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Biomedical subjects

C Springer

Publications and source records attributed to C Springer.

At least 55 records · Page 3Linked to original sources
PubMed1995

Comparison of adenosine 5'-monophosphate and methacholine for the differentiation of asthma from chronic airway diseases with the use of the auscultative method in very young children.

Methacholine and adenosine 5'-monophosphate bronchial challenges were performed in 54 young children--39 with asthma and 15 with other chronic airway diseases (CADs), with the use of the auscultative method. Children with asthma were sensitive to both methacholine and adenosine; children with CAD responded only to methacholine. We conclude that bronchial challenge with adenosine can help differentiate asthma from CAD in young children.

Adenosine Monophosphate↗
PubMed1995

Activation and repression of the yeast ARO3 gene by global transcription factors.

The ARO3 gene of Saccharomyces cerevisiae codes for the phenylalanine-inhibited 3-deoxy-D-arabinoheptulosonate-7-phosphate synthase (EC 4.1.2.15) and is regulated by the general control system of amino acid biosynthesis through a single GCN4-binding site in its promoter. A combined deletion and mutation analysis of the ARO3 promoter region in a delta gcn4-background revealed two additional regulatory systems involved in ARO3 transcription. The ARO3 gene is (i) activated through a sequence element which binds the multifunctional DNA-binding protein ABF1 in vitro and (ii) repressed through an URS1 element, which binds the same protein in vitro as the URS1 element in the CAR1 promoter. Since both the ABF1-binding site and the URS1 element represent cis-acting elements of global transcription regulatory systems in yeast, the ARO3 gene is the first example of a GCN4-regulated gene which is both activated and repressed by global transcription factors. Activation of the ARO3 gene through the ABF1-binding site and repression through the URS1 element seem to be independent of each other and independent of activation by the GCN4 protein.

Arginase↗
PubMed1995

A complex unidirectional signal element mediates GCN4 mRNA 3' end formation in Saccharomyces cerevisiae.

The yeast GCN4 3' element represents a class of polyadenylation sites which function unidirectionally and efficiently in test systems in vivo as well as in vitro. A complex signal element is required for polyadenylation activity with a minimal size of 116 nucleotides for the functional element. We subdivided this element into five regions (EL1 to EL5) of 16 to 26 nucleotides each. Each region was characterized by deletion analysis in an in vivo test system. Two TTTTTAT motifs are located in different regions (EL1 and EL4) upstream of the poly(A) site. The 3' end processing activity was significantly reduced when both motifs were mutated by site-directed mutagenesis and abolished when EL1 and EL4 were deleted. The major poly(A) site is located in EL5, 3 nucleotides downstream of the second TTTTTAT motif. Additional minor poly(A) sites are used in less than 10% of the mRNA 3' ends. Deletion of EL3 resulted in a changed pattern of mRNA 3' ends by increased usage of the minor poly(A) addition sites. The major poly(A) site in EL5 can be removed without loss of function when sequences upstream of EL1 are present. The tripartite TAG...TATGT...TTT sequence located downstream of EL5 is not required for function.

Base Sequence↗
PubMed1995

Adenosine, methacholine, and exercise challenges in children with asthma or paediatric chronic obstructive pulmonary disease.

BACKGROUND: Bronchial hyperreactivity to methacholine is present in children with asthma and other types of paediatric chronic obstructive pulmonary disease (COPD), while hyperreactivity to exercise is more specific for asthma. Adenosine 5'-monophosphate (AMP) is a potent bronchoconstrictor and, like exercise, may provoke asthma by activating mast cells. This study investigated the suitability of AMP as a specific challenge for asthma in children. METHODS: Bronchial provocation challenges with methacholine and AMP were performed in a double blind fashion using tidal breathing in 51 children with asthma, 21 with paediatric COPD of various types, and in 19 control children. Each subject also underwent a standardised exercise challenge after inhalation challenges were completed. Sensitivity and specificity curves were constructed and the intersection point of sensitivity and specificity for each type of challenge was determined. RESULTS: When the asthmatic patients were compared with the children with COPD, the intersection points for AMP, exercise and methacholine were 90%, 85%, and 50%, respectively. When compared with the controls the same intersection points were 98%, 84%, and 92%, and when children with paediatric COPD were compared with controls they were 55%, 50%, and 82%. CONCLUSIONS: Methacholine distinguishes both asthma and paediatric COPD from controls with a sensitivity of 82-92%, but does not distinguish between asthma and paediatric COPD; exercise and AMP distinguish asthma from controls with a sensitivity and specificity of 84-98% but they also distinguish asthma from paediatric COPD with a sensitivity and specificity of 85-90%. AMP inhalation is a practical aid for diagnosing asthma and distinguishing it from COPD in children of all ages.

Adenosine Monophosphate↗
PubMed1995

The safety of air transportation of patients with advanced lung disease. Experience with 21 patients requiring lung transplantation or pulmonary thromboendarterectomy.

Air travel can cause severe respiratory decompensation in a patient with advanced lung disease due to high altitude hypoxemia. We report our experience in flying 21 patients with advanced lung disease to a medical center remote from Israel for lung transplantation or pulmonary thromboendarterectomy (PTE). All patients had severe lung disease with marked hypoxemia (PaO2, 40 to 59) and 16 had significant pulmonary hypertension. Nine patients (with emphysema and pulmonary fibrosis) required single lung transplant, four (with cystic fibrosis and emphysema) required double-lung transplant, six (with primary or secondary pulmonary hypertension) required heart-lung transplant, and two (with major vessel pulmonary thrombosis) required PTE. All patients were flown by commercial aircraft to centers located 2,634 to 13,181 km away from Israel. Length of flight was between 4 and 21 h. Patients were given oxygen supplementation during the flight and were monitored by portable oximeters. All but three patients were hemodynamically stable and 19 of them were escorted by physicians. All but one hemodynamically unstable patient who died on board arrived safely at their destinations. We conclude that with careful preparation, sufficient oxygen supply, oximetric monitoring, and medical escort, almost any patient with severe lung disease can travel by air to any necessary destination.

Adult↗
PubMed1994

Effect of natural oxygen enrichment at low altitude on oxygen-dependent patients with end-stage lung disease.

OBJECTIVE: To assess the effect of lowering altitude to that of the lowest place on earth (Dead Sea) on arterial oxygenation and exercise performance in patients with hypoxemia and end-stage lung disease. DESIGN: A cohort of 10 patients. SETTING: Pulmonary function laboratories in Jerusalem, Israel, and at the Dead Sea. PATIENTS: 10 patients with end-stage lung disease who were receiving long-term oxygen therapy. The 4 males and 6 females were 12 to 77 years old. Four patients had chronic obstructive pulmonary disease; 2 had cystic fibrosis; 3 had pulmonary fibrosis; and 1 had pulmonary hypertension (thromboembolic). Mean forced vital capacity was 1.54 L (54% of predicted value) and mean forced expiratory volume in 1 second was 0.85 L (35% of predicted value). MEASUREMENTS: Spirometry, blood gas analysis, progressive exercise testing, and sleep oximetry were done in Jerusalem (altitude, 800 m above sea level; barometric pressure, 696 mm Hg); the same measurements were done 6 days after arrival at the Dead Sea (altitude, 402 m below sea level; barometric pressure, 800 mm Hg) and then 7 to 14 days later in Jerusalem. RESULTS: Arterial oxygenation increased from a median partial pressure of arterial oxygen of 51.6 mm Hg in Jerusalem to 67.0 mm Hg at the Dead Sea, an increase of 15.2 mm Hg (95% CI of paired difference, 4.1 to 20.4 mm Hg; P = 0.001). Partial pressure of arterial carbon dioxide increased from a median of 43.2 to 45.9 mm Hg, an increase of 2.7 mm Hg (CI, 0.5 to 6.4 mm Hg; P = 0.004), with a borderline significant change in the alveolar-arterial gradient. Arterial oxygen saturation increased from a median of 87.7% to 92.8%, a change of 4.8% (CI, 1.9% to 9.8%; P = 0.003). Exercise performance also improved as maximum oxygen uptake increased from a median of 827 mL/min to 1056 mL/min, an increase of 203 mL/min (CI, 54 to 388 mL/min; P = 0.006). Sleep oximetry also improved as median arterial oxygen saturation measured during sleep increased from 85% to 90%, a change of 5% (CI, 2% to 7%; P = 0.005), and percentage of sleep time with an oxygen saturation rate of 90% or more increased from a median of 24% to 73%, a change of 49% (CI, 20% to 87%; P = 0.02). No change in spirometry was noted. All patients felt less dyspneic and reported improved functional capacity with reduced need for oxygen. CONCLUSION: Descent to low altitude can improve arterial oxygenation, exercise performance, and sleep oximetry and consequently the quality of life in patients with hypoxemia and advanced lung disease.

Adolescent↗
PubMed1994

Protective effect of albuterol delivered via a spacer device (Babyhaler) against methacholine induced bronchoconstriction in young wheezy children.

Nine young asthmatic children aged 2-5 years underwent methacholine challenge after placebo or albuterol administered by metered dose inhaler through a spacer device (Babyhaler) with a face mask in a double-blind, cross-over, randomized study. The methacholine challenge was performed using chest auscultation to define the provocative concentration of methacholine that causes wheezing (PCW). The PCW increased from a geometric mean of 0.28 mg/mL after placebo to 3.59 mg/mL after albuterol (P < 0.0001). The protective effect of albuterol against methacholine-induced bronchospasm was 3.7 +/- 1.2 doubling doses. We conclude that administration of drugs from a metered dose inhaler through the Babyhaler with a face mask is effective. Albuterol causes a major reduction in the bronchial hyperreactivity in young wheezy children shortly after administration.

Albuterol↗
PubMed1994

Assessment of the ability of young children to use a powder inhaler device (Turbuhaler).

The purpose of the study was to determine the age at which young asthmatic children could master the use of a new powder inhaler device (Turbuhaler). We studied 59 children with asthma between the ages of 3 and 6 years who consecutively attended the asthma clinic of the pediatric department. Efficiency of inhalation and the pharmacological effect of the terbutaline in the inhaler were measured by scores for inhalation technique and clinical response. None of the 3-year-old children used the device efficiently, but 43% of the 4-year-old, 67% of the 5-year-old, and 80% of the 6-year-old children used the inhaler correctly. Although inhaler technique was not perfect in the younger age group, 50% of the 3-year-old children demonstrated clinical improvement of asthma symptoms after inhalation. In the older age groups, 79%, 92%, and 100% of the 4, 5, and 6-year-old children demonstrated clinical improvement of asthma symptoms after inhalation. It is concluded that the new mode of dry powder delivery system (Bricanyl Turbuhaler) can be used in young asthmatic children who are 4 years of age and above.

Age Factors↗
PubMed1994

Chloroquine treatment of interstitial lung disease in children.

Seven children aged 3 months to 11 years with histologically confirmed interstitial lung disease (ILD) [6 with desquamative interstitial pneumonitis (DIP) and 1 with chronic interstitial pneumonitis] were treated with chloroquine, 10 mg/kg/day. One patient, diagnosed late in the course of the disease, died after three weeks of treatment, despite the addition of systemic corticosteroids. Another patient responded to combined therapy with chloroquine and prednisone and had a normal lung biopsy after 6 months of treatment. He underwent surgical repair of mitral valve stenosis and died after extensive brain infarction. The other 5 patients responded well to chloroquine therapy with major improvement in oxygenation within a few weeks and in lung function over the next few months. They remained well clinically and physiologically, including a normal response to incremental exercise, during a mean follow-up period of 9.8 years (range 3.5 to 15.7 years). None of the patients has developed retinopathy or any other ocular complication. Bronchoalveolar lavage was a useful tool for evaluation of the activity of the disease (predominance of neutrophils) in 3 out of 4 patients. We suggest that chloroquine should be considered as an effective treatment in ILD in children. Incremental exercise test may be helpful for routine follow-up and evaluation of the efficacy of a specific treatment.

Child↗
PubMed1993

Complications following oat head aspiration.

We report 5 cases of oat head aspiration in children that resulted in serious complications due to the unidirectional migration of the oat head to the periphery of the lung. The complications included pneumothorax, pneumomediastinum, recurrent hemoptysis, chronic lung disease, bronchiectasis, lobectomy, bronchopleural and bronchocutaneous fistulae, pleural effusion, empyema cavity, and, one not described before, osteomylitis of the rib. Physicians should be aware of the dangers with this particular foreign body aspiration.

Bronchoscopy↗
PubMed1993

Total population survey of the frequency and severity of asthma in 17 year old boys in an urban area in Israel.

BACKGROUND: There is evidence that the prevalence of asthma in children and young people is increasing. METHODS: An examination of a total population (35,170) of 17 year old Jewish boys of one seaside urban area in Israel was undertaken during two years, 1986 and 1990, by trained respiratory physicians in a regional recruiting office of the Israel Defence Forces. All boys who had ever been diagnosed as having asthma or symptoms that could have been due to asthma underwent a further examination by respiratory physicians that included spirometry at rest. A test to evaluate exercise induced asthma was performed on a treadmill in 88% of the boys. RESULTS: Lifetime prevalence (asthma in the past or at present) increased from 7.9% in 1986 to 9.6% in 1990. Point prevalence (current asthma) increased from 5.0% to 5.9%. The prevalence of current asthma increased in all degrees of severity (mild disease from 3.3% to 3.7%, moderate disease from 1.7% to 2.2%, and severe disease from 0.03% to 0.04%). By the age of 17, 77.4% of boys who had suffered from asthma had no or only very mild symptoms. CONCLUSIONS: It is considered that the measured increase in prevalence of asthma from 1986 to 1990 reflects a true increase among the Jewish Israeli population.

Adolescent↗
PubMed1993

Comparison of airway resistance and total respiratory system resistance in infants.

Airway resistance (Raw) can be measured throughout the respiratory cycle by whole body plethysmography. Total resistance of the respiratory system (Rrs) can be measured from the relaxed expiration that follows end inspiratory occlusion. The purpose of this study was to compare the two methods in normal infants and in infants with airway obstruction of different types and severity. Fifteen infants with essentially normal lungs aged 24.6 +/- 18.0 (SD) wk, nine infants with congenital stridor aged 36.0 +/- 17.3 wk, and eleven wheezy infants aged 20.1 +/- 11.3 wk had simultaneous measurements of Raw and Rrs. Rrs was similar to Raw both during inspiration and expiration in the normal infants, to all expiratory Raw in those with congenital stridor, and to all inspiratory and early expiratory Raw in the wheezy infants. Raw was markedly and significantly higher than Rrs during mid and late inspiration in infants with congenital stridor and during late expiration in the wheezy infants. We conclude that Rrs is a good estimate of Raw in normal infants and of early expiratory Raw in all infants. In infants with airway obstruction, Rrs does not reveal the dynamic changes in Raw during tidal breathing, nor can it differentiate between infants with upper and lower airway obstruction.

Airway Resistance↗
PubMed1992

Increase in bicarbonate stores with exercise.

We previously described bicarbonate exchange dynamics in humans at rest and during exercise using a three-compartment model. In the present study we tested the effect of certain assumptions of this model on the prediction of the change in exchangeable bicarbonate with the increased metabolic rate of exercise. We compared this prediction with a measurement of CO2 retention after exercise onset determined from gas exchange data. The change in tissue bicarbonate stores was estimated from differences in the kinetics of adjustment of VO2 and VCO2, and this was added to an estimate of the changes in venous blood gas stores to estimate the total change in bicarbonate. When the commonly held assumption that endogenous CO2 production, thought to occur in a rapidly equilibrating peripheral compartment at rest, was also applied to the exercise condition, the three-compartment bicarbonate model predicted an unphysiologically large increase in bicarbonate stores (700 mmol, or over 15 L). In contrast, the 'gas exchange' approach predicted a relatively small increase in bicarbonate (26 mmol), consistent with other reports. The incompatibility of these findings with the assumption about the source of endogenous CO2 production in the bicarbonate model requires that the underlying physiological correlates of the three compartments change from rest to exercise.

Bicarbonates↗
PubMed1992

Role of infection in the middle lobe syndrome in asthma.

Twenty one children with asthma aged 1.0-10.5 years (mean (SD) 3.3 (2.5) years) were admitted to the hospital to evaluate pulmonary right middle lobe or lingular collapse lasting one to 12 months (mean (SD) 4.4 (3.8) months). Seven children had mild asthma and were treated with inhaled beta 2 agonists as needed. Nine had moderate asthma treated with either sodium cromoglycate or slow release theophylline. Five had severe asthma treated with inhaled steroids. Each child underwent fibreoptic bronchoscopy under local anaesthesia and a bronchoalveolar lavage. Differential cell counts of the lavage fluid revealed predominance of neutrophils in 12 patients (57%). In nine of these patients cultures grew pathogenic bacteria, mainly Haemophilus influenzae and Streptococcus pneumoniae. There was no correlation between the severity of asthma and a positive bacterial culture. There was also no correlation between the duration of the right middle lobe collapse and a positive culture. We conclude that longstanding right middle lobe collapse in asthmatic children is often associated with bacterial infection.

Asthma↗
PubMed1992

Hollow bone in the bronchus or the danger of chicken soup.

A 6-month-old infant arrived at the emergency room with severe respiratory distress after being spoon-fed chicken soup. Air entry was normal, chest X-rays were normal, and bronchoscopy revealed a hollow chicken bone lining the whole left main bronchus.

Animals↗