William Dock

Renal Blood Flow After Subtotal Nephrectomy

Conclusions Rats which become hypertensive several months after subtotal nephrectomy do not have renal ischemia; the flow per gram of renal tissue is 19% less than in rats a few days after sub-total nephrectomy, but the same as that in rats with unilateral nephrectomy and without hypertension.

Hemolysins to which Reticulocytes are Especially Vulnerable in the Plasma of Primary Anemia

Ucko 1 has described a saponin-like substance present in normal plasma but in much larger amounts in active cases of primary anemia. It is more toxic to the reticulocytes than to the mature cells. It seemed to us that the presence of such a substance, rather than a structural defect in the reticulocytes of patients with primary anemia, might explain the fall of 30–60% in the reticulocyte count on incubating sterile defibrinated blood of active cases of primary anemia. 2 Blood from normal persons, from secondary anemia cases, or from cases of primary anemia during remission does not have a fall in reticulocyte count when incubated in the same way. 2 , 3 We therefore took blood from 4 active cases of primary anemia just before starting intensive parenteral liver therapy and preserved the plasma on ice for 4–7 days. Washed cells obtained at the height of the reticulocyte rise were then mixed with twice their volume of fresh plasma, and also, in the same proportion, with plasma obtained before treatment. These tubes were incubated at 37° C. All the blood was handled with sterile technique and counts were made only if there was no bacterial growth on incubation. In one case, the mildest and least jaundiced (Van den Bergh, indirect, 1.25 units), the blood taken during the active stage had to be transported and cells and plasma were not separated until several hours after being drawn. This patient had 2.4 million red cells per cu. mm. before treatment and in this case the reticulocyte count in the tubes containing pre- and post-treatment plasma was the same after 24 hours incubation. The other 3 patients all had counts under 1.4 million and indirect Van den Berghs of 1.5 to 3 units before treatment. At the time the reticulocyte peak was reached the Van den Berghs had fallen to 0.6 to 0.8 units. In all of these the reticulocyte count fell on incubating the cells in plasma taken before treatment, but not in that taken during the period of high reticulocytosis. In the first 2 cases the proportion of cells to plasma was as 1 to 2 during incubation; in the third case a 1 to 10 suspension was also observed and showed a more striking fall in reticulocyte count in the plasma taken during the acute stage (Table 1).

The Use of the Cathode Ray Oscillograph for Electrocardiography.

In order to time the point in the cardiac cycle at which a number of rapid roentgen ray films of the heart are taken, it was wished to develop a small portable electrocardiograph with no string or delicate part to be damaged by the currents from the X-ray circuit. The cathode ray oscillograph, as first used by Erlanger and Gasser, 1 has proved quite satisfactory for making electrocardiographs. Gasser 2 found that with his amplifier the heart currents gave lower curves than similar voltages in nerve preparations, due to the low resistance of the body as compared with the resistance of the amplifying tube. The apparatus with which this record was made differs from that of Gasser and Erlanger (a) in that the same source of current is used for cathode ray tube and amplifiers; (b) the sensitive film moves over the face of the tube giving a continuous curve instead of standing curves; (c) four amplifying tubes are used, the first three with amplification constant 20, the last a UX112 tube with a constant of 7; (d) one lead goes directly to the filament of the first tube, the other passes through a 2 microfarad condenser to the grid, which connects to the filament through a one megaohm leak. The apparatus gives curves with a motion of one cm. per one millivolt input and at rates of motion of film up to fifteen cm. per second.

Reticulocytogenic Effects of Liver Extract and Congo Red in Guinea Pigs under Reduced Oxygen Tension

Conclusions Guinea pigs subjected to reduced oxygen tensions showed prompt rises in reticulated red cells which reached a peak (8-14%), in 7-12 days. Then the reticulocytes decreased and in 3-4 weeks approached the control level. Intramuscular injection of liver extract prior to, simultaneously with, or following, exposure to reduced oxygen pressure, had no demonstrable effects on the reticulocyte response; and the bone marrow of liver-treated animals could not be distinguished from that of untreated controls. Congo red was also without effect on the reticullocyte response of guinea pigs under reduced oxygen tensions.