Plasma from persons with high titers of hepatitis B antibody (anti-HBs) was used to manufacture one lot of hepatitis B "immune" globulin sufficient for four interlocking clinical trials of prevention or modification of hepatitis B infections. The trials were carried out in renal dialysis units, in medical personnel with accidental exposures to hepatitis B, in transfused patients, and in patients with fulminant hepatitis. A single policy board developed protocols that allowed comparisons among the four studies while respecting the unique requirements of each. 相似文献
Three rat monoclonal antibodies specific for mouse IgE (C12B9, 23G3, and B1E3) were established by using monoclonal anti-DNP mouse IgE (mIgE) as immunogen. These antibodies, as well as a fourth, (R1E4) were characterized. It was found that one antibody (C12B9) recognizes an allotypic determinant (Igh-7a) found on the C epsilon chain of mIgE. Antibody cross-blocking studies and epitope mapping studies using recombinant mIgE indicated that 3 antibodies (C12B9, R1E4 and 23G3) were directed against the C epsilon 3 domain while one (B1E3) was directed against the C epsilon 4 domain. A highly specific sandwich RIA for mIgE was developed using these antibodies. Use of these monoclonal anti-mIgE antibodies in conjunction with recombinant chimeric mIgE-human IgG1 molecules, demonstrated that the C epsilon 3 domain is important in the binding of mIgE to the murine B cell Fc epsilon RII as well as to the murine mast cell F epsilon RI. The presence of the C epsilon 4 domain influenced the binding of the recombinant IgE to the Fc epsilon RII; in contrast to the C epsilon 4 domain had no effect on binding to the Fc epsilon RI. 相似文献
Unreliable quantification of flow pulsatility has hampered many efforts to assess the importance of pulsatile perfusion. Generation of pulsatile flow depends upon an energy gradient. It is necessary to quantify pressure flow waveforms in terms of hemodynamic energy levels to make a valid comparison between perfusion modes during chronic support. The objective of this study was to quantify pressure flow waveforms in terms of energy equivalent pressure (EEP) and surplus hemodynamic energy (SHE) levels in an adult mock loop using a pulsatile ventricle assist system (VAD). A 70 cc Pierce-Donachy pneumatic pulsatile VAD was used with a Penn State adult mock loop. The pump flow rate was kept constant at 5 L/min with pump rates of 70 and 80 bpm and mean aortic pressures (MAP) of 80, 90, and 100 mm Hg, respectively. Pump flows were adjusted by varying the systolic pressure, systolic duration, and the diastolic vacuum of the pneumatic drive unit. The aortic pressure was adjusted by varying the systemic resistance of the mock loop EEP (mm Hg) = (integral of fpdf)/(integral of fdt) SHE (ergs/cm3) = 1,332 [((integral of fpdt)/(integral of fdt))--MAP] were calculated at each experimental stage. The difference between the EEP and the MAP is the extra energy generated by this device. This difference is approximately 10% in a normal human heart. The EEP levels were 88.3 +/- 0.9 mm Hg, 98.1 +/- 1.3 mm Hg, and 107.4 +/- 1.0 mm Hg with a pump rate of 70 bpm and an aortic pressure of 80 mm Hg, 90 mm Hg, and 100 mm Hg, respectively. Surplus hemodynamic energy in terms of ergs/cm3 was 11,039 +/- 1,236 ergs/cm3, 10,839 +/- 1,659 ergs/cm3, and 9,857 +/- 1,289 ergs/cm3, respectively. The percentage change from the mean aortic pressure to EEP was 10.4 +/- 1.2%, 9.0 +/- 1.4%, and 7.4 +/- 1.0% at the same experimental stages. Similar results were obtained when the pump rate was changed from 70 bpm to 80 bpm. The EEP and SHE formulas are adequate to quantify different levels of pulsatility for direct and meaningful comparisons. This particular pulsatile VAD system produces near physiologic hemodynamic energy levels at each experimental stage. 相似文献
The relative immaturity of the neonatal immune system limits CD4(+) Th1 and cytotoxic T lymphocyte (CTL) responses, and represents a significant challenge for the development of vaccines against intracellular pathogens. In this report, we demonstrate the ability of a non-replicative delivery system based on parvovirus-like particles (VLP) to induce CTL responses in the neonatal period. A single immunization of 1-week-old BALB/c mice with recombinant VLP carrying a CD8(+) T cell determinant from lymphocytic choriomeningitis virus (VLP-LCMV) induced antigen-specific CD8(+) cytotoxic T cells that were similar to those elicited by adult immunization, as assessed by cytotoxic activity, interferon (IFN)-gamma secretion, cytotoxic precursor cell frequencies, in vitro avidity for antigen and protective activity against viral challenge. These CTL responses are elicited within 2 weeks of a single immunization, in the absence of adjuvant and independently of the presence and help of CD4(+) T cells, highlighting the potential of VLP as candidate vaccine vectors in early life. 相似文献
REceptors for IgE of rat basophilic leukaemia (RBL) cells, maintained in different laboratories were isolated by means of IgE-Sepharose or IgE and anti-IgE, and characterized by SDS-polyacrylamide gel electrophoresis. All cell lines were found to be associated with a receptor molecule (R) which could be isolated either with IgE-Sepharose or IgE and anti-IgE and a second receptor (H) which could only be isolated with the aid of IgE-Sepharose. The relative amounts of these two molecules, as isolated from surface iodinated cells, varied from the RBL cell line to the other and their apparent molecular weights were not identical on all cell lines. Since comparisons were made on the same gel using receptors isolated from cells labelled with different isotopes of iodine, differences in molecular weight must be considered as being intrinsic and not due to methodological variations. These results provide an explanation why differences were observed among receptors for IgE as characterized in various laboratories. In spite of the fact that the various RBL cell lines originated from the same chemically-induced tumour they have, over the years, undergone changes which are reflected in the receptors for IgE. 相似文献
The relationship between work rate (W˙) and time to exhaustion (t) during intense exercise is commonly described by either a hyperbolic function (NLin), t=W′/(W˙?W˙cp), or by its linear equivalent (LinW) Wlim=W′+W˙cp(t). The parameter W˙<INFcp (critical power) has been described as an inherent characteristic of the aerobic energy system, while W?′ has been shown to be a ralid estimate of anaerobic work capacity. Recent studies have demonstrated that oral supplementation of creatine monohydrate (CrH2O) increases total muscle creatine stores, and have linked these increases to improved performances in intense intermittent exercise. This study was conducted to determine the effect of CrH2O supplementation on estimates of W?′ and W˙<INFcp derived from the NLin and LinW equations, and to determine the effect of CrH2O on t in exhaustive constant power exercise of different intensities. Fifteen active but untrained university students completed three phases of testing on a cycle ergometer: (1) familiarization, three learning trials, (2) baseline determination of W?′ and W˙<INFcp, four bouts performed at a W˙ selected to elicit fatigue in 90–600?s, and (3) experimental determination of W?′ and W˙cp, four bouts performed at the same W˙ as baseline, but performed after 5 days of ingesting either a placebo (4?×?6?g of glucose/day) or CrH2O (4?×?5?g of CrH2O and 1?g glucose/day). Testing was administered in a double-blind manner. Analyses of covariance revealed a significant effect for CrH2O on both estimates of W?′ (NLin, P=0.04; LinW, P<0.01), but not on estimates of W˙cp (NLin, P=0.37; LinW; P=0.30). Within groups, t was significantly different for only CrH2O at the two highest W˙s (P=0.04). It is concluded that oral ingestion of CrH2O increases estimates of W?′ due to an improved t at the shorter, more intense exercise bouts.
Serum samples before and after electroconvulsive therapy (ECT) from eight women patients revealed that prolactin blood levels reached a peak about 11 min after the end of the seizure. On average, the peak elevation over baseline was 385%; this elevation correlated strongly (r = 0.6, p < 0.001) with baseline blood levels. Prolactin peaks after bilateral ECT were significantly (p < 10(-5)) higher than those after unilateral ECT, although seizure duration was not longer. Application of a mathematical model gave an estimate of 17.3 min for the half-life of prolactin elimination from the blood, close to published metabolic measurements. The rate of prolactin release into the blood was greater than the rate of its elimination from the blood. 相似文献