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Biomedical subjects

J W Finley

Publications and source records attributed to J W Finley.

16 recordsLinked to original sources
PubMed1991

Effect of light chain V region duplication on IgG oligomerization and in vivo efficacy.

A human immunoglobulin G1 (IgG1) antibody oligomer was isolated from a transfected myeloma cell line that produced a monoclonal antibody to group B streptococci. Compared to the IgG1 monomer, the oligomer was significantly more effective at protecting neonatal rats from infection in vivo. The oligomer was also shown to cross the placenta and to be stable in neonatal rats. Immunochemical analysis and complementary DNA sequencing showed that the transfected cell line produced two distinct kappa light chains: a normal light chain (Ln) with a molecular mass of 25 kilodaltons and a 37-kilodalton species (L37), the domain composition of which was variable-variable-constant (V-V-C). Cotransfection of vectors encoding the heavy chain and L37 resulted in production of oligomeric IgG.

Animals↗
PubMed1991

Effect of sex and time of sampling on selenium and glutathione peroxidase activity in tissues of mature rats.

Sprague-Dawley rats were used to investigate variations in measures of glutathione peroxidase (GSH-Px) and selenium (Se) concentration resulting from diurnal cycles and sex. Mature rats (equal numbers of males and females) were killed at 4 h intervals over a 48 h period (0200, 0600, 1000, 1800 and 2200 h each day). Selenium and GSH-Px were measured in plasma, erythrocytes, and liver and kidney cytosols. Selenium concentrations did not vary diurnally, but plasma GSH-Px activities were higher during the light than dark periods. Males had greater plasma GSH-Px activities and Se concentrations (42 EU and .45 mg/kg, respectively) than females (35 EU and .41 mg/kg respectively). GSH-Px activities were also higher in male kidney cytosols than females (117 and 76 EU, respectively). Selenium and GSH-Px activities, however, were lower in male liver cytosols (.48 mg/kg and 272 EU) than females (1.19 mg/kg and 795 EU, respectively). These data suggest that Se is distributed differently in male and female rats and the difference in Se distribution is accomplished by differences in GSH-Px activities.

Animals↗
PubMed1989

Improved wheat for baking.

To bakers, wheat quality means the performance characteristics of the flour milled from the wheat when used in specific wheat products. The tremendous increase in the number of wheat cultivars grown in the U.S. in recent years, along with the unusual climate, new advances in milling technology, and increased automation of baking lines, have resulted in bakery production problems partly attributed to wheat flour quality. In this review various factors affecting wheat quality are explained. Concerns of bread and cookie/cracker manufacturers on deterioration of the wheat quality are discussed, and, finally, some solutions are proposed.

Bread↗
PubMed1987

Evaluation of nuclear magnetic resonance spectroscopy for determination of deuterium abundance in body fluids: application to measurement of total-body water in human infants.

Nuclear magnetic resonance (NMR) spectroscopy was used to quantitate abundance of 2H in body water of human infants. This method provides precise measurement of total-body water without the extensive sample preparation requirements of previously described methods for determination of 2H content in body fluids. 2H2O (1 g/kg body weight) was administered to infants and saliva and urine were collected for up to 5 h. An internal standard was added directly to the fluid specimen and 2H enrichment in water was measured by NMR spectroscopy. Working range of deuterium abundance was 0.04-0.32 atom %. Coefficients of variation for saliva samples at 0.20 atom % 2H was 1.97%. 2H content in urine and saliva water reached a plateau by 4 h after administration, and amounts in the two fluids were virtually identical. Mean total-body water determination for six infants was 58.3 +/- 5.8% of body weight (range 53-66%).

Body Fluids↗
PubMed1977

Reactions of proteins with dehydroalanines.

Reactions of proteins with dehydroalanine or derivatives of dehydroalanine were studied as models for protein crosslinking. Treatment of casein, bovine serum albumin, lysozyme, wool or polylysine with acetamido- and phenylacetamido acrylic acid methyl esters at pH 9-10 converted varying amounts of lysine to lysinoalanine residues. Howver, complete transformation was not achieved. Incomplete reaction is atributed to partial hydrolysis of the esters to the less reactive acrylic acids under the reaction conditions. Similar studies were made of the reactivities of protein SH groups generated by reduction of disulfide bonds by tributylphosphine. The SH groups could be completely alkylated at pH 7.6 in aqueous propanol, as shown by nearly quantitative recovery of lanthionine. Such a procedure might therefore be used to estimate cystine contents of proteins.

Alanine↗
PubMed1977

Inhibitory effect of mercaptoamino acids on lysino-alanine formation during alkali treatment of proteins.

Alkali treatment of food proteins converts some amino acid residues to the unnatural amino acid lysinoalanine which has been found to cause kidney damage when fed to rats. Formation of lysinoalanine was essentially prevented when isolates of soy protein and casein were exposed to alkali in the presence of thio-alamino acids such as cysteine. The results suggest that added thiols minimize the formation of potentially toxic lysinoalanine.

Alanine↗
PubMed1977

New amino acid derivatives formed by alkaline treatment of proteins.

Intense heat treatment of proteins at high pH favors formation of transient, reactive intermediates derived from serine and cystine. The postulated dehydroalanine intermediate reacts further with the epsilon-amino groups side chains and sulfhydryl groups of cysteine residues to form derivatives of lysinoalanine and lanthionine. Recent studies indicate that besides these crosslinked products, several others are formed, by reaction of histidine, arginine, and possibly other residues. For this reason, caution should be exercised in assigning the prelysine peak(s) of an amino acid chromatogram to lysinoalanine. These results suggest that unnatural amino acid derivatives, other than lysinoalanine, may also contribute to the toxic effects reported from studies in which alkali-treated protein was fed to rats.

Alanine↗
PubMed1976

Relative reactivities of sulfhydryl groups with N-acetyl dehydroalanine and N-acetyl dehydroalanine methyl ester.

The reaction rates in aqueous solutions of aminothiols, thiols, and other compounds with N-acetyl dehydroalanine and its methyl ester (2-acetamindoacrylic acid and methyl 2-acetamidoacrylate) were studied as a function of the structure of the thiol compound in aqueous solutions. Correction of the observed second-order rate constants to identical thiol anion concentration gave a series of computed rate constants whose logarithms showed a linear dependence on the pK's of the thiol group in similar steric environments. Comparison of the addition rates of penicillamine to N-acetyl dehydroalanine and its methyl ester showed the methyl ester to react approximately 11,400 times faster than the acid. Addition rates for thiol acids and aromatic and heterocyclic thiols were also compared; each showed sluggish reactivity with dehydroalanine, but each reacted readily with methyl dehydroalanine. The kinetic data were applied in developing a method for preparing lanthionine in high yield.

Alanine↗
PubMed1975

A kinetic study of the hydrolysis of N-acetyl dehydroalanine methyl ester.

Hydrolysis rates of N-acetyl dehydroalanine methyl ester (methyl 2-acetamidoacrylate) and related model compounds were measured in aqueous, organic and mixed aqueous media. Adding dimethylsulfoxide (DMSO) to water, retarded hydrolysis of the ester by a factor of 2 to 500, depending on the pH of the medium and concentration of DMSO. Ethanol also slowed hydrolysis, but the effect was not so pronounced. Related studies show that the acetamido group C-N bond of sodium 2-acetamido-acrylate is hydrolyzed only about 1/130 as fast as the ester group C-O bond. Aqueous dimethyl sulfoxide should by a useful medium for synthesis of peptide, amino acid and protein derivatives of N-acetyl dehydroalanine methyl ester.

Acrylates↗
PubMed1975

Reactions of proteins with ethyl vinyl sulfone.

Ethly vinyl sulfone (EVS) alkylates xi-amino groups of lysine side chains and imidazole groups of histidine residues in proteins. Amino acid analysis of hydrolyzates of EVS-treated polylysine shows that lysine forms two derivatives, presumably xi-N-(ethylsulfonylethyl)lysine and xi, xi, N,N-bis(ethylsulfonylethyl)lysine that are eluted as well-resolved peaks on the (long basic) physiological column of our amino acid analyzer at about 118 and 60 min, respectively. Peaks with identical elution times were also observed after EVS-treatment of BSA and wool. The postulated histidine derivative, presumably N3-im-(ethylsulfonylethyl)histidine is also eluted as a well-resolved peak on the same column at about 90 min. A peak with an identical elution time was observed in a hydrolyzate of EVS-treated polyhistidine. The described alkylation has potential utility for modifying proteins.

Alkylation↗
PubMedDate not supplied

Technological necessity of antioxidants in the food industry.

Antioxidants are one of the principal lines of defence in protecting quality as food or ingredients move from the farm through processing and distribution to the consumer. The urbanization of society and the resultant need to process complex, higher-quality foods have required that products survive a longer transportation time and an extended shelf-life. Consumers are also becoming more quality oriented and health conscious in their food selections. The food manufacturer, therefore, is faced with the challenge of supplying wholesome high-quality foods to the consumer. One of the major sources of change that occurs during processing, distribution and final preparation of foods is oxidation. Among the major food quality issues influenced by lipid oxidation are nutritional quality, toxicity, flavour, texture and colour. Antioxidants significantly extend the shelf-life of foods containing oxidizable lipids such as vegetable oils, animal fats, flavourings, spices, nuts, processed meats and snack products. It is important to note that oxidation and the need for antioxidants is not limited to high-fat foods, but includes cereals and other items that contain only small amounts of lipids.

Antioxidants↗