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Biomedical subjects

E Heller

Publications and source records attributed to E Heller.

At least 19 recordsLinked to original sources
PubMed1992

[Occupational scleroderma due to organic solvent exposure].

Progressive systemic sclerosis (PSS; scleroderma) is a multisystem disease characterized by inflammation, fibrosis and degeneration of the integument, with similar changes and vascular lesions in the heart, lungs, kidneys, gastrointestinal tract and synovia. Its etiology is not clear. Several occupational exposures have been implicated as potential causes of PSS and scleroderma-like diseases. Among them are vinyl chloride monomer, silica dust, epoxy resin, and benzene and other solvents, aromatic and aliphatic, specifically chlorinated (trichloroethylene, perchloroethylene and trichloromethane). We present a patient whose illness was diagnosed as occupationally induced PSS. During 13 years of work renovating carburetors he was heavily exposed to trichloromethane. To the best of our knowledge this is the first reported case of PSS due to exposure to organic solvents in Israel; very few cases have been reported from abroad.

Adult↗
PubMed1985

Bone marrow transplantation for malignant histiocytosis in childhood.

This report describes a girl who was diagnosed with malignant histiocytosis at the age of 5 years. The disease was controlled initially with chemotherapy for 3 years and had then recurred with meningeal involvement on three occasions. Four years and 8 months from diagnosis, bone marrow transplantation (BMT) was undertaken from an HLA-identical and mixed lymphocyte culture (MLC) nonreactive brother after conditioning with VP-16-213 5 mg/kg/day X 2, cyclophosphamide 60 mg/kg/day X 2, and total body irradiation 200 rad twice daily to a total dose of 1000 rad delivered at 7 rad/minute. At the time of transplant, the disease was in remission. Currently, more than 48 months after the transplant, the child remains free of disease, with a normally functioning donor marrow and with no evidence of graft versus host disease. This is the first recorded case of BMT in the treatment of malignant histiocytosis. The outcome in this patient in late-stage disease suggests that BMT could be considered early in management as definitive therapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1979

Purification and primary structure of the neuropeptide egg-laying hormone of Aplysia californica.

Egg-laying hormone (ELH), a neuropeptide synthesized by the bag cell neurons, induces egg laying and its correlated behavior in Aplysia californica. In the present study, ELH has been purified to homogeneity and its primary structure has been determined. We find this molecule to have 36 amino acid residues with a M(r) of 4385 and a calculated isoelectric point of 9.7. Direct microsequence analysis revealed a single amino acid sequence that is in agreement with the amino acid composition determined after acid hydrolysis of ELH: H-Ile-Ser-Ile-Asn-Gln-Asp-Leu-Lys-Ala-Ile-Thr-Asp-Met-Leu-Leu-Thr-Glu-Gln- Ile-Arg-Glu-Arg-Gln-Arg-Tyr-Leu-Ala-Asp-Leu-Arg-Gln-Arg-Leu-Leu-Glu-Lys-OH. Enzyme data indicate that the COOH-terminal lysine may be modified but its exact nature remains to be determined. There is no similarity between the amino acid sequence of ELH and that of presently known vertebrate neuropeptides. The two-step purification procedure, starting with a homogenate of bag cell clusters, consisted of cation exchange chromatography on SP C25 (Sephadex) followed by gel filtration on Bio-Gel P-6. Our purification results in a 100-fold enrichment of ELH from bag cell homogenates and a 36% recovery of purified radiolabeled marker ELH. Analysis of purified ELH radiolabeled with [(35)S]methionine or [(3)H]leucine on isoelectric focusing gels and on 8 M urea/sodium dodecyl sulfate gels showed only a single peak containing 90% of the radiolabel. Radiolabeled ELH migrated with a pI of 9.0-9.2 and an apparent M(r) of 3500-5700. ELH retained egg-laying bioactivity when eluted from this segment of the gel. We find that 2.5 nmol of pure ELH consistently induces egg laying at 20 degrees C.

Amino Acid Sequence↗
PubMed1976

The vitelline envelope of eggs from the giant keyhole limpet Megathura crenulata. I. Chemical composition and structural studies.

The egg vitelline envelope of the marine invertebrate Megathura crenulata is a glycoprotein composed of 37.3 mol % protein and 62.7 mol % carbohydrate. Of the total amino acid content, 61 mol % consists of a single amino acid, threonine. The carbohydrate content includes galactosamine, galactose, and fucose. The molar ratio of threonine to galactosamine is about 1:1. Most of the threonine residues are linked to galactosamine residues via O-glycosidic bonds. A single peptide that was purified following alkaline borohydride treatment of the vitelline envelope had the structure: Abu-Pro-Abu-(Abu6, Pro1, Thr1), where Abu is 2-aminobutyric acid. Several sugar residues have been isolated following the alkaline hydrolysis of the vitelline envelope that include an octasaccharide Gal4Fu4, an hexasaccharide Gal3Fu3, a trisaccharide Gal3, fucose, and galactose. It is proposed that the vitelline envelope of Megathura crenulata eggs is composed of polypeptide chains built to a large extent of closely spaced threonine residues. Almost every threonine residue is linked to a saccharide moiety.

Amino Acids↗
PubMed1976

The vitelline envelope of eggs from the giant keyhole limpet Megathura crenulata. II. Products formed by lysis with sperm enzymes and dithiothreitol.

The egg vitelline envelope of the marine invertebrate, Megathura crenulata, was lyzed either by sperm lysins A, B, C or by dithiothreitol. In each case the lysis mixture consisted of two major fractions, I and II, that could be separated by hydroxylapatite chromatography and had different electrophoretic mobilities on cellulose acetate strips. The amino acid, amino sugar, and neutral sugar compositions of fractions I and II were similar and resembled that of the intact vitelline envelope. Fractions I and II of each lysis mixture emerged in the exclusion volume of a Sepharose 6B column. A vitelline envelope fragment enzymatically formed by lysin was further degraded by dithiothreitol to form smaller fragments. A model of the vitelline envelope of the Megathura crenulata egg is suggested whereby the envelope is composed of polypeptide chains cross-linked by disulfide bonds and built to a large extent of closely spaced threonine residues. Most of the threonine residues are linked to carbohydrate units. Dithiothreitol dissolves the envelope by reducing disulfide bonds, whereas lysins most likely dissolve the envelope by degrading polypeptide chains.

Amino Acids↗
PubMed1971

Inhibition by rifampin of African swine fever virus replication in tissue culture.

Vaccinia virus and African swine fever virus are deoxyribonucleic acid viruses of cytoplasmic origin. The fact that rifampin inhibits the replication of the former virus led to an investigation of its effect on African swine fever virus. The virus used was cytopathogenic to a PK-15 cell line, hemadsorbing in pig leukocyte cultures and lethal to pigs. Rifampin clearly inhibited the multiplication and cytopathogenicity of the virus in PK-15 cells. There was a 1- to 5-log reduction in virus titer depending upon the rifampin concentration, the multiplicity of infection, and the time after infection. Inhibition was greatest at a concentration of 200 mug of rifampin/ml. The drug was not viricidal per se, and the inhibition of virus replication was not due to the cell-granulating effect of rifampin since cultures which were transiently pretreated for long as 90 hr with 200 mug of drug/ml supported viral replication to the same degree as untreated cultures.

African Swine Fever↗