Use Of Human Plasma Research Articles

The Daily Profile of Plasma Melatonin in Obese and Prader-Willi Syndrome Children

Daily plasma melatonin profiles were determined by RIA in exogenously obese and Prader-Willi syndrome children. The melatonin RIA was validated for use in human plasma by evaluating melatonin immunoreactivity in the resultant eluate fractions of a high performance liquid chromatogram of a chloroform-extracted pooled human plasma sample. Melatonin immunoreactivity in the plasma profile occurred only in the fraction that corresponded to the chromatographic position of authentic melatonin. Exogenously obese patients had plasma melatonin profiles characterized by low levels during the day (20-30 pg/ml plasma) and high levels at night (65-130 pg/ml plasma). The plasma melatonin profile did not vary as a function of weight or pubertal status. Prader-Willi syndrome patients had similar melatonin profiles to those of exogenously obese patients. Although the Prader-Willi children had a delayed onset of puberty, the plasma melatonin profile was unaltered. These data indicate that plasma melatonin may not play a role in the onset of puberty. However, the daily melatonin profile is a temporally precise hormonal rhythm in humans.

Lymphocyte transformation by pollen extracts and purified protein derivative (PPD) in leukocyte cultures of normal human subjects: I. Description of findings and conditions required

It is shown in a large number of experiments that short ragweed extract, mixed-grass pollen extract, and purified protein derivative (PPD) can produce very substantial tritiated thymidine uptake and lymphocyte blast transformation of peripheral blood leukocytes from normal individuals. Cord blood lymphocytes were also stimulated by pollen extracts. Differing conditions of culture probably explain the discrepancy between these results and many previous studies in which normal cells were not stimulated by these agents. Of particular importance are the use of human plasma in the cultures, restricted washing of the cells, the culture medium, and prolonged (8-day) cell culture times. Heparin has considerable influence on the results.

The use of human plasma in the blood incubation infectivity test to differentiate trypanosoma brucei and trypanosoma rhodesiense

The infectivity test of Rickman and Robson was shown to be an excellent method for distinguishing betweenT. brucei andT. rhodesiense in the small number of samples tested. A modification of the test by the use of human plasma in lieu of whole blood revealed that a one-half hour incubation was long enough for the factor found present in human plasma to act as an inhibitor of infection of mice withT. brucei.

PLASMA VOLUME EXPANDERS

Although the misconceptions and errors associated with the use of human plasma have resulted in some unfortunate experiences, these experiences should not be permitted, by themselves, to obscure the desirability and value of human plasma for the treatment of the injured. The major misadventures associated with the use of human plasma appear to have resulted, for the most part, from overcredulous, undercritical, and premature acceptance of doctrines, procedures, and practices which frequently were proposed without sufficient experimental verification of their soundness or without recognition of their potential hazards. Comprehension of the mechanisms of these errors and misconceptions should provide a valuable means for avoiding similar regrettable experiences in the future acceptance and use, not only of plasma volume expanders of human origin but also of plasma volume expanders from other sources. This is discussed on p. 1617 of this issue. Ignorance regarding the etiologic agent of serum hepatitis appears to

Human plasma as antigen in the preparation of precipitin serum.

HUMAN serum is generally used as an antigen for the preparation of anti-human serum in precipitin tests. The use of human plasma does not seem to have had sufficient trials for this purpose. Johnson and Rawson1 concluded that plasma of some wild animals was unsatisfactory in the preparation of precipitin serum. We have not found any reference to human plasma being used as antigen in the literature available to us.

RED CELL TRANSFUSIONS IN THE TREATMENT OF ANEMIA

The extensive use of human plasma in recent years has made available large quantities of red blood cells. These for the most part have been discarded. Interest in the use of red cells for transfusion purposes has arisen in England during the last few years. MacQuaide and Mollison, 1 Williams and Davie 2 and Watson 3 all have used concentrated erythrocyte suspensions successfully for the treatment of anemia. In this country Warren Cooksey 4 has given numerous transfusions of red cells suspended in saline solution. He has been responsible for the increasing interest and use of such transfusions by physicians in the Detroit area. Red cells were used for transfusion purposes by Robertson 5 during the first world war and by Castellanos and Riera 6 in 1937. In 1938 I gave a transfusion of washed red cells to a patient with subacute leukemia who suffered reactions from whole blood. The

The Use of Human Plasma in Spinal Anesthesia

During the relatively short history of spinal anesthesia, attention has been focused on two problems in designing technic for placing drugs into the subarachnoid space. The first of these has been to produce the desired extent of anesthesia in a manner predictable and with minimal dangers; the second, to secure the required duration of anesthesia with doses of the agent that provide a wide margin of safety. The latter problem has been approached in several ways. Recently, nupercaine and pontocaine, drugs more toxic but more potent than procaine, have been given in relatively smaller amounts and act for longer periods of time. Retarding the absorption of anesthetic drugs has been attempted by dissolving them in various foreign substances of higher osmotic tension than spinal fluid. Finally, prolonged spinal anesthesia is being accomplished by the repeated administration of relatively small doses of the drug. The problem of obtaining predictable levels of