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Biomedical subjects

G R Sutherland

Publications and source records attributed to G R Sutherland.

At least 361 records · Page 20Linked to original sources
PubMed1991

A normal 46,XX infant with a 46,XX/69,XXY placenta: a major contribution to the placenta is from a resorbed twin.

A predominantly triploid 69,XXY placenta was found associated with a normal 46,XX infant. Therefore, a triploid placenta is apparently capable of supporting normal fetal development. The chromosome and pathological results support the conclusion that the triploid placenta originates from a 'vanishing twin' pregnancy. This case is unusual in that persistence of the placenta from the vanished twin has virtually replaced most of the normal placenta.

Amniocentesis↗
PubMed1991

Frequent deletions at Xq28 indicate genetic heterogeneity in Hunter syndrome.

Hunter syndrome is a human X-linked disorder caused by deficiency of the lysosomal exohydrolase iduronate-2-sulphatase (IDS). The consequent accumulation of the mucopolysaccharides dermatan sulphate and heparan sulphate, in the brain and other tissues, often results in death before adulthood. There is, however, a broad spectrum of severity that has been attributed to different mutations of the Hunter syndrome gene. We have used an IDS cDNA clone to localise the IDS gene to Xq28, distal to the fragile X mutation (FRAXA). One-third of Hunter syndrome patients had various deletions or rearrangements of their IDS gene, proving that different mutations are common in this condition. Deletions of the IDS gene can include a conserved locus that is tightly linked to FRAXA, suggesting that deletion of nearby genes may contribute to the variable clinical severity noted in Hunter syndrome. The cDNA clone was also shown to span the X chromosome breakpoint in a female Hunter syndrome patient with an X;autosome translocation.

Blotting, Southern↗
PubMed1991

An ultrahigh-sulphur keratin gene of the human hair cuticle is located at 11q13 and cross-hybridizes with sequences at 11p15.

A human hair cuticle ultrahigh-sulphur keratin Q (UHSK) gene (KRN1) has been mapped by Southern analysis of a somatic cell hybrid panel and by in situ hybridization. A probe containing the coding region of this gene mapped to 11pter- greater than 11q21 using the hybrid cell panel and on in situ hybridization mapped to two regions on chromosome 11: the distal part of 11p15, most likely 11p15.5, and the distal part of 11q13, most likely 11q13.5. A probe from the 3' noncoding region of KRN1 mapped to 11q13.5 indicating that this was the map location of the cloned gene. The sequence of 11p15.5 is termed KRN1-like (KRN1L). The results reveal that the cuticle UHSK gene family is clustered in the human genome.

Blotting, Southern↗
PubMed1991

Aortic atresia with normal left ventricle: one-stage repair in early infancy.

Successful one-stage repair of aortic atresia with a left ventricle was performed in a 6-week-old infant using a new technique. After patch enhancement of the hypoplastic aortic arch, the transected proximal pulmonary artery was directly anastomosed to the aortic arch. An intraventricular baffle established continuity between the left ventricle and neoaortic valve, and a homograft conduit was inserted between the right ventricle and pulmonary artery bifurcation.

Anastomosis, Surgical↗
PubMed1991

The effects of caffeine on ischemic neuronal injury as determined by magnetic resonance imaging and histopathology.

The effects of caffeine on ischemic neuronal injury were determined in rats subjected to forebrain ischemia induced by bilateral carotid occlusion and controlled hypotension (50 mmHg for 10 min). High resolution (100 microns) multi-slice, multi-echo magnetic resonance images were obtained daily for three consecutive days post-operatively in sham-operated rats and in rats that received either saline vehicle (controls), a single i.v. injection of 10 mg/kg caffeine 30 min prior to an ischemic insult (acute caffeine group), or up to 90 mg/kg per day of caffeine for three consecutive weeks prior to an ischemic insult (chronic caffeine group). Rats in the control group exhibited enhanced magnetic resonance image intensity in the striatum 24 h after ischemia which increased in the striatum and also appeared in the hippocampus after 48 h, and which began to resolve in both regions by 72 h post-ischemia. Histopathological analysis of each rat following the final magnetic resonance examination showed that ischemic neuronal injury was strictly confined to the brain regions showing magnetic resonance image changes. Acute caffeine rats showed accelerated changes in the magnetic resonance images, with increased hippocampal intensity appearing at 24 h post-ischemia. Although there was magnetic resonance evidence of accelerated injury, quantitative analysis of the histopathological data at 72 h showed no significant difference in the extent of neuronal injury in any brain region between control-ischemic and acute caffeine rats. Nine out of 11 rats in the chronic caffeine group showed no magnetic resonance image changes over the three study days. Chronic caffeine rats had significantly less neuronal damage in all vulnerable brain regions than either of the other groups of ischemic rats. The accelerated ischemic injury in rats treated with an acute dose of caffeine may occur secondary to antagonism of adenosine receptors, whereas protection from ischemic injury following chronic administration of caffeine may be mediated by up-regulation of adenosine receptors.

Adenosine↗
PubMed1991

Transesophageal echocardiography in evaluation and management after a Fontan procedure.

Transesophageal echocardiography was used in 18 patients (aged 1.6 to 34 years, mean age 12.6) to assess the immediate (5 patients) or intermediate (13 patients) results after a Fontan-type procedure. The findings were correlated with precordial echocardiographic (all patients) and cardiac catheterization (11 patients) data. Atrial shunting was documented by transesophageal studies in three patients (precordial in one patient). In two patients it was confirmed by cardiac catheterization; the third underwent reoperation based on the transesophageal study alone. Pulmonary artery obstruction was documented in three patients (precordial in one patient) and was confirmed by subsequent cardiac catheterization in all. Evaluation of anterior Fontan connections was successful in 5 of 8 patients (precordial in 6 of 8), and posterior connections in 10 of 10 patients (precordial in 5 of 10). A Glenn shunt could be evaluated in eight of nine patients (precordial in three of nine). Thrombus formation was detected by transesophageal studies in three patients (precordial in one patient); repeat studies were used to evaluate thrombolytic therapy in two. Atrioventricular valvular regurgitation (11 of 18 patients) was better defined by transesophageal than by precordial studies (5 of 18). A coronary artery fistula was identified in two cases (precordial in none). Transesophageal pulsed Doppler interrogation of pulmonary artery and pulmonary vein flow patterns consistently allowed a detailed evaluation of the Fontan circulation. Transesophageal echocardiography is an important diagnostic and monitoring technique after the Fontan procedure. In this series, it was far superior to precordial ultrasound evaluation and of substantial additional value to cardiac catheterization.

Adolescent↗
PubMed1991

Addition of MT, D16S10, D16S4, and D16S91 to the linkage map within 16q12.1-q22.1.

A 10-point genetic linkage map of the region 16q12.1 to 16q22.1 has been constructed using the CEPH reference families. Four loci, MT, D16S10, D16S91, and D16S4, not previously localized on a multipoint linkage map, were incorporated on the map presented here. The order of loci was cen-D16S39-MT, D16S65-D16S10-FRA16B-D16S38, D16S4, D16S91, D16S46-D16S47-HP-qter. The interval between D16S10 and 4D16S38 is 3.1 cM in males and 2.3 cM in females, and contains FRA16B. The cloning strategy for FRA16B will now be based on YAC walking from D16S10 and D16S38. The location of FRA16B between D16S10 and D16S38 provides a physical reference point for the multipoint linkage map on the short arm of chromosome 16.

Chromosome Mapping↗
PubMed1991

Human chromosome 16 physical map: mapping of somatic cell hybrids using multiplex PCR deletion analysis of sequence tagged sites.

Physical mapping of human chromosome 16 has been undertaken using somatic cell hybrid DNAs as templates for polymerase chain reaction (PCR) deletion analysis of sequence tagged sites (STSs). A panel of 29 somatic cell hybrids was analyzed, confirming and refining previous chromosome 16 breakpoint orders and distinguishing between the locations of breakpoints in new hybrids. Ten STS markers were coamplified in three multiplex reactions allowing the rapid, simultaneous deletion analysis of nine different loci. The locations of the protamine (PRM1), sialophorin (SPN), complement component receptor 3A (CR3A), NAD(P)H menadione oxidoreductase 1 (NMOR1), and calbindin (CALB2) genes were refined.

Animals↗
PubMed1991

The interleukin-4 receptor gene (IL4R) maps to 16p11.2-16p12.1 in human and to the distal region of mouse chromosome 7.

The chromosomal location of both the human and the mouse interleukin-4 receptor (IL4R) genes have been determined. The human gene was localized to 16p11.2-16p12.1 by in situ hybridization and confirmed by Southern blot analysis of DNA from a panel of mouse-human hybrid somatic cell lines. The mouse homolog was positioned in the distal region of chromosome 7 by interspecific backcross analysis. The results suggest that the IL4R locus is unlinked to other members of the hematopoietin receptor family. Interestingly, the position on human chromosome 16 suggests that the IL4R may be a candidate for rearrangements, as 12;16 translocations are often associated with myxoid liposarcomas.

Animals↗
PubMed1991

The early and long-term results of surgery for coarctation of the aorta in the 1st year of life.

The cases of 110 infants less than 1 year of age, who had surgical repair for coarctation of the aorta between June 1974 and February 1988, were analysed. Three groups of patients were identified. In group 1 there were 39 patients with isolated coarctation. In group 2 there were 25 infants with additional ventricular septal defects (VSD), while in group 3 there were 46 infants with other associated congenital cardiac defects. Repair was performed using the subclavian flap aortoplasty (SFA) procedure in 83 patients, resection with end-to-end anastomosis (EEA) in 23, patch aortoplasty in 3 and Goretex tube bypass in 1. Twenty-eight patients had simultaneous pulmonary artery banding and one concomitant closure of the VSD. The overall early mortality rate was 8.2% (5.1% in group 1, 0% in group 2, and 15.2% in group 3). Age at operation (under 1 month, p = 0.04) and other associated cardiac anomalies (p = 0.03) increased early mortality significantly. There were 11 late deaths (10.8%) among 101 patients followed from 1 to 15 years (mean 5.3 years). Twelve patients underwent further surgery for recoarctation, eight of them within 11 months. A further 11 patients currently have a Doppler gradient across their coarctation site of more than 20 mmHg, but have not undergone further surgery to the coarctation repair site.

Anastomosis, Surgical↗
PubMed1991

Pulmonary atresia with intact ventricular septum: is neonatal repair advisable?

The optimal management of pulmonary atresia with an intact ventricular septum in the neonate remains controversial. The introduction of balloon septostomy and prostaglandin has significantly reduced early mortality but early surgical intervention is necessary to obtain a more adequate pulmonary blood flow. Fourteen neonates with pulmonary atresia and an intact ventricular septum were admitted to the Wessex Cardiothoracic Unit, Southampton from 1979 to 1986. Thirteen patients underwent cardiac catheterization. Cardiac catheterization data and right ventricular angiograms were reviewed retrospectively. Four patients with tripartite ventricles underwent total repair. The others received various palliative operations (valvotomy + modified Blalock-Taussig shunt or modified Blalock-Taussig shunt alone). Retrospective analysis of the angiograms indicated that right ventricular morphology alone is not a satisfactory criterion for surgical management. We have been able to demonstrate that there is a good correlation between the diameter of the tricuspid valve and the diameter of the infundibulum and that successful neonatal repair is possible when the tricuspid valve diameter is above 80% of the normal value for weight and when the tricuspid valve diameter to infundibular diameter ratio (TV/Inf ratio) is 2.2 or less. In patients with a tripartite ventricle but inadequate TV diameter and TV/Inf ratio, a closed pulmonary valvotomy with a modified Blalock-Taussig shunt remains the treatment of choice.

Cardiac Catheterization↗
PubMed1991

The use of duplex sonography in the detection of colorectal hepatic metastases.

Conventional imaging techniques are of limited value in identifying small liver metastases. Indirect methods of measuring blood-flow have shown that metastases may be associated with subtle changes in liver blood-flow. Doppler ultrasonography has the ability to measure liver blood-flow directly. In this study, the role of duplex sonography in the detection of hepatic metastases was evaluated. Hepatic arterial and portal venous blood-flows were measured in 30 patients awaiting surgery for colorectal cancer and 16 controls. The ratio of hepatic arterial: portal venous blood-flow (Doppler flow ratio; DFR) and the ratio of hepatic arterial:hepatic arterial and portal venous blood-flow (Doppler perfusion index; DPI) were calculated. Clear separation of the DPI and DFR values of controls and patients with histologically confirmed liver metastases was observed (P less than 0.001). The data suggest that the measurement of liver blood-flow by duplex sonography may be of value in the diagnosis of colorectal liver metastases.

Adult↗
PubMed1991

The comparative value of exercise echocardiography and 99m Tc MIBI single photon emission computed tomography in the diagnosis and localization of myocardial ischaemia.

To determine the relative value of exercise two-dimensional echocardiography and 99m Tc methoxyisobutylisonitrile single photon emission computed tomography (MIBI SPECT) for the detection of myocardial ischaemia, 103 consecutive patients with either proven or suspected coronary artery disease, who were referred for perfusion scintigraphy, were studied by a combination of the two techniques during the same symptom-limited upright bicycle exercise test. Appropriate echocardiographic images were recorded both at rest and immediately post-exercise and subsequently analysed by means of digital cine loop processing. Both echocardiographic and MIBI SPECT images were visually analysed. For each technique, three different responses to exercise were defined: normal (absence of rest and exercise abnormalities); ischaemic (transient scintigraphic perfusion defects and transient wall motion abnormalities during exercise echocardiography); and fixed abnormalities (fixed scintigraphic perfusion defects; echocardiographic wall motion abnormalities at rest without worsening after exercise). To allow a valid comparison of each technique in localizing ischaemia, the left ventricle was divided into the following six major regions for both methods: anterior, posterolateral, inferior, interventricular septum (subdivided in anterior and posterior septum) and apex. Eleven of the 103 patients had to be excluded from the final analysis because of unsatisfactory examinations: seven with non-interpretable exercise echocardiograms and four with non-interpretable MIBI SPECT images. The response to exercise was concordantly classified by both techniques in 84% of patients (k = 0.78). Exercise echocardiography revealed the presence of ischaemia in 38 and MIBI SPECT in 45 patients (agreement = 77%).(ABSTRACT TRUNCATED AT 250 WORDS)

Contrast Media↗
PubMed1991

The role of transoesophageal echocardiography in adolescents and adults with congenital heart defects.

Between April 1985 and December 1989, outpatient transoesophageal echocardiography was performed in 133 adolescent and adult patients (14% of all outpatient transoesophageal studies) (age range 11-78 years; weight 30-95 kg) to determine the value of this technique both in establishing the primary diagnosis (62 patients) and in the post-surgical follow up (71 patients) of congenital heart disease. The results were correlated with the findings of precordial echocardiography, catheterization and surgical inspection. Clear advantages of transoesophageal imaging over precordial imaging include: (1) direct identification of atrial appendage morphology in all patients; (2) delineation of systemic and pulmonary venous connections; (3) atrial baffle function (eight patients); (4) better evaluation of the Fontan-type circulation (five patients); (5) improved morphologic assessment of the atrioventricular junction and valves (29 patients); (6) definition of subaortic obstruction (18 patients); and (7) definition of ascending aortic morphology in Marfan's syndrome and supravalvar aortic stenosis (13 patients). The problems encountered with transoesophageal imaging include: (1) limited imaging planes; (2) poor visualization of specific intracardiac regions (antero-apical trabecular septum, right ventricular outflow tract); (3) flow masking behind implanted intracardiac prosthetic material.

Adolescent↗
PubMed1991

The value of colour flow mapping in the diagnosis of a combined pseudoaneurysm and large true left ventricular aneurysm.

During ultrasound assessment of a large postinfarct apical left ventricular aneurysm, a related localized area of ventricular wall rupture was discovered by colour flow mapping. Other non-invasive and invasive techniques failed to demonstrate the pseudoaneurysm. The rare combination of a true and false left ventricular aneurysm in one patient and the diagnostic difficulties in this case uniquely illustrate the recent controversy concerning the definition and diagnosis of pseudoaneurysm. The clinical importance of colour flow mapping, as the most sensitive technique in detecting pseudoaneurysm, is emphasized.

Blood Flow Velocity↗
PubMed1991

Detection of hepatic metastases using duplex/color Doppler sonography.

Current imaging modalities are unable to detect small liver metastases because of limited resolution and contrast differentiation. The association between liver metastases and altered liver blood flow has been demonstrated by dynamic scintigraphy, but the clinical feasibility of this test has been questioned. In this study a novel approach to detecting liver metastases was assessed by measurement of liver blood flow using a duplex/color Doppler System. Hepatic arterial and portal venous blood flows were measured in 16 controls, 50 patients with gastrointestinal cancer, and 6 patients with breast cancer. The ratio of hepatic arterial to total liver blood flow (Doppler perfusion index, DPI) and the ratio of hepatic arterial: portal venous blood flow (Doppler flow ratio, DFR) were calculated. The DPI and DFR values of controls and patients with overt liver metastases were clearly separated (p less than 0.0001). The results suggest that duplex/color Doppler ultrasound measurement of hepatic perfusion changes may be of value in the detection of liver metastases.

Adult↗
PubMed1991

Role of intraoperative ultrasound examination in patients undergoing a Fontan-type procedure.

To determine its potential impact on perioperative surgical management intraoperative ultrasound examination (cross sectional imaging, colour flow mapping, pulsed and continuous wave Doppler) was used in 16 consecutive patients undergoing a Fontan-type procedure. Epicardial cross sectional imaging before bypass defined the precise intracardiac morphology in 15 of 16 patients. The preoperative morphological diagnosis was refined in four patients (25%), and this influenced surgical management in two (12%). Epicardial studies after bypass identified seven residual haemodynamic lesions in five patients (three residual intercardiac shunts, one ventricular outflow obstruction, one pulmonary artery obstruction, two mitral valve regurgitation), and led to immediate revision during a second period of bypass in three (18%). In one patient who required early reoperation residual shunting was not detected after bypass by either colour flow mapping or a contrast study. Final intraoperative studies showed a good surgical result in 14 patients (87%). Flow characteristics and flow velocities within the Fontan circulation could be assessed immediately after the patient came off cardiopulmonary bypass by means of combined pulsed wave Doppler and colour flow mapping in 14 of the 16 patients. Cross sectional studies of the left heart after bypass showed no change in ventricular function and allowed monitoring of volume replacement and ventricular filling. Intraoperative ultrasound was a valuable monitoring technique in patients undergoing a Fontan-type procedure. It refined preoperative diagnosis, monitored ventricular function, and identified or excluded residual haemodynamic lesions in most patients.

Adult↗