Application of an in-line positron emission tomography and computerized tomography (PET-CT) in endodermal sinus tumor (EST) is described in this study. CASE 1: A young female with massive ascites postovarian mass resection had elevated alpha-fetoprotein (AFP) serum levels. Following a positive PET-CT study with increased (18)F-fluorodeoxyglucose (FDG) uptake, a CT-guided core biopsy of a peritoneal mass was performed. EST was diagnosed histologically. The patient was disease free after chemotherapy. Follow-up PET-CT was negative in keeping with no viable tumor tissue. CASE 2: A large pelvic mass diagnosed histologically as primarily EST was removed in a teenage patient with elevated AFP levels. PET-CT showed diffuse abdominal spread of FDG uptake, suggesting extensive peritoneal seeding. The patient was disease free after chemotherapy. Follow-up PET-CT was negative. EST is an FDG-avid tumor. PET-CT delineated the prechemotherapy tumor extent adequately ruled out the presence of residual tumor after a successful treatment.

Adolescent↗

PubMedDate not supplied

GM-CSF induces eosinophilic cell growth-promoting activity on human fetal liver cells.

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) has been described as a multi-lineage growth factor that induces in vitro colony formation of bone marrow erythroid burst-forming units (BFU-E), multipotential colony-forming units (CFU-GEMM), granulocyte-macrophage CFU (CFU-GM), granulocyte CFU (CFU-G), macrophage CFU (CFU-M), as well as eosinophil colony-forming units (CFU-Eo). Because of the preeminent role of the liver in fetal hematopoiesis, the effect of human recombinant GM-CSF (hrGM-CSF) on hematopoietic cells isolated from human fetal liver was tested in liquid cultures and in semisolid colony assays. hrGM-CSF induced a significant increase in the number of mature eosinophils in liquid culture and to a lesser extent in semisolid cultures when compared to untreated culture controls. The kinetics of this effect on eosinophils reached its peak on day 21 of culture. When GM-CSF and erythropoietin (Ep) were added simultaneously to the cultures, no significant change in the number of eosinophils compared to hrGM-CSF alone was observed. Ep or granulocyte colony-stimulating factor (G-CSF) did not show any CFU-Eo activity when added separately or simultaneously to both liquid and semisolid cultures. These results indicate that hrGM-CSF alone may be a potent stimulating factor for CFU-Eo obtained from human fetal liver and, in combination with other growth factors, control optimal development of human fetal eosinophils.

Cell Differentiation↗

PubMedDate not supplied

Neurophysiological changes in the brain following central administration of immunomodulatory factors.

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Animals↗

PubMedDate not supplied

Structure and function of immunoglobulin genes and immunoglobulin precursors.

To gain information on the origin of antibody diversity (somatic mutation or germ line hypothesis) it is necessary to determine the number of V region genes. For this purpose the capacity of a distinct V region probe to hybridize and quantify V genes of the same and different subgroups should be established. Relevant information on this issue was obtained from the extent of cross-hybridization of a distinct L chain cDNA with mRNAs coding for L chains of the same and different subgroups. The results indicated that: (1) V regions of similar amino acid sequence are coded by similar nucleotide sequence (this is not self-evident because of the degeneracy of the genetic code); (2) the nucleic acid probe to one V region may anneal and quantify V genes of members of the same subgroup. Molecular hybridizations of the cDNA probe with nuclear DNA showed that: (1) the number of kappa type C genes is small (about 2 per haploid genome); (2) the number of V genes presumably is also small; (3) there is no amplification of these genes in myeloma cells that produce large amounts of the Ig. These results support the somatic mutation model for the generation of antibody diversity. New information on the structure and controlled expression of Ig genes was obtained from the study of L chain precursors, which are the immediate product of L chain mRNA translation in vitro. In the precursors extra peptide segments (19-22 residues in length) precede the N-terminus of the mature L chain. Amino acid sequence analyses of the precursors provide evidence that: (1) the gene coding for the V region is larger than hitherto known; (2) duplication of a short DNA segment occurred in the structural gene coding for the MOPC-321 precursor; (3) translation of the L chain mRNA may be contingent on the nucleotide sequence coding for the extra piece; (4) cleavage of the extra piece may regulate secretion of mature L chain; (5) the extra piece is remarkably hydrophobic, suggesting that the role of the extra piece is to anchor the precursor in cell membranes, in a manner similar to the function of the "hydrophobic domain" of membrane bound proteins. We propose that most precursor molecules are directed to the endoplasmic reticulum where the extra piece is cleaved to yield mature Ig destined for secretion; a few precursor molecules escape cleavage and are anchored by means of the hydrophobic extra piece in the cell-surface membrane to serve as the antigen-recognizing receptor.

Amino Acid Sequence↗