摘要:

Infant whole-body plethysmography offers a unique possibility of measuring end-expiratory resting level (thoracic gas volume; TGV), and hence lung volume in its close interrelationship to airway function (airway resistance; Raw, its reciprocal value, airway conductance, Gaw). Therefore, this technique is a valuable aid for objective evaluation of lung diseases in infants. This article gives an overview of the physiological background of this particular measuring technique and its usefulness in the clinical routine. Plethysmographic data obtained in infant survivors of the infant respiratory distress syndrome (iRDS), in infants with cystic fibrosis (CF) and in the so-called ‘wheezy infants’ are presented. Special emphasis is given to the fact that in such infants the interrelationship between changes in end-expiratory resting level and the deficit in airway mechanics is of great importance and, consequently, for the determination of functional lung derangement in each particular case of lung disease, both TGV and the closely related Raw and Gaw have to be evaluated. This recommendation has to be kept in mind when the different diagnostic tools for evaluation of treatment facilities are applied in this particular young age group of patients with lung disease. In children as in adult patients, inhalative treatment must be considered the mainstay of all therapeutic measures. However, in infants, the efficacy of such treatment regimens must first be evaluated by adequate functional investigations. Infant whole-body plethysmography offers one such possibil

ISSN:0025-7931    

DOI:10.1159/000196165

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Respiratory tract infections (RTIs) are among the most frequent infections in man and lower tract infections account substantially for the overall mortality in hospitals. Regarding the etiology of pneumonias, one has to consider different pathogenic mechanisms, age of the patients, underlying diseases, concomitant medications, symptomatologies, seasonal influences, and clinical conditions, e.g. intensive care environment and mechanical ventilation. To optimize the rational management of respiratory infections, identification of the etiologic agent would be desirable. The decision of how to treat is often based on epidemiologic, clinical, and radiological assessments. Epidemiologic studies have shown a pronounced difference in the etiologic spectrum between community- and hospital-acquired RTIs. In community-acquired pneumonias, pneumococci, Haemophilus influenzae, Legionella, Mycoplasma and viruses predominate, whereas in nosocomially acquired pneumonias, Enterobacteriaceae, e.g. Klebsiella, Proteus, Enterobacter as well as Pseudomonas and staphylococci comprise the most frequent isolates. Empirical therapy has to cover all possible etiologic pathogens which most likely cause the infection. In addition, an adequate kinetic profile, e.g. once or twice daily dosing, sufficient pulmonary tissue or fluid penetration, and acceptable tolerance and costs are prerequisites for optimal therapy. Drugs of choice for the treatment of community-acquired pneumonia are aminobenzylpenicillins or macrolides. Oral cephalosporins exhibit excellent activity against many bacterial pathogens of typical community-acquired pneumonia, and are active against β-lactamase-producing H. influenzae

ISSN:0025-7931    

DOI:10.1159/000196242

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The past and present clinical history of 13 patients with hemodynamic and angiographic diagnosis of chronic thromboembolic pulmonary hypertension (CTPH) was reviewed in order to investigate the reasons for failure of resolution of acute pulmonary embolism (PE) and findings useful for diagnosis of CTPH. All patients had chest radiograph, ECG, arterial blood gas analysis and pulmonary perfusion scintigraphy performed. Clinical assessment demonstrated that no patient had diagnosis and treatment of the several retrospectively identified episodes of PE (from 1 to 8); the lack of diagnosis was due to underestimation of symptoms and signs such as dyspnea (85%), pleuritic chest pain (31%) or phlebitis (46%) that were present months or years earlier. Alternative diagnoses erroneously made were dyspnea of unknown origin (5 cases), left heart failure (4 instances) and pneumonia (2 cases). Once CTPH has developed, chronic dyspnea (92%) and substernal chest pain (100%) are almost always present: chest radiograph and ECG show signs of chronic hypertension such as enlargement of hila (100%), right heart sections (77%), azygos vein (46%) and P pulmonale (67%), T inversion on right precordial leads (75%), S-T segment depression (75%), respectively. Perfusion scintigraphy shows severe perfusion impairment (55.7% of the total vascular bed) paralleled by severe hypoxia (standard PaO2 = 49 ± 14.1 mm Hg). In conclusion, patients with PE who develop CTPH are not diagnosed and thus untreated because clinical symptoms and signs of acute PE have not been recognized. If CTPH develops, clinical assessment (including simple and noninvasive techniques such as chest radiograph, ECG and blood gas analysis) may show a quite characteristic pattern useful for diagnosis

ISSN:0025-7931    

DOI:10.1159/000196166

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

In respiratory tract infections Streptococcus pneumoniae, Moraxella catarrhalis, Haemophilus influenzae and Klebsiella spp. are the most frequently encountered bacterial pathogens. Resistance of clinical S. pneumoniae isolates is known to be independent of β-lactamase production, whereas resistance of the other species mentioned is due to β-lactamase production. With respect to M. catarrhalis the first β-lactamase-producing (bla+) isolate was detected in clinical specimens in 1976 and now, 70-90% of all clinical isolates are bla+. The enzymes BRO-1 and BRO-2 are transposon-mediated thus explaining their rapid spread; they hydrolyze penicillin compounds very rapidly and, to a lesser extent, the older cephalosporins. Resistance in clinical H.influenzae isolates is mainly due to the prevalence of the most widespread transposon-mediated β-lactamase, TEM-1, which has a substrate profile resembling that of the BRO enzymes. Bla+ H. influenzae isolates make up to 6% of the total in Northern Europe, in Southern Europe up to 55% and in many African countries more than 80%. More than 95% of Klebsiella spp. isolates possess a chromosomally encoded penicillinase and to a varying extent a plasmid-mediated enzyme in addition. Recently, reports from several countries have pointed to the clinical relevance of ‘extended-spectrum enzymes’ derived by point mutation from the ‘classical’ TEM-1 or TEM-2 enzymes. These new enzymes (TEM-3 to TEM-21) exhibit a broadened substrate profile, inactivating even the oxyiminocephalosporins. The most stable compounds are ceftibuten and cefetamet. With respect to the future, these enzymes may spread between species due to their location on transposons. Selection of such strains can be reduced by the use of agents fairly stable to th

ISSN:0025-7931    

DOI:10.1159/000196244

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

This study includes 61 patients referred with pulmonary embolism (PE) during 1 year. At admission, blood gas analysis, chest radiography and pulmonary lung scan were obtained in each patient; in a subset of patients pulmonary angiography was also performed to make the definitive diagnosis. Patients were treated with heparin and, later, with oral anticoagulants. Blood gas analysis, chest radiograph and perfusion lung scan were repeated 7,30,180 and 365 days after the diagnosis to evaluate the usefulness of these techniques in the follow-up of PE. Arterial hypoxemia and perfusion impairment recovered in parallel, both in the acute phase after embolism (7 days) and later up to 1 year. The great majority of recovery occurred within the first month after embolization. Radiographic signs compatible with PE tended to decrease early and disappeared almost completely after 30 days. Arterial blood gas analysis and perfusion scintigraphy detected 8 recurrences of PE that would be missed by chest radiograph. Arterial hypoxemia and the enlargement of descending pulmonary artery were positively correlated with the number of unperfused lung segments and, thus, may help predicting the severity of perfusion impairment in the acute stage. In conclusion, blood gas analysis and chest radiograph may be employed with or without perfusion lung scan to follow patients with PE up to 1 month after embolization; after that, only blood gas analysis and perfusion lung scan may give useful information about recovery from or recurrence of PE.

ISSN:0025-7931    

DOI:10.1159/000196167

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Infection is regarded as an imbalance between microbial pathogenicity factors and the host defense system. The virulence mechanisms include adhesion, chemotaxis, invasion, resistance and production of toxins. In addition, local and/or systemic immune functions in patients undergoing infections are altered. Nonspecific as well as specific cellular and humoral defense mechanisms are affected. The interaction of defined microbial pathogenicity factors with immune effector cells results in the activation of a variety of inflammatory mediators; they are a prerequisite for protective immunity but also induce local or systemic damage in the host when they occur in excessive amounts and when their metabolism is inadequately controlled. The analysis of the pathophysiological events during infection in patients by taking advantage of modern molecular and cell-biological methods may contribute to the development of novel therapeutic strategies.

ISSN:0025-7931    

DOI:10.1159/000196245

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The effects of nedocromil sodium and placebo on the asthmatic response to antigen bronchial provocation were studied in a double-blind, randomized, crossover trial. Twelve subjects sensitized to Dermatophagoides pteronyssinus were challenged with successive doubling doses of this allergen (1.25-80×10-3 mg) on two separate occasions, at least 15 days apart. A single dose of either nedocromil sodium 4 mg, or, a matching placebo was given 30 min before challenge. Forced expiratory volume in 1 s (FEV1) was measured 5,10 and 15 min after challenge. Early asthmatic response was analyzed using three indices: dose producing a 20% decrease in FEV1 (PD20), the slope of and area under the dose-response curve. Nedocromil sodium was significantly superior to placebo with respect to all three indices, providing significant inhibition of the early asthmatic responses. Seven of the 12 patients showed a late asthmatic response. There was no significant difference between the effects of nedocromil sodium and placebo treatments on the decline in peak expiratory flow rate (PEFR) during the late asthmatic response but it should be noted that when patients had been treated with nedocromil sodium they were receiving two to eight times the dose of allergen given after placebo treatment

ISSN:0025-7931    

DOI:10.1159/000196168

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The oral cephalosporins cefaclor, cefetamet, Ro 40-6890 and cefpodoxime were studied with regard to their effects to modulate the chemiluminescence response, the rate of phagocytosis, bactericidal action and leukotriene formation from human granulocytes, the release of histamine from human basophils and the induction and release of tumor necrosis factor (TNF) and interleukin-6 (IL-6) from a preparation of human lymphocytes, monocytes and basophils. The cephalosporins increased the histamine release induced by Escherichia coli and Staphylococcus aureus whereas the synthesis of leukotrienes from human neutrophils was decreased. The studies with regard to adherence and phagocytosis showed a significant increase in phagocytosis for E. coli. The bactericidal activity of human granulocytes was also enhanced. Furthermore, the studied cephalosporins decreased the release of IL-6 and TNF.

ISSN:0025-7931    

DOI:10.1159/000196246

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

We compared the inhibitory effects of calcium channel blockers, gallopamil and verapamil on acetylcholine (Ach)-induced contractions of ovine tracheal muscle in vitro. Adult sheep were sacrificed and tracheal strips were obtained by cutting the single tracheal rings from the mid-trachea. Tracheal strips were suspended in Krebs-Henseleit solution and isometric tension measured upon stimulation with cumulative doses of Ach (10-7to 10-6 M) without and after pre-treatment with gallopamil (10-7 to 10-6M) or verapamil (10-6 to 10-6M). In untreated tissues, the mean concentration of Ach required to produce 50% of maximal response (EC50) was 4.3 × 10-6 M Ach. Both gallopamil and verapamil inhibited the Ach-induced contractions of ovine tracheal smooth muscle, by shifting the dose-response curves to Ach to the right. EC50 Ach for gallopamil (10-6M) and verapamil (10-6M) was 2.6 × 10-5 and 5.2 × 10-6M, respectively. Dose ratio defined as postantagonist EC50 Ach/control EC50 Ach, was 7.7 for gallopamil and 2.0 for verapamil. Thus, the inhibitory effect of gallopamil was approximately 4-fold more potent than that of verapamil. Gallopamil was 17-fold more potent than verapamil in relaxing precontracted tracheal strips. The dose of calcium antagonists required to produce 25% relaxation (EC25) of tracheal strips precontracted with 10-4 Ach was 3.7 × 10-5 M for verapamil and 2.2 × 10-6M for gallopamil. These results indicate that gallopamil is effective against Ach-induced contractions of ovine trachealis muscles, and is more potent than verap

ISSN:0025-7931    

DOI:10.1159/000196169

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Supernatants, obtained from normal neutrophil polymorphonuclear leukocytes (PMN), challenged with opsonized zymosan (OPZ), were found to inactivate the PMN elastase inhibitor, α1-proteinase inhibitor (A1PI). As the supernatants were treated with methionine to quench residual oxidants, primarily chloramines, the observed inactivation of A1PI appears to be due to enzymes. The activity of the supernatants was in fact inhibited by metalchelators and by the tissue inhibitor of metalloproteinases (TIMP), which is consistent with the intervention of metalloproteinases. Supernatants from normal PMN triggered by OPZ in the presence of inhibitors of the myeloperoxidase (MPO) system as well as supernatants from MPO-deficient PMN were inactive but displayed the capacity of inactivating A1PI after treatment with the metalloproteinases activator 4-aminophenylmercuric acetate. These data suggest that the A1PI inactivation is due to metalloenzymes released by PMN as latent molecules, in turn activated by the MPO system. The MPO-dependent autoactivation of latent metalloenzymes by PMN, with consequent A1PI inactivation, was inhibited by the nonsteroidal anti-inflammatory drug nimesulide (NMS). As PMN-derived HOCl is well known to inactivate A1PI directly, through a process previously shown to be inhibitable by NMS, the present results suggest: (1) both the oxidative and proteolytic inactivation of A1PI depend on the HOCl-generating MPO system; (2) the tissue-destructive activity of PMN elastase could be controlled by interfering pharmacologically with the PMN-MPO system, directly and indirectly responsible for the breakdown of the tissue antielastase screen

ISSN:0025-7931    

DOI:10.1159/000196170

出版商:S. Karger AG    

年代:1993

数据来源: Karger