Lower Respiratory Tract (lower + respiratory_tract)

Distribution by Scientific Domains
Distribution within Medical Sciences

Terms modified by Lower Respiratory Tract

  • lower respiratory tract disease
  • lower respiratory tract infection
  • lower respiratory tract infections

  • Selected Abstracts

    Bilateral periventricular nodular heterotopia and lissencephaly in an infant with unbalanced t(12;17)(q24.31; p13.3) translocation

    Salvatore Grosso MD PhD
    Periventricular nodular heterotopia and Miller-Dieker syndrome are two different disorders of brain development. Miller-Dieker syndrome exhibits classical lissencephaly and is related to defects in the lissencephaly gene (LIS1). Periventricular nodular heterotopia is characterized by aggregates of grey matter adjacent to the lateral ventricle and is mainly linked to mutations in the Filamin A (FLNA) gene. We describe a male infant presenting with facial dysmorphisms resembling those of Miller-Dieker syndrome, neuromotor delay, and drug - resistant infantile spasms. Magnetic resonance imaging of the brain showed periventricular nodular heterotopia overlaid by classical lissencephaly with complete agyria. Cytogenetic and molecular investigations detected a maternally inherited unbalanced translocation involving chromosome arms 17p and 12q. This resulted in partial monosomy of 17p13.3,pter and partial trisomy of 12q24.3,qter No mutation was found in the FLNA gene. The patient died at the age of 22 months from respiratory insufficiency during an infection of the lower respiratory tract. Our observation extends the list of the overlying cortical malformations associated with periventricular nodular heterotopia. It remains to be established whether this peculiar neuronal migration disorder represents a phenotype totally linked to 17q13.3 deletion or results from a combination of gene defects at 17q13.3 and 12q24.3. [source]

    Simultaneous cytological diagnosis of herpes simplex virus infection and primary lung cancer: Report of two cases

    Nicoletta Maounis M.D., Ph.D.
    Abstract Herpes simplex is an uncommon cause of lower respiratory tract infection that requires prompt diagnosis and treatment to prevent late complications. We report two cases with simultaneous herpes simplex virus infection of the lower respiratory tract and lung carcinoma. Cytology of bronchial brushing and washing fluids and postbronchoscopic sputum established the diagnosis, which was further corroborated by real-time polymerase chain reaction. Diagn. Cytopathol. 2008;36:818,822. © 2008 Wiley-Liss, Inc. [source]

    Antibody-mediated bacterial clearance from the lower respiratory tract of mice requires complement component C3

    Abstract To assess the contribution of complement to respiratory immunity in the context of a natural bacterial infection, we used mice genetically deficient in complement components and the murine pathogen Bordetella bronchiseptica. Complement component C3 was not required for the control of bacterial infection or for the generation of infection-induced protective immunity. However, C3-deficient (C3,/,) mice were severely defective, compared to wild type, in vaccine-induced protective immunity. Adoptively transferred immune serum from convalescent wild-type or C3,/, animals rapidly cleared B.,bronchiseptica from the lungs of wild-type mice but did not affect its growth in C3,/, mice, indicating that the defect is not in the generation of protective immunity, but in its function. Immune serum was effective in C5-deficient mice but had little effect in the lungs of mice lacking either Fc, receptors (Fc,R) or CR3, suggesting bacterial clearance is not via direct complement-mediated lysis. Together, these data indicate that complement is required for antibody-mediated clearance of Bordetella and suggest the mechanism involves C3 opsonization of bacteria for phagocytosis that is both CR3- and Fc,R-dependent. [source]

    Prevention of respiratory infections in the elderly

    Mutsuo Yamaya
    The risk of nosocomial infections is 3,5-fold higher among older patients than among younger adults. Both the increased incidence of respiratory infections and the high mortality among older people are a consequence of a number of age-related factors, including coexisting illnesses, therapeutic interventions, and the aging process itself. Risk factors for the development of respiratory infections in older people can be broadly classified into factors that alter host defenses and factors that increase exposure to bacteria. These factors combine to adversely affect the person's capacity to defend against pathogens of the upper and lower respiratory tract. Despite the availability of potent new antimicrobials, the increasingly limited treatment efficacy of these antimicrobials is related to emerging microbial resistance. Recently, new methods of treating respiratory infections according to the mechanisms of infection have been introduced. Effective methods of preventing respiratory infections in older people were reviewed. [source]

    Effect of an Educational Intervention on Optimizing Antibiotic Prescribing in Long-Term Care Facilities

    (See Editorial Comments by Dr. Lona Mody on pp 130, 1302)
    OBJECTIVE: To assess the effect of an educational intervention aimed at optimizing antibiotic prescribing in long-term care (LTC) facilities. DESIGN: Cluster randomized, controlled trial. SETTING: Eight public LTC facilities in the Montreal area. PARTICIPANTS: Thirty-six physicians. INTERVENTION: The educational intervention consisted of mailing an antibiotic guide to physicians along with their antibiotic prescribing profile covering the previous 3 months. Targeted infections were urinary tract, lower respiratory tract, skin and soft tissues, and septicemia of unknown origin. In the prescribing profile, each antibiotic was classified as adherent or nonadherent to the guide. Physicians in the experimental group received the intervention twice, 4 months apart, whereas physicians in the control group provided usual care. MEASUREMENTS: Data on antibiotic prescriptions were collected over four 3-month periods: preintervention, postintervention I, postintervention II, and follow-up. A generalized estimating equation (GEE) model was used to compare the proportion of nonadherent antibiotic prescriptions of the experimental and control groups. RESULTS: By the end of the study, nonadherent antibiotic prescriptions decreased by 20.5% in the experimental group, compared with 5.1% in the control group. Based on the GEE model, during postintervention II, physicians in the experimental group were 64% less likely to prescribe nonadherent antibiotics than those in the control group (odds ratio=0.36, 95% confidence interval=0.18,0.73). CONCLUSION: An educational intervention combining an antibiotic guide and a prescribing profile was effective in decreasing nonadherent antibiotic prescriptions. Repetition of the intervention at regular intervals may be necessary to maintain its effectiveness. [source]

    Smoke Exposure Exacerbates an Ethanol-Induced Defect in Mucociliary Clearance of Streptococcus pneumoniae

    ALCOHOLISM, Issue 5 2005
    Elizabeth A. Vander Top
    Background: Alcoholics and smokers are particularly susceptible to pulmonary infections caused by Streptococcus pneumoniae, the pneumococcus. Infection begins when pneumococci colonizing the nasopharynx are aspirated into the lower respiratory tract. The major host defense against this movement is the mucociliary clearance apparatus. Both cigarette smoke and ethanol (EtOH) exposure alter ciliary beating and protein kinase activity in the respiratory mucosa in vitro, but their effects on bacterial clearance in the intact animal have not been determined. Methods: Male Sprague Dawley rats were exposed twice daily for 12 weeks to either the smoke generated from 30 cigarettes (smoke,exposed) or room air (sham,exposed). For the last five weeks of smoke exposure, the rats were fed Lieber-DeCarli liquid diets containing 0%, 16%, 26%, or 36% EtOH calories. The rats then were infected intranasally with S. pneumoniae, and movement of the organisms into the lower respiratory tract was quantified by plate counts of the tracheas and lungs 4 hr later. Ciliary beat frequency (CBF) analysis was performed on tracheal ring explants from each animal before and after stimulation with the ,-agonist isoproterenol, and tracheal epithelial cell protein kinase C (PKC) activity was measured. Results: Ingestion of any of the EtOH-containing diets resulted in a dose-dependent increase in movement of S. pneumoniae into the rats' lungs. This EtOH-induced defect was augmented further by concurrent smoke exposure, although smoke exposure alone had little effect on S. pneumoniae movement. Smoke, but not EtOH exposure, activated tracheal epithelial cell PKC. Increased movement of organisms into lungs correlated with a decrease in CBF and loss of the ciliary response to isoproterenol. Conclusion: EtOH ingestion in our model facilitated movement of S. pneumoniae into rats' lungs, a phenomenon exacerbated by concurrent smoke exposure. Furthermore, the organism's movement into the lungs correlated with a blunting of the rats' ciliary response to an established stimulus. Defects in mucociliary clearance thus may be one cause of the increased risk of pneumococcal infections in people who abuse alcohol, particularly if they also smoke. [source]

    Presence of cystic fibrosis-related diabetes mellitus is tightly linked to poor lung function in patients with cystic fibrosis: Data from the European Epidemiologic Registry of Cystic Fibrosis

    C. Koch MD
    Abstract Data derived from a cross-sectional analysis of 7,566 patients stratified into six age groups were used to compare lung function, body mass index (BMI), and weight for age in patients with and without cystic fibrosis-related diabetes mellitus (CFDM). The presence of CFDM was tightly linked to poor lung function, regardless of age. The mean value of FEV1 % predicted in the age groups,<,10, 10,<,15, 15,<,20, 20,<,25, 25,<,30, and 30 years or older were 87%, 77%, 69%, 58%, 55%, and 53% in the nondiabetic cystic fibrosis (CF) patients as compared to 79%, 66%, 55%, 49%, 46%, and 44% in the diabetic CF patients. BMI and weight for age were also lower in diabetic than nondiabetic CF patients in all age groups, except for BMI in the youngest patients. The difference in lung function and in nutritional parameters between diabetic and nondiabetic CF patients was not linked to presence or absence of any specific pathogen in the lower respiratory tract. These results confirm and extend those of earlier studies in smaller numbers of patients, and they clearly identify CFDM as a powerful determinant of severe lung disease and reduced survival in patients with CF and diabetis mellitus. Pediatr Pulmonol. 2001; 32:343,350. © 2001 Wiley-Liss, Inc. [source]

    Macroscopic Anatomy of the Ringed Seal [Pusa (Phoca) hispida] Lower Respiratory System

    H. Smodlaka
    Summary This investigation serves to document the normal anatomical features of the lower respiratory tract of the ringed seal [Pusa (phoca) hispida]. Evaluation of embalmed specimens and tracheobronchial casts showed that the right lung of this seal consists of four lobes while the left has only three lobes. The ventral margins of the lungs do not reach the sternum causing them to form the boundary of the broad recessus costomediastinalis. Lung lobation corresponds with bronchial tree division. Pulmonary venous drainage includes right and left common veins draining ipsilateral cranial and middle lung lobes, and one common caudal vein draining both caudal lobes and the accessory lobe. The right and left pulmonary arteries divide into cranial and caudal branches at the level of the principal bronchus. The ringed seal has three tracheobronchial lymph nodes. The trachea has an average of 87 cartilages that exhibit a pattern of random anastomoses between adjacent rings. The trachea exhibits to a small degree the dorsoventrally flattened pattern that is described in other pinnipeds. The tracheal diameter is smaller than that of the canine. [source]

    A single nasal allergen challenge increases induced sputum inflammatory markers in non-asthmatic subjects with seasonal allergic rhinitis: correlation with plasma interleukin-5

    K. M. Beeh
    Summary Background Seasonal allergic rhinitis (SAR) is a risk factor for asthma in affected individuals. Nasal allergic inflammation enhances bone-marrow eosinophil production, mainly via IL-5, and rhinitis patients have increased airway inflammation during the pollen season. Objective To assess the impact of nasal allergy on sputum inflammatory markers. Methods In an open-labelled, randomized, placebo-controlled cross-over study with 16 non-asthmatic SAR patients (median age 25 years, 56% males), the effect of a single nasal allergen challenge performed out of season on induced sputum inflammatory parameters was evaluated. SAR patients were identified by history, skin-prick test and specific IgE. All patients had normal lung function/bronchial hyper-responsiveness out of season and a negative asthma/wheezing history. Sputum cells and supernatant levels of ECP, sICAM, IL-5 and IL-10, and plasma levels of IL-5 and ECP, were measured before and 24 h after nasal allergen challenge. After a washout period of at least 4 weeks, the procedure was repeated with placebo challenge (diluent). Results Nasal allergen challenge led to an increase in sputum ECP (pre = 60 ± 12, post = 212 ± 63 µg/L, P = 0.02 vs. placebo), and sICAM (4.8 ± 2.7 to 6.5 ± 2.9 ng/mL, P = 0.02 vs. placebo), whereas IL-10 decreased after provocation (44 ± 11 to 29 ± 6 pg/mL, P = 0.06 vs. placebo). Sputum IL-5 was undetectable in all patients. The absolute number of blood and sputum eosinophils did not change significantly after allergen or placebo challenge (P > 0.07, both comparisons). Plasma levels of IL-5 increased after allergen challenge (8.7 ± 2.9 to 14.5 ± 3.9 pg/mL, P = 0.001), and the increase in plasma IL-5 was positively correlated with the rise in sputum ECP in a subgroup of ,responders' (n = 12, r = 0.71, P = 0.01). Conclusions A single nasal allergen challenge in SAR patients increased markers of allergic inflammation in the lower respiratory tract, possibly via pronounced activation of inflammatory cells through circulating immediate-type reaction cytokines like IL-5. These findings may provide additional explanatory data for the high susceptibility of SAR patients to incident asthma. [source]

    Cysteinyl leukotrienes as common mediators of asthma and allergic disease

    S-E. Dahlén
    Summary The cysteinyl leukotrienes (CysLTs) induce a number of pro-inflammatory effects including smooth muscle contraction, an increase in blood flow, plasma exudation, mucous secretion, and activation of inflammatory cells. They play a key role in asthma and allergy, and can be recovered from different body fluids (e.g. bronchoaleveolar or nasal lavage and urine) during allergen-induced hypersensitivity reactions. The advent of antileukotriene agents (i.e. leukotriene receptor antagonists or leukotriene synthesis inhibitors) has helped clarify how the different mechanisms contribute to inflammation, as well as offer new treatment options for both asthma and allergy. It is now clear that the release of leukotrienes is the final common path for the many different factors causing airway obstruction and inflammation. In asthma, clinical studies have shown that treatment with antileukotrienes can improve pulmonary function, alleviate symptoms, reduce asthma exacerbations, and decrease the need for bronchodilator therapy. Similarly, in patients with allergic rhinitis, improvements have been seen in nasal symptoms, eye symptoms and quality of life. Antileukotrienes provide a new opportunity for simultaneous management of allergic diseases of the upper and lower respiratory tract, and are a rational treatment approach to the concept of ,one airway' disease. In future, their utility may also extend to inflammatory disorders of other organ systems (e.g. skin). [source]

    Comment on: nitric oxide evaluation in upper and lower respiratory tracts in nasal polyposis.

    Delclaux C, et al
    No abstract is available for this article. [source]

    Nitric oxide evaluation in upper and lower respiratory tracts in nasal polyposis

    C. Delclaux
    Summary Background A decrease in nasal nitric oxide (NO) and an increase in exhaled NO have been demonstrated in patients with nasal polyposis (NP). Objectives The aims were to evaluate the flux of NO from the three compartments of the respiratory tract, namely, upper nasal, lower conducting and distal airways, and to search for relationships between NO parameters and indexes of upper and lower disease activity (bronchial reactivity and obstruction). The effect of medical treatment of polyposis was also evaluated. Methods Seventy patients with polyposis were recruited. At baseline, pulmonary function tests (spirometry, plethysmography, bronchomotor response to deep inspiration using forced oscillation measurement of resistance of respiratory system, methacholine challenge, multiple flow rates of exhaled NO and nasal NO measurements) were performed together with an assessment of polyposis [clinical, endoscopic and computed tomography (CT) scores]. Results Statistical relationships were demonstrated between nasal NO flux and severity scores (clinical: ,=,0.31, P=0.015; endoscopic: ,=,0.57, P<0.0001; CT: ,=,0.46, P=0.0005), and between alveolar NO concentration and distal airflow limitation (FEF25,75, ,=,0.32, P=0.011). Thirty-six patients were assessed after 11 [7,13] (median [interquartile]) months of medical treatment, demonstrating an improvement in clinical and endoscopic scores, an increase in nasal NO flux, a decrease in NO flux from conducting airways, an improvement in the mild airflow limitation (forced expiratory volume in 1 s, FEF25,75, even in non-asthmatic patients) and a decrease in the bronchoconstrictor effect of deep inspiration. Conclusions The medical treatment of NP improves both airway reactivity and obstruction, whatever the presence of asthma, suggesting a functional link between upper and lower airway functions. [source]