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S C Weil

Publications and source records attributed to S C Weil.

23 records · Page 2Linked to original sources
PubMed1985

Melanin inclusions in the peripheral blood leukocytes of a patient with malignant melanoma.

Dark pigmented inclusions were found in the monocytes and polymorphonuclear leukocytes of a patient with widely metastatic malignant melanoma. Special stains demonstrated the granules were composed of melanin. The authors are not aware of any previous case report of patients with metastatic malignant melanoma that had leukocytic melanin inclusions. Prospective search for this phenomenon in malignant melanoma patients may allow such a finding to be used as a diagnostic tool.

Humans↗
PubMed1984

Changes in tRNA levels during the induction of hemoglobin synthesis in Friend leukemia cells.

There is a three- to four-fold decrease in the content/cell of tRNAs for ten different amino acids four days after the induction of erythroid differentiation in Friend leukemia cells, consistent with the decrease in cell volume that occurs. Surprisingly, there is an approximately two-fold increase in the cellular content of each of these tRNAs between day 4 and day 6 after induction, indicating the net synthesis of tRNA late in induction. The tRNA changes affect all species and do not result in tRNA specialization for hemoglobin synthesis, as occurs in normal erythroid development. The tRNA content of imidazole-treated cells, which do not synthesize hemoglobin although they undergo other changes of erythroid differentiation, decreases initially as described above, but shows no increase from day 4 to day 6.

Animals↗
PubMed1982

Dissociation of hemoglobin accumulation and commitment during murine erythroleukemia cell differentiation by treatment with imidazole.

The effect of imidazole on DMSO-induced murine erythroleukemia (MEL) cell differentiation has been examined. While imidazole does inhibit heme, globin mRNA, and hemoglobin accumulation in DMSO-induced MEL cells, it does not affect the commitment of MEL cells to the specific limitation of proliferative capacity associated with the in vitro differentiation program. Furthermore, imidazole treatment does not affect DMSO-induced changes in cell volume, in the relative proportion of nuclear protein IP25, and in the specific activity of the enzyme cytidine deaminase. A clonal analysis in the presence of imidazole indicated that the drug prevents heme accumulation even in MEL cells already committed to terminal differentiation. These observations suggest that imidazole effectively dissociates two aspects of the erythroid differentiation program of MEL cells: globin gene expression and commitment to loss of proliferative capacity.

Animals↗
PubMed1980

Hemin does not cause commitment of murine erythroleukemia (MEL) cells to terminal differentiation.

The effect of hemin on the differentiation program of murine erythroleukemia (MEL) cells has been investigated. While hemin treatment does induce increased levels of globin mRNA and hemoglobin, it fails to lead to other biochemical changes associated with MEL cell differentiation induced by DMSO and thioguanine. These include increased levels of the nuclear protein IP25 and of the enzyme cytidine deaminase. Clonal analysis of hemin-treated cells revealed that unlike other inducers, hemin does not cause a reprogramming of MEL cells to a specific limitation of proliferative capacity. These observations suggest that hemin differs from DMSO and thioguanine in that it exerts specific effects on globin expression in MEL cells without triggering commitment to the terminal differentiation program.

Animals↗