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Biomedical subjects

G R Sutherland

Publications and source records attributed to G R Sutherland.

At least 577 records · Page 32Linked to original sources
PubMed1980

Additions to the exclusion map of man.

Exclusion mapping was applied to individuals with monosomic segments defined by chromosomal banding. A range of genetic markers and blood groups was determined resulting in new exclusions for unassigned markers at the following segments : (3)(p25 leads to pter) - JK, GPT, PI ; (4)(127 leads to 31) - MNS, JK, PI, C3, F13A, F13B ; (7))q22) - LU, F13A ; (12)(p12) - MNS ; (12)(p13) and (15)(q15) - GPT, C3 ; (12) (pter) and (19)(p or qter) - MNS, GPT, PI ; and (18)(q21 leads to 23) - MNS, JK, F13A. These exclusions may be useful for narrowing the regional localisations of any genetic markers subsequently assigned to the chromosome involved in the exclusion. No new gene assignments were made from cases where family data was available.

Chromosome Deletion↗
PubMed1979

Down's syndrome in South Australia.

In a survey of Down's syndrome in South Australia, 921 persons, both living and deceased, were identified; 717 individuals with the disorder were living in South Australia. Cytogenetic confirmation of the diagnosis had been made in 774 cases. From 1955 to 1977, the over-all incidence of Down's syndrome at birth was found to be 1.175/1000 live births. The incidence of Down's syndrome was significantly lower over the last five years of this period than for the first 18 years; thus it appears that the incidence of Down's syndrome in South Australia is falling. Analysis of maternal age changes with time has not revealed any changes to the maternal age-specific rates for Down's syndrome, although the rate for mothers aged 25 years or younger appears to be falling. The proportion of Down's syndrome babies born to women aged 35 years or more has decreased from 65.7% for those born before 1950 to 30.4% for those born from 1975 to 1977; similarly, the median maternal age has fallen from 37.12 years to 28.25 years. Regression analyses of maternal age rates for Down's syndrome by single years have produced figures suitable for genetic counselling. A plea is made that Down's syndrome should become a notifiable condition.

Australia↗
PubMed1979

Heritable fragile sites on human chromosomes. III. Detection of fra(X)(q27) in males with X-linked mental retardation and in their female relatives.

The fragile site at Xq27 which is associated with X-linked retardation with macroorchidism has been studied in 21 retarded males. These males were from 12 families, and studies of nine of the familes were possible. Detection of carrier females is difficult, especially with increasing age. The fragile site was demonstrated in only five of 13 obligate carrier females. It is concluded that using present methods, cytogenetic detection of carriers is fairly reliable in females aged less than 20--25 years but unreliable in older females.

Adolescent↗
PubMed1979

Genetic counselling for neurological disorders.

When parents have a child with any problem, they usually become concerned about the chances of this problem recurring if they have further children, or of appearing in their grandchildren. Similarly, persons with any congenital disorder themselves or family history of such disorder, often worry about their future children. Genetic counselling can in most cases provide reassurance that there is little need for concern. In those instances where the risks are real, they can be put into perspective and often effectively circumvented by procedures such as prenatal diagnosis. Pregnant women of advanced age run increased risks of having children with chromosome disorders; it is of benefit to individual couples and to the community to refer such women for amniocentesis.

Adult↗
PubMed1979

Heritable fragile sites on human chromosomes I. Factors affecting expression in lymphocyte culture.

The expression of heritable fragile sites on human chromosomes has been shown to be dependent upon composition of the tissue medium for sites at 2q11, 10q23, 11q13, 16p124, 20p11 and Xq27 or 28 but not for the site at 16q22. Expression of the fragile sites is inhibited by folic acid, thymidine, folinic acid, and probably bromodeoxyuridine, and induced by methrotrexate. In addition, there is a correlation between frequency of expression of the sites and pH of the culture medium for the sites on 2q, 10q and Xq. Possible reasons for these findings are discussed, and a definition and classification of fragile sites is proposed.

Cells, Cultured↗
PubMed1979

Heritable fragile sites on human chromosomes II. Distribution, phenotypic effects, and cytogenetics.

Individuals and families have been documented in which there are a number of fragile sites on chromosomes. These include sites at 2q11, 10q23, 11q13, 16p124, 16q22, 20p11, and Xq27 or 28. Fragile sites reported in the literature are compiled. The cytogenetics of the sites is discussed. The phenotypic effects of the sites are considered, and it is speculated that homozygosity of the autosomal sites might be deleterious as is hemizygosity of the site on Xq. These sites are used in the previous report which documents the effect of tissue medium components on their expression.

Adult↗
PubMed1978

Chromosome studies at the paediatric necropsy.

The results of chromosome studies from 1193 consecutive paediatric necropsies in Edinburgh and 331 in Adelaide are given. In the Edinburgh series 51 major chromosome abnormalities were detected in 780 (6.5%) necropsies where chromosome studies were successful and in Adelaide 16 in 295 (5.4%) were found. It is suggested that chromosome studies should become an integral part of the paediatric necropsy except for deaths due to primary central nervous system lesions and trauma.

Australia↗
PubMed1978

Potassium studies in chronic obstructive airways disease.

Seventeen male patients with chronic obstructive airways disease in remission were separated into two groups according to arterial carbon dioxide tensions. Hypercapnia was associated significantly with hypoxia and increased red cell volume whereas normocapnia was not. Normocapnic patients were significantly lighter than those with hypercapnia. Total body potassium (TBK) measured by the whole body monitor was significantly low in two of the patients studied (P less than 0.005). The mean value for TBK for the normocapnic group as a whole was significantly low (P less than 0.005), but the mean value for the hypercapnic group was not. Serum potassium and erythrocyte potassium concentrations were normal even when TBK was low, and diuretics had no apparent influence on these potassium values. Of four patients (two in the series and two others) who had TBK measured after a recent episode of cor pulmonale, three had significantly low values. The only previous studies using a whole body monitor to measure TBK in chronic obstructive airways disease found no such low values, though other workers estimating exchangeable potassium by isotope dilution techniques had found evidence of gross potassium depletion. It is concluded that low TBK does indeed occur in patients with chronic obstructive airways disease and that gross depletion is more likely to follow an episode of cor pulmonale.

Adult↗
PubMed1978

The contribution of echography in the diagnosis of proptosis.

Echography was used to examine the retro-bulbar space of 150 patients with protosis. An NE Diasonograph was used with an 8 MHz probe using a water bath in the supine position. Lesions were classified ultrasonically as (1) tumour, (2) inflammatory oedema (including pseudo-tumour or other granulomas), (3) traumatic, (4) dysthyroid ophthalmopathy, (5) normal. Thirty-one patients were placed in the tumour group but three of these were subsequently found to have granulomas. In addition, one patient with a normal ultrasonic appearance, was found to have a meningioma en plaque at operation. There were no false positive results in the inflammatory group but again one patient with a normal ultrasonic appearance was eventually diagnosed as having an orbital inflammatory process. The ultrasonic findings in inflammatory disease are non-specific and three were found to be associated with or possibly caused by venous thrombosis or arteritis of the orbit. The changes have to be distinguished from the thyroid ophthalmopathy but this disorder is generally bilateral which is unusual in inflammatory disease. Traumatic oedema and haemorrhage are distinguidhed by the obvious antecedent history. Because of the variability of the amount and position of the retrobulbar fat in the posterior part of the orbit, it is necessary to make a comparative scan of the normal orbit in all patients with suspected retro-bulbar pathology.

Adolescent↗
PubMed1978

46,XX/46,XX,r (2)(p25q37) mosaicism: clinical and cytogenetic studies.

A severely mentally retarded and physically handicapped girl is described who has 46,XX/46,XX,r(2)(p25q37) mosaicism. This is the first ring 2 chromosome to be described in Man. Studies of the behaviour of the ring showed that it was stable in diploid cells which had increased in frequency over a period of seven years, but unstable in tetraploid cells which were at a much higher frequency than in normal individuals. It is concluded that in some cases the phenotypic consequences of ring chromosome formation may be due more to their disturbing the regulation of cell division than to the loss of genetic material. Current models of ring chromosome behaviour do not account for the induction of tetraploidy.

Cell Division↗
PubMed1977

Experimental vitreous haemorrhage: echographic appearances.

Vitreous haemorrhages were induced in rabbits and the echographic appearances of A and B scan were correlated with the gross and histologic appearances over a period of twenty weeks. In all cases, visible vitreous opacities produced distinct echo patterns. As the haemorrhages cleared, the echo amplitudes became progressively weaker. Several patterns of vitreous "membranes" on B scan were also observed. Pathological examination revealed that such membranes were composed of red cells, macrophages and condensed vitreous collagen. It is suggested that haematogenous vitreous membranes of this type are readily diagnosed by combined A- and B-scan ultrasonic examination, and are probably amenable to surgery.

Eye Diseases↗
PubMed1977

Fragile sites on human chromosomes: demonstration of their dependence on the type of tissue culture medium.

The observation of heritable fragile sites on human chromosomes prepared for lymphocyte cultures has been shown to depend on the type of tissue culture medium in which the lymphocytes are grown. The sites are observed at a much greater frequency when medium 199 is used than when RPMI 1640, Ham's F10, Eagle's (basal), and CMRL 1969 are used. One site on the X chromosome is of clinical significance in that it is a marker for X-linked mental retardation.

Cells, Cultured↗