ET-1 cooperates with EGF to induce mitogenesis via a PTX-sensitive pathway in airway smooth muscle cells

We have examined the mitogenic effect of endothelin-1 (ET-1) alone or in combination with epidermal growth factor (EGF) in cultured airway smooth muscle cells (ASM) from guinea pig. ET-1 showed a weak mitogenic activity compared with the effect of EGF. However, when ET-1 and EGF were applied simultaneously, ET-1 synergistically enhanced the mitogenic activity of EGF. Neither inhibition of phospholipase C-beta nor depletion of protein kinase C affected this synergism. On the other hand, pertussis toxin (PTX), a Gi protein inhibitor, abolished the synergistic effect of ET-1 on EGF-induced mitogenesis. ET-1 induced a transient mitogen-activated protein (MAP) kinase activation peaking at 5 min. In contrast, EGF induced a stronger signal that was maintained for up to 20 min. However, concomitant stimulation of ASM with ET-1 and EGF caused an enhanced MAP kinase activation compared with EGF alone. Moreover, PTX abolished the enhanced MAP kinase activation observed in this condition. These results indicate that ET-1 can interact with an EGF-induced mitogenic axis through the Gi protein-dependent pathway, which is distinct from its direct mitogenic pathway.

Efficacy of cardiopulmonary resuscitation using intratracheal insufflation

The effects of constant-flow insufflation (CFI) of air in the trachea at the distal end of a modified endotracheal tube as the sole mode of ventilation during cardiopulmonary resuscitation (CPR) were studied in pigs. The ventilatory effect of CFI (15 +/- 2 L/min) generating a positive pressure of about 10 cm H2O with concomitant chest compression was studied first. In nine sedated, paralyzed animals disconnected from the ventilator, CFI alone did not significantly alter the decrease in PaO2 and the rise in PaCO2 observed during apnea. By contrast, the combination of precordial compression and CFI (CFI-CPR) maintained arterial blood gases over a 4-min period at the level obtained during mechanical ventilation. In the second part of the study, ventricular fibrillation was induced and CFI-CPR was compared with standard CPR using conventional mechanical ventilation during two successive 4-min periods, in random order. Ventilatory parameters were identical in the two situations, whereas hemodynamic parameters were similar or better with CFI-CPR than with standard CPR. Significant differences were observed between standard CPR and CFI-CPR for systolic aortic pressure (72 +/- 22 versus 82 +/- 27 mm Hg, respectively; p < 0.02) and for systolic (322 +/- 216 versus 431 +/- 237 ml/s; p < 0.01) and mean (116 +/- 106 versus 143 +/- 108 ml/s; p < 0.01) common carotid blood flows. The ease of use of CFI together with its beneficial hemodynamic effects suggests that CFI deserves to be investigated further as a mode of ventilation during CPR.

IL-4 differentiates naive CD8+ T cells to a "Th2-like" phenotype: a link between viral infections and bronchial asthma

Viral infections of the lung have been postulated to be a major factor in the etiology of bronchial asthma, a disease characterized by eosinophilic inflammation of the airways. In addition, upper respiratory tract infection in asthmatic individuals results in an exacerbation of the disease. Nevertheless, the mechanisms by which viral infection leads to disease exacerbation are poorly understood. CD8+ T cells play an important role in the host defense responses against viral infection, although to date, there are no reports to suggest that CD8+ T cells play any role in eosinophil recruitment. In the present study, we report that CD8+ T cells activated by either immobilized CD3 mAb or specific antigen can switch to a phenotype that produces Th2 cytokines and secretes less IFN-gamma. Moreover, in vivo, if a lung mucosal Th2 immune response exists, then antigen-specific activation of CD8 cells results in the development of lung eosinophilic inflammation mediated by the secretion of IL-5 from CD8+ T cells. These results may explain the link between viral infections and bronchial asthma, as this IL-4-dependent switch to CD8+ T cells to IL-5 secretion may not only exacerbate asthma by recruiting eosinophils into the lungs, but the impaired IFN-gamma production may also lead to delayed viral clearance.

The induction of a biphasic bronchospasm by the ETB agonist, IRL 1620, due to thromboxane A2 generation and endothelin-1 release in guinea-pigs

1. IRL 1620 (0.01-0.1 mg kg-1, i.v.), a selective endothelin B (ETB) receptor agonist, induced a dose-dependent biphasic increase in total lung resistance and a decrease in dynamic compliance in anaesthetized and artificially ventilated guinea-pigs. After intravenous injection of IRL 1620 (0.03 mg kg-1), the first phase was observed within 2 min whereas the second phase started between 5 and 10 min after injection and was long lasting. 2. In order to characterize which endothelin receptors are involved in both phases of bronchoconstriction, we studied the effect of ETA and ETB receptor antagonists (BQ 123 and BQ 788, respectively). BQ 788 (0.1-1 mg kg-1, i.v.) inhibited, in a dose-dependent manner, both phases of bronchoconstriction. BQ 123 (3 mg kg-1, i.v.) markedly inhibited (by 76%) the second phase of bronchoconstriction but had no effect on the early component of the response. 3. The effect of atropine, neurokinin-I (NK1) and neurokinin-2 (NK2) receptor antagonists (SR140333 and SR48968, respectively) were tested to investigate the possible involvement of cholinergic and sensory nerve activation, respectively, in the response to IRL 1620. Likewise, the role of arachidonic acid metabolites (leukotriene D4 antagonist, ONO-1078 and thromboxane A2 (TXA2) inhibitor, OKY-046) in this response was also investigated. OKY-046 (1 mg kg-1, i.v.) and atropine (1 mg kg-1, i.v.) partially inhibited the first phase (by 80% and 20%, respectively) without affecting the late phase of bronchoconstriction. Neither ONO-1078 (1 mg kg-1, i.v.) nor the combination of SR140333 (0.2 mg kg-1, i.v.) and SR 48968 (0.2 mg kg-1, i.v.) modified IRL 1620-induced bronchoconstriction. 4. A low dose of IRL 1620 (0.005 mg kg-1, i.v.) induced a monophasic bronchoconstriction. Pretreatment by phosphoramidon (100 mumol kg-1, i.v.) restored the second phase of bronchoconstriction. In this condition, BQ 123 (3 mg kg-1, i.v.) was able to inhibit partially the second phase of bronchoconstriction. 5. These results suggest that both phases of bronchoconstriction induced by IRL 1620 were mediated primarily by ETB receptor activation, the first phase being a consequence of TXA2 and acetylcholine release. The inhibition by an ETA receptor antagonist and the restoration by a neutral endopeptidase (NEP) inhibitor of the second phase of bronchoconstriction suggests that primary activation of ETB receptors leads to autocrine/paracrine endothelin-1 (ET-1) release that would subsequently cause profound bronchoconstriction through both ETA and ETB receptor activation.

NK1 receptor antagonist CP-99,994 inhibits cigarette smoke-induced neutrophil and eosinophil adhesion in rat tracheal venules

The involvement of neurokinin NK1 receptors in cigarette-induced adhesion of neutrophils and eosinophils to venules of the airway mucosa was investigated. Rats were pretreated with the NK1 receptor antagonist CP-99,994 (4 mg/kg IV), its vehicle, or its inactive enantiomer CP-100,263 before exposure to cigarette smoke. Adherent neutrophils and eosinophils were stained histochemically for endogenous peroxidase activity and were counted in tracheal whole mounts. Plasma leakage was quantified be stereological measurements of the extravasation of Monastral blue. Cigarette smoke induced the adhesion of 104 + 17 neutrophils and 10.4 +/- 1.7 eosinophils per square millimeter of mucosa. CP-99,994 reduced neutrophil and eosinophil adhesion by 66 and 61%, respectively, and reduced plasma extravasation by 61% (p < .05), but CP-100,263 had no significant effect. The inhibitory effects of CP-99,994 appeared to be specific because CP-99,994 had no effect on neutrophil and eosinophil adhesion, or on plasma extravasation induced by platelet activating factor, an inflammatory stimulus acting independently of NK1 receptors. These results suggest that NK1 receptors are involved in cigarette smoke-induced adhesion of neutrophils and eosinophils to the endothelium of venules in the rat tracheal mucosa.

Tachykinin and kinin receptor antagonists: therapeutic perspectives in allergic airway disease

The morbidity of allergic airway disease and the number of deaths resulting from it have not declined in the past ten years. The multiplicity of mediators released in the acute allergic reaction and our limited knowledge of the basic mechanisms that drive chronic inflammation have hampered the design of effective therapeutic regimens for this type of disease. In this article, Claude Bertrand and Pierangelo Geppetti summarize recent studies in which new, potent and selective tachykinin and kinin receptor antagonists demonstrate the involvement of tachykinins and kinins in airway anaphylaxis, and review how these antagonists might be of use in treating allergic asthma and rhinitis.

Control of construction-associated nosocomial aspergillosis in an antiquated hematology unit

OBJECTIVE

To determine the incidence of aspergillosis in patients with leukemia or bone marrow transplants during a construction-associated outbreak, and the effect of an environmental control program for Aspergillus.

DESIGN

Clinical, microbiological, and pathological records were reviewed retrospectively once the outbreak was appreciated, and prospectively thereafter, to determine the presence or absence of aspergillosis and duration of neutropenia.

SETTING

A university tertiary-care center with a single designated hematology-oncology unit.

PATIENTS

From January 1988 to September 1993, there were 141 patients with leukemia or bone marrow transplants identified as being neutropenic during 231 admissions to this specialized unit.

INTERVENTIONS

Installation of wall-mounted portable high-efficiency particulate air (HEPA)-filter air purifiers, application of copper-8-quinolinolate-formulated paint, replacement of perforated ceiling tiles with nonperforated type, sealing of all windows, replacement of horizontal, dust-accumulating blinds with vinyl, opaque, roller shades, and systematic and regular cleaning of surfaces.

RESULTS

Thirty-six cases of nosocomial aspergillosis were diagnosed during this period. The incidence density (ID) in the preconstruction period was 3.18 per 1,000 days at risk. During construction activity-before the implementation of a control strategy-the ID increased dramatically to 9.88 per 1,000 days at risk. With infection control measures implemented and continued construction work, the ID decreased to 2.91 per 1,000 days at risk, comparable to the preconstruction baseline rate.

CONCLUSIONS

An environmental control strategy incorporating widely available technology may have played an important role in controlling this outbreak of construction-associated invasive aspergillosis.

Laparoscopic treatment of nonparasitic liver cysts: adequate selection of patients and surgical technique

Results of laparoscopic fenestration in patients with a highly symptomatic solitary liver cyst (17 patients) or polycystic liver disease (PLD) (9 patients) were prospectively evaluated in a multicenter practice of general surgeons. Conversion to laparotomy was required in two patients because of inaccessible deep liver cyst in one and a diffuse form of PLD in the other. There was no mortality or major morbidity. Mean postoperative hospital stay was 4.6 days after successful laparoscopic procedures. During a mean follow-up of 9 months, 23% of the patients had recurrence of symptoms and 38% had radiographic reappearance of cysts. Factors predicting failure included previous surgical treatment, deepsited cysts, incomplete deroofing technique, location in the right posterior segments of the liver, and a diffuse form of PLD with small cysts. Adequate selection of patients and type of cystic liver disease and meticulous and aggressive surgical technique are recommended.

End-tidal carbon dioxide during cardiopulmonary resuscitation in humans presenting mostly with asystole: a predictor of outcome

OBJECTIVE

To determine whether continuous semiquantitative assessment of end-tidal CO2 could provide a highly sensitive predictor of return of spontaneous circulation during cardiopulmonary resuscitation (CPR).

DESIGN

Prospective, clinical study.

SETTING

Prehospital CPR.

PATIENTS

One hundred twenty patients, during nontraumatic cardiac arrest.

INTERVENTIONS

End-tidal CO2 values were measured continuously after tracheal intubation, and were categorized as the initial value, and as minimal and maximal values during the first 20 mins.

MEASUREMENTS AND MAIN RESULTS

Presenting rhythm was asystole in 22 of the first 24 patients. Return of spontaneous circulation occurred in eight patients. Initial, minimal, and maximal end-tidal CO2 values were significantly (p < .01) higher in these patients than in the patients without return of spontaneous circulation. Cutoff values providing a 100% sensitivity and the highest specificity in predicting return of spontaneous circulation were found to be 10 torr for initial and maximal end-tidal CO2 values, and 2 torr for the minimal end-tidal CO2 value. The number of patients required to reject (with a risk error of <.05) the hypothesis of an actual sensitivity of < or = 90% for an observed sensitivity of 100% was found to be 95. In the second part of the study, this hypothesis was prospectively tested for initial and maximal end-tidal CO2 values in the subsequent 96 patients. Presenting cardiac rhythm was asystole in 87 patients. Return of spontaneous circulation was obtained in 30 patients. The cutoff value of 10 torr for maximal end-tidal CO2 during the first 20 mins after tracheal intubation provided an observed sensitivity of 100% in predicting return of spontaneous circulation with a specificity of 67%. This result allows rejection of the hypothesis of an actual sensitivity of < or = 90% (p = .042). By contrast, the observed sensitivity of initial end-tidal CO2 was only 87%.

CONCLUSIONS

End-tidal CO2 represents a valuable tool for monitoring patients presenting with asystole during prehospital CPR. Fluctuations in end-tidal CO2 during CPR and the utility of end-tidal CO2 in detecting return of spontaneous circulation justify its continuous measurement. In addition, a high sensitivity (>90%) in predicting return of spontaneous circulation is prospectively demonstrated using the maximal end-tidal CO2 during the first 20 mins after tracheal intubation, with a cutoff value of 10 torr. Such a prognostic indicator could be used for a more rational approach to prolonged CPR.

Mice lacking the IFN-gamma receptor have impaired ability to resolve a lung eosinophilic inflammatory response associated with a prolonged capacity of T cells to exhibit a Th2 cytokine profile

To investigate the modulatory role of IFN-gamma on the induction and maintenance of Th2 mucosal immunity in vivo, experiments were performed in mice lacking the IFN-gamma R. Aerosol OVA challenge of immunized wild-type mice resulted in an infiltration of eosinophils into the lung, associated with the ex vivo production of Th2 cytokines (IL-4 and IL-5) from purified lung Thy1.2+ cells stimulated via the CD3/TCR complex. However, while immunized IFN-gamma R-deficient mice exhibited elevated levels of IgE, IgG1, and reduced levels of IgG2a compared with wild-type mice, there was no difference in the recruitment of eosinophils into the lung or the production of IL-4 and IL-5 from lung T cells on day 3. In contrast, up to 2 mo after a single Ag challenge, eosinophils were still present in the lungs of IFN-gamma R-deficient, but not wild-type, mice. Likewise, lung-derived T cells from IFN-gamma R-deficient mice produced higher levels of IL-4 and IL-5, both at 1 and 2 mo after OVA challenge compared with T cells from wild-type mice. We conclude that endogenous IFN-gamma regulates the humoral isotype Ab pattern, but does not modulate the commitment of T cells to a Th2 phenotype in vivo or the acute infiltration of eosinophils to the lung. However, in the absence of IFN-gamma-mediated signaling, there is a transition from a spontaneously resolving to a persisting eosinophilic inflammation of the lungs, associated with a sustained capacity of lung T cells to secrete a Th2 cytokine profile.

Mice lacking the IFN-gamma receptor have impaired ability to resolve a lung eosinophilic inflammatory response associated with a prolonged capacity of T cells to exhibit a Th2 cytokine profile

To investigate the modulatory role of IFN-gamma on the induction and maintenance of Th2 mucosal immunity in vivo, experiments were performed in mice lacking the IFN-gamma R. Aerosol OVA challenge of immunized wild-type mice resulted in an infiltration of eosinophils into the lung, associated with the ex vivo production of Th2 cytokines (IL-4 and IL-5) from purified lung Thy1.2+ cells stimulated via the CD3/TCR complex. However, while immunized IFN-gamma R-deficient mice exhibited elevated levels of IgE, IgG1, and reduced levels of IgG2a compared with wild-type mice, there was no difference in the recruitment of eosinophils into the lung or the production of IL-4 and IL-5 from lung T cells on day 3. In contrast, up to 2 mo after a single Ag challenge, eosinophils were still present in the lungs of IFN-gamma R-deficient, but not wild-type, mice. Likewise, lung-derived T cells from IFN-gamma R-deficient mice produced higher levels of IL-4 and IL-5, both at 1 and 2 mo after OVA challenge compared with T cells from wild-type mice. We conclude that endogenous IFN-gamma regulates the humoral isotype Ab pattern, but does not modulate the commitment of T cells to a Th2 phenotype in vivo or the acute infiltration of eosinophils to the lung. However, in the absence of IFN-gamma-mediated signaling, there is a transition from a spontaneously resolving to a persisting eosinophilic inflammation of the lungs, associated with a sustained capacity of lung T cells to secrete a Th2 cytokine profile.

Central role of immunoglobulin (Ig) E in the induction of lung eosinophil infiltration and T helper 2 cell cytokine production: inhibition by a non-anaphylactogenic anti-IgE antibody

Elevated levels of immunoglobulin (Ig) E are associated with bronchial asthma, a disease characterized by eosinophilic inflammation of the airways. Activation of antigen-specific T helper (Th) 2 cells in the lung with the subsequent release of interleukin (IL) 4 and IL-5 is believed to play an important role in the pathogenesis of this disease. In this study, we have used a non-anaphylactogenic anti-mouse-IgE antibody to investigate the relationship between IgE, airway eosinophil infiltration, and the production of Th2 cytokines. Immunization of mice with house dust mite antigen increased serum levels of IgE and IgG. Antigen challenge of immunized but not control mice induced an infiltration of eosinophils in the bronchoalveolar lavage associated with the production of IL-4 and IL-5 from lung purified Thy1.2+ cells activated through the CD3-T cell receptor complex. Administration of the anti-IgE monoclonal antibody (mAb) 6h before antigen challenge neutralized serum IgE but not IgG and inhibited the recruitment of eosinophils into the lungs and the production of IL-4 and IL-5 but not interferon gamma. Studies performed using an anti-CD23 mAb, CD23 deficient and mast cell deficient mice suggest that anti-IgE mAb suppresses eosinophil infiltration and Th2 cytokine production by inhibiting IgE-CD23-facilitated antigen presentation to T cells. Our results demonstrate that IgE-dependent mechanisms are important in the induction of a Th2 immune response and the subsequent infiltration of eosinophils into the airways. Neutralization of IgE, for example, non-anaphylactogenic anti-IgE mAbs may provide a novel therapeutic approach to the treatment of allergic airway disease.

Expression of two FGF-2 isoforms in pancreatic acinar cells (AR4-2J). Intracellular localization and role in the regulation of the extracellular matrix biosynthesis

Fibroblast growth factor (FGF-2) is a multifunctional growth factor. In cells producing this factor, FGF-2 is synthesized as different molecular weight isoforms lacking the signal peptide sequence for secretion. All forms are highly concentrated in cells. The presence of a nuclearization signal sequence in some isoforms suggests the involvement of these isoforms in cell functions bypassing the cell surface receptors. Our aims were to better define the intracellular localizations of the FGF-2 isoforms by immunocytochemistry and confocal microscopy and to analyze whether these isoforms were involved in the expression of extracellular matrix (ECM) components. We chose the pancreatic acinar cell line AR4-2J since it does not synthesize FGF-2. These cells were retrovirally transfected by point-mutated FGF-2 cDNAs. The cell lines obtained produced either the 18 kDa form (A5 cells) or the 22.5 kDa form (A3 cells). In A5 cells, the 18 kDa form was found in the cytoplasm, on the cell surface reflecting its secretion, and in the nucleoli. Parental AR4-2J cells treated with exogenous FGF-2 exhibited identical localizations, suggesting that in A5 cells the 18 kDa form followed the same translocation pathways than the exogenous FGF-2. By contrast, in A3 cells the 22.5 kDa form was predominantly localized in the nucleoplasm but was undetectable on the cell surface, suggesting its direct translocation to the nucleus. Northern and Western blot analysis showed that cells expressing the high molecular weight form exhibited a decrease of laminin B1 protein level and mRNA stability. In contrast, collagen IV and fibronectin expressions were unmodified either in FGF-2-transfected cells or in parental cells treated by exogenous FGF-2. Thus, these data indicate that: 1) 18 and 22.5 kDa FGF-2 are preferentially localized in different nuclear compartments and 2) the high molecular weight form plays a role on the expression of some ECM components.

Evidence that tachykinins relax the guinea-pig trachea via nitric oxide release and by stimulation of a septide-insensitive NK1 receptor

1. This study investigated the possibility that tachykinins relax the guinea-pig isolated trachea by releasing nitric oxide (NO) from the epithelium. The types of tachykinin receptor mediating both relaxation and contraction of the trachea were also studied. Isometric tension was recorded in isolated tracheal tube preparations precontracted with acetylcholine (10 microM) in which compounds were administered intraluminally in the presence of phosphoramidon and indomethacin (both 1 microM) and the tachykinin NK2 receptor antagonist, SR 48,968 ((S)-N-methyl-N[4-(4-acetyl amino-4-phenylpiperidino)-2-(3,4-dichlorophenyl)butyl]benzamide), 0.1 microM). 2. In the presence of the inactive enantiomer of an NO-synthase inhibitor, NG-monomethyl-D-arginine (D-NMMA, 100 microM), substance P (SP), neurokinin A (NKA), neurokinin B (NKB) and the selective NK1 receptor agonist, [Sar9, Met(O2)11]-SP, (0.1-10 nM) relaxed tracheal tube preparations. This relaxation was changed into a contraction by pretreatment with the NO-synthase inhibitor, NG-monomethyl-L-arginine (L-NMMA, 100 microM). The effect of L-NMMA on SP- and [Sar9, Met(O2)11]-SP-induced responses was reversed by L-arginine (L-Arg, 1 mM), but not by D-Arg (1 mM). After removal of the epithelium SP, NKA and NKB and [Sar9, Met(O2)11]-SP (0.1-10 nM) evoked contractile responses in the presence of either L-NMMA (100 microM) or D-NMMA (100 microM). The effects of SP and [Sar9, Met(O2)11]-SP obtained in the presence of another NO-synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME, 100 microM) or its inactive enantiomer, NG-nitro-D-arginine methyl ester (D-NAME, 100 microM) were similar to those observed with L-NMMA or D-NMMA, respectively. 3. The selective NK1 receptor agonist, [pGlu6, Pro9]-SP(6-11) (septide, 0.1-10 nM) evoked contractile responses of tracheal tube preparations in the presence of either D-NMMA (100 microM) or L-NMMA (100 microM). The log concentration-response curve to septide obtained in the presence of L-NMMA was similar to that obtained in the presence of D-NMMA. [Sar9, Met(O2)11]-SP (0.1-10 nM) relaxed tracheal tube preparations precontracted with septide (1 microM), whereas septide (0.1 nM-1 microM) further contracted tracheal tube preparations precontracted with [Sar9, Met(O2)11]-SP (1 microM). 4. Relaxant and contractile responses evoked by SP, NKA, NKB and by [Sar9, Met(O2)11]-SP (0.1-10 nM) were not affected by a combination of the histamine H1 (pyrilamine, 1 microM) and H2 (cimetidine, 1 microM) receptor antagonists, but were abolished by the tachykinin NK1 receptor antagonist, CP-99,994 ((2S,3S)-3-(2-methoxybenzylamino)-2-phenylpiperidine, 1 microM), though not by its inactive enantiomer CP-100,263 (1 microM). Contractile responses evoked by septide (10 nM and 1 microM) were also abolished by CP-99,994 (1 microM) but not by CP-100,263 (1 microM). 5. These results demonstrate that tachykinins relax guinea-pig tracheal tube preparations by releasing NO via the stimulation of epithelial NK1 receptors by a mechanism independent of histamine release. The NK1 receptor type involved is sensitive to SP, NKA, NKB and [Sar9, Met(O2)11]-SP but not to septide, and is pharmacologically distinct from the NK1 receptor that mediates contraction, which is stimulated by all the agonists, including septide.

The starch phosphorylase gene is subjected to different modes of regulation in starch-containing tissues of potato

Analysis of the levels of starch phosphorylase mRNA and its product in the various organs of the potato plant indicates that the gene is differentially regulated, leading to a high accumulation of the gene product in tubers. The amount of phosphorylase transcripts synthesized in nuclei isolated from tubers and leaves indicates that the difference in the steady-state levels of phosphorylase mRNA in these organs can be explained by different rates of initiation of transcription. However, while rates of initiation of transcription are similar in tubers and stems, the steady-state level of phosphorylase mRNA is much lower in the stem. Transgenic potato plants expressing the beta-glucuronidase (GUS) gene under the control of 5'-flanking sequences of the phosphorylase gene exhibited high levels of GUS activity in petioles, stems, stolons, tubers and roots, but low levels in leaves. This confirms the results of transcription assays observed for leaves, stems and tubers, and indicates that accumulation of phosphorylase mRNA in stems and tubers is not controlled solely by transcription initiation. Finally, histochemical analysis for GUS activity in transgenic potato plants suggests that transcription of the phosphorylase gene predominantly occurs in starch-containing cells associated to vascular tissues, and suggests a role for starch phosphorylase in the mobilization of starch stored along the translocation pathway.

Activation of the Fas receptor on lung eosinophils leads to apoptosis and the resolution of eosinophilic inflammation of the airways

While considerable progress has been made in understanding the events by which eosinophils accumulate in various pathophysiological conditions, the mechanisms controlling the resolution of eosinophilic inflammation are poorly understood. In the present study, we demonstrate that lung eosinophils obtained by bronchoalveolar lavage (BAL) after aerosol allergen provocation of immunized mice expressed the Fas receptor. Stimulation of purified eosinophils in vitro with a monoclonal anti-Fas mAb (1 ng-1 microg/ml) induced a dose/time dependent loss of cell viability from 24-72 h. Measurement of DNA fragmentation with propidium iodide confirmed that anti-Fas induced eosinophil death by apoptosis. While incubation with IL-3, IL-5, or GM-CSF prevented spontaneous apoptosis, these factors failed to prevent anti-Fas induced apoptosis. Administration of anti-Fas mAb to the lungs after the induction of a lung eosinophilia increased the number of peroxidase positive macrophages in BAL fluid 4-12 h later which was followed by a marked reduction in the number of eosinophils in the airways. Importantly, Fas-mediated resolution of eosinophilic inflammation occurred in the absence of any overt secondary inflammatory changes in the lungs. We speculate that defects in this pathway may at least in part explain the chronic eosinophilic inflammation often observed in the lungs of asthmatic individuals.

Mitochondrial very long chain acyl-CoA dehydrogenase deficiency--a new disorder of fatty acid oxidation

Very long chain acyl-CoA dehydrogenase is a newly characterised enzyme in mitochondrial fatty acid oxidation. A girl who presented on the second day of life with a sudden and severe illness due to deficiency of this enzyme is reported. There is evidence that some children (and perhaps all) originally diagnosed with a deficiency of long-chain acyl-CoA dehydrogenase, in fact, have a defect involving very long chain acyl-CoA dehydrogenase.

Viral infection potentiates the increase in airway blood flow produced by substance P

We examined the effect of respiratory tract infection with Sendai virus on the responsiveness of airway blood flow to substance P (SP) in rats. Pathogen-free rats were inoculated with either Sendai virus suspension or sterile viral growth medium into each nostril. Five days later, we measured airway and esophageal blood flows before and immediately after injection of SP or histamine into the left ventricle of rats in both groups using a modification of the reference-sample microsphere technique. Viral infection potentiated the increase in airway blood flow evoked by SP but not by histamine. We also examined the effect of neutral endopeptidase (NEP) and angiotensin-converting enzyme (ACE) on the SP-induced increase in airway blood flow. Both phosphoramidon (NEP inhibitor) and captopril (ACE inhibitor) potentiated the increase in airway blood flow produced by SP in pathogen-free rats. In the presence of both peptidase inhibitors, a submaximal dose of SP increased blood flow to a similar level in infected and pathogen-free rats. Thus decreased activity of both ACE and NEP may be involved in the exaggerated increase in airway blood flow evoked by SP in virus-infected rats.

New aspects on the role of kinins in neurogenic inflammation

The inflammatory response to injury consists of the activation of several protective mechanisms involving different cellular systems. Among the mechanisms and systems that exert their effects rapidly, peptide transmitters released from peripheral endings of primary sensory neurons (evoking neurogenic inflammation) play a major role in the response to tissue injury. Noxious stimuli may directly activate sensory nerves to release proinflammatory neuropeptides. More recently, evidence has accumulated suggesting that indirect mechanisms leading to sensory neuropeptide release are also activated in relevant models of pathophysiological conditions. Tachykinin NK1 and NK2 receptor antagonists reduced the plasma extravasation in the trachea and nasal mucosa and the bronchoconstriction caused by antigen challenge in sensitized guinea-pigs. Blockage of kinin B2 receptors with the selective antagonist HOE-140 had a similar inhibitory effect. The magnitude of the inhibition observed with the kinin receptor antagonist alone was similar to that caused by a combination a tachykinin and kinin receptor antagonists. This suggests activation of a common final pathway by these two groups of mediators. Pharmacological and biochemical evidence suggests that in the airways of sensitized guinea-pigs, kinins released by the anaphylactic reaction stimulate the release of tachykinins from sensory nerves, thus contributing to their proinflammatory action.

Interleukin-4 is required for the induction of lung Th2 mucosal immunity

Aerosol antigen challenge of ovalbumin-sensitized mice induced an eosinophilic airway inflammation that was dependent on interleukin (IL)-5 and CD4+, but not CD8+, T lymphocytes. The involvement of the Th2 phenotype of CD4+ T cells was supported by demonstrating that FACS-sorted purified lung T cells from sensitized, but not control, mice produced IL-4, IL-5, and IL-10 after activation of the CD3/TCR complex. To determine the role of IL-4 in this process, we used mice in which the gene for IL-4 was deleted by homologous recombination. Antigen challenge of IL-4 gene-targeted mice resulted in a marked attenuation of eosinophilic inflammation and IL-5 secretion. To more fully understand the time when IL-4 was involved, we administered a neutralizing anti-IL-4 antibody (11B11) either immediately before antigen challenge or during immunization. Inhibition of IL-4 before antigen challenge had little effect on antigen-induced eosinophil infiltration. However, when 11B11 was administered during immunization, there was a marked reduction in eosinophil infiltration. Cross-linking of the CD3/TCR complex of FACS-sorted lung T cells revealed that only when anti-IL-4 was administered during immunization was there an inhibition of T cell-derived IL-5 and IgE production. These results suggest that IL-4 is central both to the induction of a local Th2 response and to the development of eosinophilic inflammation of the lung. Moreover, we suggest a sequential involvement of IL-4 and IL-5, with IL-4 committing naive T cells to a Th2 phenotype which upon activation by aerosol provocation secrete IL-5, resulting in eosinophil accumulation.

Long-term risk stratification with dipyridamole imaging

This study was undertaken to assess the reliability of clinical parameters and dipyridamole-thallium 201 images for predicting the occurrence of future cardiac events (nonfatal myocardial infarction or cardiac death). Dipyridamole myocardial perfusion imaging is routinely performed in patients who have possible or known coronary disease and a low exercise tolerance. A total of 753 patients underwent clinical assessment and semiquantitative dipyridamole-201TI imaging and were followed up as outpatients. Patients who underwent coronary revascularization during the follow-up period were excluded from the study because the decision to intervene would have been based at least in part on the test itself. There were 82 cardiac events and 54 noncardiac deaths, and 11 patients were lost to follow-up after a mean follow-up of 15 months. With use of a quantitative index reflecting the amount of jeopardized myocardium, patients could be stratified by dipyridamole imaging into subsets with coronary morbidity and mortality rates ranging from 1% to 89%, (p = 0.0001). When clinical and scintigraphic variables were subjected to backward stepwise logistic regression analysis, the significant predictors of cardiac events were the jeopardized myocardium index by scintigraphy (p < 0.0001), left ventricular hypertrophy on the electrocardiogram (p = 0.0009), and transient dipyridamole-induced left ventricular cavitary dilatation (p = 0.0073). Quantitative dipyridamole-201TI imaging appears to be a powerful predictor of future cardiac events in patients with coronary disease and a low exercise tolerance and is a potentially useful contributor to risk-profile assessment and to the treatment of these patients.

Utilization of gas heater humidifier in the course of coelioscopies

The increasing utilization of coelioscopic interventions has needed the use of a larger number of trocars, which involves in some cases (especially at the beginning of personal experience) longer operations. In our clinical experience we have met hypothermies that compelled us to modify our way of working. The use of conventional means (like warming cushion, warming of irrigation fluids) could limit the temperature loss only moderately. So we imagined to warm and moisten the gases insufflated into the peritoneal cavity. We give a description of the accessories and the results with some patients.