Far-infrared laser scattering studies of density fluctuations in tokamak fusion plasmas

Development of a far-infrared Thomson scattering system for the study of density fluctuations in fusion plasmas is described. New data are presented of naturally occurring low-frequency microturbulence and also of electrostatic modes generated at the ion cyclotron range of frequencies (ICRF). The latter studies are important in understanding ICRF supplementary heating experiments. They have produced the first internal observation of mode-converted ion -Bernstein waves in a tokamak plasma.

A simple washing technique for solid-phase radioimmunoassays and enzyme-linked immunosorbent assays

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High resolution optical ranging system

An optical ranging system which can see through opaque material has been demonstrated. It uses picosecond pulses, generated in a mode-locked dye laser for viewing and, as a very fast gate, a second frequency offset pulse train with a variable delay at the detector. The system could detect a reflection from a mirror inside an opaque mixture with 64-dB round-trip loss and with 1.7-mm range resolution. Transverse resolution of 0.1 mm was also observed. With certain obvious changes in instrumentation this could be converted into a scanning device. The present depth of penetration (round-trip attenuation) would correspond to 0.67 cm in human tissue.

Chromosomal mapping of human creatine kinase (brain type) using human-rodent somatic cell hybrids

Concordant segregation of human brain-type creatine kinase, CK(BB), expression with nucleoside phosphorylase (NP) expression and the presence of chromosome 14 was observed in 53 independently derived cell hybrids between CK(BB)-positive human cells and CK(BB)-negative rodent cells. Further analysis of 26 subclones of two CK(BB)-positive human-mouse cell hybrids confirmed the positive correlation of CK(BB) expression with NP expression. The results suggest that the gene coding for human CK(BB) can be assigned to chromosome 14.

New technique for solid-phase immunoassay: application to hepatitis B surface antigen

I describe a new technique for improving the sensitivity of the solid-phase "sandwich" assay, by using the through-passage receptacle in a novel flow-communication device. The technique allows a large volume of serum to flow through the antibody-coated receptacle repeatedly during the incubation and is thus termed the "flow-through large-volume incubation" method. Binding of 125I-labeled hepatitis B surface antigen to its corresponding antibody on a solid-phase by this method was more rapid and persistent than binding by the conventional method. When the method was applied to the first incubation of the sandwich assay, the test for the antigen was rendered four-, eight-, and 32-fold as sensitive as an accepted third-generation test for the antigen, by incubating 5-mL volumes of serum at (a) room temperature for 18 h, (b) 45 degrees C for 8 h, or (c) room temperature for seven days, respectively.

Thrombotic thrombocytopenic purpura in early pregnancy. Remission after plasma exchange

A 24-year-old Chinese female developed fever, fluctuating neurological and renal manifestations, microangopathic hemolytic anemia, and thrombocytopenia during the 11th week of her first pregnancy. Therapy for thrombotic thrombocytopenic purpura (TTP), initiated during the 15th week of her pregnancy, including corticosteroids, platelet aggregation inhibitors, hysterotomy, and splenectomy was ineffective. However, dramatic improvement and remission occurred after plasma exchange of 3,560 ml was performed with the Haemonetics Model 30 Blood Cell Separator.

New technique for solid-phase immunoassay: application to hepatitis B surface antigen

I describe a new technique for improving the sensitivity of the solid-phase "sandwich" assay, by using the through-passage receptacle in a novel flow-communication device. The technique allows a large volume of serum to flow through the antibody-coated receptacle repeatedly during the incubation and is thus termed the "flow-through large-volume incubation" method. Binding of 125I-labeled hepatitis B surface antigen to its corresponding antibody on a solid-phase by this method was more rapid and persistent than binding by the conventional method. When the method was applied to the first incubation of the sandwich assay, the test for the antigen was rendered four-, eight-, and 32-fold as sensitive as an accepted third-generation test for the antigen, by incubating 5-mL volumes of serum at (a) room temperature for 18 h, (b) 45 degrees C for 8 h, or (c) room temperature for seven days, respectively.

A new plastic receptacle for solid phase immunoassays

A new, simple, inexpensive plastic device for solid phase immunoassay, the through-passage receptacle (TPR), with a large ratio of surface area to volume, is described. It was substantially more efficient in non-specific protein adsorption and specific immunological binding than the conventional wells of microtiter plates. It was also easier to wash since washing was facilitated by a through-passage with a gravity flow. This device, which should be more conducive to automation than currently used receptacles, should increase the sensitivity and decrease the incubation time of the solid phase immunoassay technique.

Studies of the precipitating antibody response in pulmonary aspergillosis

Fractions of <i>Aspergillus fumigatus </i>obtained by DEAE-cellulose chromatography were used for studying the precipitating antibody in sera from four patients with bronchopulmonary aspergillosis (BPA) and in an additional patient with a pulmonary aspergilloma. Three of the 4 BPA sera demonstrated the precipitin reaction with one or more fractions in gel diffusion, but no individual pattern was identical. In order to further evaluate the nature of the precipitating antibody, the mold fractions prior to testing were exposed to either heat, papain, or to reduction and alkylation. The serum from one subject continued to show a precipitin response in gel in spite of antigen treatment, whereas heating and reduction and alkylation abolished a detectable precipitin reaction by the other two sera. Papain had no apparent effect upon any of the antigens tested. In contrast to BPA, the serum from a subject with an aspergilloma contained multiple precipitating antibodies to the mold fractions studied. These antibodies were developed against antigens which showed varying degrees of lability when exposed to either heat or to reduction and alkylation.