Search PubMed⌕ Search

Biomedical subjects

S Cullen

Publications and source records attributed to S Cullen.

At least 37 records · Page 2Linked to original sources
PubMed1995

The growth and cardiovascular effects of high dose growth hormone therapy in idiopathic short stature.

OBJECTIVE: It is possible that high dose GH treatment may have beneficial effects on growth but important adverse effects on cardiac function. We have therefore investigated the efficacy and cardiovascular effects of high dose biosynthetic human GH (r-hGH) treatment in children with idiopathic short stature and a normal pretreatment height velocity. STUDY DESIGN: Randomized controlled study. PATIENTS: Twenty-nine short (height SDS < 1.5), normally growing (height velocity SDS > -1.5), prepubertal children referred to two specialist growth clinics. INTERVENTIONS: Children were randomly assigned to an observation group or to receive 'standard' (20 IU/m2/week) or 'high' (40 IU/m2/week) dose r-hGH by daily subcutaneous injection. At the end of 1 year the observation group were randomly assigned to 'standard' or 'high' dose r-hGH therapy for the second year of the study. Regular growth, biochemical and echocardiographic monitoring were performed throughout the study period. MAIN OUTCOME MEASURES: Changes in height velocity, HtSDS for bone age (HtSDSBA), left ventricular mass index (LVMI) and left ventricular function (fractional shortening) during 2 years treatment. RESULTS: Twenty-seven children completed the study. Ht velocity SDS increased with r-hGH therapy in a dose dependent fashion. First-year height velocity SDS was +5.7 in the high dose r-hGH group compared with +2.7 in the standard dose r-hGH group and -0.5 in the observation group (P < 0.001). In those children treated for 2 years HtSDSBA was -0.5 in the high dose group but had not changed significantly in the standard dose group (-1.7) (P = 0.01). After one year r-hGH treatment LVMI was 71 g/m2 (observation group), 73 g/m2 (20 IU/m2/week group) and 74 g/m2 (40 IU/m2/week group) (P = 0.77). LVMI increased significantly from baseline to 76 g/m2 after 2 years therapy with 40 IU/m2/week r-hGH (P = 0.04) but nevertheless remained within the normal range. Fractional shortening did not change significantly over 2 years of r-hGH therapy. CONCLUSIONS: High dose (40 IU/m2/week) r-hGH treatment of children with idiopathic short stature resulted in a greater short-term acceleration in growth rate than 'standard' dose therapy without an excessive advance in skeletal maturity and probably represents the optimal growth promoting dose for short, normally growing children. Whether continued high dose r-hGH therapy increases final height requires further study. Left ventricular morphology and function remained within the normal range during r-hGH therapy but regular monitoring of cardiovascular status should continue in non-GHD children receiving r-hGH in high doses over a longer time period.

Body Height↗
PubMed1995

Snoring and sleep apnea. A population study in Australian men.

Snoring and sleeping apnea are reportedly associated with morbidity. We used home monitoring (MESAM IV) to measure snoring and sleep apnea in 294 men aged 40 to 65 yr from the volunteer register of the Busselton (Australia) Health Survey. In this group, 81% snored for more than 10% of the night and 22% for more than half the night; 26% had a respiratory disturbance index (RDI) > or = 5, and 10% had an RDI > or = 10. There was a relatively low correlation between percentage of night spent snoring and RDI (rho = 0.47, p < 0.005). Subjective daytime sleepiness plus RDI > or = 5 occurred in a minimum of 3%. Obesity was related to snoring, RDI, and minimum SaO2 (all p < 0.0001). There was no relationship between age and either RDI or snoring, but increased age was related to minimum SaO2 < 85% (p < 0.05). Alcohol consumption was not related to sleep-disordered breathing. Smokers snored for a greater percentage of the night than nonsmokers (41 versus 31%, p = 0.01). We conclude that, in middle-aged men, both snoring and sleep apnea are extremely common, and in this age range both are associated with obesity but not with age. However, a high percentage of snoring is not essential for the occurrence of sleep apnea, nor does it necessarily indicate that apnea is present.

Adult↗
PubMed1994

Ebstein's anomaly: presentation and outcome from fetus to adult.

OBJECTIVES: This study was conducted to investigate the presentation and outcome of patients with Ebstein's anomaly of the tricuspid valve. BACKGROUND: Ebstin's anomaly may present at any age and has a highly variable clinical course. Previous natural history studies have been based on clinical and angiographic diagnosis and have included mainly older children and adults. Echocardiography, however, has facilitated fetal and neonatal diagnosis so that the natural history needs to be redefined. METHODS: We reviewed 220 cases of Ebstein's anomaly presenting from fetal to adult life between 1958 and 1991, with 1 to 34 years of follow-up. RESULTS: The most common presentation in each age group was abnormal routine prenatal scan for fetuses (86%), cyanosis for neonates (74%), heart failure for infants (43%), incidental murmur for children (63%) and arrhythmia for adolescents and adults (42%). Early presentation was frequently associated with other cardiac lesions, usually pulmonary stenosis or atresia. Surgery was undertaken at some stage in 86 (39%) of the 220 patients. Actuarial survival for all liveborn patients was 67% at 1 year and 59% at 10 years. There were 58 deaths, including 26 from heart failure, 19 perioperative and 8 sudden. Predictors of death included echocardiographic grade of severity at presentation (relative risk 2.7 for each increase in grade, 95% confidence limits 1.6 to 4.6), fetal presentation (6.9, confidence limits 1.6 to 16.5) and right ventricular outflow tract obstruction (2.1, confidence limits 1.1 to 4.4). Morbidity was mainly related to arrhythmias and late hemodynamic deterioration. Of 155 survivors, 129 (83%) were in functional class 1 and 104 (67%) were receiving no medical therapy. CONCLUSIONS: In Ebstein's anomaly, fetal and neonatal presentation is associated with a poor outcome and can be predicted by the echocardiographic appearance and presence of associated lesions. In older children and adults, incidental findings and arrhythmia are common and the long-term outcome is superior.

Adolescent↗
PubMed1994

Prognostic significance of ventricular arrhythmia after repair of tetralogy of Fallot: a 12-year prospective study.

OBJECTIVE: The aim of this study was to examine the prognostic significance of ventricular arrhythmia on the ambulatory electrocardiogram (ECG) after repair of tetralogy of Fallot. BACKGROUND: Ventricular arrhythmia is common after repair of tetralogy of Fallot and has been proposed as the basis for late sudden death. The prognostic significance of ventricular arrhythmia on ambulatory ECG and the indications for therapy are uncertain. METHODS: We performed a 48-h ambulatory ECG in 86 patients (3 to 45 years old [mean age 14 years]) after repair of tetralogy of Fallot. These patients were then followed up prospectively for 12 years. RESULTS: At initial assessment in 1980, 47 patients (55%) had infrequent uniform ventricular extrasystoles (16 patients) or normal cardiac rhythm (31 patients) Group 1), and 39 patients (45%) had frequent uniform ventricular extrasystoles (> 30/h, 2 patients), complex extrasystole (30 patients) or nonsustained ventricular tachycardia (7 patients) (Group 2). There were no significant clinical or hemodynamic differences between the groups. In addition, nine patients had supraventricular tachyarrhythmia. Antiarrhythmic therapy was prescribed only for the 10 patients who had symptoms attributable to arrhythmia. There were two sudden deaths in Group 1 (4%) and one nonsudden death in Group 2 (2.5%). The absolute difference in mortality between groups was therefore 1.5% (95% confidence limits -6% to +9%), excluding a clinically significant difference in outcome. All but 1 of the 39 patients with complex ventricular arrhythmia are alive and well, including those with elevated (> or = 60 mm Hg) right ventricular pressure. CONCLUSIONS: Nonsustained ventricular arrhythmia on ambulatory ECG does not identify patients at high risk for sudden death after repair of tetralogy of Fallot. There does not appear to be any advantage in potentially dangerous long-term antiarrhythmic therapy for asymptomatic postoperative patients.

Adolescent↗
PubMed1993

In vivo detection of endothelium dependent and independent pulmonary artery relaxation in children.

BACKGROUND: In vitro studies have suggested an important role for the endothelium in the control of pulmonary vascular tone, but endothelium dependent and independent relaxation of pulmonary arteries have not been studied in children in vivo. METHODS: The response of the pulmonary circulation to graded infusions of acetylcholine (an endothelial dependent vasodilator) and to nitroprusside (a dilator not dependent on endothelium) was studied in 10 children aged four to 16 years who had normal pulmonary haemodynamics. Arterial diameter was measured by quantitative angiography, and pulmonary blood flow velocity was measured with a 3F intra-arterial Doppler catheter placed in a lower lobe segmental artery. RESULTS: There was a dose dependent increase in flow velocity in response to acetylcholine (maximum response 93%) (SEM 7%), and an increase of 51% (8%) in response to nitroprusside. By contrast, segmental artery diameter was unchanged during acetylcholine infusion in all patients, and increased only modestly in response to nitroprusside (5% (1%)). CONCLUSIONS: The most important site of action of endothelium dependent and independent pulmonary vasodilators is distal to the segmental pulmonary arteries. Despite low resting tone in the pulmonary circulation, endothelium dependent vasodilatation can be shown in vivo. This may allow study of the role of endothelial dysfunction in children with abnormal pulmonary haemodynamic secondary to congenital heart disease.

Acetylcholine↗
PubMed1993

Impairment of endothelium-dependent pulmonary artery relaxation in children with congenital heart disease and abnormal pulmonary hemodynamics.

BACKGROUND: Endothelial injury may be an important event in the pathophysiology of pulmonary hypertension. We therefore investigated whether endothelial dysfunction occurs early in children with congenital heart defects who are at risk of developing pulmonary vascular disease. METHODS AND RESULTS: In 25 children aged 3-16 years, we studied the response of the pulmonary circulation to graded infusions of acetylcholine (an endothelium-dependent vasodilator) and nitroprusside (a dilator not dependent on endothelial function). Diameter of a bronchopulmonary segment artery and pulmonary blood flow velocity were measured using quantitative angiography and intra-arterial Doppler catheters in 10 children aged 4-16 years with normal pulmonary hemodynamics (controls), seven children aged 3-12 years with left-to-right shunt lesions resulting in increased pulmonary flow, and eight children aged 3-14 years with established pulmonary vascular disease. In the controls, there was a dose-dependent increase in flow velocity in response to acetylcholine (maximal increase, 93 +/- 7%) and in response to nitroprusside (51 +/- 8%). In contrast, in patients with pulmonary vascular disease, the response of flow velocity to similar doses of acetylcholine (33 +/- 7%, p < 0.01) and nitroprusside (7 +/- 13%, p < 0.01) were impaired. In the patients with high pulmonary flow, there was an impaired response to acetylcholine (46 +/- 9%, p < 0.01), but response to nitroprusside was preserved (42 +/- 8%, p > 0.10), consistent with endothelial dysfunction. Arterial diameter was unchanged during acetylcholine infusion in all subjects and increased only modestly in response to nitroprusside (< or = 10%), indicating that the major site of action of each agent is distal to the segmental pulmonary arteries. CONCLUSIONS: Endothelium-dependent pulmonary artery relaxation can be demonstrated in vivo and is impaired in young patients with increased pulmonary flow secondary to congenital heart disease. This impairment may be an important early event in the pathogenesis of pulmonary vascular disease.

Acetylcholine↗
PubMed1992

Illness perception and symptom components in chronic fatigue syndrome.

Two-hundred and eight patients with chronic fatigue syndrome (post-viral fatigue syndrome) completed a questionnaire which dealt both with their illness in general and with the extent to which they experienced specific symptoms. A factor analysis of the symptom data yielded four components: emotional distress; fatigue; somatic symptoms; and cognitive difficulty. Emotional disturbance is a common feature of the disorder and its role has been widely debated. When the symptom components were considered independently, fatigue, somatic symptoms and cognitive difficulty were associated with questionnaire items relating to general illness severity, but emotional distress was not. Thus negative emotions did not contribute directly to patients' perception of illness severity. They were, however, correlated with the other symptom components. It is argued that this correlation reflects a reciprocal influence, with negative emotions exacerbating fatigue and other key symptoms and the debilitating nature of these symptoms enhancing emotional vulnerability.

Activities of Daily Living↗
PubMed1992

Outcome in neonates with Ebstein's anomaly.

The presentation and outcome of 50 patients with neonatal Ebstein's anomaly seen from 1961 to 1990 were reviewed. The majority (88%) presented in the 1st 3 days of life; cyanosis (80%) was the most common presenting feature. Associated defects, present in 27 infants (54%), included pulmonary stenosis in 11 and atresia in 7. Nine patients (18%) died in the neonatal period; there were 15 late deaths (due to hemodynamic deterioration in 9, sudden death in 5 and a noncardiac cause in 1) at a mean age of 4.5 years (range 4 months to 19 years). Actuarial survival at 10 years was 61%. A new echocardiographic grade (1 to 4 in order of increasing severity of the defect) was devised with use of the ratio of the area of the right atrium and atrialized right ventricle to the area of the functional right ventricle and left heart chambers. Cardiac death occurred in 0 of 4 infants with grade 1, 1 (10%) of 10 with grade 2, 4 (44%) of 9 with grade 3 and 5 (100%) of 5 with grade 4. In a multivariate analysis of clinical and investigational features at presentation, echocardiographic grade of severity was the best independent predictor of death. Neonates with Ebstein's anomaly have a high early mortality rate and those surviving the 1st month of life remain at high risk of late hemodynamic deterioration or sudden death. Echocardiographic grading of severity of the defect permits prognostic stratification.

Abnormalities, Multiple↗
PubMed1992

Potential impact of population screening for prenatal diagnosis of congenital heart disease.

The potential impact of prenatal screening for the detection of congenital heart disease (CHD) was assessed by prospective analysis of 428 consecutive infant admissions to a supraregional centre; 28 (6.5%) did not have CHD and were excluded from analysis. Of the 400 cases with CDH, 396 (99%) underwent fetal ultrasonography but scanning was performed only before 18 weeks' gestation in 200 (50%). One hundred and forty nine (37%) of all cardiac abnormalities and 149/283 (53%) of severe abnormalities were considered to be detectable prenatally in a screening echocardiographic four chamber view had this technique been used. Prenatal diagnosis of severe CHD actually occurred in only eight (2%) cases and was after 30 weeks' gestation in all. There were 181/347 (52%) of all mothers and 177/253 (70%) of the subgroup with severe abnormalities who expressed an opinion volunteered their preference for termination of pregnancy if mid-trimester diagnosis had been available. Mid-trimester detection of congenital heart disease rarely occurs at present despite fetal ultrasound scanning in almost all pregnancies. More than half of all severe congenital heart defects seen in infancy are potentially detectable by screening. Major training at primary scan level and modification of the timing of existing fetal anomaly scanning would be required for a screening programme to be effective.

Female↗
PubMed1992

Growth hormone treatment in idiopathic short stature: a preliminary analysis of cardiovascular effects.

Growth hormone (GH) hypersecretion is associated with an increased incidence of hypertension and cardiac hypertrophy, resulting in excess cardiovascular morbidity and mortality. Abnormalities in the renin-angiotensin-aldosterone (RAA) system have been reported in acromegaly and in normal adults treated with recombinant human GH. The RAA system was investigated in prepubertal children with idiopathic short stature during treatment with recombinant human GH in doses up to 40 IU/m2/week. In addition, left ventricular size and function were assessed by serial echocardiography over an initial 12-month period. Modest and transient increases in blood pressure and body weight were observed during the first 7 days of GH treatment, but this was not accompanied by activation of the RAA system. Echocardiographic parameters of left ventricular size and function remained within the normal range for age and body size. Short-term GH treatment of idiopathic short stature was thus not associated with an increase in risk factors known to be associated with later cardiovascular morbidity. Longer follow-up studies will be required to confirm the safety of high-dose GH in this respect.

Blood Pressure↗
PubMed1991

Pituitary adenylate cyclase-activating polypeptide: a novel, long-lasting, endothelium-independent vasorelaxant.

The vasoactivity of the 27- and 38-amino acid forms of the novel peptide pituitary adenylate cyclase-activating polypeptide (PACAP) was tested in vitro. Both forms of PACAP caused endothelium-independent vasodilation (assayed by their vasodilator action on rabbit aorta). When superfused for 1 min the relaxation EC50 of PACAP27 was 23 +/- 8 nM and of PACAP38 was 152 +/- 66 nM. PACAP was 100-fold more potent than vasoactive intestinal polypeptide (VIP) (PACAP27 shows 68% amino acid sequence homology with VIP), and had a prolonged duration of action, a 1 min exposure to 1 microM PACAP27 lasting 135 +/- 7 min and to 1 microM PACAP38 108 +/- 3 min. Adenylate cyclase activity in homogenates of rabbit aortic smooth muscle cells was increased by PACAP27 and PACAP38 with EC50s of 4.4 and 0.73 nM, respectively. PACAP27 and PACAP38 are potent, long-lasting, endothelium-independent vasodilators.

Adenylyl Cyclases↗
PubMed1991

Congenitally corrected transposition and Ebstein's anomaly of the systemic atrioventricular valve: association with aortic arch obstruction.

Aortic arch abnormalities are uncommon in patients with congenitally corrected transposition of the great arteries. Over a 20-year period, 10 patients with congenitally corrected transposition and Ebstein's anomaly of the systemic atrioventricular (AV) valve were identified. Five neonates had severe systemic AV valve regurgitation with severe coarctation of the aorta (n = 4) or aortic atresia (n = 1) and presented with heart failure. Four died in the neonatal period and one who had coarctation repair died 7 months postoperatively. The remaining five patients with congenitally corrected transposition and Ebstein's anomaly had mild left AV valve regurgitation; none of these had aortic arch obstruction. In neonates who have coexisting Ebstein's anomaly of the systemic AV valve and congenitally corrected transposition, obstruction to aortic arch flow is common. Severe systemic AV valve regurgitation with a morphologic systemic right ventricle may have contributed to low anterograde flow in the ascending aorta prenatally and thereby to the aortic arch abnormality.

Aorta, Thoracic↗
PubMed1991

The miscarriage clinic: an audit of the first year.

We preview the results of the first year in a Miscarriage Clinic set up in 1989 in an effort to improve the support and counselling of women who have a miscarriage. Of 381 patients referred, 79% attended. The only statistically significant difference between the women who attended and those who did not attend was in the proportion of women who had planned their pregnancies (65% versus 33%, P less than 0.01). Of the 300 patients who attended, 4% reported no grief reaction; 75% experienced a reaction which had resolved within one month and 21% experienced a reaction which had not resolved. No factor was identified which could predict the duration of the grief reaction. This audit demonstrates that there is a strong demand and need for this service for couples who experience a miscarriage.

Abortion, Spontaneous↗