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Biomedical subjects

J M Reid

Publications and source records attributed to J M Reid.

At least 109 records · Page 6Linked to original sources

Effects of oxygen tension and pH on the ultrasonic absorption properties of sickle cells.

The ultrasonic absorption of sickle cells was compared with the morphological changes in these cells are produced by varying oxygen tensions and pH. A decrease in oxygen tension caused increased sickling and an increase in the ultrasonic absorption of the blood. An increase in pH reduced the ultrasonic absorption and decreased sickling. These findings indicate that ultrasonic absorption can detect changes in the aggregation state of sickle cell hemoglobin in situ within the red cell and that the method may be used to monitor the degree of sickling under various environmental conditions.

Adult↗

Ultrasound velocity in major bovine blood vessel walls.

Data on ultrasound velocity, compressibility. and specific acoustic impedance in bovine aorta, pulmonary artery, vena cava, and myocardium are reported and analyzed based on amounts of structural proteins present in these tissues.

Animals↗

Relation of angina to coronary artery disease in mitral and in aortic valve disease.

Of 129 patients with either mitral or aortic valve disease angina was present in 55 (42%). It was more frequent in aortic (60%) than in mitral valve disease (33%). The standard 12-lead electrocardiogram was not helpful in distinguishing underlying occlusive coronary artery disease. Coronary arteriography demonstrated coronary artery disease in 26 patients (20%), only 2 of whom had no angina. The incidence of coronary artery disease was almost identical in both the mitral and aortic groups (22% and 17%, respectively), but the percentage of those with demonstrable coronary artery disease accompanying angina was much higher in the mitral group (67% as against 29%). Angina in mitral valve disorders is thus much more likely to be the result of disease of the coronary arteries. Coronary arteriography is mandatory in all patients in both groups who have angina. Otherwise it seems unnecessary as coronary artery disease was found in only 2 patients who did not have angina.

Adult↗

Post-partum cardiomyopathy.

A report is presented of a patient who developed signs of cardiac failure 6 weeks after the birth of her fourth child. Detailed cardiac investigation indicated the diagnosis to be post-partum cardiomyopathy, a condition more commonly encountered in Negro women and comparatively rare in this country. The aetiology and mode of presentation are discussed.

Adult↗

Comparative studies of pulsatile and nonpulsatile flow during cardiopulmonary bypass. II. The effects on adrenal secretion of cortisol.

Previous studies have indicated that a significant reduction in plasma cortisol levels occurs during nonpulsatile cardiopulmonary bypass as a result of adrenocorticol hypofunction. The Stöckert pulsatile pump system described in Part I has been employed in a comparative study of plasma cortisol levels in 20 patients subjected to pulsatile or nonpulsatile perfusion during open-heart surgery. The plasma cortisol response pattern in the nonpulsatile group was identical to the pattern previously described, with no significant rise in cortisol levels during the period of perfusion. In the pulsatile group, however, plasma cortisol levels rose significantly during perfusion, reaching a mean level at the end of perfusion which was highly significantly greater than that in the nonpulsatile group (p less than 0.001). Correction of the plasma cortisol values for the effect of hemodilution was performed and, again, corrected cortisol values indicated a highly significant increase in end-bypass levels in the pulsatile groups (p less than 0.001). These results clearly indicate that the reduction in cortisol secretion during nonpulsatile bypass may be prevented by the use of pulsatile perfusion.

Adrenal Glands↗

Long-term results of surgical treatment for pulmonary valve stenosis.

109 children who survived surgical treatment for isolated pulmonary valve stenosis were followed for up to 17 years. In all the postoperative status was assessed as satisfactory. Cardiac catheterization repeated in 43 gave a resting valve gradient below 40 mmHg. The 22 children whose pulmonary valves had been excised were as healthy as the 87 who had undergone pulmonary valvotomy. Consideration was given to the desirable length of postoperative review. Except for the few children with symptoms before operation, a postoperative increase in exercise tolerance was not a feature.

Adolescent↗

Reversion to sinus rhythm 11 years after surgically induced heart block.

A patient is presented in whom the heart reverted spontaneously to sinus rhythm 11 years after surgical closure of a ventricular septal defect complicated by complete heart block. It seems unlikely that regeneration of fibres in the bundle of His, if these had indeed been destroyed, could account for the restoration of sinus rhythm after so long an interval.

Adolescent↗

A cytoarchitectonic and Golgi study of the red nucleus in the rat.

The cytology of rubral neurons was investigated using both paraffin and 1 mu thick Epon sections. The neurons were divided into four size categories which form a continuum with regard to cellular characteristics. Giant neurons (greater than 40 mu) and large neurons (26-40 mu) predominate in the caudal one-third of the nucleus. Large neurons extend up the ventral, medial and lateral borders of the nucleus into its middle one-third. The caudal one-third of the nucleus together with this extension of large cells is designated as the magnocellular part of the nucleus. The more rostral part of the nucleus contains predominantly small (less than 20 mu) and medium size (20-25 mu) neurons, and this constitutes the parvocellular part of the nucleus. The characteristics of each cell type are described. Camera lucida drawings of the rubral neurons were made in three different planes of section, and the extent of the magnocellular and parvocellular portions of the nucleus was determined. Dorsomedial and ventrolateral subgroups of the magnocellular part of the nucleus are found 300-400 mu from the caudal pole. A lateral horn of small and medium size neurons with the addition of a few large neurons extends from the lateral part of the nucleus 500-700 mu from the caudal pole. Golgi preparations of the red nucleus were examined in three planes of section. Giant and large neurons display short spines on the soma and also, along the entire length of the dendrites. Inaddition, more elongate spinous processes are seen on these dendrites and are frequently aggregated into tufts at loci on the dendrites or at their terminations. The dendrites of these neurons radiate in all directions from the soma but remain within the confines of the nucleus. Medium size neurons demonstrate radially arranged dendrites. Sparsely positioned spines are seen along the length of the dendrites but are absent on the soma. A number of such neurons demonstrate tufts of elongate spines on their dendrites. The dendrites of small neurons branch infrequently and remain within the confines of the nucleus. A few dendritic but no somatic spines are seen in association with these neurons.

Animals↗

An ultrastructural study of the red nucleus in the rat.

The red nuclei of 14 adult male rats of the Wistar strain were prepared for electron microscopic study following perfusion with a mixture of aldehydes, Neurons of four size categories were identified in 1 mu Epon sections and their ultrastructural characteristics were studied in adjacent thin sections. Giant (greater than 40 mu) and large (26-40 mu) neurons are distinguished primarily by size and possess similar ultrastructural features: extensive areas of rough endoplasmic reticulum (RER), a prominent perinuclear Golgi complex, numerous mitochondria and pigment granules and a large, ovoid nucleus which occasionally contains intranuclear rodlets. Medium size neurons (20-25 mu) have less extensive, poorly organized RER and randomly distributed Golgi complexes. The nuclear envelopes of these cells frequently show multiple invaginations and continuity with the RER cisternae. In small neurons (less than 20 mu) the RER occurs as single or anastomosing strands whi le golgi complexes and pigment granules are few. In both medium size and small neurons, aggregates of condensed chromatin are adherent to the inner nuclear membrane. Three main types of synaptic terminals may be distinguished in the red nucleus: (1) small terminals with flattened vesicles and symmetrical densities (F terminals), (2) small terminals with rounded vesicles and asymmetrical densities (RS terminals), and (3) large (10-15 mu) asymmetrical, rounded vesicle terminals which form multiple contacts along their length (RL terminals). The small neurons receive both F and RS terminals on their dendrites and infrequently on their cell somas. The large and giant neurons receive F, RS and RL terminals on their somas and proximal dendrites and F and RS terminals on their distal dendrites. The somas and dendrites of medium size neurons receive both F and RS terminals but RL terminals do not lie in relation to them. Spine contacts are common throughout the nucleus and occur on both somas and dendrites.

Animals↗

Coronary artery fistula: report of three cases.

Three children are described with a right coronary artery fistula communicating with a right heart chamber. Each had a continuous murmur like that of a patent ductus arteriosus but situated at a lower level. Aortography established the diagnosis and excluded any accompanying malformation. It is concluded that to prevent complications surgical treatment should be recommended.

Cardiopulmonary Bypass↗

Respiratory intensive care: a 10-year survey.

The work of the respiratory intensive care unit at the Glasgow Royal Infirmary covering a period of 10 years and involving more than 2,000 patients has been analysed. The rate of admission of patients with acute respiratory or metabolic disturbances remained surprisingly constant over the years, allowing for the increase in available beds after 1965. A disturbing feature was the notable increase in the incidence of severe self-poisonings. The continued importance of infection as a life-threatening complication is also emphasized. The reduction in mortality observed in some of the most gravely ill patients appears to justify this approach to patient care.

Adolescent↗