Cytotoxicity of anti-beta 2-microglobulin xenoantisera to human and murine myeloid progenitor cells and lack of cross-reactivity with colony-stimulating activity.

A previous report has suggested an antigenic relationship between beta 2-microglobulin (beta 2 mu) and granulocyte colony-stimulating activity (CSA). Since human myeloid progenitor cells (CFU-C) express HLA antigens and beta 2 mu is a known molecular component of HLA antigens, we wondered whether the reported effect of anti-beta 2 mu heteroantisera on in vitro granulopoiesis might result from cytotoxicity to CFU-C rather than from cross-reactivity with CSA. To test this, we used rabbit antibody reactive with human and murine beta 2 mu (anti-beta 2 mu).

Insertion of a new gene of viral origin into bone marrow cells of mice.

DNA containing the herpes simplex virus thymidine kinase (HSVtk) gene was used to transform wild-type tk+ mouse L cells to a tk++ status in vitro using methotrexate as a selective agent. HSVtk DNA was also used to transform mouse bone marrow cells in vitro. Transformed marrow cells injected into irradiated and methotrexate-treated recipient mice gave rise to proliferating cells which in some cases dominated the marrow population and which contained HSVtk gene sequences.

Inhibition of human bone marrow-granulocyte precursors by serum from patients with Felty's syndrome.

Eight of 19 patients with Felty's syndrome were shown to have a serum factor capable of inhibiting in vitro colony formation by human bone marrow-granulocyte precursors. These data raise the possibility that a serum factor may play a role in the induction of leukopenia in Felty's syndrome.

Gene transfer in intact animals.

Resistance to methotrexate was induced in bone marrow cells of mice by transformation in vitro with DNA from a drug-resistant cell line. Transformed cells were injected in vivo and haematopoietic cells expressing resistance were selected by drug treatment of recipients. Transformed cells had elevated levels of dihydrofolate reductase and demonstrated a proliferative advantage over untransformed cells, indicating successful gene transfer.

Differentiation of subpopulations of human and murine hemopoietic stem cells by hypotonic lysis.

Both human and mouse bone marrow contain subpopulations of hemopoietic stem cells that greatly vary in their resistance to water exposure: The cells forming erythroid colonies or bursts in methyl cellulose in vitro are most sensitive to hypotonic conditions and are destroyed within 60 s in the hypotonic milieu. The murine pluripotent stem cells assayed by the spleen colony technique, as well as both murine and human myeloid stem cells assayed by the plasma clot diffusion chamber technique, displayed intermediate sensitivity and were nearly completely eliminated by 120 s of exposure to water. Both human and mouse bone marrow stem cells producing myeloid colonies in agar are most resistant to hypotonic conditions.

Post-transcriptional modifications of oat coleoptile ribonucleic acids. 5'-Terminal capping and methylation of internal nucleosides in poly(A)-rich RNA.

Evidence is presented for the occurrence of 5'-terminal capping structures in poly(A)-rich RNAs from oat coleoptile tissue. Similar to the cap structures in mRNA from other eukaryotic organisms, the 5' terminus of these oat coleoptile RNA molecules consists of 7-methylguanosine joined 5' to 5' with the adjacent (penultimate) nucleoside by means of three phosphate groups in two pyrophosphate linkages. The penultimate nucleoside contains primarily purine bases, but small amounts of pyrimidines (cytidine) are also detectable.

Amphotericin B plus combination chemotherapy for extensive non-small cell bronchogenic carcinoma.

Sixteen patients with extensive non-small carcinoma of the lung were treated with methotrexate, vincristine, cyclophosphamide, and adriamycin. Cyclophosphamide and adriamycin were administered after pretreatment with amphotericin B. Amphotericin B-related toxicity was mild; cytotoxic chemotherapy-related toxicity was tolerable.

[Evidence for CFU-C self-replication (author's transl)].

To explore the proliferative potential of committed myeloid progenitor cells (CFU-C), we placed suspensions of mouse spleen cells in short-term liquid culture with colony stimulating activity and subcultured the cells in agar at intervals to assay for CFU-C. Prior to liquid culture, aliquots of spleen cells were exposed briefly to hypotonic conditions to lyse CFU-S but not CFU-C. A 50-fold increase in CFU-C was observed in control cultures.

Serum inhibitors of myelopoiesis.

A modification of the microcytotoxicity assay of Terasaki & McClelland was used to screen for serum inhibitors of myeloid progenitor cells (CFU-C). Sera from 104 patients with neutropenia or bone marrow failure and from 104 controls, including 30 normal subjects and 74 patients with various disorders or multiple transfusions, were studied. Inhibitors of CFU-C were found in 19 of the 104 patients with neutropenia or marrow failure: three with acquited neutropenia and 16 with aplastic anaemia.

Cyanide Inhibition of Acid-induced Growth in Avena Coleoptile Segments.

The comparative effects of metabolic inhibitors on acid- and auxininduced growth in oat (Avena sativa L. var. Victory) coleoptile segments have been examined.

Human myeloid precursors forming colonies in diffusion chambers expresses the Ia-like antigen.

Normal human bone marrow contains cells capable of forming myeloid colonies (CFU-DG) in fibrin clots in diffusion chambers placed in the peritoneal cavity of cyclophosphamide-treated mice. Evidence has accumulated indicating that these colony-forming cells represent an earlier stem cell than the granulocyte-monocyte precursor cell (CFU-C) assayed in soft agar. We provide data showing that these stem cells express the "Ia-like" or DR antigen.

Splenic irradiation in myelofibrosis: effect on circulating myeloid progenitor cells.

We have investigated the mechanism of splenic irradiation-induced granulocytopenia in two patients with myelofibrosis and marked splenomegaly. Serial assays were performed for circulating granulocyte-monocyte progenitors capable of colony formation in vitro (CFU-C). For comparison, similar studies were performed on two patients receiving whole brain irradiation for glioma.

Predictors of mortality in chronic obstructive pulmonary disease. A 15-year follow-up study.

The relative usefulness of various initial findings in predicting survival is reported for 200 patients with chronic obstructive pulmonary disease who have been followed for approximately 15 years. After 5 years of follow-up, subjects 62 or more years of age showed a poorer survival rate than younger subjects. After controlling for age, the per cent predicted forced expiratory volume in 1 sec after administration of bronchodilator was the best indicator of prognosis.

Cure of aplastic anaemia in paroxysmal nocturnal haemoglobinuria by marrow transfusion from identical twin: Failure of peripheral-leucocyte transfusion to correct marrow aplasia.

The ability of syngeneic peripheral leucocytes to cure marrow aplasia was tested in a patient with paroxysmal nocturnal haemoglobinuria (P.N.H.

Human myeloid progenitor cells expressing HLA antigens.

Marrow cells of known HLA type were incubated with HLA antiserum plus complement and then plated in soft agar. Colony formation was consistently inhibited by appropriate HLA antisera. Mixing experiments excluded an indirect effect on CFU-C by lysis of mature leukocytes.

Cellular interactions in haematopoiesis.

In vitro culture of haematopoietic cells has provided some surprising insights into critical interactions of blood-forming cells. Subpopulations of lymphoid cells have been shown to produce colony-stimulating activity, to interact with macrophages, and to have important effects on the very early stages of erythropoiesis. Macrophages have multiple influences on the proliferation and differentiation of other haematopoietic cells.

The stability of the postulated wall-loosening enzyme in acid-induced growth.

Long-term pretreatments with cycloheximide (CH) caused inhibition of subsequent acidinduced growth of Avena coleoptile segments, but only after 6 or more h of CH treatment. These results together with previous, published evidence with frozen-thawed tissue are consistent with the hypothesis that there exists a wall-loosening enzyme responsible for acid-induced elongation and that it has a half-life of at least 7-8 h.

Growth of mouse and human bone marrow in diffusion chambers in mice. Development of myeloid and erythroid colonies and proliferation of myeloid stem cells in cyclophosphamide- and erythropoietin-treated mice.

Both murine and human bone marrow cells were cultured in plasma clots which were formed inside diffusion chambers implanted into cyclophosphamide- and saline-treated mice. After an initial fall, the number of mouse bone marrow cells and numbers of mouse myeloid stem cells (CFU-C) and agar cluster-forming units rose faster in the cyclophosphamide-treated animals. These hosts also favored formation of myeloid (CFU-D-G) and erythroid (CFR-D-E) colonies and myeloid higher than those of CFU-C from the same marrow population.