BP-1/6C3 expression defines a differentiation stage of transformed pre-B cells and is not related to malignant potential

BP-1 antibody recognizes a cell surface molecule related to the zinc-dependent metallopeptidases that is expressed during a narrow window early in B cell differentiation. Expression of the same molecule, as originally recognized by the mAb 6C3, is widely accepted to be associated with the complete malignant transformation of pre-B lymphoid cells. We have examined BP-1/6C3 expression in a panel of established Abelson virus-transformed cells that includes both cells analogous to pre-B cells and to less differentiated B lineage cells that have not yet completed Ig H chain gene rearrangement. This analysis reveals that many of the less differentiated transformants do not express BP-1/6C3 for an extended culture period. In contrast, virtually all transformants that are analogous to normal pre-B cells express the determinant early in their culture history. The BP-1/6C3 negative transformants are fully tumorigenic in syngeneic mice, demonstrating that BP-1/6C3 expression is not required for complete malignant transformation. Our data thus suggest that the pattern of BP-1/6C3 expression in Abelson virus-transformed cells mimics that observed in normal cells and is indicative of a differentiation event unrelated to the malignant potential of the cells.

[Effect of blood-activating and stasis-removing drugs on hypercoagulability data in nephrotic syndrome]

Platelet aggregation test (PAgT), plasma factor VIII related antigen (VIII R:Ag) and kaolin partial thromboplastic time (KPTT) in 32 nephrotic children were determined.

RESULTS

(1) PAgT induced by ADP and adrenaline which included 1 minute and 5 minute aggregation rate in the patients (30. 78 +/- 7.44%, 72.56 +/- 18.09%, 22.16 +/- 9.24%, 67.53 +/- 22.32%) was significantly increased (P less than 0.02-0.001) as compared with the normal control group (30.65 +/- 8.38%, 57.98 +/- 13.60%, 18.14 +/- 7.33%, 55.92 +/- 16.10%) except 1 minute aggregation rate induced by ADP (P greater than 0.05). (2) VIII R:Ag and KPTT in patients (226.97 +/- 50.47%, 32.04 +/- 5.88 sec) were obviously different (P less than 0.001, P less than 0.02) from the normal control group (107.11 +/- 24.55%, 35.42 +/- 5.00 sec). The results suggested that PAgT, VIII R:Ag and KPTT could be used as laboratory data reflecting the hypercoagulable state in nephrotic children. According to their age, sex and the clinical types of nephrotic syndrome, 24 nephrotic children with abnormality of PAgT, VIII R:Ag and KPTT were random divided into group 1 given prednisone only and group 2 given prednisone, blood-activating and stasis-removing drugs.

RESULTS

the difference of PAgT, VIII R:Ag and KPTT in two groups between pre- and post-treatment was significant statistically (P less than 0.05-P less than 0.001). The decline in PAgT and VIII R:Ag was faster in group 2 than in group 1 (P less than 0.05-P less than 0.01). The results showed that blood-activating and stasis-removing drugs were likely to improve abnormal PAgT and VIII R:Ag in nephrotic children.

[Purification and identification of antimicrobial peptides of rabbit neutrophils]

Five antimicrobial peptides were extracted from the cytoplasmic granules of rabbit neutrophils with 0.01 mol/L citric acid. SDS-PAGE gel densitometric analysis of the citric acid extract showed that they accounted for 34%-42% of the total extract proteins. When subjected to acid urea polyacrylamide gel electrophoresis, five peptides migrated much further to the cathode than lysozyme. Beginning with the most cathodal component, they were in turn referred to as NP1, NP2, NP3, NP4, and NP5. They were purified from the citric acid extract by virtue of preparative polyacrylamide gel electrophoresis. Each of them was of low molecular weight (2,500-6,000) as determined by SDS-PAGE. Three of the peptides were tested in vitro for fungicidal activity. When Candida albicans (10(7)/ml) were incubated with 12.5 micrograms/ml of NP1 or NP2 at 37 degrees C for 2 h, the death rates of the organisms were 96.6% and 93.3% respectively. NP3 was shown to be active against Candida albicans although less potent than NP1 and NP2.

Molecular cloning of the murine BP-1/6C3 antigen: a member of the zinc-dependent metallopeptidase family

The BP-1/6C3 antigen is a phosphorylated cell surface glycoprotein that can be identified by monoclonal antibodies on mouse pre-B cells, immature B cells, and certain stromal cell lines from bone marrow. Expression of this antigen is increased in stromal-dependent pre-B cell lines and retrovirally transformed pre-B cells. Expression of the BP-1/6C3 antigen thus correlates with proliferation and transformation of immature B-lineage cells. In this study, we report the isolation and characterization of cDNAs encoding the BP-1/6C3 antigen. Northern blot analysis revealed a major 4.1-kilobase mRNA in all BP-1/6C3+ mouse pre-B lines and in a human pre-B cell line. BP-1/6C3 mRNA was either absent or truncated in BP-1/6C3- cell lines. The cDNA sequence predicts a type II integral membrane protein of 945 amino acids with an intracytoplasmic amino terminus of only 17 amino acids and a typical zinc-binding motif in its extracellular domain. BP-1/6C3 has significant homology to aminopeptidase N and is the second member of the zinc-dependent metallopeptidase gene family to be found on the surface of early B-lineage cells.

[Correlation of steroid hormone receptors (SR) with clinical and pathological features of human breast cancer]

Paraffin-embedded materials from 104 patients with breast cancer were assayed for the expression of estrogen receptor (ER), progesterone receptor (PR) and androgen receptor (AR) with avidin-biotin complex method. A significant positive correlation was found between SR status and cell differentiation or lymph node status. Tumors with elastosis tend to contain ER, PR and AR more frequently. Patients with positive ER, PR or AR tumors were 1.2 to 2.6 times more likely to survive than those with negative ones. The five-year survival rate increased with the increase of number and amount of positive SR. These results indicate that ER, PR and AR detected by ABC method may be used as biomarkers for tumor differentiation and have prognostic values in breast cancer.

The early B lineage antigen BP-1 and the transformation-associated antigen 6C3 are on the same molecule

Biochemical similarities and cellular distribution patterns of the early B lineage-specific BP-1 alloantigen and the B lineage transformation-associated 6C3 Ag prompted this comparative study of the reactivities of the BP-1 and 6C3 mAb. Both Ag were found to be expressed on the same cells in normal tissues, and on the same cell lines when a large panel was analyzed. The Ag are both phosphorylated and have identical m.w., which may vary in different cell types because of differences in glycosylation. Immunoprecipitation of pre-B cell lysates with the BP-1 antibody removed the 6C3-reactive molecules and vice versa. However, the 6C3 antibody did not inhibit binding of the BP-1 antibody to viable cells and, in fact, enhanced immunofluorescence staining was observed when both antibodies were added together. These results indicate that the BP-1 and 6C3 antibodies react with different epitopes on the same molecule that is expressed in relatively low levels on normal early B lineage cells, and in relatively high levels on most neoplastic pre-B cells, pre-B cells in long term bone marrow cultures and certain stromal cell lines.

The early B lineage antigen BP-1 and the transformation-associated antigen 6C3 are on the same molecule

Biochemical similarities and cellular distribution patterns of the early B lineage-specific BP-1 alloantigen and the B lineage transformation-associated 6C3 Ag prompted this comparative study of the reactivities of the BP-1 and 6C3 mAb. Both Ag were found to be expressed on the same cells in normal tissues, and on the same cell lines when a large panel was analyzed. The Ag are both phosphorylated and have identical m.w., which may vary in different cell types because of differences in glycosylation. Immunoprecipitation of pre-B cell lysates with the BP-1 antibody removed the 6C3-reactive molecules and vice versa. However, the 6C3 antibody did not inhibit binding of the BP-1 antibody to viable cells and, in fact, enhanced immunofluorescence staining was observed when both antibodies were added together. These results indicate that the BP-1 and 6C3 antibodies react with different epitopes on the same molecule that is expressed in relatively low levels on normal early B lineage cells, and in relatively high levels on most neoplastic pre-B cells, pre-B cells in long term bone marrow cultures and certain stromal cell lines.

Formation of lymphocyte colonies under serum-free culture conditions in normal individuals and patients with chronic lymphocytic leukemia

This paper describes a culture system which supports the formation of B cell and some T cell colonies under serum-free conditions in peripheral blood samples of normal individuals and patients with chronic lymphocytic leukemia (CLL) of B cell type. In this system, serum is replaced by bovine serum albumin, transferrin, cholesterol, insulin and catalase or horseradish peroxidase. In addition, it is necessary to add staphylococcus protein A, mitomycin-treated T cells as feeders and phytohemagglutinin leukocyte-conditioned medium as a source of growth factors. The plating efficiency is greatly enhanced when normal cells are incubated with galactose oxidase prior to plating and when CLL cells are exposed sequentially to neuraminidase and galactose oxidase.

Mobile phase effects on the separations of substituted anilines with a beta-cyclodextrin-bonded column

The capacity factors of several substituted anilines were measured on a beta-cyclodextrin (beta-CD)-bonded column with mobile phases varying from the classical, normal-phase condition, e.g. n-heptane-2-propanol, to the classical, reversed-phase condition, e.g. water-2-propanol. Different modifiers, such as acetonitrile, methanol, and tetrahydrofuran and a Partisil PXS-ODS column were also used for comparison. In general, it was found that the beta-CD column, having the ability to form inclusion complexes with certain substrates is better and more selective in the reversed-phase separation of many aromatic compounds than the Partisil PXS-ODS column. The normal-phase separation on beta-CD was even more efficient, owing to the presence of large number of hydroxy groups on the surface of beta-CD molecules and the more rapid mass transfer in the column. In the present case, alcohols were found to be better modifiers than aprotic solvents. The effects of organic solvents on both normal-and reversed-phase separations are also discussed. The minima observed for the log k' vs. percent organic solvent plots for a number of substituted anilines are reasoned to originate from solute-solvent competition, which interacts with the stationary phase, as well as from the "relative solubility" of solutes in the stationary and mobile phases.

Bioavailability of selenium to residents in a low-selenium area of China

For 8 wk 5 groups of 10 men each were given 0.5 g/day DL-methionine, 150 micrograms Se/day as sodium selenite with or without methionine or 150 micrograms Se/day as selenomethionine with or without methionine. Twenty subjects received placebo as controls. Initially plasma Se rose more rapidly than RBC Se. Increases in Se levels were significantly greater with selenomethionine than with the selenite supplement. In the placebo and methionine supplemented groups neither plasma nor RBC Se varied significantly over the course of the study. Supplementation with selenium resulted in marked increases in plasma and RBC GSH-Px within 2 and 4 wk, respectively. Plasma and RBC GSH-Px activity did not differ significantly between Se-supplemented groups. These studies suggest that selenomethionine-Se was more effective in raising plasma and RBC Se than was selenite-Se. Methionine supplements may increase the bioavailability of selenium in severely deficient subjects.

Selenium intake and metabolic balance of 10 men from a low selenium area of China

Selenium intake and urinary and fecal Se excretion of 10 healthy men from a low Se area in China were determined for three consecutive days, in summer, fall, and winter of 1983, and the spring of 1984 while self-selected diets were being consumed. Mean daily Se intake was 8.8 micrograms/day with a range of 2.3-35.5 micrograms/day, and was far below the recommended range of safe and adequate Se intake of 50-200 micrograms Se/day (National Academy of Sciences/National Research Council). Mean urinary and fecal Se outputs were 3.7 and 3.4 micrograms Se/day, respectively. Mean Se balance during this time was +1.8 micrograms Se/day. Apparent absorption of Se approximated 57%. The low Se intake in this area is a cause for concern since the residents of Molimo may be at risk for Se deficiency diseases.

Studies on optic nerve of Lipotes vexillifer-structure, fiber count and diameter spectrum

Four optic nerves obtained from two Lipotes Vexillifer have been studied with the aid of electron microscope. The fiber diameter spectra of all the four optic nerves are unimodal. The diameters of fibers range from 0.35 to 7.45 microns with the highest frequency at 1.5 microns. T test indicates there is no significant difference in fiber density and fiber diameter between the central and peripheral regions of the optic nerve. The ratio of axon diameter to the total fiber diameter is 0.6 +/- 0.02 (p less than 0.05). The examination of four optic nerves indicates a mean count of 78,900 fibers; none of unmyelinated fibers have been seen. The shapes of the cross sections of fibers are very irregular. The myelin sheaths of some nerve fibers are very thick while those of some others are thinner.