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Biomedical subjects

D Abramson

Publications and source records attributed to D Abramson.

At least 91 records · Page 5Linked to original sources
PubMed1984

Retinoblastoma and cell cycle cytofluorometric analysis.

Flow cytofluorometric analysis of retinoblastoma tumor cells studied immediately after removal from patients and as cultured cell lines disclosed aneuploid cell populations in all samples. The percentage of cells in the different compartments of the cell cycle varied. The G0-G1 compartment contained from 62% to 83% of the cell population. From 16% to 38% of cells were in the S, G2, or M phase of the cell cycle, an observation that coincides with the apparent slow growth of the tumor in some of these patients.

Adult↗
PubMed1983

Mycotoxins and mycoflora in animal feedstuffs in western Canada.

Feed samples associated with 51 cases of suspected or potential mycotoxicoses of farm animals in western Canada were examined during a three year study. Ochratoxin A was detected in four cases, T-2 toxin and diacetoxyscirpenol in one, and sterigmatocystin in one. Samples examined for microflora associated with production of these mycotoxins contained Penicillium spp., Aspergillus ochraceus, Fusarium spp. and fungi of the Aspergillus glaucus group. Samples were analyzed for T-2 toxin and diacetoxyscirpenol only if Fusarium spp. were present. The first known incidence of suspected sterigmatocystin poisoning of poultry through feed ingestion has been encountered.

Animal Feed↗
PubMed1982

Mycotoxin formation in moist wheat under controlled temperatures.

One-kilogram parcels of wheat with 20.5% moisture content were maintained at 15 degrees and 22 degrees C for 10 weeks to study quality changes. Temperature, moisture, oxygen and carbon dioxide levels, microflora incidence and abundance, seed germination, fat acidity values, aflatoxins, sterigmatocystin, ochratoxin A, penicillic acid, citrinin and zearalenone were monitored. By two weeks, trace levels of ochratoxin had formed at both temperatures. By 10 weeks, the wheat contained at least three times more ochratoxin A at 22 degrees C than at 15 degrees C. Strains of Penicillium verrucosum var. cyclopium were associated with ochratoxin A production. No other mycotoxins were detected. The effect of temperature was significant for all variables (greater effect at 22 degree C) except A. glaucus gr. and Penicillium (P less than .01). The effect of time was significant for all variables except bacteria (P less than .01). The shape of the response was fully characterized by the linear and quadratic terms, except for % moisture which was linear only, and for bacteria for which time was not significant. The interaction between time and temperature was significant (P less than .01) for total fungal propagule count, % moisture, and Aspergillus versicolor, indicative of the steeper rise in slope for 22 degrees C.

Food Contamination↗
PubMed1978

Increased aqueous lactate dehydrogenase in Coats' disease.

A 3-year-old boy had glaucoma and a total left retinal detachment that displayed peripheral intraretinal telangiectasis. The most probable clinical diagnosis was Coats' disease. A suspicion of retinoblastoma also existed, and an aqueous aspirate was assayed for lactate dehydrogenase (LDH) and found to contain three times the level present in a matching sample of serum. We enucleated the eye and verified the diagnosis of Coats' disease pathologically. The results of aqueous LDH determinations in eyes with glaucoma, phthisis, or large numbers of histiocytes, erythrocytes, and polymorphonuclear leukocytes should be interpreted with caution.

Aqueous Humor↗
PubMed1977

Postnatal triiodothyronine concentrations in healthy preterm infants and in infants with respiratory distress syndrome.

Postnatal changes in triiodotyronine (T3) concentration were investigated in 12 preterm infants of 26-34 weeks of gestational age. Blood for measurement of T3 was obtained from the cord at delivery and from infants at 1 day of age and at weekly intervals for 4 weeks. Seven of the babies suffered from respiratory distress syndrome (RDS) and five were considred healthy. Gestational ages and body weight were comparable in both groups. In preterm infants with RDS, cord blood T3 concentration was significantly lower than that in cord blood of babies without RDS (22 +/- 2.6 versus 36 +/- 5 ng/dl, P less than 0.05). There was no significant rise in T3 concentration of RDS babies at 24 hr of age (22 +/- 2.6 versus 34.0 +/- 8 ng/dl, P greater than 0.05), and hypotriiodothyroninemia persisted for 3 weeks. At 4 weeks of age, T3 concentration in babies with RDS, although within the normal range (80-190 ng/dl), was significantly lower than that in the healthy preterm infants (110 +/- 10 versus 165 +/- 11 ng/dl, P less than 0.05). Postnatal T3 changes in healthy preterm infants wre characterized by the absence of the initial hypertriiodothyroninemia and by a gradual rise within the first month of life. The noted difference in the pattern of postnatal T3 changes in healthy preterm infants compared to full term infants may reflect thyroid immaturity. The machanism and the significance of the neonatal hypotriiodothyroninemia in RDS and its long term effects on the development of these babies remain to be investigated.

Body Weight↗
PubMedDate not supplied

Chromatography of mycotoxins on precoated reverse-phase thin-layer plates.

Reverse-phase thin-layer chromatography of 18 common mycotoxins was carried out on Merck C18 and Whatman C18 and diphenyl bonded phases. The mobile phases included neutral and acidified binary mixtures of water and methanol, acetonitrile or tetrahydrofuran. Mycotoxins studied included aflatoxins B1, B2, G1, G2, sterigmatocystin, ochratoxin A, citrinin, penicillic acid, patulin, zearalenone, and the trichothecenes diacetoxyscirpenol, HT-2 toxin, nivalenol, neosolaniol, fusarenone-X, T-2 toxin, deoxynivalenol and 3-acetyl-deoxynivalenol. Both C18-bonded phases performed well, and could serve as a convenient confirmation for mycotoxins appearing in normal-phase (silica) thin-layer chromatographic screening procedures.

Chromatography, Thin Layer↗
PubMedDate not supplied

Organ weights, liver constituents, and serum components in growing chicks fed ochratoxin A.

Chicks were fed diets containing 0, 1, 5 and 10 mg/kg ochratoxin A (OA) over a four-week period to study the effects of OA on growth, weight of internal organs, liver RNA, DNA, protein, and glycogen and serum enzymes. Ochratoxin A depressed the rate of growth and relative weight of the bursa of Fabricius, and increased the relative weights of the liver, kidney, pancreas, and various sections of the gastrointestinal tract, but had no effect on the heart and spleen. Concentrations of liver RNA, DNA and protein were decreased while glycogen was increased. Serum alkaline phosphatase and gamma-glutamyl transferase activities, and uric acid and creatinine concentrations were elevated while serum proteins, albumin, phosphorus, potassium, and cholesterol were depressed. The effects of OA were time- and dose-dependent.

Animal Feed↗
PubMedDate not supplied

Potential antitumor agents. XVII. physalin B and 25,26-epidihydrophysalin C from Witheringia coccoloboides.

An investigation of Witheringia coccoloboides (Dammer) A. T. Hunziker [Capsicum fuscoviolaceum (Cufodontis) Mort. And Standl.] roots has resulted in the isolation of two cytotoxic compounds: physalin B (1) and a novel physalin, which was characterized by spectral analysis as 25,26-epidihydrophysalin C (2). Both compounds have demonstrated cytotoxic activity in 9KB and 9PS tumor cells (in vitro). Physalin B (1) has demonstrated moderate activity against the 3PS mouse leukemia (in vivo).

Animals↗