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Biomedical subjects

B Yuksel

Publications and source records attributed to B Yuksel.

At least 19 recordsLinked to original sources
PubMed2004

Effect of in utero growth retardation on lung function at follow-up of prematurely born infants.

The aim of the study was to determine if prematurely born children who had suffered intra-uterine growth retardation (IUGR) had more severe lung function abnormalities than those born an appropriate weight for gestational age (AGA). Analysis of the lung function results of 119 infants (median (range) gestational age of 30 (23-35) weeks) was undertaken. In total, 31 of the infants had suffered IUGR and were born small for gestational age (SGA). Functional residual capacity and airways resistance (Raw) were measured at a median post-natal age of 10 (6-24) months. Specific airway conductance (sGaw) was calculated from thoracic gas volume and Raw. The SGA children were born at a greater gestational age and had a lower body weight at testing than the AGA children. Raw and sGaw differed between the SGA and AGA children. Regression analysis demonstrated that lung volumes were significantly related to body weight at testing, Raw was related to IUGR, maternal smoking and bronchopulmonary dysplasia, and sGaw to maternal smoking. In conclusion, these results suggest that prematurely born infants who have suffered intra-uterine growth retardation may be at increased risk of impaired lung function at follow-up.

Birth Weight↗
PubMed2003

Urinary N-acetyl-beta-D-glucosaminidase activity in type I diabetes mellitus.

We measured urinary albumin excretion rate (AER) and N-acetyl-beta-D-glucosaminidase (NAG) activity in relation to disease duration, acetylated hemoglobin (HbA1c), hypertension and puberty in 44 children and adolescents with type 1 diabetes mellitus. AER and Urinary NAG activity were significantly higher in the patients compared to controls (AER 19.4 +/-; 35.8 vs 4.7 +/- 4.4, NAG activity 5.6 +/- 0.6U vs. 1.6 +/- 0.2U). Microalbuminuria was present in seven patients (15.9%), all of whom were pubertal. There was no correlation between AER and urinary NAG activity. There was a significant direct correlation between AER and disease duration (P <0.05), HbA1c (P < 0.05), diastolic blood pressure (P <0.05) and puberty (P <0.05). None of the microalbuminuria related variables was significantly correlated with urinary NAG activity. Puberty was an independent factor for elevated urinary NAG activity. This study shows that urinary NAG is elevated in children and adolescents with type 1 diabetes mellitus, but is not associated with AER related factors except for puberty. Urinary NAG activity does not appear to be a useful marker for early detection of diabetic nephropathy in children and adolescents with type 1 diabetes mellitus.

Acetylglucosaminidase↗
PubMed2002

Increased first-trimester nuchal translucency as a prenatal manifestation of salt-wasting congenital adrenal hyperplasia.

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder that results from a deficiency in one or other of the five enzymes of cortisol biosynthesis. The most common form of CAH is 21-hydroxylase deficiency (21-OHD) and this may be manifest clinically in the neonatal period as a life threatening salt-wasting condition along side genital ambiguity. Prenatal diagnosis is available for CAH, however, there is poor correlation between the specific genotype and the phenotypic expression of the condition. We report two cases of severe salt-wasting CAH in one family that presented in both pregnancies with increased nuchal translucency (NT) in the first trimester. This is the first report of the association, between increased NT and CAH 21-OHD.

Adrenal Hyperplasia, Congenital↗
PubMed1999

Mutations in the gene encoding the human matrix Gla protein cause Keutel syndrome.

Keutel syndrome (KS, MIM 245150) is an autosomal recessive disorder characterized by abnormal cartilage calcification, peripheral pulmonary stenosis and midfacial hypoplasia. A genome search using homozygosity mapping provided evidence of linkage to chromosome 12p12.3-13.1 (maximum multipoint lod score, 4.06). MGP was a candidate on the basis of its localization to this chromosomal region and the known function of its protein. MGP maps to chromosome 12p near D12S363. Human MGP is a 10-kD skeletal extracellular matrix (ECM) protein that consists of an 84-aa mature protein and a 19-aa transmembrane signal peptide. It is a member of the Gla protein family, which includes osteocalcin, another skeletal ECM protein, and a number of coagulation factors (factors II, VII, IX, X and proteins S and C). All members of this family have glutamic acid residues modified to gamma-carboxyglutamic acids (Gla) by a specific gamma-carboxylase using vitamin K as a cofactor. The modified glutamic acid residues of Gla proteins confer a high affinity for mineral ions such as calcium, phosphate and hydroxyapatite crystals, the mineral components of the skeletal ECM. The pattern and tissue distribution of Mgp expression in mice suggest a role for Mgp in regulating ECM calcification. Mglap-deficient mice (Mglap-/-) have been reported to have inappropriate calcification of cartilage. Mutational analysis of MGP in three unrelated probands identified three different mutations: c.69delG, IVS1-2A-->G and c.113T-->A. All three mutations predict a non-functional MGP. Our data indicate that mutations in MGP are responsible for KS and confirm its role in the regulation of extracellular matrix calcification.

Abnormalities, Multiple↗
PubMed1998

Outcome of chromosomally normal livebirths with increased fetal nuchal translucency at 10-14 weeks' gestation.

The aim of this study was to determine the outcome of chromosomally normal livebirths with increased fetal nuchal translucency at 10-14 weeks' gestation. Clinical follow up of 89 chromosomally normal livebirths that in fetal life had a minimum nuchal translucency thickness of 3.5 mm and a comparison group of 302 infants whose fetal nuchal translucency thickness at 10-14 weeks of gestation was less than 3.5 mm was performed. Major abnormalities, mainly structural defects of the cardiovascular or skeletal systems, were found in 10.1% (nine of 89) of the group with increased translucency, compared to 2% (five of 302) in those with translucency of less than 3.5 mm (chi2=11.9, p<0.001). Delay in achievement of developmental milestones was observed in one of the infants with increased translucency and in one of the comparison group. The findings of this study show that in chromosomally normal fetuses increased nuchal translucency thickness at 10-14 weeks of gestation is a marker for fetal abnormalities including structural defects and genetic syndromes.

Chromosome Aberrations↗
PubMed1997

First trimester invasive procedures: effects on symptom status and lung volume in very young children.

First trimester procedures have been associated with perinatal lung function abnormalities that may suggest subsequent respiratory problems. Our aim was, therefore, to assess the impact of first trimester invasive procedures [early amniocentesis (EA) and chorion villus sampling (CVS)] on respiratory morbidity in very young children. A questionnaire was issued to parents of 439 EA and 453 CVS (subjects), and 435 controls (their mothers had undergone no invasive procedures) when their children were one year old. Data were also obtained from diary cards issued to a subset of 278 of the EA, 262 of the CVS, and 264 of the control infants followed prospectively. Functional residual capacity (FRC) was measured at a median age of 5 months (range: 0.25-24) in 159 children whose mothers had undergone EA, 168 following CVS and in 165 controls. Analysis of the one-year questionnaire demonstrated an excess of symptomatic infants in the EA group (31%) compared to the CVS (22%; P < 0.01) and control groups (17%; P < 0.01). Findings from the prospective follow-up study confirmed those results and also demonstrated an increase in chest-related hospital admissions in the EA group (3%) compared to the controls (0.4%; P < 0.05). Logistic regression analysis revealed that positive symptom status related significantly to EA and CVS interventions (P < 0.0001), bottle feeding (P < 0.001), parental smoking (P < 0.01), a family history of atopy (P < 0.01), and immaturity (P < 0.01). In the control group, FRC correlated best with weight (r = 0.92). The mean FRC of the EA and CVS groups was higher than that of the controls (P < 0.01). A higher proportion of children had an FRC two standard deviations above the controls' mean in the EA group (n = 14) compared to the CVS group (n = 3; P < 0.01). The symptomatic infants tended to have higher FRCs than the asymptomatic children. We conclude that first trimester procedures are associated with increased respiratory morbidity in very young children.

Amniocentesis↗
PubMed1997

Invasive antenatal procedures and requirement for neonatal intensive care unit admission.

Neonatal respiratory difficulties are increased following second trimester amniocentesis. In preterm, prolonged rupture of the membranes, respiratory outcome is particularly poor when rupture occurs in the first trimester. It therefore seems likely that first trimester/ early amniocentesis (EA) would be associated with severe respiratory problems necessitating a high neonatal intensive care unit (NICU) admission rate. To test that hypothesis, the requirement for admission to the NICU of 278 infants whose mothers had undergone EA, 262 whose mothers had undergone chorion villus sampling (CVS group) and 264 controls whose mothers had undergone no invasive procedures were reviewed as were their diagnoses if they needed admission. There was no significant difference in the mode of delivery, gestational age or gender distribution of the three groups and the median maternal age of the EA and CVS groups was similar. Nineteen EA, eight CVS and five control infants required admission to the NICU (EA versus controls, P < 0.01; EA versus CVS plus controls, P < 0.005). Nine EA, one CVS and four control infants had suffered respiratory problems (EA versus CVS P < 0.05). Logistic regression analysis demonstrated that immaturity and EA were significantly associated with a requirement for NICU admission. We conclude infants whose mothers have undergone EA may be at increased risk for NICU admission, this is partly due to respiratory problems but the association is uncommon.

Amniocentesis↗
PubMed1997

First-trimester invasive procedures and congenital abnormalities.

A prospective study was undertaken to determine whether first-trimester amniocentesis or chorion villus sampling was associated with an increased incidence of congenital anomalies. The infants of mothers who had undergone first-trimester amniocentesis (EA) (n = 352), chorion villus sampling (CVS) (n = 348) or no invasive antenatal procedure (controls) (n = 264) were examined at a median age of 5 months. Both the EA and CVS groups had a higher proportion of infants with congenital anomalies (n = 18 and n = 22, respectively) than the control group (n = 4) (p < 0.01). Certain of the abnormalities, however, affected only single infants. Compression abnormalities were more common in the EA group than in the controls (p < 0.05), but not in the CVS group. The isolated limb abnormalities which occurred were minor anomalies affecting the digits and were seen in both the CVS (n = 6) and EA (n = 3) groups. First-trimester invasive procedures are thus associated with an excess of congenital anomalies.

Adolescent↗
PubMed1996

Tidal breathing parameters in the first week of life and subsequent cough and wheeze.

BACKGROUND: Assessment of tidal breathing parameters may be a useful method of predicting respiratory problems in early childhood. Low values of TPTEF/TE (the ratio of the proportion of time to reach peak tidal expiratory flow to total expiratory time) outside the neonatal period have been significantly related to respiratory tract illness with wheezing in boys in the first year of life. METHODS: TPTEF/TE measurements in the perinatal period were evaluated in nonsedated infants and the predictive value of this early measurement for subsequent respiratory morbidity during infancy was assessed. Flow during tidal breathing was measured while the infant slept quietly in a plethysmograph using a Fleisch pneumotachograph inserted into an infant face mask. Recruitment continued until traces from 60 infants with 10 consecutive flow curves without artefacts were obtained. In addition, plethysmographic measurements of airway resistance (Raw) and thoracic gas volume (TGV) were measured and specific conductance (sGaw) calculated. Parents recorded their infant's cough and wheeze during the first 12 months of life. RESULTS: Sixty five measurements were made in 60 infants with a mean age of two days and gestational age of 40 weeks. Two observers separately calculated TPTEF/TE ratios on 25 traces randomly selected from the pool of 60. The mean difference between the two observers was -0.004 (limits of agreement 0.048 to -0.056). Thirteen infants became symptomatic (wheeze, with or without cough); their median TPTEF/TE ratio (0.349) was significantly lower than the rest of the cohort (median 0.412) and they also had significantly higher Raw and lower sGaw. The positive predictive value of a low TPTEF/TE ratio, however, was only 41%. CONCLUSIONS: These results suggest that the use of this test in the prediction of future respiratory disease in an individual is limited.

Cohort Studies↗
PubMed1996

Cysteinyl leukotriene involvement in chronic lung disease in premature infants.

The pathophysiology of chronic lung disease (CLD) in premature infants who require mechanical ventilation and prolonged oxygen supplementation has been well-described but the underlying mechanisms are not understood. Our aim was to test the hypothesis that excess cysteinyl leukotriene (LT) production was a contributing factor in CLD. We compared LT production and lung function, at 7 months of age, in nine premature infants with CLD and in eight control infants without CLD. None of the control infants developed any neonatal respiratory problems, but two subsequently required bronchodilator therapy. Respiratory function was assessed by the measurement of thoracic gas volume (TGV), airways resistance (Raw) and functional residual capacity (FRC). Total cysteinyl LT production was quantified by measurement of leukotriene E4 (LTE4) in a spot urine sample. Although all patients were asymptomatic at follow-up, there was evidence of significant lung function abnormalities in infants with CLD. The CLD infants had significantly elevated TGV, Raw and FRC values reflecting airway obstruction when compared to the controls. Urinary LTE4 levels were significantly higher in the CLD infants when compared to the controls (geometric mean: 741 and 337 pmol.mmol-1 creatinine, respectively). There was no direct correlation between urinary LTE4 levels in the CLD group and TGV, Raw or FRC values. Although this study is small and a direct correlation between lung function and urinary leukotriene E4 was not demonstrated, pathological lung function and an enhanced urinary leukotriene E4 production in infants with chronic lung disease would tend to suggest that the cysteinyl leukotrienes were involved in the sequelae of this disease.

Airway Obstruction↗
PubMed1995

Does a family history of atopy influence lung function at follow-up of infants born prematurely?

The aim of this study was to assess whether a family history of atopy influenced lung function at follow-up of infants born prematurely. Analysis was made of thoracic gas volume and airways resistance measurements performed at 1 year of age in 86 infants born at a median gestational age of 29 weeks. These measurements had been made during a prospective follow-up study. The 30 infants with a family history of atopy were found to have a higher airways resistance (median 35 cmH2O/l/s) than the 56 infants without such a family history (median 30 cmH2O/l/s) (p < 0.05). However, when the results from 18 infants with a family history of atopy were compared with 18 controls who were matched for requirement for neonatal ventilation, parental smoking and were within at least 1 week of gestational age, no significant difference in airways resistance was found between the two groups. Multiple regression analysis demonstrated that gestational age and birth weight explained the apparent relationship between a family history of atopy and an elevated airways resistance at follow-up.

Adult↗
PubMed1995

Suprasellar tuberculoma causing endocrinologic disorders and imitating craniopharyngioma.

A patient is reported with a suprasellar tuberculoma which imitated a craniopharyngioma on computed tomography scan and magnetic resonance imaging of the brain. This lesion developed during irregularly used antituberculous therapy and caused endocrinologic disorders 3 years after the original diagnosis of tuberculous meningitis. Surgery was performed to confirm the diagnosis and also to decompress the optic pathways. Five months later, the lesion disappeared completely after appropriate antituberculous treatment.

Antitubercular Agents↗
PubMed1994

Does the duration of oxygen dependence after birth influence subsequent respiratory morbidity?

The relationship of respiratory morbidity at follow up to the development and type of "neonatal" chronic lung disease has been assessed. Three groups, each of ten infants matched for gestational age and gender, were compared. Group A had Type I chronic lung disease and group B bronchopulmonary (BPD), the most severe form of neonatal chronic lung disease (Type II CLD); group C had developed neither Type I or Type II CLD. Group B compared to group A compared to group C required a significantly longer duration of oxygen therapy on the neonatal unit. All three groups were prospectively followed; the occurrence of symptoms was documented in each of the first 3 years of life and lung function was measured using a plethysmographic technique at the end of year 1. In all 3 years a significantly greater proportion of groups A and B were symptomatic compared to group C, but there was no significant difference in the proportion so affected between groups A and B. Airway resistance was higher in both groups A and B compared to C but only reached statistical significance on comparing groups A and C. We conclude oxygen dependency beyond 1 month of age, irrespective of the development of BPD, significantly increases respiratory morbidity at follow up.

Airway Resistance↗
PubMed1994

Airways resistance and lung volume before and after bronchodilator therapy in symptomatic preterm infants.

Preterm infants who are symptomatic at follow-up frequently have a high airways resistance (RAW) and a low functional residual capacity to thoracic gas volume ratio (FRC:TGV). The aim of this study was to assess the effect of bronchodilator therapy on these lung function abnormalities. Thirty-four infants who had recurrent respiratory symptoms and a median gestational age 28 weeks, were studied at a median postnatal age of 10 months (range 6-20). TGV and RAW were measured using a plethysmographic technique and FRC by helium gas dilution. Specific conductance (SGAW) was calculated from TGV and RAW. All measurements were made immediately before and 15 min after nebulized salbutamol. Administration of nebulized salbutamol was associated with a reduction of RAW (P < 0.001) and an increase in SGAW (P < 0.001), FRC (P < 0.001). These effects on lung function were independent of postnatal age.

Airway Resistance↗
PubMed1994

Comparison of the effects on lung function of two methods of bronchodilator administration.

The aim of this study was to assess if administration of bronchodilator via a metered dose inhaler (MDI), rather than by a nebulizer, avoided the early paradoxical deterioration in lung function but, resulted in equally effective late bronchodilation. Fifteen children were studied at a median postnatal age of 9 months (range 9-18), all had been born prematurely at a median gestational age of 27 weeks (range 23-31). Lung function was measured by plethysmography before and 10 min after normal saline and 5 and 15 min after salbutamol given via an MDI and a nebulizer in random order. At 5 min, compared to baseline values, airways resistance (RAW) deteriorated by 16% after nebulized salbutamol but improved by 3% following salbutamol by the MDI (P < 0.03). At 15 min RAW improved by 14% following nebulized salbutamol and 15% after salbutamol via the MDI, there was no significant difference in the magnitude of bronchodilation between the two methods of administration. Our results therefore suggest, that as the early paradoxical deterioration in lung function is usually avoided by administering salbutamol via an MDI, this should be the preferred method of administration.

Aerosols↗
PubMed1994

Viral infections acquired during neonatal intensive care and lung function of preterm infants at follow-up.

Respiratory function was assessed at a median postnatal age of seven months in seven infants born prematurely who suffered from chronic lung disease and had a proven viral infection while on the neonatal unit (study group). The results were compared with those of seven infants with chronic lung disease who were gestational age- and gender-matched but who did not have a viral infection (controls). Six of the study group and two controls were symptomatic at follow-up. Airways resistance was significantly higher (p < 0.04) and specific conductance significantly lower (p < 0.05) in the study group compared with the controls. We conclude in premature infants with chronic lung disease that viral infections acquired in the neonatal nursery are associated with impaired lung function at follow-up.

Chronic Disease↗
PubMed1994

Prediction of respiratory morbidity in the third year of life in children born prematurely.

We have tested the hypothesis that recurrent respiratory symptoms in the third year of life in patients born prematurely were more likely to reflect a family history of atopy rather than adverse neonatal events. Comparison of 28 symptomatic and 72 asymptomatic children revealed that a family history of atopy (p < 0.01), prolonged dependence on respiratory support in the neonatal period (p < 0.01) and extreme immaturity (p < 0.02) were significantly commoner in the symptomatic group. The relative risk of having symptoms was 2.27 for a family history of atopy, 2.48 for prolonged dependence on respiratory support and 1.7 for low gestational age. We conclude that respiratory morbidity in the third year of life following premature delivery has a multifactorial aetiology.

Child↗