Biomedical subjects

B Yuksel

Publications and source records attributed to B Yuksel.

At least 37 records · Page 2Linked to original sources

PubMed1994

Abnormalities of lung volume at follow-up after antenatal rhesus iso-immunization.

Rhesus iso-immunization is associated with fatal pulmonary hypoplasia. We have examined the hypothesis that abnormalities of lung volume, as an index of lung growth, may also be found in survivors. At a median age of nine months, lung volume was assessed by measurement of functional residual capacity in 23 patients affected antenatally by rhesus iso-immunization. Seventeen of the patients had required at least one intrauterine transfusion. Five patients (group A) had an FRC < 24 ml/kg (median 21 ml/kg, range 19-22 ml/kg) and the other 18 (group B) an FRC > or = 24 ml/kg (median 27 ml/kg, range 24-36 ml/kg) (p < 0.01). The only significant difference between these two groups was the timing of the first foetal blood sampling and intrauterine transfusion, being a median of 22 weeks (range 20-23 weeks) in group A and 30 weeks (range 17-36 weeks) in group B (p < 0.01).

Blood Transfusion, Intrauterine↗

PubMed1993

Comparison of helium dilution and nitrogen washout measurements of functional residual capacity in premature infants.

Comparison has been made of measurements of functional residue capacity (FRC) by a helium gas dilution (He) and a nitrogen washout (N2) technique. Twenty infants (median gestational age, 29.5 weeks) were studied at a median postnatal age of 25 days. No infant was oxygen dependent. The coefficient of repeatability of FRC (He) was 6.4 mL/kg and of FRC (N2), 6.3 mL/kg. The coefficient of repeatability of the two methods combined was 13.8 mL/kg. In 10 infants the results of two techniques differed by more than 20% of the mean FRC; those infants were born at a significantly earlier gestation than the rest of the cohort (P < 0.01). We conclude that, except in very immature infants, techniques for measuring FRC (He) and FRC (N2) yield reproducible and comparable results in convalescent premature infants.

Female↗

PubMed1993

Neonatal meconium aspiration syndrome and respiratory morbidity during infancy.

Respiratory morbidity in the first 6 months of life of 35 infants who had had neonatal meconium aspiration syndrome (MAS) was compared to that of 70 controls, also born at term, matched for gender and ethnic origin. The number of infants in the two groups who were symptomatic was compared. Infants were described as symptomatic if, following discharge from hospital, they had at least one episode of wheezing and/or coughing which lasted for 3 days or more. There was no significant difference between the two groups regarding parental smoking or the proportion of infants who had a family history of atopy. A significantly greater proportion of the MAS group (49%) than of the control group (20%) was symptomatic at follow-up. Eight (23%) infants with MAS and 2 (3%) controls had symptoms which necessitated regular bronchodilator therapy. The 8 infants with MAS who were on maintenance bronchodilator therapy had required significantly longer neonatal respiratory support and had larger lung volumes at follow-up than the other 27 infants. We conclude that neonatal meconium aspiration syndrome is associated with increased respiratory morbidity in the first 6 months of life.

Bronchodilator Agents↗

PubMed1993

The effect of sodium cromoglycate on upper and lower respiratory symptoms in children born prematurely.

The aims of this study were to assess whether sodium cromoglycate (SCG) was an effective prophylaxis against both upper and lower respiratory tract signs and to determine factors which affected the site and magnitude of the response to SCG. Sixteen children born prematurely were entered into a randomised placebo-controlled trial at 15 months of age (range 4-31 months). The patients received, in random order, either 3 weeks' treatment with SCG (5 mg) or placebo, both given four times a day by inhalation via a spacer device. Parents were asked to record the occurrence and severity of their child's upper respiratory tract signs; sneezing and runny nose and lower respiratory tract signs; day and night time cough and wheeze. During the active compared to the placebo period there was an overall reduction of 47% and 53% in upper and lower respiratory tract signs, respectively. The magnitude of response to SCG as assessed by either the change in upper or lower respiratory tract signs was not significantly related to the patient's gestational or postnatal age, the occurrence of neonatal chronic lung disease, family history of atopy or the order in which the therapy was administered. We conclude that inhaled SCG may be a useful prophylaxis for both upper and lower respiratory tract signs for children born prematurely and less than 3 years of age.

Administration, Inhalation↗

PubMed1993

Effect of gender on blood pressure levels of very low birthweight infants in the first 48 hours of life.

Systolic blood pressure was measured in 98 very low birthweight (VLBW) infants in the first 48 h of life. Measurements were made on 49 male infants, median gestational age 29 weeks and 49 female infants who were matched with the male infants for gestational age. Blood pressure was measured either from an indwelling arterial line or non-invasively using a Doppler technique; measurements were made on all infants on day 1 and day 2. In both male and female infants on day 1 and day 2, blood pressure levels correlated significantly with gestational age (P < 0.01). On day 1, but not on day 2, the blood pressure of the male infants was significantly lower than the female infants. We conclude it is important to use gender appropriate regression equations for blood pressure in VLBW infants in the first 24 hours of life.

Blood Pressure↗

PubMed1993

Variable response to bronchodilator therapy in young children born prematurely.

The response to nebulized therapy was studied at a median postnatal age of 16 months (range 6-24 months) in 15 children born prematurely. Thoracic gas volume (TGV) and airways resistance (RAW) were measured by total body plethysmography and specific conductance (SGAW) calculated. The measurements were made prior to, and then 5 and 10 min after, nebulized saline (3 ml), and then 5, 10 and 15 min after administration of nebulized salbutamol (2.5 mg in 2.5 ml normal saline). There was no significant change in TGV throughout the study period. One child showed a significant improvement in airways resistance following nebulized saline, and no child had a significant deterioration. RAW and SGAW both significantly improved in the group overall at 15 min following salbutamol (P < 0.05, P < 0.03 respectively). Individual patients, however, showed a variable serial response in RAW and SGAW: four children had a paradoxical response (an increase in RAW and a decrease in SGAW) at 5 min and at 10 or 15 min, seven children had a significant improvement (decrease) in RAW and eight a significant improvement (decrease) in SGAW. The children who had an initial paradoxical effect did not differ significantly in either age or baseline lung function from the other infants. Patients in whom RAW and SGAW improved following bronchodilator did not differ in age from the rest of the study group, but had tended to have worse lung function prior to bronchodilator administration. We conclude that there is a variable response to nebulized salbutamol in children born preterm, this treatment should only be administered in association with careful monitoring.

Aerosols↗

PubMed1993

Respiratory function at follow-up after neonatal surfactant replacement therapy.

Respiratory function was assessed at a median of 7 months (range 6-12) in 17 preterm infants who, in the neonatal period, had been entered into a multi-centre randomized placebo-controlled trial of prophylactic surfactant replacement therapy. Seven infants (median gestational age 28 weeks) received surfactant and the remaining ten infants (median gestational age 27 weeks) placebo. Respiratory function was assessed by measuring functional residual capacity (FRC), thoracic gas volume (TGV) and airways resistance (RAW). Specific conductance (SGAW) was calculated from RAW and TGV. There was no significant difference in FRC or TGV between the two groups. RAW, however, was significantly lower in the surfactant (median 41, range 21-48 cmH2O l-1 s-1) compared to the placebo group (median 57, range 40-68 cmH2O l-1 s-1), P < 0.05 and SGAW significantly higher in the surfactant (median 0.136, range 0.063-0.289 l cmH2O-1 s-1) compared to the placebo group (median 0.081, range 0.062-0.134 l cmH2O-1 s-1), P < 0.05. These results suggest that surfactant replacement therapy improves lung function at follow-up.

Follow-Up Studies↗

PubMed1993

Inhaled ipratropium bromide and terbutaline in asthmatic children.

Inhaled bronchodilator therapy in young asthmatic children reduces symptoms and improves lung function. After a single dose of therapy, however, lung function may still be abnormal, as evidenced by an elevated function residual capacity (FRC). The aims of this study were to assess if a second dose of bronchodilator therapy resulted in further improvement in lung function and to determine whether additional therapy was more effective if given as a second dose of a beta-adrenergic agonist or if instead an anticholinergic was used. Twenty-one asthmatics (median age 7.5 years) received in random order on two separate occasions, 1 week apart, either two doses of terbutaline (500 micrograms) or terbutaline plus ipratropium bromide (20 micrograms). FRC and peak expiratory flow rate (PEFR) were measured immediately prior to and then 20 min after each dose of bronchodilator therapy. In the group, overall FRC and PEFR improved after the first and second dose of bronchodilator, regardless of regime used, the response to the second dose, however, was smaller than the first dose. There was no significant difference overall between the two regimes in baseline FRC or PEFR, or FRC and PEFR measured after each dose of bronchodilator. Eight children failed to show a significant change in FRC following two doses of terbutaline, but seven of these eight did have a significant change in FRC in response to the combination of terbutaline and ipratropium bromide. We conclude that a second dose of bronchodilator therapy does further improve lung function. Our results suggest the more efficacious regime consists of a combination of single doses of ipratropium bromide and terbutaline.

Administration, Inhalation↗

PubMed1993

Nebulized sodium cromoglycate in preterm infants--protection against water challenge-induced bronchoconstriction.

Nebulized water is an effective bronchoprovocative agent in asthmatic adults and children. The aim of this study was to assess the bronchoconstrictor effect of this agent in preterm infants studied at follow-up and if their response to it was altered by pre-treatment with nebulized sodium cromoglycate. Lung function, thoracic gas volume and airway resistance, was measured by whole body plethysmography and specific conductance (SGAW) calculated. Measurements were made before and after nebulized saline, nebulized water (first water challenge), nebulized sodium cromoglycate and again nebulized water (second water challenge). There was no significant change in SGAW following either normal saline or sodium cromoglycate. In nine infants SGAW deteriorated by more than 16% (twice the coefficient of variation of the measurement) after the first water challenge but only in one after the second water challenge (P < 0.01). We conclude that nebulized water is an effective bronchoconstrictor in preterm infants and that sodium cromoglycate can protect against this challenge.

Bronchi↗

PubMed1993

Prediction of chronic lung disease from the chest radiograph appearance at seven days of age.

The aim of this study was to assess if the chest radiograph appearance at seven days of age could be used to predict chronic lung disease (oxygen dependency at 28 days of age). Sixty preterm infants (median gestational age 28 weeks), who were ventilated and/or had supplementary oxygen at seven days of age and had a chest radiograph performed at that postnatal age, were prospectively recruited. These chest radiographs were scored according to lung volume, presence of opacification, haziness, interstitial changes and cystic elements (maximum score 18). Twenty-eight infants subsequently developed chronic lung disease; their median chest radiograph score was 5.5 (range 2-14) which was significantly higher than that of the non-chronic lung disease infants (median 3; range 0-6). A chest radiograph score of 4 had a 71% sensitivity and 88% specificity in predicting chronic lung disease. We conclude that chest radiograph appearance at seven days of age is a sensitive and specific predictor of chronic lung disease and thus could be used to indicate the need for preventive therapy.

Age Factors↗

PubMed1993

Bronchodilator effect of nebulized sodium cromoglycate in children born prematurely.

We wished to determine whether nebulized sodium cromoglycate (SCG) has bronchodilator effects in very young children. In 18 children born prematurely and studied at a median of 15 months of age, thoracic gas volume (TGV) and airways resistance (Raw), were measured and hence specific airways conductance (sGaw) was calculated before (baseline) and after nebulized saline, and then after sodium cromoglycate. sGaw improved significantly in 10 infants after SCG, compared to only in two following saline. These preliminary results suggest that nebulized SCG may have an acute bronchodilator effect in some children born prematurely.

Aerosols↗

PubMed1992

Lung function in 6-20 month old infants born very preterm but without respiratory troubles.

Lung function results of 21 healthy infants born very prematurely are reported. The median gestational age was 29 weeks, but none had developed respiratory distress or required any form of respiratory support in the neonatal period. Lung function was assessed by measurements of thoracic gas volume (TGV) and airway resistance (Raw) plethysmographically, and of functional residual capacity (FRC) using a helium gas dilution technique. Two separate measurements were made between 6 and 20 months of age; all infants were measured once in the first and once in the second year of life. Regression equations were calculated for TGV, Raw, and FRC related to weight, height, and postnatal age. These data provide a new set of values for very preterm infants, in part small for gestational age, without neonatal respiratory trouble.

Age Factors↗

PubMed1992

Acute deteriorations in neonatal chronic lung disease.

Preterm infants with chronic lung disease (CLD) have frequent respiratory relapses. The aim of this study was to assess the aetiology of such deteriorations and in particular the proportion due to viral infections. During the study period 118 preterm infants with birth weight less than 1500 g were consecutively admitted to the neonatal intensive care unit; 22 (18.6%) developed CLD. At the onset of all respiratory deteriorations, infants were examined for the presence of patent ductus arteriosus, apnoea or aspiration; they were also carefully screened for both viral and bacterial infection. The 22 infants had a total of 74 episodes of respiratory deterioration; median 3 per baby (range 1-8). Two episodes were associated with patent ductus arteriosus, 18 with apnoea and 5 with aspiration. Infection was suspected or proven in association with all other episodes. On ten occasions the infants had positive blood cultures and on a further eight, bacteria were isolated only from the endotracheal or nasopharyngeal secretions. On the remaining 31 occasions, 27 associated with chest X-ray film abnormalities, infection was suspected, but no bacteria isolated. Viral infections were identified in association with 8 (11%) of these episodes. We conclude viral infection should be considered as a cause of otherwise unexplained respiratory deteriorations in infants with neonatal CLD.

Acute Disease↗

PubMed1992

Age-related changes in human blood lymphocyte subpopulations.

Flow cytometric analysis of major lymphocyte populations and their subsets reveals age-related changes in the cellular human immune system. Immunophenotypic markers were evaluated in 110 normal pediatric subjects, divided into groups of newborn infants, infants aged 2 days to 11 months, and children aged 1 to 6 years and 7 to 17 years; results were then compared with those obtained from 101 normal adults aged 18 to 70 years. Comparisons among age groups from newborn infants through adults reveal progressive declines in the absolute numbers of leukocytes, total lymphocytes, and T, B, and natural killer (NK) cells. The percentages of T cells within the total lymphocyte population increase with age, in both CD4+ and CD8+ subsets. Percentages of B and NK cells are higher in newborn infants than in adults. The expression of the activation markers interleukin-2R and HLA-DR on T cells increases with age, as does the NK-associated expression of CD57 on CD8 cells. The proportions of B lymphocytes that coexpress CD5 or CDw78 decrease with age, whereas expression of Leu-8 and CD23 increases. The proportion of CD4 cells bearing the CD45RA and Leu-8 markers is consistently lower in adults than in children. These data may serve as a reference range for studies of pediatric subjects.

Adolescent↗

PubMed1992

Neonatal respiratory support and lung function abnormalities at follow-up.

We have investigated if respiratory distress syndrome (RDS) treated by an increased inspired oxygen concentration, rather than mechanical ventilation, was associated with impaired lung function at follow-up and/or an increase in respiratory symptoms. Thoracic gas volume (TGV) and airways resistance (RAW) were measured in eight pre-term infants (median gestational age 29 weeks) at 6 and 12 months of age. The infants had suffered from RDS but had not required mechanical ventilation. Their results were compared to 16 other infants, matched for gestational age; eight who had required ventilation in the neonatal period and eight who had had no RDS. In all three groups the occurrence of respiratory symptoms was recorded. The lung function of the infants requiring oxygen in the neonatal period was similar to those who had not suffered from RDS, but their airways resistance was significantly lower at 6 but not 12 months than that of infants ventilated in the neonatal period (P less than 0.05). There was no significant difference in recurrent respiratory symptoms between the three groups although a greater proportion of the infants ventilated in the neonatal period were symptomatic in the first 6 months of life. These results suggest that oxygen therapy alone does not result in an impairment of lung function which is independent of the effect of prematurity.

Airway Resistance↗

PubMed1992

Inhaled sodium cromoglycate for pre-term children with respiratory symptoms at follow-up.

Children born prematurely frequently have recurrent respiratory symptoms at follow-up and benefit from bronchodilator therapy. We have assessed if regular inhaled sodium cromoglycate would reduce this respiratory morbidity and need for bronchodilator therapy. Sixteen symptomatic children (median gestational age 29 weeks, post-natal age 15 months) were entered into a randomized double-blind, placebo-controlled trial. In two 3-week periods, the patients received either placebo or sodium cromoglycate (5 mg) as one puff q.d.s. from an inhaler via a coffee cup. Parents recorded their child's symptoms and need for bronchodilator therapy throughout and lung function was assessed by measurement of functional residual capacity (FRC) at the beginning and end of each 3-week period. The symptom score was reduced by 49% in the active compared to the placebo period (P less than 0.01) and bronchodilator was taken on a mean of 2.9 days per infant in the active period compared to 7.9 days in the placebo period (P less than 0.01). There was a significant improvement in FRC in ten of 16 patients over the active period but only in two infants over the placebo period (P less than 0.01). We conclude regular inhaled sodium cromoglycate is useful prophylaxis for symptomatic pre-term children.

Administration, Inhalation↗

PubMed1992

Repertoire of CD5+ and CD5- cord blood B cells: specificity and expression of VH I and VH III associated idiotopes.

Epstein-Barr (EBV)-immortalized B cell clones were established from CD5+ and CD5- cord blood B cells separated by flow cytometry. We have previously shown that IgM from many of the clones was polyreactive, exhibiting reactivity with a number of autoantigens. In this study, IgM produced by the clones was analysed by MoAb for the expression of cross-reactive idiotypes (CRI) associated with rheumatoid factor paraproteins and from defined VH and V kappa subgroups of immunoglobulin heavy and light chains. IgM produced by clones established from CD5+ and CD5- B cells expressed the VH I associated idiotope G8. Furthermore, IgM produced by both sets of clones exhibited a similar frequency of VH III heavy chain subgroup expression, as determined by reactivity with staphylococcal protein A (SpA) and VH III-associated CRI expression (B6 and/or D12). In contrast, expression of the V kappa III-associated 17.109 CRI was significantly higher in IgM antibodies produced by clones established from CD5+ compared with the CD5- clones (32 versus 5%: P less than 0.05). Analysis of the VH and VL subgroup expression by IgM produced by the CD5+ and CD5- cord blood clones, and their autoantigen reactivity profile did not reveal restriction or selection within CD5+ and CD5- populations. However, our data suggest that differences may exist in the expression of certain germ-line genes between CD5+ and CD5- cord blood B cells and might indicate an expansion of CD5+ B cells within the fetal environment.

Animals↗

PubMed1992

Persistence of respiratory symptoms into the second year of life: predictive factors in infants born preterm.

Preterm infants frequently suffer from recurrent respiratory symptoms in the first year of life. Our aims were to assess if such respiratory morbidity persisted beyond the first year and to define the predictive factors. One hundred and seventeen infants (median gestational age 29 weeks) were followed prospectively for two years. Thirty-eight infants had symptoms only in the first year (group A) and in a further 20 infants, symptoms were present in both years (group B). Comparison of these two groups revealed no significant difference in birth weight or gestational age, but the duration of ventilation and increased inspired oxygen concentration were significantly longer in group B. Significantly more infants in group B had had an air leak in the neonatal period, and airways resistance at six months of age was also significantly higher in group B. We conclude that infants with severe neonatal respiratory distress are likely to have persisting respiratory morbidity and that respiratory function measurements at six months of age provide the most accurate predictor of chronic respiratory symptoms.

Airway Resistance↗