In vitro test of phagocytic ability of human platelets using colloidal carbon

A simple and reproducible test for phagocytic ability of human platelets are described. Platelets obtained from heparinized venous blood were incubated with colloidal carbon (particle diameter = 0.11 micron) in autologous plasma at 37 degrees C. The number of platelets with or without carbon particles on smear preparations was determined at fixed intervals. Electron microscopic observation confirmed the apparent inclusion of carbon particles in platelets as being an internalization of these particles in the vesicular or canalicular structures. Under optimum conditions, the percentage of phagocytosis-positive platelets in healthy donors was 66.6 +/- 14.3 (S.D.)% and the reproducibility of the test was considered to be satisfactory. There was no significant difference between men and women.

Defects in the archenteron of mouse embryos homozygous for the T-mutation

The development of the head process was studied in mouse embryos homozygous for the Brachyury (T) mutation at stages between days 7 1/2 and 8 1/2 using scanning electron microscopy. Intact T/T embryos removed from deciduae were distinguished from their normal littermates at the presomite stage on the basis of an abnormally short allantois. In the homozygotes so distinguished, the prenotochordal cells were fewer in the archenteron area, and the typical indentation of the archenteron was not observed. These defects are probably early indicators of the abnormality of the notochord previously described for later stages of development.

Haploid accumulation and translational control of phosphoglycerate kinase-2 messenger RNA during mouse spermatogenesis

The intracellular location of the mRNA for the testis-specific isozyme of phosphoglycerate kinase-2 (PGK-2) has been determined for two spermatogenic cell types. The mRNA activity for PGK-2 from the polysomal and nonpolysomal fractions of pachytene primary spermatocytes or round spermatids has been assayed by cell-free translation with the polypeptide products monitored by immunoprecipitation, followed by one-dimensional or two-dimensional electrophoresis and fluorography. The results reveal that the majority of PGK-2 mRNA activity of round spermatids was present in the polysomal fraction while the relatively less abundant PGK-2 mRNA of pachytene primary spermatocytes was present in the nonpolysomal fraction. No PGK-2 mRNA activity was observed in the cytoplasmic RNA from primitive type A spermatogonia or prepubertal Sertoli cells. These data indicate that mature PGK-2 mRNA first appears in the cytoplasm of spermatogenic cells during the prophase of meiosis and increases in amount after meiosis. Although mature PGK-2 mRNA is present in meiotic cells it is not actively translated until after meiosis has been completed. Thus, mRNA accumulation and translational mechanisms are involved in the control of phosphoglycerate kinase-2 synthesis during spermatogenesis.

Receptors to Dolichos biflorus agglutinin. A new cell surface marker common to teratocarcinoma cells and preimplantation mouse embryos

Dolichos biflorus agglutinin (DBA), a lectin specific to N-acetylgalactosamine residue, identifies cell surface markers on teratocarcinoma cells. These receptors are found in very limited types of adult tissues. In the present investigation, mouse embryos collected on day 1 (2-cell) to 3 (early blastocyst) were shown to be stained with FITC-conjugated DBA. Embryos homozygous for tw32 were also positively stained. These results suggest that receptors for DBA on preimplantation embryos include components distinct from Forssman, F9, and SSEA-1 antigens.

Viability under the testis capsule of inner cell masses isolated from TOr/TOr mouse embryos

Single inner cell masses (ICM) isolated by immunosurgery from late blastocysts were able to develop into benign teratomas under the testis capsule after 1 month with a frequency of 76%. This technique was used to examine viability and developmental potency of embryos homozygous for the TOr mutation. The number of teratomas formed by the ICMs derived from TOr/+ X TOr/+ crosses was consistent with what is expected if TOr/TOr ICMs did not produce them. After ectopic culture for a short period, presumed TOr/TOr ICMs gave rise to abnormal spherical structures resembling embryonic parts of the mutant embryos at the egg cylinder stage. These results suggest that TOr/TOr ICMs have greatly decreased competency for developmental potency.

Establishment and characterization of cell lines from homozygous brachyury (T/T) embryos of the mouse

Lethal mutations in the T/t complex cause stage-specific morphologic abnormalities during early embryogenesis of mice. Although mutant embryos are lethal at the early stages of development, we have succeeded in establishing several cell lines from one of these mutants (T/T). Mutant-specific abnormality was not observed in gross morphology and growth patterns of cells. They, however, retained the characters of freshly dissociated embryonic cells to form smaller aggregates than the wild-type in rotation-mediated aggregation. One of the T/T cell lines (T-1) formed tumors when injected into one-day-old syngeneic and allogeneic host. Expression of H-2 antigens was serologically studied with H-2 specificity 5 as a marker antigen. All lines except T-1 were shown to have this specificity.

Growth of Candida in the upper intestinal tract as a possible source of systemic candidiasis in mice

The relationship between Candida growth in the upper or lower intestinal tract and the occurrence of systemic candidiasis was examined in mice. A significant increase in Candida growth was observed in the upper intestinal tract of mice in which systemic candidiasis was induced by combined x-ray irradiation and dexamethasone treatment.

Effect of the T-mutation on histogenesis of the mouse embryo under the testis capsule

Mouse embryos homozygous for the T-mutation show abnormalities, severer at the posterior embryonic regions, by day 9 of gestation and die before day 11 in utero. To analyse development potentially of the T/T embryos fragments of their anterior and posterior portions were grafted into the testes of adult T/+ mice, and examined histologically for the tissues formed after 1 month. The grafted tissues of the T/T embryos grew beyond the destined lethal stage and gave rise to benign teratomas composed of mature tissues. Although there were some different features of the tissues formed in the teratomas derived from different portions and stages of the embryos, their types were essentially identical between wild-type and the mutant teratomas. Statistical analysis showed that frequency of the cartilage and/or bone formation was significantly lower in the posterior mutant teratomas. It cannot be concluded, however, that this difference is essentially caused by T-mutation. The main conclusion of present experiments is that grafted portions of T/T embryos have the potentiality to develop into teratomas containing derivatives of all three germ layers.

Effect of the T-mutation on histogenesis of the mouse embryo under the testis capsule

Mouse embryos homozygous for the T-mutation show abnormalities, severer at the posterior embryonic regions, by day 9 of gestation and die before day 11 in utero.

To analyse developmental potentiality of the T/T embryos, fragments of their anterior and posterior portions were grafted into the testes of adult T/+ mice, and examined histologically for the tissues formed after 1 month.

The grafted tissues of the T/T embryos grew beyond the destined lethal stage and gave rise to benign teratomas composed of mature tissues. Although there were some different features of the tissues formed in the teratomas derived from different portions and stages of the embryos, their types were essentially identical between wild-type and the mutant teratomas. Statistical analysis showed that frequency of the cartilage and/or bone formation was significantly lower in the posterior mutant teratomas. It cannot be concluded, however, that this difference is essentially caused by T-mutation. The main conclusion of present experiments is that grafted portions of T/T embryos have the potentiality to develop intoteratomas containing derivatives of all three germ layers.

Viability and metabolic activity of homozygous Brachyury (T) embryos

Some features of metabolic activity of homozygous mutants for the Brachyury (T) mutation were studied. The embryos incorporated tritium-labelled thymidine up to about the ‘32–36 somite’ stage. The total amount of protein per embryo increased until the same stage. T/T cells proved viable in vitro over the in utero lethal period. Several cell lines were established from +/+ and T/T embryonic cells.

Differences in rotation-mediated aggregation between wild-type and homozygous Brachyury (T) cells

Rotation-mediated aggregation was studied in dissociated cells from 9- and 10-day-old (‘ 12–40 somite’ stage) mouse embryos homozygous for the Brachyury (T) mutation. Average diameter of the aggregates formed by wild-type cells increased up to the 27-somite stage. In T/T cells, however, a completely different pattern was observed. The disappearance of free cells and the process of aggregate formation were also followed. The possibility that T/T cells have different adhesive properties from +/+ cells is discussed.

Differences in rotation-mediated aggregation between wild-type and homozygous Brachyury (T) cells

Rotation-mediated aggregation was studied in dissociated cells from 9- and 10-day-old ('12-40 somite' stage) mouse embryos homozygous for the Brachyury (T) mutation. Average diameter of the aggregates formed by wild-type cells increased up to the 27-somite stage. In T/T cells, however, a completely different pattern was observed. The disappearance of free cells and the process of aggregate formation were also followed. The possibility that T/T cells have different adhesive properties from +/+ cells is discussed.

Measurement of fibrinogen degradation products (FDP) in serum of normal and tumor-bearing rats

The level of serum fibrinogen degradation products (FDP) in rat was quantified by hemagglutination-inhibition immunoassay which utilized anti-rat-fibrinogen antiserum of rabbit and fibrinogen-coated rat erythrocytes. The sensitivity of this method was high enough to detect minute amounts of serum FDP in rats. The normal value ranged from 1.25 to 10 mug/ml with a mean value of 5.7 mug/ml as expressed as fibrinogen equivalents. The changes in FDP level were noted in tumor-bearing rats which were transplanted subcutaneously with 10(6) tumor cells (AH-109A, a strain of Yoshida rat ascites hepatoma). The FDP level was unchanged in an early stage, elevated to 56 mug/ml on 12th day and to 92 mug/ml on 16th day on an average. These elevations were statistically significant.

Reassembly of functionally active 50S ribosomal particles from proteins and RNAs of Escherichia coli. Dependency of 50S ribosomal reassembly on 30S subunits

Further studies were made on the reassembly of 50S ribosomal subunits from proteins and RNAs of E. coli. The reassembled particles had high activity in poly U-directed polyphenylalanine synthesis and their sucrose sedimentation properties were similar to those of the original intact particles. Several factors affecting the reassembly were examined. The optimal pH for solubilization of ribosomal proteins was pH 9.5, and the optimal Tris concentration was 0.75 to 1.00 M. In the reassembly mixture the pH was adjusted to 8.2 A sharp optimum magnesium ion concentration of 6 to 10 mM was observed. The reassembly required 0.2 to 0.5 M KCl, the optimum concentration being 0.40 M. On incubation for 20 min a temperature of 34 and 40 degrees was necessary, 37 degrees being best. Oligonucleotides, which we previously added to the reassembly mixture were found not to be necessary for inhibition of RNase II [EC 3.1.4.20] activity remaining in the reaction was found necessary to dialyze the reassembly mixture against a buffer containing 10 mM magnesium ion after the incubation. Simultaneous reassembly of 30 and 50S subunits with time was observed, showing that 70S ribosomes were formed first and that they then dissociated into subunits. Reassembly of 50S subunits from their component proteins and RNAs was completely dependent on either 30S particles or the simultaneous reassembly of 30S subunits. Other critical factors affecting the reassembly of 50S subunits must be examined, since the reproducibility of this reassembly is only about 60%, even under the above controlled conditions.