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Biomedical subjects

D A Gordon

Publications and source records attributed to D A Gordon.

At least 109 records · Page 6Linked to original sources
PubMed1978

Comparison of osteitis condensans ilii and ankylosing spondylitis in female patients: clinical, radiological and HLA typing characteristics.

A study comparing 12 patients with ankylosing spondylitis (AS) to 25 with osteitis condensans ilii (OCI), referred to a rheumatic disease center, was carried out to determine whether OCI represents a varient of AS in women. In the group with OCI, chronic lumbodorsal pain was present in 9, 36%, a 'fibrositis' syndrome in 6, 24%, and 16, 64% had recurrent episodes of polyarthralgia. A definite arthritis with effusion developed in 10 patients, 40%. No patient with OCI had iritis or colitis, whereas 4 patients with AS had iritis and four had colitis. Radiographs of the spine showed no evidence of spondylitis in the OCI group. Of the 25 patients with OCI, only 2, 8% were HLA B27 positive compared with 11 of 12 patients with AS, 92%. These results suggest that OCI is not a variant of AS in women.

Adult↗
PubMed1978

The role of displacement of the mitral annulus in left atrial filling and emptying in the intact dog.

The variations in ventricular-atrial mitral annular position during the cardiac cycle and the simultaneous changes in left atrial silhouette area (obtained by angiography after injections of contrast material into the main pulmonary artery) were investigated in six experiments on intact dogs with chronically implanted intracardiac markers. Frame-by-frame measurements of the angiograms (120 frames/s) were used to determine, under various hemodynamic conditions, the duration, magnitude, and average rate of the mitral annular motion and of the simultaneous changes in left atrial area during atrial filling (ventricular systole) and atrial emptying (early in ventricular diastole). The mitral annulus was seen to move towards the ventricular apex during systole and towards the atrium early in diastole with the duration, average rate, and magnitude of displacement (although varying widely) showing good statistical correlations (P less than 0.0005-0.005) with the changes in projected left atrial area. These findings suggest that the duration, rate, and magnitude of atrial filling and emptying may be, in the intact heart, determined by the movements of the atrioventricular junction.

Animals↗
PubMed1978

Relation of mitral valve opening and closure to left atrial and ventricular pressures in the intact dog.

The exact times of mitral valve opening and closure were determined in dogs under varying hemodynamic conditions in 143 cardiac cycles (five experiments). Radiopaque markers had been sutured to the cusps and the valve annulus 7-124 wk before the studies. Valve opening and closure times were correlated with simultaneously obtained high-fidelity intracardiac pressures. Closure of the mitral valve was completed 5-105 ms after the atrial-ventricular pressure crossover; the time interval between the onset of ventricular systole and the instance of complete valve closure varied less (10-40 ms). These observations suggest that in the intact heart alpha, rapid mitral cusp closure at the end of diastole is initiated and completed by ventricular systole alone, and beta, the ventricular isovolumic contraction period might be shorter than assumed. Opening of the valve during ventricular relaxation was characterized by 1) initial separation of the markers placed on the free edges of the cusps, of variable duration, apparently due to alterations in ventricular geometry, and 2) a rapid opening motion which clearly preceded the diastolic pressure crossover by 5-60 ms. This finding would suggest that ventricular isovolumic relaxation might be shorter than generally accepted, although the mechanism of early opening is not adequately explained by the data.

Animals↗
PubMed1977

Left atrial size and geometry in the intact dog.

Multiple determination of size, shape, and diameter of the left atrium were made during the control state and under conditions of varied ventricular outflow resistance in intact anesthetized dogs with markers chronically attached to the mitral annulus and the valve cusps. Measurements were made from left atrial angiograms (120 frames/s) obtained after injections of contrast medium into the pulmonary artery. Changes in atrial size were characterized by symmetrical circumferential diameter changes and eccentric variations of anteroposterior axis due almost entirely to valve ring displacement. With normal aortic pressure, maximal atrial area averaged 11.0+/-3.1 cm2. When aortic pressure was increased maximal area increased to 12.9+/-3.7 cm2 and percent emptying decreased, whereas maximal and minimal atrial areas were similar to control values during decreased aortic pressure. These findings suggest the possibility that atrial emptying may be near maximal at the resting control state.

Acetylcholine↗
PubMed1977

Children's beliefs in internal-external control and self-esteem as related to academic achievement.

Previous work has shown high self-esteem to be related to an internal locus of control (LOC) orientation. Both have been shown to be related to academic achievement. It was hypothesized that LOC and self-esteem are each independently related to achievement, and that these relationships may vary according to the sex of the child and the measure of achievement used. Subjects were 113 ten-year-old, fourth grade children, 60 males and 53 females. They were administered questionnaire measures of LOC and self-esteem (Nowicki-Strickland and Piers-Harris). An internal LOC orientation was significantly related to greater academic achievement and high self-esteem. Males' LOC scores were related to grade point averages and not achievement test scores, while the reverse held for females. Differential socialization of females from males might account for the lack of a relationship between grades and LOC.

Achievement↗
PubMed1977

HLA antigens in osteitis condensans ilii and ankylosing spondylitis.

Using a standard microdroplet lymphocyte cytotoxicity test for tissue typing, the distribution of the HLA antigens was determined in 37 female patients; 25 with osteitis condensans ilii (OCI) and 12 with ankylosing spondylitis (AS). Although low back pain was a common feature of OCI, none of these patients exhibited the limitation of spinal involvement, radiological evidence of spondylitis, or progressive clinical course seen in the AS group. Four of the 25 patients with OCI (16 per cent) were B27 positive vs 11 of the 12 patients with AS (92 per cent). These results suggest that OCI is not a variant of AS in women.

Cytotoxicity Tests, Immunologic↗
PubMed1977

Developmental analysis of outerdirectedness in noninstitutionalized EMR children.

Outerdirectedness has been found in nonretarded and institutionalized retarded children to be related inversely to cognitive level and directly to history of failure experiences. The developmental nature of outerdirectedness was investigated among noninstitutionalized EMR children using two independent measures of outerdirectedness. Forty subjects, comprising two MA levels, were given a block-design task that was equally difficult for both MA groups. Glancing from the task was found to be related inversely to MA. On a task in which subjects were scored for the amount of imitation of the experimenter's behavior, imitation was also found to be related inversely to MA. However, imitation and glancing were not correlated, suggesting that they may tap different aspects of outerdirectedness.

Adolescent↗
PubMed1977

Systemic lupus erythematosus. A review of 110 cases with reference to nephritis, the nervous system, infections, aseptic necrosis and prognosis.

Observations made on 110 patients with SLE over a four and a half year period have been reviewed. The patients were seen at intervals of two months when, both clinical and serological findings were recorded, according to a set protocol. The results have been presented with particular reference to nephritis, neurological manifestations, infections, aseptic necrosis, mortality and predicted survival. Such studies have led to the identification of various prognosis factors in SLE, and assisted in providing better directed therapy. The results indicate a milder from of SLE in the patients of this series when compared with previously published studies, and is more representative of the wide spectrum of disease severity seen in the general population.

Adolescent↗
PubMed1976

The bimodal mortality pattern of systemic lupus erythematosus.

The changing pattern of mortality in systemic lupus erythematosus (SLE) led to an examination of the deaths in a long-term systematic analysis of 81 patients followed for five years at the University of Toronto Rheumatic Disease Unit. During the follow-up 11 patients died; six patients died within the first year after diagnosis (group I) and five patients died an average of 8.6 years (from 2.5 to 19.5 years) after diagnosis (group II). In those who died early, the SLE was active clinically and serologically, and nephritis was present in four. Their mean prednisone dose was 53.3 mg/day. In four patients a major septic episode contributed to their death. In those who died late in the course of the disease, only one patient had active lupus and none had active lupus nephritis. Their mean prednisone dose was 10.1 mg/day taken for a mean of 7.2 years. In none was sepsis a contributing factor to their death. All five of these patients had had a recent myocardial infarction at the time of death; in four, ti was the primary cause of death. Mortality in SLE follows a bimodal pattern. Patients who die early in the course of their disease, die with active lupus, receive large doses of steroids and have a remarkable incidence of infection. In those who die late in the course of the disease, death is associated with inactive lupus, long duration of steroid therapy and a striking incidence of myocardial infarction due to atherosclerotic heart disease.

Adult↗
PubMed1976

Pericardial fluid analysis in scleroderma (systemic sclerosis).

A patient with scleroderma who presented with pericarditis and effusion is described. Aspirates from this pericardial effusion had the characteristics of an exudate with no evidence of autoantibodies, immune complexes or complement depletion. These findings suggest that the mechanisms operating in the production of pericardial effusion in scleroderma may be different from those found in rheumatoid arthritis and systemic lupus erythematosus.

Aged↗
PubMed1976

Sudden interruption of leaflet opening by ventricular contractions: a mechanism of mitral regurgitation.

The motion of both mitral cusps and the presence of valvular regurgitation during ventricular contractions were investigated in seven experiments on dogs in which radiopaque markers had been sutured to the cusps and the valve annulus 1-32 wk before the studies. Cineangiograms of the left ventricle were obtained during ventricular ectopic beats, interposed throughout the cardiac cycle (20-99% of cycle length) and during induced variations in the P-R interval (0-200 ms). Mitral regurgitation was observed only during a) weak, early ectopic beats (peak pressure below 34 mmHg) which were incapable of closing the cusps and b) when ventricular contractions suddenly interrupted normal leaflet motion toward the ventricle, during three well-defined periods of diastole (diastolic valve opening, diastolic rebound, and atrial opening). Valve closure following sudden reversal of cusp opening was slow and the leaflets often did not arrive simultaneously at their closed positions. These findings suggest that sudden interruption of leaflet opening by ventricular contractions is an important mechanism of transient mitral regurgitation in the normal heart.

Animals↗
PubMed1976

Rheumatoid pericarditis: comparison of immunologic characteristics of pericardial fluid, synovial fluid, and serum.

A comparison was made of the immunological characteristics of serum, synovial and pericardial fluids obtained from a 54 year old man with classic rheumatoid arthritis and pericarditis. The synovial and pericardial fluids had low complement levels and immune complexes were detected using both biological and physical methods. The serum had normal complement levels and no immune complexes could be demonstrated. The presence of immune complexes and complement depletion in the synovial and pericardial fluids supports the concept of local production of immune complexes, and is in keeping with a Type III mechanism of immunologic injury.

Antibodies↗