA were investigated by mapping the somatic immunolabeling of the different substances within brainstem regions previously shown by Miceli and other authors to project upon the centrifugal neurons. The data suggests that, besides the rapid retino-tecto-NIO-retinal loop, which facilitates the transfer of meaningful or more relevant information within particular portions of the visual field, the multiple afferent input which stems from various brainstem regions utilizes a wide range of neuroactive substances. Some of these afferent projections upon the centrifugal neurons appear to belong to nonspecific systems which might play a role in modulating the excitability of centrifugal neurons as a function of arousal.

Interleukin-1beta induces bradykinin B2 receptor gene expression through a prostanoid cyclic AMP-dependent pathway in human bronchial smooth muscle cells

We investigated the hypothesis that inflammatory mediators such as interleukin-1beta (IL-1beta) might be responsible for the hyperreactivity of asthmatic patients to bradykinin. In cultured human bronchial smooth muscle cells, IL-1beta elicited a rapid and transient increase in the density of bradykinin B2 receptors without affecting their affinity for ligands. The increase in B2 receptors was correlated to an enhancement of inositol phosphate formation elicited by bradykinin, indicating its relevance to the contractile response of smooth muscle cells to bradykinin. The increase in receptor density was related to an increase in B2 receptor mRNA level corresponding to a 5-fold enhancement of the transcriptional rate and to a lengthened half-life of mRNA. These effects of IL-1beta were largely inhibited by indomethacin, suggesting the involvement of a prostanoid pathway in IL-1beta transduction process. An increase in prostaglandin E2 levels preceded the mRNA increase, confirming this involvement. Moreover, IL-1beta and prostaglandin E2 led to cAMP formation. We propose this predominant transduction pathway of IL-1beta to stimulate the transcription of the bradykinin B2 gene in human bronchial smooth muscle cells as a major mechanism involved in the hyperresponsiveness of asthmatic patients to bradykinin.

Penetration of ceftazidime into middle ear fluid in children with otitis media with effusion

Twenty-five children with otitis media with effusion received ceftazidime 50 mg/kg intravenously before bilateral myringotomy with insertion of tympanostomy tubes. Concentrations of ceftazidime measured in serum and middle ear fluid exceeded 4 mg/L (i.e., largely above the minimal inhibitory concentrations for the gram-negative pathogens commonly recovered from children with otitis media) for at least 4 hours. Mean peak concentrations occurred 30 to 90 minutes after the injection and reached 11 to 14 mg/L. These results are in keeping with the clinical efficacy of ceftazidime in the treatment of chronic middle ear infections in children.

[Study of the toxicity and results of intraperitoneal hyperthermic chemotherapy in 28 patients with peritoneal carcinomatosis]

Based on a few previous studies, intra-peritoneal hyperthermic perfusion (IPHP) with Mitomycin C could become a beneficial treatment for peritoneal carcinomatosis. Twenty eight patients with peritoneal carcinomatosis arising from intra-abdominal cancers were treated by IPHP, Mitomycin C, diluted in 3 liters of saline solution warmed to a mean temperature of 45 degrees C, was injected into the abdominal cavity for one hour. Median survival for the whole series (postoperative mortality included) was 260 days. For patients with incomplete resection, median survival was 104 days. For patients with complete resection of carcinomatous nodules larger than 3 mm (19 patients), it was 450 days. In this group, actuarial survival was 56% at 1 year and 42% at 2 years. Only 5 (18%) of the 28 patients developed ascitic effusion during follow-up. These results confirm the efficacity of IPHP on ascitic effusion and on survival rate in patients with nearly complete resection of peritoneal carcinomatosis.

Hypervariable Domains of Self-Incompatibility RNases Mediate Allele-Specific Pollen Recognition

Self-incompatibility (SI) in angiosperms is a genetic mechanism that promotes outcrossing through rejection of self-pollen. In the Solanaceae, SI is determined by a multiallelic S locus whose only known product is an S RNase. S RNases show a characteristic pattern of five conserved and two hypervariable regions. These are thought to be involved in the catalytic function and in allelic specificity, respectively. When the Solanum chacoense S12S14 genotype is transformed with an S11 RNase, the styles of plants expressing significant levels of the transgene reject S11 pollen. A previously characterized S RNase, S13, differs from the S11 RNase by only 10 amino acids, four of which are located in the hypervariable regions. When S12S14 plants were transformed with a chimeric S11 gene in which these four residues were substituted with those present in the S13 RNase, the transgenic plants acquired the S13 phenotype. This result demonstrates that the S RNase hypervariable regions control allelic specificity.

Endothelin receptor antagonists inhibit antigen-induced lung inflammation in mice

In this study, we have examined the effect of endothelin (ET) receptor antagonists on lung granulocyte inflammation after antigen challenge in sensitized mice. The antagonists used were BQ-123, an ETA antagonist, BQ-788, an ETB antagonist, and SB209670, an ET(A&B) antagonist. Thirty minutes prior exposure to aerosolized ovalbumin, ET antagonists (50 pmol/mouse) were administered directly into the lungs of sensitized Balb/c mice via the intranasal route. BQ-123 and SB209670 significantly decreased eosinophil number in the bronchoalveolar lavage fluid by 47 and 68%, respectively. Both compounds also inhibited neutrophil infiltration into the lungs. In contrast, BQ-788 did not affect granulocyte infiltration. A similar inhibition of lung eosinophilia was also obtained with an anti-ET antibody applied via the intranasal route. BQ-123 and SB209670, but not BQ-788, significantly increased the production of interferon-gamma (Th1 cytokine) from purified lung Thy1.2+ cells without affecting interleukin-4 and interleukin-5 (Th2 cytokines) secretion. Furthermore, neutralizing antibody against interferon-gamma prevented the inhibitory effect of the ETA antagonist. Taken together, these results suggest an important pathophysiologic role for ET in the development of lung inflammation in asthma and highlight the potential of ET antagonists for the treatment of the disease.

Differential activation of the epithelial and smooth muscle NK1 receptors by synthetic tachykinin agonists in guinea-pig trachea

1. The presence of tachykinin NK1 receptors have been shown in the epithelium and smooth muscle of guinea-pig airways. Previous data showed that substance P (SP), and the NK1 receptor agonist, [Sar9, Met (O2)11]-SP, relax guinea-pig tracheal tube preparations by stimulation of epithelial NK1 receptors and via nitric oxide (NO) release. However, the selective tachykinin NK1 receptor agonist, septide, was unable to produce this effect. The aim of the present study was to investigate the ability of a series of SP analogues to stimulate NK1 receptors of guinea-pig airway epithelium. 2. Isometric tension was recorded in isolated tracheal tube preparations in which compounds were administered intraluminally in the presence of phosphoramidon, indomethacin (both 1 microM) and the tachykinin NK2 receptor antagonist, SR 48,968 ((S)-N-methyl N-(4-acetyl-amino-4-phenylpiperidino)-2-(3,4-dichlorophenyl)butyl)benzam ide) (0.1 microM). Cumulative concentration-response curves were obtained in preparations under resting tone or in preparations precontracted with acetylcholine (ACh, 10 microM). 3. Contractile responses to low concentrations (0.1-10 nM) of substance P (SP) and the selective agonist of NK1 receptors, [Pro9]-SP. in non precontracted tracheae were higher in preparations pretreated with the NO-synthase inhibitor, NG-monomethyl L-arginine (L-NMMA, 100 microM) than in preparations pretreated with its inactive enantiomer D-NMMA (100 microM). Tracheal tube preparations precontracted with ACh and pretreated with D-NMMA were relaxed by low concentrations of SP and [Pro9]-SP (0.1-10 nM). In contrast, after pretreatment with L-NMMA, SP and [Pro9]-SP contracted tracheae at all the concentrations tested. 4. Concentration-response curves to the NK1 receptor agonists, SP methyl ester, [Apa9-10]-SP and [pGlu6] SP (6-11) obtained in non-precontracted tracheae were similar in the presence of either D-NMMA or L-NMMA. SP methyl ester, [Apa9-10]-SP and [pGlu6] SP (6-11) did not produce any relaxation, but instead, cause contractions in tracheal tube preparations precontracted with ACh and pretreated with D-NMMA. Concentration-response curves produced by all these agonists were similar in preparations precontracted with ACh and pretreated with L-NMMA or D-NMMA. 5. In guinea-pig tracheal tube preparations two groups of NK1 receptor agonists can be distinguished: one group, including [Pro9]-SP, stimulator epithelial NK1 receptors, the other group, including SP methyl ester, [Apa9-10]-SP and [pGlu6] SP (6-11), does not. One possible explanation for these findings and for the existence of compounds with a peculiar 'septide-like' pharmacological profile in the guinea-pig trachea could be the recently proposed phenomenon referred to as 'agonist-directed receptor trafficking'.

Demonstration of the therapeutic potential of non-anaphylactogenic anti-IgE antibodies in murine models of skin reaction, lung function and inflammation

BACKGROUND

Allergies and allergic asthma are believed to be mediated by allergen-specific IgE antibodies. We have investigated the therapeutic potential of inhibiting endogenous IgE by a non-anaphylactogenic anti-mouse IgE antibody 1-5 with respect to its effects on antigen-induced skin reaction, lung function changes and lung inflammation in mice.

METHODS

Mice were immunized with benzylpenicillinoyl-KLH or ovalbumin, and antigen-mediated skin reaction, bronchoconstriction, bronchopulmonary hyperresponsiveness (BHR) and lung eosinophilic inflammation determined in anti-IgE 1-5-treated versus untreated animals.

RESULTS

Application of anti-IgE 1-5 inhibited (by 90%) the serum IgE and, 3-4 days after onset of treatment, blocked the antigen-induced skin reaction. Furthermore, the antibody also inhibited (by 90%) the antigen-induced infiltration of eosinophils into the lung. This latter effect seems to be mediated by blocking the IgE-CD23 interaction and indicates that lung eosinophilic inflammation also depends on IgE. Moreover, when applied to rats passively sensitized with mouse IgE, antibody 1-5 inhibited the antigen-induced bronchoconstriction. A similar effect could be seen in actively immunized mice, where antibody 1-5 was able to inhibit (by 70%) the ovalbumin-induced bronchoconstriction as well as BHR.

CONCLUSIONS

In summary, non-anaphylactogenic anti-IgE antibodies can markedly inhibit IgE levels and IgE-mediated allergic reactions. Since bronchoconstriction, BHR and lung eosinophilic inflammation can be suppressed, such antibodies may be attractive principles for the treatment of allergic asthma.