Biomedical subjects

R E Hardy

Publications and source records attributed to R E Hardy.

At least 37 records · Page 2Linked to original sources

PubMed1984

Correlation between plasma carcinoembryonic antigen (CEA) and sialyltransferase as tumor marker.

Plasma carcinoembryonic antigen (CEA) and sialyltransferase levels were assayed in 21 cancer patients to correlate them in response to therapy. Plasma sialyltransferase and CEA level correlated well in 10 colon, 4 breast and 1 lung cancer patients in response to therapy. There was a negative correlation in one colon cancer, 3 breast cancer and 2 lung cancer patients. Plasma sialyltransferase was a better marker for breast and lung cancer. CEA was a good marker for colon cancer.

Breast Neoplasms↗

PubMed1983

Possible role of the carbohydrate residues in the display of the MN blood group determinants by glycophorin A.

Heterozygous glycophorin AM,N and homozygous glycophorin AM were reductively methylated with 13C-enriched formaldehyde in the presence of cyanoborohydride. Total reductive methylation modified the five lysine residues, and the N-terminal amino acid residues (serine and leucine) of glycophorins AM and AN, respectively. The 13C resonances of the incorporated labels were monitored as a function of the degree of glycosylation of the glycoprotein. While minimal, if any, structural changes were observed near the N-terminal amino acid upon removal of alpha-D-N-acetylneuraminic acid residues, gross structural changes were observed when most of the oligosaccharide chains were removed. We also found that progressive methylation of the lysine residues of glycophorin AM may influence either the chemical shift of one of the nonequivalent methyl groups of the N alpha, N-[13C]dimethyl serine residue, or one of the two states of glycophorin AM.

Animals↗

PubMed1983

Specific 13C reductive methylation of glycophorin A. Possible relation of the N-terminal amino acid and the lysine residues to MN blood group specificities.

Heterozygous and homozygous glycophorin A were partially and fully reductively methylated with 13C-enriched formaldehyde in the presence of sodium cyanoborohydride. Total reductive methylation modified the five lysine residues (to produce N epsilon,N-[13C]dimethyl lysine) and the N-terminal amino acid residues (N alpha,N-[13C]dimethyl serine and leucine) of glycophorins AM and AN, respectively. 13C-NMR spectra of these species indicated that the 13C-enriched methyl carbons of the five lysyl derivatives all occur at 44.1 ppm downfield from Me4Si. Titration results indicate that the pK alpha of these methylated lysines is greater than 10. The chemical shift equivalent methyl resonances of the 13C-enriched methylated N-terminal Leu derivative were found to occur at 42.8 ppm downfield from Me4Si and exhibited a normal pH titration behavior (pK alpha approximately 7.4). The methyl resonances of the N alpha,N-[13C]dimethyl Ser derivative, on the other hand, were found to exhibit chemical shift nonequivalence, indicating rotational constraints about the C alpha-N bond. The linewidths of the two methyl resonances were also found to be considerably different; this phenomenon could be eliminated by running spectra of the sample (pH approximately 5.0) at elevated temperatures (75 degrees C). This result suggested that for the N alpha,N-[13C]dimethyl Ser derivative of glycophorin AM, hindered rotation must occur about one of the N alpha-13CH3 bonds. This structural difference at the N-terminal residue of glycophorins AM and AN may be related to the MN blood group determinants displayed by these related glycoproteins.

Amino Acid Sequence↗

PubMed1982

Magnetic resonance study of glycophorin A-containing 13C-enriched methionines.

Methionine-81 and/or -8 of the transmembrane sialoglycoprotein, glycophorin A, have been specifically alkylated with 13CH3I to produce the sulfonium ion derivatives [S-[13C]methylmethionine-8]glycophorin A and [S-[13C]methylmethionine-8 and -81]glycophorin A. 13C NMR spectra of these species show that the resonances of the methyl groups of the modified glycophorins occur at 26.1 ppm downfield from Me4Si. A spin-lattice relaxation time of 0.4 s was observed for the 13C-enriched methyl resonances of the sulfonium ion derivatives of Met-8 and -81, which corresponds to an effective correlation time of less than 2 X 10 - 10 s. Demethylation of the 2 glycophorin A sulfonium ion species with 2-mercaptoethanol produces native glycophorin A which now has the epsilon-carbon of the methionine residue(s) 45% isotopically enriched. The epsilon-carbon of Met-8 was found to occur at 15.7 ppm downfield from Me4Si whereas the epsilon-carbon of Met-81 exhibited an unusual chemical shift of 2.0 ppm downfield from Me4Si. The spin-lattice relaxation time of both resonances was found to be approximately 0.3 s.

Carbon Isotopes↗

PubMed1981

Multiple primary malignancies in black patients.

Charts of 42 black patients with multiple malignant neoplasms were among 1,953 cancer patients selected for review during the period of 1959 through 1979. The incidence was 2.15 percent. Most patients were female and the breast was the most frequent initial primary carcinoma. With this relatively small number of cases, there was no consistent cluster of initial and second primaries about which to make inferences. In the absence of a regional registry of primary tumor incidence, no generalities could be obtained concerning a matched non-black population on the incidence of multiple primaries. However, comparison of this group could be made with data previously recorded.

Adult↗

PubMed1980

Comparison of expressive and receptive measures of intelligence.

The Revised Beta Examination (RBE) and the Peabody Picture Vocabulary Test (PPVT) were administered to 34 disabled male and female students (ages 15 to 20 years) in a special education rehabilitation unit in western Virginia; a correlation coefficient of .46 was found. It was concluded that since the two tests measured different facets of intelligence (the PPVT is a receptive measure, the RBE an expressive measure) each should be administered as part of a battery and that this would be more economical than administering the Wechsler Adult Intelligence Scale (WAIS). A significant difference between the mean scores of the two tests was verified through a t test. In making a choice between them researchers and test administrators will want to choose whether they want an expressive or receptive measure of intelligence.

Adolescent↗

PubMed1980

Communication between cancer patients and physicians.

A total of 185 practicing physicians in middle Tennessee responded to a questionnaire regarding their communication patterns with cancer patients. This represented 61% of a total of 320 area physicians to whom questionnaires were mailed. Nearly 98% of responding physicians always or usually inform patients that they have cancer. No difference in communication was noted as a function of specialty or age. A number of terms are used at different times during the course of a patient's illness.

Adult↗

PubMed1974