Owner-reported coughing and nasal discharge are associated with clinical findings, arterial oxygen tension, mucus score and bronchoprovocation in horses with recurrent airway obstruction in a field setting.

REASONS FOR PERFORMING STUDY In clinical practice, veterinarians often depend on owner-reported signs to assess the clinical course of horses with recurrent airway obstruction (RAO). OBJECTIVES To test whether owner-reported information on frequency of coughing and observation of nasal discharge are associated with clinical, cytological and bronchoprovocation findings in RAO-affected horses in nonstandardised field conditions. STUDY DESIGN Cross-sectional study comparing healthy and RAO-affected horses. METHODS Twenty-eight healthy and 34 RAO-affected Swiss Warmblood horses were grouped according to owner-reported 'coughing frequency' and 'nasal discharge'. Differences between these groups were examined using clinical examination, blood gas analyses, endoscopic mucus scores, cytology of tracheobronchial secretion and bronchoalveolar lavage fluid, and airway hyperresponsiveness determined by plethysmography with histamine bronchoprovocation. RESULTS Frequently coughing horses differed most markedly from healthy control animals. Histamine bronchoprovocation-derived parameters were significantly different between the healthy control group and all RAO groups. Mucus grades and tracheobronchial secretion and bronchoalveolar lavage fluid neutrophil percentages had particularly high variability, with overlap of findings between groups. Owner satisfaction with the clinical status of the horse was high, even in severely affected horses. CONCLUSIONS Owner-reported coughing and nasal discharge are associated with specific clinical and diagnostic findings in RAO-affected horses in field settings. While airway hyperresponsiveness differentiates best between healthy horses and asymptomatic RAO-affected horses, the absence of coughing and nasal discharge does not rule out significant neutrophilic airway inflammation. Owner satisfaction with the clinical status of the horse was uninformative.

Primum et super omnium: nihil nocere Operationsindikation im Wandel bei Divertikulitis

Diverticulitis is a common disease in western countries and its incidence is increasing especially among young patients. Colonic diverticulosis, incidentally diagnosed by endoscopy or CT-scanning, has no immediate clinical consequences. Progression to diverticulitis develops in only 4 % of cases. In the last decades management of diverticular disease evolved and expectative treatment and less invasive techniques have gained importance. Elective resection has traditionally been advised after a second episode of diverticulitis or after a first episode if the patient was less than 50 years of age or complicated disease occurred. Recent changes in understanding the natural history of diverticular disease have substantially modified treatment paradigms. Elective resection in case of recurrent diverticular disease should be performed on a individual basis and in cases with complications like intestinal obstruction or fistulas. Primary anastomosis is an option even in emergency surgery due to colonic perforation, while diverting operations are indicated for selected patient groups with a high risk profile. Several prospective studies showed good results for laparoscopic drainage and lavage in the setting of perforated diverticulitis with generalized peritonitis, though this concept needs to be controlled with randomized clinical trials before application into the daily practice. This article should provide a short overview of trends in the surgical treatment of diverticulitis, help to understand the natural history of the disease and thereby explain the currently lower frequency of surgical interventions for diverticulitis.

Determination of respiratory gas flow by electrical impedance tomography in an animal model of mechanical ventilation

Background A recent method determines regional gas flow of the lung by electrical impedance tomography (EIT). The aim of this study is to show the applicability of this method in a porcine model of mechanical ventilation in healthy and diseased lungs. Our primary hypothesis is that global gas flow measured by EIT can be correlated with spirometry. Our secondary hypothesis is that regional analysis of respiratory gas flow delivers physiologically meaningful results. Methods In two sets of experiments n = 7 healthy pigs and n = 6 pigs before and after induction of lavage lung injury were investigated. EIT of the lung and spirometry were registered synchronously during ongoing mechanical ventilation. In-vivo aeration of the lung was analysed in four regions-of-interest (ROI) by EIT: 1) global, 2) ventral (non-dependent), 3) middle and 4) dorsal (dependent) ROI. Respiratory gas flow was calculated by the first derivative of the regional aeration curve. Four phases of the respiratory cycle were discriminated. They delivered peak and late inspiratory and expiratory gas flow (PIF, LIF, PEF, LEF) characterizing early or late inspiration or expiration. Results Linear regression analysis of EIT and spirometry in healthy pigs revealed a very good correlation measuring peak flow and a good correlation detecting late flow. PIFEIT = 0.702 · PIFspiro + 117.4, r2 = 0.809; PEFEIT = 0.690 · PEFspiro-124.2, r2 = 0.760; LIFEIT = 0.909 · LIFspiro + 27.32, r2 = 0.572 and LEFEIT = 0.858 · LEFspiro-10.94, r2 = 0.647. EIT derived absolute gas flow was generally smaller than data from spirometry. Regional gas flow was distributed heterogeneously during different phases of the respiratory cycle. But, the regional distribution of gas flow stayed stable during different ventilator settings. Moderate lung injury changed the regional pattern of gas flow. Conclusions We conclude that the presented method is able to determine global respiratory gas flow of the lung in different phases of the respiratory cycle. Additionally, it delivers meaningful insight into regional pulmonary characteristics, i.e. the regional ability of the lung to take up and to release air.

What's in a name? Inflammatory airway disease in racehorses in training

The term 'inflammatory airway disease' (IAD) is often used to describe the syndrome of lower airway inflammation that frequently affects young racehorses in training around the world. In practice, this inflammation is generally diagnosed using a combination of endoscopic tracheal examination, including grading of amounts of mucus present and tracheal wash sampling. However, a recent consensus statement from the American College of Veterinary Internal Medicine concluded that bronchoalveolar lavage (BAL) sampling, rather than tracheal wash (TW) sampling, is required for cytological diagnosis of IAD and that tracheal mucus is not an essential criterion. However, as BAL is a relatively invasive procedure that is not commonly used on racing yards, this definition can only be applied routinely to a biased referral population. In contrast, many practitioners continue to diagnose IAD using endoscopic tracheal examination and sampling. We argue that, rather than restricting the use of the term IAD to phenotypes diagnosed by BAL, it is important to distinguish in the literature between airway inflammation diagnosed by BAL and that identified in the field using TW sampling. We suggest the use of the term brIAD for the former and trIAD for the latter. It is essential that we continue to endeavour to improve our understanding of the aetiology, pathogenesis and clinical relevance of airway inflammation identified in racehorses in training using tracheal examination and sampling. Future studies should focus on investigations of the component signs of airway inflammation.

In vivo Evolution of CMY-2 to CMY-33 β-Lactamase in Escherichia coli ST131: Characterization of an Acquired Extended-Spectrum AmpC (ESAC) Conferring Resistance to Cefepime.

Cefepime is frequently prescribed to treat infections caused by AmpC-producing Gram-negative bacteria. CMY-2 is the most common plasmid-mediated AmpC (pAmpC) β-lactamase. Unfortunately, CMY variants conferring enhanced cefepime resistance are reported. Here, we describe the evolution of CMY-2 to an extended-spectrum AmpC (ESAC) in clonally identical E. coli isolates obtained from a patient. The CMY-2-producing E. coli (CMY-2-Ec) was isolated from a wound. Thirty days later, one CMY-33-producing E. coli (CMY-33-Ec) was detected in bronchoalveolar lavage. Two weeks before the isolation of CMY-33-Ec, the patient received cefepime.CMY-33-Ec and CMY-2-Ec were identical by rep-PCR, being of hyperepidemic ST131, but showed different β-lactam MICs (e.g., cefepime 16 vs. ≤0.5 μg/ml). Identical CMY-2-Ec isolates were also found in a rectal swab. CMY-33 differs from CMY-2 by a Leu293-Ala294 deletion. Expressed in E. coli DH10B, both CMYs conferred resistance to ceftazidime (≥256 μg/ml), but cefepime MICs were higher for CMY-33 than CMY-2 (8 vs. 0.25 μg/ml). The kcat/Km or kinact/KI (μM(-1) s(-1)) indicated that CMY-33 possesses an ESBL-like spectrum compared to CMY-2 (cefoxitin: 0.2 vs. 0.4; ceftazidime: 0.2 vs. not measurable; cefepime: 0.2 vs. not measurable; tazobactam 0.0018 vs. 0.0009). Using molecular modeling, we show that a widened active site (∼4 Å shift) may play a significant role in enhancing cefepime hydrolysis. This is the first in vivo demonstration of a pAmpC that under cephalosporin treatment expands its substrate spectrum resembling an ESBL. The prevalence of CMY-2-Ec isolates is rapidly increasing worldwide, therefore awareness that cefepime treatment may select for resistant isolates is critical.

Intra-articular corticosteroid for knee osteoarthritis.

BACKGROUND Knee osteoarthritis is a leading cause of chronic pain, disability, and decreased quality of life. Despite the long-standing use of intra-articular corticosteroids, there is an ongoing debate about their benefits and safety. This is an update of a Cochrane review first published in 2005. OBJECTIVES To determine the benefits and harms of intra-articular corticosteroids compared with sham or no intervention in people with knee osteoarthritis in terms of pain, physical function, quality of life, and safety. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE (from inception to 3 February 2015), checked trial registers, conference proceedings, reference lists, and contacted authors. SELECTION CRITERIA We included randomised or quasi-randomised controlled trials that compared intra-articular corticosteroids with sham injection or no treatment in people with knee osteoarthritis. We applied no language restrictions. DATA COLLECTION AND ANALYSIS We calculated standardised mean differences (SMDs) and 95% confidence intervals (CI) for pain, function, quality of life, joint space narrowing, and risk ratios (RRs) for safety outcomes. We combined trials using an inverse-variance random-effects meta-analysis. MAIN RESULTS We identified 27 trials (13 new studies) with 1767 participants in this update. We graded the quality of the evidence as 'low' for all outcomes because treatment effect estimates were inconsistent with great variation across trials, pooled estimates were imprecise and did not rule out relevant or irrelevant clinical effects, and because most trials had a high or unclear risk of bias. Intra-articular corticosteroids appeared to be more beneficial in pain reduction than control interventions (SMD -0.40, 95% CI -0.58 to -0.22), which corresponds to a difference in pain scores of 1.0 cm on a 10-cm visual analogue scale between corticosteroids and sham injection and translates into a number needed to treat for an additional beneficial outcome (NNTB) of 8 (95% CI 6 to 13). An I(2) statistic of 68% indicated considerable between-trial heterogeneity. A visual inspection of the funnel plot suggested some asymmetry (asymmetry coefficient -1.21, 95%CI -3.58 to 1.17). When stratifying results according to length of follow-up, benefits were moderate at 1 to 2 weeks after end of treatment (SMD -0.48, 95% CI -0.70 to -0.27), small to moderate at 4 to 6 weeks (SMD -0.41, 95% CI -0.61 to -0.21), small at 13 weeks (SMD -0.22, 95% CI -0.44 to 0.00), and no evidence of an effect at 26 weeks (SMD -0.07, 95% CI -0.25 to 0.11). An I(2) statistic of ≥ 63% indicated a moderate to large degree of between-trial heterogeneity up to 13 weeks after end of treatment (P for heterogeneity≤0.001), and an I(2) of 0% indicated low heterogeneity at 26 weeks (P=0.43). There was evidence of lower treatment effects in trials that randomised on average at least 50 participants per group (P=0.05) or at least 100 participants per group (P=0.013), in trials that used concomittant viscosupplementation (P=0.08), and in trials that used concomitant joint lavage (P≤0.001).Corticosteroids appeared to be more effective in function improvement than control interventions (SMD -0.33, 95% CI -0.56 to -0.09), which corresponds to a difference in functions scores of -0.7 units on standardised Western Ontario and McMaster Universities Arthritis Index (WOMAC) disability scale ranging from 0 to 10 and translates into a NNTB of 10 (95% CI 7 to 33). An I(2) statistic of 69% indicated a moderate to large degree of between-trial heterogeneity. A visual inspection of the funnel plot suggested asymmetry (asymmetry coefficient -4.07, 95% CI -8.08 to -0.05). When stratifying results according to length of follow-up, benefits were small to moderate at 1 to 2 weeks after end of treatment (SMD -0.43, 95% CI -0.72 to -0.14), small to moderate at 4 to 6 weeks (SMD -0.36, 95% CI -0.63 to -0.09), and no evidence of an effect at 13 weeks (SMD -0.13, 95% CI -0.37 to 0.10) or at 26 weeks (SMD 0.06, 95% CI -0.16 to 0.28). An I(2) statistic of ≥ 62% indicated a moderate to large degree of between-trial heterogeneity up to 13 weeks after end of treatment (P for heterogeneity≤0.004), and an I(2) of 0% indicated low heterogeneity at 26 weeks (P=0.52). We found evidence of lower treatment effects in trials that randomised on average at least 50 participants per group (P=0.023), in unpublished trials (P=0.023), in trials that used non-intervention controls (P=0.031), and in trials that used concomitant viscosupplementation (P=0.06).Participants on corticosteroids were 11% less likely to experience adverse events, but confidence intervals included the null effect (RR 0.89, 95% CI 0.64 to 1.23, I(2)=0%). Participants on corticosteroids were 67% less likely to withdraw because of adverse events, but confidence intervals were wide and included the null effect (RR 0.33, 95% CI 0.05 to 2.07, I(2)=0%). Participants on corticosteroids were 27% less likely to experience any serious adverse event, but confidence intervals were wide and included the null effect (RR 0.63, 95% CI 0.15 to 2.67, I(2)=0%).We found no evidence of an effect of corticosteroids on quality of life compared to control (SMD -0.01, 95% CI -0.30 to 0.28, I(2)=0%). There was also no evidence of an effect of corticosteroids on joint space narrowing compared to control interventions (SMD -0.02, 95% CI -0.49 to 0.46). AUTHORS' CONCLUSIONS Whether there are clinically important benefits of intra-articular corticosteroids after one to six weeks remains unclear in view of the overall quality of the evidence, considerable heterogeneity between trials, and evidence of small-study effects. A single trial included in this review described adequate measures to minimise biases and did not find any benefit of intra-articular corticosteroids.In this update of the systematic review and meta-analysis, we found most of the identified trials that compared intra-articular corticosteroids with sham or non-intervention control small and hampered by low methodological quality. An analysis of multiple time points suggested that effects decrease over time, and our analysis provided no evidence that an effect remains six months after a corticosteroid injection.

Influence of two types of self-retaining retractors on multifidus muscle blood flow during dorsolateral thoracolumbar hemilaminectomy in dogs

OBJECTIVES To assess the influence of the use of Gelpi and Grevel retractors on multifidus muscle blood flow during hemilaminectomy, using a dorsolateral approach, for acute disc extrusion in dogs as measured by laser speckle contrast imaging (LSCI). METHODS Blood flow in the multifidus muscles was measured intra-operatively using LSCI prior to insertion of the retractors, immediately after hemilaminectomy and removal of the retractors, and after 10 minutes of lavage of the surgical site. Plasma creatine kinase levels were measured preoperatively and 12-24 hours postoperatively. RESULTS Muscular blood flow was significantly decreased following retraction and remained lower than initial values 10 minutes after lavage in all dogs. The decrease in blood flow was significantly greater with Gelpi retractors (n = 8) than with Grevel retractors (n = 10). No significant relation was found between the duration of retraction and postoperative changes in creatine kinase levels or blood flow. CLINICAL SIGNIFICANCE Findings in this study demonstrate a drop in blood flow within the multifidus muscles using the dorsolateral approach regardless of retractor type used. Gelpi retractors seem to have greater influence on muscular blood flow than Grevel retractors. Further studies are warranted to confirm this second finding.

Effect of tympanic cavity evacuation and flushing on microbial isolates during total ear canal ablation with lateral bulla osteotomy in dogs.

OBJECTIVE To evaluate differences in bacterial numbers, identity, and susceptibility in samples obtained from the tympanic cavity on entry (preflush) and after evacuation and lavage (postflush) and assess perioperative and empiric antimicrobial selection in dogs that underwent total ear canal ablation (TECA) with lateral bulla osteotomy (LBO) or reoperation LBO. DESIGN Prospective clinical study. ANIMALS 34 dogs. PROCEDURE TECA with LBO or reoperation LBO was performed on 47 ears. Pre- and postflush aerobic and anaerobic samples were obtained from the tympanic cavity. Isolates and antimicrobial susceptibility patterns were compared. RESULTS Different isolates (31/44 [70%] ears) and susceptibility patterns of isolate pairs (6/44 [14%] ears) were detected in pre- and postflush samples from 84% of ears. Evacuation and lavage of the tympanic cavity decreased the number of bacterial isolates by 33%. In 26% of ears, bacteria were isolated from post-flush samples but not preflush samples. Only 26% of isolates tested were susceptible to cefazolin. At least 1 isolate from 53% of dogs that received empirically chosen antimicrobials postoperatively was resistant to the selected drugs. Anaerobic bacteria were recovered from 6 ears. CONCLUSIONS AND CLINICAL RELEVANCE Accurate microbiologic assessment of the tympanic cavity should be the basis for selection of antimicrobials in dogs undergoing TECA with LBO. Bacteria remain in the tympanic cavity after evacuation and lavage. Cefazolin was a poor choice for dogs that underwent TECA with LBO, as judged on the basis of culture and susceptibility testing results.

Vaginal cytokines do not correlate with postmenopausal vulvovaginal symptoms.

OBJECTIVES Exploratory pilot study to determine the correlation between postmenopausal vulvovaginal symptoms and vaginal cytokine levels. METHODS Postmenopausal women (n = 34) not using menopausal hormone therapy and presenting with or without symptoms of vulvovaginal irritation were screened. Each participant underwent a vaginal examination and screening for vaginitis. A cervicovaginal lavage (CVL) with sterile saline and a peripheral blood sample were obtained. Main outcome measures were assessed by Luminex® X-map method on the Bio-Plex® platform. Main outcome measures were cervicovaginal and serum interleukin (IL)-4, IL-5, IL-10, IL-12, IL-13, TNF-α, GM-CSF, MIP-1-alpha and RANTES level. Cervicovaginal cytokines were adjusted to total protein concentration [pg/mcg protein]. RESULTS Twenty-six postmenopausal women were enrolled (symptomatic: n = 15; asymptomatic: n = 11). There were no significant differences between groups: age, age at menopause, vaginal pH and all CVL and serum cytokines (IL-4, IL-5, IL-10, IL-12, IL-13, TNF-α, GM-CSF, MIP-1-alpha and RANTES). GM-CSF was the most abundant vaginal cytokine (symptomatic: 146.5 ± 165.6 pg/mcg protein; asymptomatic: 146.0 ± 173.5 pg/mcg protein; p = 0.99). CONCLUSIONS Postmenopausal vulvovaginal symptoms did not correlate with vaginal inflammatory marker. There was no difference in serum or CVL cytokines between symptomatic and asymptomatic postmenopasual women. Vaginal symptoms after menopause are not related to the vaginal cytokine changes associated with loss of estrogen.

Vitamin D represses rhinovirus replication in cystic fibrosis cells by inducing LL-37.

Vitamin D has immunomodulatory properties in the defence against pathogens. Its insufficiency is a widespread feature of cystic fibrosis (CF) patients, which are repeatedly suffering from rhinovirus (RV)-induced pulmonary exacerbations.To investigate whether vitamin D has antiviral activity, primary bronchial epithelial cells from CF children were pre-treated with vitamin D and infected with RV16. Antiviral and anti-inflammatory activity of vitamin D was assessed. RV and LL-37 levels were measured in bronchoalveolar lavage (BAL) of CF children infected with RV.Vitamin D reduced RV16 load in a dose-dependent manner in CF cells (10(-7 )M, p<0.01). The antiviral response mediated by interferons remained unchanged by vitamin D in CF cells. Vitamin D did not exert anti-inflammatory properties in RV-infected CF cells. Vitamin D increased the expression of the antimicrobial peptide LL-37 up to 17.4-fold (p<0.05). Addition of exogenous LL-37 decreased viral replication by 4.4-fold in CF cells (p<0.05). An inverse correlation between viral load and LL-37 levels in CF BAL (r=-0.48, p<0.05) was observed.RV replication in primary CF bronchial cells was reduced by vitamin D through the induction of LL-37. Clinical studies are needed to determine the importance of an adequate control of vitamin D for prevention of virus-induced pulmonary CF exacerbations.

Characterization of Staphylococcus aureus adhesins important for respiratory tract infection

Staphylococcus aureus is a leading cause of lower respiratory tract infections in both adult and pediatric populations. In the past two decades, reports have described emergent incidence of severe necrotizing pneumonia in previously healthy individuals, frequently caused by antibiotic resistant strains. Additionally, S. aureus remains the most common cause of ventilator-associated pneumonia, contributing morbidity and mortality in intensive care units. As treatment of infection is made more difficult by the resistance to multiple antibiotics including vancomycin, there is a pressing need for novel strategies to prevent and treat S. aureus infections. Targeting essential mechanisms that promote infection such as adhesion, colonization, invasion, evasion of immune system and signaling may lead to inhibition of pathogenic surge. Staphylococcal adhesins of the MSCRAMM family (microbial surface components recognizing adherent matrix molecules) represent viable targets for such investigations. Understanding the molecular mechanism of binding is the first step toward the development of such therapies. Analysis of bacterial strains isolated from patients with staphylococcal pneumonia show increased expression of protein A, SdrD, SdrC and ClfB, cell surface proteins members of the MSCRAMM family. In this study the interaction of these MSCRAMMs with candidate ligands has been examined. We found that SdrD mediates S. aureus adherence to the lung epithelial cell line A549. Consistently, bacteria expressing SdrD have increased persistence in the lungs of infected mice after bronchoalveolar lavage in comparison with bacteria lacking this protein. Inhibition studies revealed that bacterial attachment can be abolished using neutralizing antibodies against SdrD. Using phage display, neurexin β isoforms were identified as SdrC binding partners. Previous reports postulated that MSCRAMMS bind their ligands by a 'dock, lock and latch' mechanism of interaction. Our data suggested that ClfB, an MSCRAMM responsible for nasal colonization, binds cytokeratin 10 by a 'dock and lock' variant of this model, in which the 'latching' event is not necessary. In summary, we have characterized aspects of molecular interaction between several MSCRAMMS and host components. We hope that continued delineation of these interactions will lead to identification of novel therapeutic targets or preventive strategies against S. aureus infections. ^

Production of β-defensins by human airway epithelia

Human β-defensins (HBDs) are antimicrobial peptides that may play a role in mucosal defense. Diminished activity of these peptides has been implicated in the pathogenesis of cystic fibrosis (CF) lung disease. We show that HBD-1 and HBD-2 mRNAs are expressed in excised surface and submucosal gland epithelia from non-CF and CF patients. The pro-inflammatory cytokine interleukin-1β stimulated the expression of HBD-2 but not HBD-1 mRNA and peptide in primary cultures of airway epithelia. HBD-1 was found in bronchoalveolar lavage (BAL) fluid from normal volunteers, CF patients, and patients with inflammatory lung diseases, whereas HBD-2 was detected in BAL fluid from patients with CF or inflammatory lung diseases, but not in normal volunteers. Both HBD-1 and HBD-2 were found in BAL fluid in concentrations of several ng/ml, and both recombinant peptides showed salt-sensitive bactericidal activity. These data suggest that in the lung HBD-2 expression is induced by inflammation, whereas HBD-1 may serve as a defense in the absence of inflammation.

Altered stability of pulmonary surfactant in SP-C-deficient mice

The surfactant protein C (SP-C) gene encodes an extremely hydrophobic, 4-kDa peptide produced by alveolar epithelial cells in the lung. To discern the role of SP-C in lung function, SP-C-deficient (−/−) mice were produced. The SP-C (−/−) mice were viable at birth and grew normally to adulthood without apparent pulmonary abnormalities. SP-C mRNA was not detected in the lungs of SP-C (−/−) mice, nor was mature SP-C protein detected by Western blot of alveolar lavage from SP-C (−/−) mice. The levels of the other surfactant proteins (A, B, D) in alveolar lavage were comparable to those in wild-type mice. Surfactant pool sizes, surfactant synthesis, and lung morphology were similar in SP-C (−/−) and SP-C (+/+) mice. Lamellar bodies were present in SP-C (−/−) type II cells, and tubular myelin was present in the alveolar lumen. Lung mechanics studies demonstrated abnormalities in lung hysteresivity (a term used to reflect the mechanical coupling between energy dissipative forces and tissue-elastic properties) at low, positive-end, expiratory pressures. The stability of captive bubbles with surfactant from the SP-C (−/−) mice was decreased significantly, indicating that SP-C plays a role in the stabilization of surfactant at low lung volumes, a condition that may accompany respiratory distress syndrome in infants and adults.

Phenotypic and physiologic characterization of transgenic mice expressing interleukin 4 in the lung: lymphocytic and eosinophilic inflammation without airway hyperreactivity.

To investigate the contribution of interleukin-4 (IL-4) to airway inflammation in vivo and to explore directly its relationship to airway reactivity, we created transgenic mice in which the murine cDNA for IL-4 was regulated by the rat Clara cell 10 protein promoter. Expression was detected only in the lung and not in thymus, heart, liver, spleen, kidney, or uterus. The expression of IL-4 elicited hypertrophy of epithelial cells of the trachea, bronchi, and bronchioles. Hypertrophy is due, at least in part, to the accumulation of mucus glycoprotein. Histologic examination of parenchyma revealed multinucleated macrophages and occasional islands of cells consisting largely of eosinophils or lymphocytes. Analysis of lung lavage fluid revealed the presence of a leukocytic infiltrate consisting of lymphocytes, neutrophils and eosinophils. Mice expressing IL-4 had greater baseline airway resistance but did not demonstrate hyperreactivity to methacholine. Thus, the expression of IL-4 selectively within the lung elicits an inflammatory response characterized by epithelial cell hypertrophy, and the accumulation of macrophages, lymphocytes, eosinophils, and neutrophils without resulting in an alteration in airway reactivity to inhaled methacholine.

Induction of mucosal immune responses against a heterologous antigen fused to filamentous hemagglutinin after intranasal immunization with recombinant Bordetella pertussis.

Live vaccine vectors are usually very effective and generally elicit immune responses of higher magnitude and longer duration than nonliving vectors. Consequently, much attention has been turned to the engineering of oral pathogens for the delivery of foreign antigens to the gut-associated lymphoid tissues. However, no bacterial vector has yet been designed to specifically take advantage of the nasal route of mucosal vaccination. Herein we describe a genetic system for the expression of heterologous antigens fused to the filamentous hemagglutinin (FHA) in Bordetella pertussis. The Schistosoma mansoni glutathione S-transferase (Sm28GST) fused to FHA was detected at the cell surface and in the culture supernatants of recombinant B. pertussis. The mouse colonization capacity and autoagglutination of the recombinant microorganism were indistinguishable from those of the wild-type strain. In addition, and in contrast to the wild-type strain, a single intranasal administration of the recombinant strain induced both IgA and IgG antibodies against Sm28GST and against FHA in the bronchoalveolar lavage fluids. No anti-Sm28GST antibodies were detected in the serum, strongly suggesting that the observed immune response was of mucosal origin. This demonstrates, to our knowledge, for the first time that recombinant respiratory pathogens can induce mucosal immune responses against heterologous antigens, and this may constitute a first step toward the development of combined live vaccines administrable via the respiratory route.