Donald C. Van Dyke

Left ventricular ejection fraction in severe chronic obstructive airways disease

The subject of left ventricular involvement in chronic obstructive airways disease is controversial. We measured left ventricular ejection fraction (LVEF) in 120 patients with severe chronic obstructive airways disease, 92 of them acutely decompensated and 28 stable. A bedside radionuclide technic using a scintillation probe was used to measure LVEF. Of the 28 patients with acute respiratory failure, LVEF was normal (larger than or equal to 55 per cent) in 60 and subnormal in 32. Of the 28 patients with stable chronic obstructive airways disease, LVEF was normal in 12 and low in 16. Coronary artery disease could be demonstrated clinically or at autopsy in 13 of the patients with acute and in 7 of the patients with stable chronic obstructive airways disease. LVEF was 28 plus or minus 10.4 per cent (average plus or minus SEM) in the patients with acute chronic obstructive airways disease and coronary artery disease which was significantly different (P smaller than 0.001) from LVEF in patients without coronary artery disease (61 plus or minus 1.9 per cent). In the patients stable with chronic obstructive airways disease and coronary artery disease, LVEF was (42 plus or minus 3.5 per cent), significantly different (P smaller than 0.001) from LVEF in those without coronary artery disease (55 plus or minus 2.1 per cent). There was no relationship between LVEF and arterial oxygen, or carbon dioxide tension, or pH. Results suggest that LVEF is normal in patients with severe lung disease alone and that reduced LVEF in patients with chronic obstructive airways disease can reasonably be ascribed to coronary artery disease.

BONE BLOOD FLOW SHOWN WITH F18 AND THE POSITRON CAMERA.

Development of the positron camera has made it possible to rapidly obtain pictures of the distribution of radioactive fluorine 18 in the living animal or human being. The distribution of F18 admini...

HUMAN BONE MARROW DISTRIBUTION SHOWN IN VIVO BY IRON-52 AND THE POSITRON SCINTILLATION CAMERA.

Radioactive iron, which concentrates in erythropoietic marrow, is given intravenously, and 16 hours later pictures of its distribution are taken with the positron camera. The instrument is an imaging device that produces pictures of the distribution of positron-emitting nuclides without scanning. Wide variations in the distribution of marrow are found in various diseases.

The Blood Volume of the Adult Rat, as Determined by Fe59 and P32 Labelled Red Cells.∗

Conclusions 1. The blood volume of normal rats determined by the use of Fe59 labeled red blood cells is essentially the same as with P32 labeled cells. 2. The use of P32 labelled red blood cells is hence satisfactory for the determination of blood volume. 3. Determinations with P32 indicate that the blood volume of the normal rat is 4.59 ± 0.57/cc 100 g body weight; the total red cell volume 2.16 ± 0.20 cc/100 g body weight; and the hematocrit 45.8 ± 2.6.

Concentration of Highly Potent Erythropoietic Activity from Urine of Anemic Patients.

Summary 1) Some patients with aplastic anemia had exceptionally high levels of erythropoietic activity in plasma. The urine of these patients was assayed, and in some it was equally as potent as the plasma. As little as 1 ml daily for 14 days of untreated urine from such a patient produced a significant polycythemia in normal adult rats. When a concentrate of such urine, prepared by ultrafiltration, was injected at a dose equivalent to 30 ml daily for 14 days into normal adult rats, a polycythemia was produced which exceeded that resulting from exposure to a simulated altitude of 15.000 feet for the same period of time. 2) The high potency of such urine has allowed its assay in normal rats. This finding, together with the easy availability of urine and the efficiency of ultrafiltration as a method for preparing concentrates of urinary erythropoietic activity, should allow for a more rapid investigation of the chemistry and biology of this factor.

Increase in circulating red cell volume of normal and hypophysectomized rats after treatment with ACTH.

Conclusions 1. Administration of ACTH prevents the decrease in the total circulating red cell volume which is normally found in hypophysectomized rats. 2. Administration of ACTH for 116 days to normal rats elevates the total circulating red cell volume to approximately 1.3 times that of the normal untreated controls.

Response of rats of various ages to erythropoietin.

Conclusions Erythropoietin of human urinary origin was injected into groups of rats of various ages, after which both measurements of total circulating red cell volume and Fe59 red cell incorporation were made. Total red cell volume of young rats throughout the period of neonatal anemia did not increase in response to administration of erythropoietin, whereas it did increase in all older groups. According to this assay, the rat most sensitive to erythropoietin was the oldest rat studied. Using the Fe39 red cell incorporation assay, no increase in erythropoiesis was observed in normal young rats(14 days of age) following erythropoietin administration. However, when erythropoiesis was depressed in young rats by hypertransfusion. red cell uptake of Fe59 was greatly reduced. When such hypertransfused rats were injected with erythropoietin, red cell incorporation of Fe59 was significantly increased.

Epilation in the Non-Irradiated Member of Parabiotically United Rats.∗

Discussion and Conclusion Parabiotically united rats influence their partners by the mixing of their body fluids through their common circulation. Therefore, an effect such as epilation must result from the transfer of material from one member to the other. Whether the epilation represents the passage of physiologically active material from the radiated to the non-radiated or is a manifestation of loss of material from the non-irradiated to the irradiated is not demonstrated.

THE PITUITARY ERYTHROPOIETIC FACTOR

Although the anterior pituitary is known to influence erythropoiesis through several of its trophic I shall not attempt to review these effects. Instead, I shall restrict this discussion to two specific questions: Is there adequate evidence for proposing the existence of a discrete pituitary erythropoietin? Is there reason to consider the pituitary as the tissue of origin of the erythropoietin that is concentrated from plasma and urine of anemic animals? In spite of considerable efforts made to separate a discrete erythropoietin from the anterior pituitary, no such separation has been accomplished4 and,

Life Span of the Red Blood Cell in the Hypophysectomized Rat.

Conclusions The life span of the red blood cell of the hypophysectomized rat is not less than that of the normal rat as measured by the use of glycine-2-C14. Since the circulating red cell volume drops to 55% of normal after hypophysectomy, it must be assumed that the marrow of the hypophysectomized rat is producing, at most, only 55% of the normal number of erythrocytes.