Enhancement of antibody formation by whole body x-radiation. (33/280)

Enhancement and acceleration of the antibody response can be achieved in some situations with large, cytotoxic doses of whole body x-radiation given after antigenic stimulation. The timing of radiation is critical and varies with the kind and physical form of the antigen. It is postulated that the x-radiation depletes the cells of the lymphoid tissues just prior to the rapid proliferation of the antigen stimulated cells. In this situation those surviving cells which are stimulated by antigen multiply more rapidly than their non-stimulated counterparts and disproportionately repopulate the depleted lymphoid tissues. Whether the x-radiation produces other effects contributing to the multiplication of the antibody forming cells was not determined. It appears that x-radiation produces its enhancement of antibody formation by means different from those operating in endotoxin and colchicine induced enhancement.  (+info)

DETECTION OF PERICARDIAL EFFUSION BY RADIOISOTOPE HEART SCANNING. (34/280)

A marked difference between the cardiac silhouette on the six-foot chest roentgenogram and the cardiac blood pool, determined by radioisotope scanning, has been shown to be consistent with pericardial effusion and/or thickening. It has also been observed that the cardiac blood pool is separated from the liver margin by the interposition of pericardial fluid and/or thickening. This separation was not demonstrated in the presence of a normal pericardium. To appreciate these features, 400 muc. of radioiodinated human serum albumin and 50 muc. of colloidal radiogold were used for scanning. The former outlind the blood pool and the latter demonstrated the position of the liver.  (+info)

SCINTILLATION SCANNING OF BRAIN TUMORS. (35/280)

Brain scanning by means of externally placed moving scintillation detectors has proven to be an easy accurate method for demonstrating size, shape and position of many types of brain tumors. In a series of 53, there were few false negatives and few false positives. The procedure is easy on the patient, does not require anesthesia and can be done on outpatients. It is recommended as a screening procedure for all brain tumor suspects.  (+info)

MECHANISMS OF ENDOTOXIN TOLERANCE. II. RELATIONSHIP BETWEEN ENDOTOXIN TOLERANCE AND RETICULOENDOTHELIAL SYSTEM PHAGOCYTIC ACTIVITY IN MAN. (36/280)

Healthy male volunteers were rendered tolerant to the pyrogenic and toxic activities of bacterial endotoxin by daily intravenous injections. Five subjects were given 0.5 microg Salmonella typhosa endotoxin for 7 days; four subjects were given Pseudomonas endotoxin, increasing over a period of 30 days from 25 to 250 microg. Reticuloendothelial system (RES) phagocytic activity was assessed by serial measurements of the clearance of I(131)-labeled aggregated human serum albumin. In no subject was an increase in RES phagocytic activity detectable. Such negative findings could not be attributed to decreased RES blood flow.-Additional studies on the pyrogenic responses of man to various schedules of endotoxin administration revealed: (a) Hyperreactivity of some subjects to a second injection of endotoxin administered 24 hours after the initial dose; (b) prevention of such hyperreactivity by plasma from donors tolerant to a heterologous endotoxin, but not from normal donors; (c) reduced reactivity to a second injection of endotoxin given 7 days after the initial dose; (d) reversal of induced tolerance by administration of half the dose of endotoxin followed 2 hours later by the second half; (e) reversal of induced tolerance 24 hours after administration of a heterologous endotoxin; (f) enhanced dermal reactivity to endotoxin induced inflammation during tolerance. The observations are consistent with the hypothesis that tolerance to the pyrogenic activity of endotoxin in man is not based upon generalized enhancement of RES phagocytic activity or exhaustion of host reactivity but rather involves the participation of specific antibody which assists the RES in the clearance and inactivation of the endotoxin molecule.  (+info)

THE EFFLUX OF SUBSTANCES FROM FROG VENTRICLES TO SUCROSE AND TO RINGER'S SOLUTIONS. (37/280)

The frog ventricle in sucrose solution contracts for several hours at 25 degrees C, and for as long as 24 hours at 5 degrees G. The possibility that a fraction of the extracellular fluid remains outside of the excitable membrane was examined by measuring the efflux of tracers. The half-time for the efflux to sucrose solution at 25 degrees C of C(14) sucrose is about 1 minute, for Na(24) is 6.5 minutes, and for Cl(86) is 4 minutes. There is no evidence for the retention of an extracellular Na fraction. The Q(10) for Na and Cl efflux is about 1.3. The half-time for K(42) efflux is about 180 minutes; the Q(10) is 1.7. The efflux rates of Na(24), Cl(36) and K(42) to sucrose and to Ringer's solutions are quite similar. Ca(45) efflux is only one-fifth as fast to sucrose solution as to Ringer's; the retention of Ca(++) may be important for maintaining excitability in sucrose solution. P(32) efflux is five times faster to sucrose solution than to Ringer's solution, and there is a similar increase in the rate of inosine loss to sucrose solution. The Q(10) for efflux to sucrose solution is 2.2 for P(32)O(4) and 2.4 for inosine. We suggest that energy metabolism is abnormal in ventricles in sucrose solution and that low temperature prolongs excitability by slowing the metabolic change.  (+info)

EVIDENCE FOR SPECIES' DIFFERENCES IN THE EFFECT OF SERUM GAMMA-GLOBULIN CONCENTRATION ON GAMMA-GLOBULIN CATABOLISM. (38/280)

The fractional rates of catabolism of isotopically labeled mouse, human, bovine, and guinea pig gamma-globulins and human serum albumin were determined in mice and in guinea pigs whose serum gamma-globulin and serum albumin levels were elevated by immunization or by injections of exogenous serum proteins. These serum proteins were also followed in mice with different serum gamma-globulin levels due to different bacterial environments. The fractional rates of catabolism of the labeled gamma-globulins from all species tested were markedly increased in mice with elevated gamma-globulins due to immunization; to injections of human, mouse, guinea pig, or rabbit gamma-globulins; to exposure to supra normal numbers of bacteria in the environment. Injections of bovine gamma-globulin were only partially effective, and injections of human serum albumin had no effect. The gamma-globulin catabolic rates were decreased in mice with subnormal serum gamma-globulin levels (germfree mice). The catabolic rate of human serum albumin was essentially the same in all mice in spite of differences in serum gamma-globulin levels. In contrast, elevation of the serum gamma-globulin levels by injections of exogenous gamma-globulins or by hyperimmunization with keyhole limpet hemocyanin produced no change in the fractional catabolic rates of the isotopically labeled gamma-globulins and labeled albumin in guinea pigs. Thus, a feedback mechanism for the control of the serum gamma-globulin concentration appears to be operative in the mouse, but not in the guinea pig. Guinea pigs immunized with antigens in complete Freund's adjuvant or a saline suspension of killed E. coli had an increase in the catabolic rates of all labeled proteins tested including human serum albumin. Evidence is presented that the mechanism of this increase in catabolism is not the same as that seen in mice with elevated serum gamma-globulin levels.  (+info)

PHYSICAL PROPERTIES OF CHICK INTERFERON. (39/280)

Kreuz, Leo E. (The Johns Hopkins University School of Medicine, Baltimore, Md.), and Allan H. Levy. Physical properties of chick interferon. J. Bacteriol. 89:462-469. 1965.-The sedimentation coefficient, diffusion coefficient, and molecular weight of chick-embryo interferon were determined by zone centrifugation and equilibrium sedimentation in cesium chloride density gradients, and by chromatography on Sephadex G-100 columns. Purified interferon is not available in quantities sufficient to permit direct analysis by chemical or physical means; its relative concentrations were determined, therefore, by bioassay. I(125)-human serum albumin was used as an internal reference in all experiments. The sedimentation coefficient of chick-embryo interferon is 2.2 to 2.3S; the diffusion coefficient is 9.5 x 10(-7) cm(2)sec(-1). A molecular weight of 26,000 was calculated from the sedimentation and diffusion coefficients, and a range of 25,000 to 34,000 daltons was obtained from equilibrium-sedimentation analyses.  (+info)

Plasma volume and outcome in pulmonary hypertension. (40/280)

Poor survival in pulmonary hypertension is known to be associated with unfavorable hemodynamic variables, including elevated right atrial pressure, elevated mean pulmonary artery pressure, and low cardiac index. However, the effect of plasma volume on outcome has not been evaluated. Our goal was to study the spectrum of plasma volume distribution in patients with pulmonary hypertension and to determine whether plasma volume could provide any prognostic insight in these patients. Our pilot study comprised 11 patients (aged 46 +/- 16 years; 7 women) who were undergoing pulmonary artery catheterization before vasodilator therapy. In all 11 patients, plasma volume was measured, with use of < 25 microCi 131I-radioiodinated serum albumin. Patient follow-up averaged 19 months. There were 2 deaths. The 2 patients who died had the highest right atrial pressures in the group: > or = 17 mmHg. Those 2 patients also had 2 of the 3 highest plasma volumes at > or = 8.4%. None of the patients underwent lung transplantation. The propensity for elevated plasma volume and right atrial pressure in patients who died in this pilot study is consistent with the advanced right-sided heart failure that occurs in the terminal stages of pulmonary hypertension. Elevated plasma volume may be a useful prognosticator; further studies are needed to assess whether manipulation of plasma volume affects prognosis.  (+info)