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Biomedical subjects

J E Fields

Publications and source records attributed to J E Fields.

9 recordsLinked to original sources
PubMed1982

Carboxyimamidate, a low-molecular-weight polyelectrolyte with antitumor properties and low toxicity.

A new polyelectrolyte was synthesized and evaluated for antitumor activity. The product is a derivative of ethylene/maleic anhydride copolymer of low molecular weight (Mn approximately equal to 1100). The anhydride groups were first converted to the half-amide, half-ammonium salt by reaction with ammonia. A percentage (14-25 wt %) of these groups was further converted to the imide by heating. The product, carboxyimamidate (Carbethimer, N-137) inhibited the growth of a number of solid tumors in vivo. Sensitive tumor models included Lewis lung carcinoma, Madison 109 lung carcinoma, M5076 ovarian tumor, colon carcinoma 26, B16 melanoma, and P815 mastocytoma. Activity was dose related between nontoxic dose levels of 300 and 2000 mg/kg ip.

Animals↗
PubMed1979

Modulation of the immune response and control of tumour spread by a new synthetic compound.

A small molecular weight biofunctional polymer, NED 137, has been investigated for its anti-neoplastic effect. Through its effect on the immune system, particularly the induction of B cell differentiation to antibody producing cells, this synthetic compound can retard tumour growth and prevent the development of distant metastases. Reactivity to tumour developed following administration of the NED 137. No toxicity has been observed. The polymer NED 137 is now being tested in phase I and phase II clinical trials.

Adjuvants, Immunologic↗
PubMed1979

Freedom from transmission of hepatitis-B of gamma-globulin and heat-inactivated plasma protein fraction prepared from contaminated human plasma by fractionation with solid-phase polyelectrolytes.

Plasma contaminated with hepatitis B surface antigen (HBsAg) and shown by others to be infectious when injected in a dilution of 1:1,000,000 in chimpanzees, was fractionated by a solid-phase polyelectrolyte (PE) procedure for its content of plasma protein fraction (PPF) and gamma-globulin (immune serum globulin; ISG). Quantitative Ausria II radioimmunoassays showed that nearly half the HBsAg was bound by the PE and could be eluted at low pH, while the rest was found in the heat-inactivated PPF. When the ISG was concentrated to 16%, the 13 mg/kg (comparable to a human dose) was injected intramuscularly in 6 chimpanzees, or when the PPF was heated at 60 degrees C for h and injected intravenously in 2 chimpanzees, there was no clinical or laboratory evidence of hepatitis B infection after 12 months, although 1 chimp of 2 who received the same material showed a borderline positive anti-HBsAg antibody result on one of 52 weekly serum samples. Since the new PE fractionation method is essentially nondenaturing, and simpler than the classical ethanol procedures, it was important to establish the noninfectivity of the final products.

Adsorption↗
PubMed1978

Preparation of the major plasma fractions by solid-phase polyelectrolytes.

The solid-phase ethylene/maleic anhydride PE's E-5 and E-100 were used to developed a flexible integrated system of batch methods for the fractionation of albumin and gamma globulin as well as the clinically important coagulation factors. Each method for the isolation and purification of the fractions or a modification of it could also be used independently or could be added onto another method or methods. Each fraction was prepared in three steps: adsorption on solid-phase PE's elution from the PE's, and concentration by ultrafiltration or by use of PEG or both. Since the methods required no organic solvent but relied primarily on electrostatic bonding, they were essentially nondenaturing. Solid-liquid phase separation was easily accomplished by centrifugation or filtration. The yield and purity of each fraction was as follows: (1) coagulation factors II, VII, IX, and X concentrates 63% and 200-fold purified; (2) AHF 43% and 52-fold; (3) vWF 43% and 71-fold; (4) PPF, as albumin, 93% yield and 92% pure; (5) albumin 92% yield and 98.5% pure; and (6) gamma globulin 92% yield and 97.5 pure. During the preparation of gamma globulin the E-100 also tended to adsorb and remove the HBSAg and infectivity, when present.

Blood Coagulation Factors↗
PubMed1971

Concentration and purification of viruses by adsorption to and elution from insoluble polyelectrolytes.

Acid-resistant, nonenveloped viruses belonging to the enterovirus, reovirus, and adenovirus groups were readily concentrated on PE60, an insoluble cross-linked polyelectrolyte based on isobutylene maleic anhydride. Hydrolysis of PE60 by NaOH increased its capacity to adsorb viruses. Hydrogen ion levels played an important role in virus concentration; optimal pH levels for maximal virus adsorption were between pH 3.0 and 4.5. Undiluted virus was easily concentrated from large volumes on PE60, and the adsorbed virus was readily eluted at pH 8 to 9.

Adenoviridae↗
PubMed1969

Concentration of viruses from sewage and excreta on insoluble polyelectrolytes.

The concentration of viruses from sewage by adsorption on and elution from an insoluble cross-linked copolymer of maleic anhydride is described. Viruses either added to sewage or naturally contained in sewage were preferentially adsorbed to this polyelectrolyte at a pH range of 5.0 to 6.0 and were eluted at pH 8.0 to 9.0. In a 2-month survey of viruses in sewage in the spring (April to May 1968), when viruses are at low levels, efficient and economical detection of these agents was accomplished with the polyelectrolyte-concentration method. This method lends itself to the detection of viruses present in minute amounts in fecal samples, urine, sewage, and other natural waters. Large volumes of these fluids can be treated with the polymer described, and virus can be concentrated sufficiently for detection.

Adsorption↗