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Biomedical subjects

G R Sutherland

Publications and source records attributed to G R Sutherland.

At least 379 records · Page 21Linked to original sources
PubMed1991

Assessment of anomalous systemic and pulmonary venous connections by transoesophageal echocardiography in infants and children.

OBJECTIVE: To assess the value of transoesophageal echocardiography in the preoperative definition of systemic and pulmonary venous connections. DESIGN: Transoesophageal echocardiographic studies were performed prospectively under general anaesthesia in 76 consecutive unoperated children. Results were compared with those obtained by earlier transthoracic ultrasound studies (n = 76), cardiac catheterisation (n = 62), and subsequent surgical inspection (n = 58). SETTING: Two tertiary referral centres. PATIENTS: 76 unoperated infants and children (age 0.2-14.8 years, mean age 4.1 years) with congenital heart disease. MAIN OUTCOME MEASURE: Identification of anomalous systemic and pulmonary venous connections. RESULTS: Transoesophageal studies showed anomalous venous connections in 14 patients. Two had both anomalous systemic and pulmonary venous connections. Transoesophageal studies showed 12 anomalous systemic venous connections in nine patients. In eight patients these were confirmed at operation or catheterisation: one patient is awaiting operation. Six anomalous systemic venous connections were missed during earlier transthoracic studies. Anomalous pulmonary venous connections (one mixed total, six partial) were shown in seven patients. These were confirmed at operation in six and by cardiac catheterisation in one. Four of these patients were missed during earlier transthoracic ultrasound studies. No patient defined as having normal venous connections by the transoesophageal study was subsequently shown to have anomalous venous connections at operation or angiography. CONCLUSIONS: Transoesophageal echocardiography is a highly sensitive tool for the preoperative definition of systemic and pulmonary venous connections. In this series it was better than transthoracic ultrasound and complemented cardiac catheterisation and angiocardiography.

Adolescent↗
PubMed1991

Fragile X syndrome: genetic localisation by linkage mapping of two microsatellite repeats FRAXAC1 and FRAXAC2 which immediately flank the fragile site.

We report the genetic localisation of the fragile site at Xq27.3 associated with fragile X syndrome. The position of the fragile site within the multipoint linkage map was determined using two polymorphic microsatellite AC repeat markers FRAXAC1 and FRAXAC2. These markers were physically located within 10 kilobases and on either side of the p(CCG)n repeat responsible for the fragile site. FRAXAC1 has five alleles with heterozygosity of 44% and is in strong linkage disequilibrium with FRAXAC2 which has eight alleles and a heterozygosity of 71%. No recombination was observed either between these markers in 40 normal CEPH pedigrees or with the fragile X in affected pedigrees. These markers provide the means for accurate diagnosis of the fragile X genotype in families by rapid polymerase chain reaction analysis and were used to position the fragile X within the multipoint map of the X chromosome to a position 3.7 cM distal to DXS297 and 1.2 cM proximal to DXS296.

Base Sequence↗
PubMed1991

Chromosomal location of the human tumor necrosis factor receptor genes.

TNFR1 and TNFR2, the genes encoding the two forms of the human tumor necrosis factor receptor, were localized to normal human chromosomes by in situ hybridization and Southern blot analysis of a series of human x mouse hybrid cell lines. TNFR1 maps to 12p13 and TNFR2 maps to 1p36.

Blotting, Southern↗
PubMed1991

Safety of transesophageal echocardiography. A multicenter survey of 10,419 examinations.

BACKGROUND: During the past few years, transesophageal echocardiography (TEE) has been increasingly used in clinical cardiology; data concerning the practicability and safety of the technique, however, are rare. METHODS AND RESULTS: This report analyzes the experience of 15 European centers performing TEE studies for at least 1 year. At the time of this survey, 10,419 TEE examinations had been attempted or performed in these institutions. These TEE examinations were carried out by 54 physicians, 53.7% of whom had been trained in endoscopic techniques. Within the same time period, 160,431 precordial echocardiographic examinations were performed in the 15 institutions; the ratio between TEE and transthoracic studies averaged 9.03 +/- 6.4% (range of the 15 centers, 1.4-23.6%). Of the 10,419 patients, 9,240 (88.7%) were conscious inpatients or outpatients at the time of the TEE examination; the vast majority of the conscious patients did not receive intravenous sedation before TEE. In 201 cases (1.9%), insertion of the TEE probe was unsuccessfully attempted because of a lack of patient cooperation and/or operator experience (98.5%) or because of anatomical reasons (1.5%). In 90 of 10,218 TEE studies (0.88%) with successful probe insertion, the examination had to be interrupted because of the patient's intolerance of the echoscope (65 cases); because of pulmonary (eight cases), cardiac (eight cases), or bleeding complications (two cases); or for other reasons (seven cases). One of the bleeding complications resulted from a malignant lung tumor with esophageal infiltration and was fatal (mortality rate, 0.0098%). CONCLUSIONS: This multicenter survey documents that TEE studies are associated with an acceptable low risk when used by experienced operators under proper safety conditions.

Data Collection↗
PubMed1991

Epidemiology of Down syndrome in South Australia, 1960-89.

During 1960-89 687 Down syndrome live births and 46 Down syndrome pregnancy terminations were identified in South Australia. Ascertainment was estimated to be virtually complete. The sex distribution of Down syndrome live births was found to be statistically different from the non-Down syndrome live-birth sex distribution (P less than .01). Smoothed maternal age-specific incidence was derived using both maternal age calculated to the nearest month and a discontinuous-slope regression model. The incidence of Down syndrome at birth for the study period was estimated to be 1.186 Down syndrome births/1,000 live births. Annual population incidence was shown to be correlated with trends in the maternal age distribution of confinements. If current trends in the maternal age distribution of confinements continue, the population incidence of Down syndrome in South Australia is predicted to exceed 1.5 Down syndrome births/1,000 live births during the 1990-94 quinquennium.

Abortion, Spontaneous↗
PubMed1991

[The echo-dobutamine test for the diagnosis of myocardial ischemia. Study on 20 patients with normal kinetics at rest].

We have assessed the value of dobutamine stress echocardiography for the diagnosis of myocardial ischemia in 20 consecutive patients referred for chest pain, without a previous myocardial infarction and with a normal left ventricular wall motion at rest. The test was considered positive when wall motion abnormalities appeared during dobutamine infusion (from 5 to a maximum of 40 micrograms/Kg/min). The results were compared to the % diameter stenosis (%DS) quantitatively measured on coronary arteriography. "Significant" coronary artery disease was defined as greater than or equal to 50% DS. No significant side effects occurred in any patients during the test. Transient wall motion abnormalities were detected in 8 of the 12 patients with significant coronary artery disease (sensitivity = 66%) and in 1 of the 8 patients without significant coronary artery disease (specificity = 88%). All the patients with false-negative dobutamine stress echocardiography had distal stenosis or stenosis in a collateral vessel; moreover, all the patients with true-positive dobutamine stress echocardiography had proximal (7 patients) or middle (1 patient) stenosis. The results of this study show that dobutamine stress echocardiography is a safe and feasible test for the noninvasive diagnosis of myocardial ischemia.

Adult↗
PubMed1991

Intraoperative ultrasonographic identification of coronary artery compression after an arterial switch procedure.

A case is reported of a neonate with transposition of the great arteries, undergoing an arterial switch operation, in whom the cause for postbypass cardiac failure was diagnosed by intraoperative epicardial echocardiography. Obvious regional dyskinesia was seen by two-dimensional echocardiography in the posterolateral segments of the left ventricle, supplied by the circumflex coronary artery. After the switch procedure, the reimplanted circumflex artery ran between the aorta and the pulmonary artery. Lifting the pulmonary artery off the circumflex artery resulted in immediate improvement of regional myocardial function, which could be monitored on-line with echocardiography. Thus compression of the circumflex by the pulmonary artery was the cause for cardiac failure. On the basis of the echocardiographic information, immediate and successful surgical revision was performed. Intraoperative epicardial echocardiography has a unique diagnostic potential in the case of cardiac failure after cardiopulmonary bypass.

Constriction, Pathologic↗
PubMed1991

Fragile X syndrome: diagnosis using highly polymorphic microsatellite markers.

We describe two highly polymorphic microsatellite AC repeat sequences, VK23AC and VK14AC, which are closely linked to the fragile X at Xq27.3. Both VK23AC (DXS297) and VK14AC (DXS292) are proximal to the fragile site. Two-point linkage analysis in 31 fragile X families gave (a) a recombination frequency of 1% (range 0.00%-4%) with a maximum lod score of 32.04 for DXS297 and (b) a recombination frequency of 7% (range of 3%-15%) with a maximum lod score of 12.87 for DXS292. Both of these polymorphisms are applicable to diagnosis by linkage in families with fragile X syndrome. A multipoint linkage map of genetic markers at Xq27.3 was constructed from genotyping these polymorphisms in the CEPH pedigrees. The DXS292 marker is in the DXS98-DXS297 interval and in 3 cM proximal to DXS297.

Alleles↗
PubMed1990

Localization of the human GM-CSF receptor gene to the X-Y pseudoautosomal region.

Mammalian sex chromosomes share a small terminal region of homologous DNA sequences, which pair and recombine during male meiosis. Alleles in this region can be exchanged between X and Y chromosomes and are therefore inherited as if autosomal. Genes from this so-called pseudoautosomal region (PAR) are present in two doses in both males and females, and escape inactivation of the X chromosome in females. Indirect evidence suggests that there must be several pseudoautosomal genes, and several candidates have been proposed. Until now, the only gene that has been unequivocally located in the PAR is MIC2, which encodes a cell-surface antigen of unknown function. We now report the localization of a gene of known function to this region--the gene for the receptor of the haemopoietic regulator, granulocyte-macrophage colony stimulating factor. The chromosomal localization of this gene may be important in understanding the generation of M2 acute myeloid leukaemia.

Chromosome Mapping↗
PubMed1990

Predictive diagnosis for polycystic kidney disease using DNA markers.

Two families in which the gene for the common, autosomal dominant form of polycystic kidney disease (PKD1) was present were examined using flanking DNA markers. The 5'HVR probe detects a linked DNA marker 8 map units distal to the PKD1 gene in males and 1 unit distal to the PKD1 gene in females. The 24-1 probe detects another linked DNA marker 4 map units proximal to the PKD1 gene in males and 0.5 map units proximal to the PKD1 gene in females. When each marker is informative they can be used as a pair flanking the disease gene to follow accurately its transmission through families for presymptomatic or prenatal prediction. For an asymptomatic individual tested in one family, DNA studies reduced the 50% prior risk of carrying the disease gene to 0.006%. An affected woman in a second family was shown to be fully informative for the flanking markers. In a future pregnancy, it will be possible to modify the 50% prior fetal risk to either 0.008% or 99.99% depending on which maternal chromosome 16 is transmitted, and provided that no cross-over occurs between the flanking markers (probability, 1.5%).

Chromosome Mapping↗
PubMed1990

Probe, VK5B, is located in the same interval as the autosomal dominant adult polycystic kidney disease locus, PKD1.

The polymorphic DNA probe VK5B (D16S94) was mapped by genetic linkage in families from the Centre d'Etude de Polymorphisme Humain (CEPH) as being in the same interval as the autosomal dominant adult polycystic kidney disease locus (PKD1). The maximum likelihood estimate of the genetic location of VK5B using multipoint linkage analysis was 9.6 cM proximal to 3'HVR (D16S85) and 5.4 cM distal to CRI-0327 (D16S63), in males. The VK5B probe may be useful in PKD1 families for prenatal and presymptomatic diagnosis of the disease. Additional typing of PKD1 families is required to determine whether the location of VK5B is distal or proximal to (PKD1).

Adult↗
PubMed1990

Subaortic obstruction: intraoperative echocardiography as an adjunct to operation.

Fourteen patients undergoing operation for subaortic obstruction (membranous obstruction in 11 patients, tunnel obstruction in 2 patients, obstruction due to reduplicated mitral valve tissue in 1 patient) were evaluated by intraoperative epicardial echocardiography. In all 9 patients with "discrete" obstruction who underwent prebypass epicardial echocardiography, the septal and lateral attachments of the lesion were correctly demonstrated. The precise extent of tunnel stenosis was seen in both patients. The lateral attachment of the membrane in 4 patients and multiple extensions in another 2 were identified by the epicardial study (having been missed on precordial echocardiography). The discrete membrane was enucleated in 10 of the 11 patients and was partially resected in 1. One tunnel obstruction was completely relieved; the other was partially relieved. Reduplicated mitral valve tissue in the remaining patient was completely resected. Epicardial imaging after bypass showed remnants of the membrane in 2 patients. Intraoperative Doppler echocardiography and color flow imaging confirmed the absence of clinically significant residual gradients (less than 20 mm Hg) in all but 1 patient with tunnel obstruction. Epicardial imaging provided excellent morphological information about obstructive lesions of the left ventricular outflow tract and enabled immediate assessment of surgical repair.

Aortic Valve Stenosis↗
PubMed1990

Obstruction of the left ventricular outflow tract in childhood--improved diagnosis by transoesophageal echocardiography.

We used transoesophageal echocardiography in 4 children with either documented or suspected obstruction of the left ventricular outflow tract to determine whether this technique may provide additional morphologic information when compared to praecordial ultrasound. Transoesophageal studies defined unsuspected mitral valvar abnormalities in two patients and involvement of the subvalvar mitral apparatus in one. In one patient, the study documented a suspected fibrous ridge associated with malalignment of the outlet septum. Transoesophageal echocardiography would appear to be a new technique with definite advantages in defining the spectrum of lesions which cause obstruction to the left ventricular outflow tract in children.

Child↗