Monoclonal anti-human T cell antibody and PAP-s conjugate--preparation and selective cytotoxic properties on leukemic cell

Pokeweed antiviral protein (PAP-s) was prepared from seeds of Phytolacca americana. Monoclonal antibody against human pan-T lymphocyte Wu71 was linked to PAP-s by a disulfide bond. The results of SDS-PAGE, double immunodiffusion of active monoclonal antibody and PAP-s showed that the conjugate was highly cytotoxic to the human T-leukemic cell line CEM, but not to antigen-negative cell line SP2/O. At a concentration of 10(-9) mol/L, 76.4% of the target cells were killed, as compared with 10.1% at 10(-9) mol/L of free PAP-s. Treatment of the CEM cells with conjugate at 10(-9) mol/L reduced their rate of protein synthesis by 72.4%, as determined with 14C-leucine incorporation. The immunotoxin may be useful for the in-vitro eradication of leukemic cells in autologous bone marrow transplantation to leukemia patients.

Electric field-induced orthogonal polarization switching in morphotropic phase boundary Pb(0.57)Ba(0.43)Nb(2)O(6) (PBN57) single crystals

Tungsten bronze crystals of Pb(0.57)Ba(0.43)Nb(2)O(6) composition near the morphotropic phase boundary were examined for possible switching of the polarization vector. It is demonstrated that for the single crystal lead barium niobate of tetragonal symmetry, the polarization vector can be switched orthogonally to an orthorhombic phase simply by the application of an electric field.

Identification of meso-hydroxyuroporphyrin I in the urine of a patient with congenital erythropoietic porphyria

A new porphyrin, meso-hydroxyuroporphyrin I, was isolated from the urine of a patient with congenital erythropoietic porphyria. The structure was characterized as the methyl ester, ethyl ester and acetoxy derivatives by fast-atom-bombardment m.s., by conversion into uroporphyrin I and by chemical synthesis.

[A research on the constituents of ginger in various preparations]

The constituents extracted by ether from ginger in different preparations were checked up by GC-MS-DS. The results are as follows: 25 constituents were found in fresh ginger; 22 in dry ginger, of which one had not been found in other forms of ginger; 23 in ginger roasted with sand in a pan, of which two had not been found in other forms of ginger; 23 in ginger charcoal, of which three had not been found in other forms of ginger. A comparison has been made of the content of the constituents in the ginger studied, and the result shows that some of the constituents have changed. All of the essential oil constituents in roasted ginger and ginger charcoal were reported for the first time.

The use of Chinese herb medicine in experimental radiotherapy

Extracts from a group of destagnative herbs, 764-1, and the effective chemical, 764-3, were tested by an in vitro experiment using a HeLa-S3 cell line. Under aerobic conditions, the shoulder of the cell survival curve diminished or disappeared according to the different doses of 764-1 used, but no change in slope was observed. In nitrogen, when the dose of 764-1 increased to 20 mg/ml (ID20), besides the disappearance of the shoulder, the slope of the curve also showed changes at lower doses (4-8 Gy); up to 10-25 Gy the curve became more flattened. 764-3 showed almost a similar effect by mainly affecting the shoulder of the survival curve. At low drug doses a SER as high as 1.87 might be obtained under hypoxic condition. At the same time 764-1 was used in testing the effect on radiation lung damage. It was found that 764-1 could markedly inhibit the change of alveolar surfactant at 1 and 3 weeks after radiation. A wide field of investigation is thus spread out in front of us on radiosensitization and protection. Further studies on 764-3 are carried out.

Accurate and specific HPLC assay of coproporphyrinogen III oxidase activity in human peripheral leucocytes

An HPLC method is described for the assay of coproporphyrinogen III oxidase in human leucocytes. The optimal pH for the assay was 6.5-7.0 and the Km for coproporphyrinogen III was 0.12 +/- 0.021 mumol/l. The mean activity in 28 apparently health subjects was 0.249 (2 SD range 0.130-0.368) nmol/h per mg protein. In two patients with hereditary coproporphyria, the activities were 0.029 and 0.078 nmol/h per mg protein.

[Effect and toxicity of entrapped polysiloxane 5-Fu polycondensate]

Entrapped 5-Fu polysiloxane polycondensate (DMS-Fu) and equivalent doses of 5-Fu were tested on S-180 mice. At the dose of 100 mg/kg, the inhibition potency of these two compounds on tumor was similar, but the inhibition on the body weight was more marked in 5-Fu treated mice. At the dose of 250 mg/kg, all mice treated with 5-Fu died of toxicity but the mice treated with DMS-Fu survived and showed no obvious toxic effect. At the dose of 150-200 mg/kg, the peripheral white blood cells and the bone marrow nucleated cells of 5-Fu treated mice were seriously reduced, which lasted for several days before recovery. In the DMS-Fu group, the inhibition was mild.

Preliminary studies on antigenic variation of poliovirus using neutralizing monoclonal antibodies

Cross-neutralization assays were done using 85 strains of poliovirus type 1 with five groups of monoclonal antibodies. These strains were classified into 10 subgroups which had marked differences in antigenicity. Subgroups P1-2 (28%) and P1-5 (43%) were dominant and have been epidemic in China in recent years. These two subgroups were antigenically different from the Sabin-1 strain, but according to their responses to one group of monoclonal antibodies they had antigenic epitopes in common with the Mahoney and Brunhilde strains. Similarly, 91 strains of type 3 poliovirus were classified into six subgroups with another five groups of monoclonal antibodies. The results showed that strain P3/Yunnan/2/84, which was isolated from cases of poliomyelitis in a local epidemic in the Yunnan province of China in 1984, and strain P3/Finland/23127/84, which was isolated in Finland in 1984, were both antigenically different from the Sabin-3 strain and the reference virulent strain.