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Biomedical subjects

M Rice

Publications and source records attributed to M Rice.

At least 109 records · Page 6Linked to original sources
PubMed1981

The effects of a post-transcriptional modification on the function of tRNALys isoaccepting species in translation.

Isoacceptors of rabbit liver tRNALys which preferentially translate the codon AAG were compared for their function in several aspects of translation. As shown in other laboratories, Lys-tRNALys1,2 are two isoacceptors which differ from each other by a single base pair and are fully modified with N6-threonyl-adenosine adjacent to the anticodon. Lys-tRNALys4, which occurs commonly in rapidly dividing mammalian cells and tissues, is hypomodified at several bases and contains a precursor of N6-threonyl-adenosine next to its anticodon. These isoacceptors were incubated in cell-free protein synthesizing systems which contain rabbit globin mRNA. (Lys-tRNALys3 which translates AAA was also included.) The resulting globin was isolated and digested with trypsin, and the relative incorporation of lysine from Lys-tRNALys1,2 and from Lys-tRNALys4 into lysine-containing sites in the globin peptides as determined. Lys-tRNALys1,2 and Lys-tRNALys4 translate AAG preferentially, but Lys-tRNALys4 wobbles more than the former and translates AAA codons more efficiently. Overall, Lys-tRNALys1,2 is preferred in globin synthesis by about 30% compared to Lys-tRNALys4, and with one exception, the incorporation of lysine into the individual AAG lysine-containing sites in globin occurs more efficiently from Lys-tRNALys1,2. There is, however, considerable variation from site to site in the relative efficiencies of the Lys-tRNAs in incorporation.

Animals↗
PubMed1981

Course evaluation in post-basic education.

Course evaluation is defined 'as the collection and use of information in order to make decisions about an educational programme' (Cronbach 1963). The study described in this paper was undertaken by members of the professional and research staff of the Joint Board of Clinical Nursing Studies, London. The paper describes how the need for work on course evaluation arose and how a package was developed and piloted in 15 course centres with a total of 205 students. The ways in which the package is being used by schools of nursing and colleges of higher and further education is also described. The philosophy that evaluation has an important part to play in developing dynamic and sound educational systems is emphasized. Evaluation should be an integral part of every course and planned at the outset with other parts of the detailed course programme, involving both students and teachers in measuring the effectiveness of the course.

Education, Nursing, Continuing↗
PubMed1979

Aminoacyl-transfer RNA populations in mammalian cells chromatographic profiles and patterns of codon recognition.

The chromatographic profiles of 20 aminoacyl-tRNAs from rabbit liver were compared to those of rabbit reticulocytes by reverse phase chromatography and the chromatographic profiles of 20-aminoacyl-tRNAs from bovine liver were compared to those of bovine brain. The two rabbit tissues showed significant differences in the elution profiles of most aminoacyl-tRNAs, while the elution profiles of the aminoacyl-tRNAs from the bovine tissues showed fewer differences. The patterns of codon recognition of several aminoacyl-tRNAs fractionated from rabbit reticulocytes have also been compared to those fractionated from rabbit liver.

Amino Acyl-tRNA Synthetases↗
PubMed1979

Viral nucleic acid synthesis in HSV infected neural cells.

HSV-1 replication and synthesis of viral DNA and RNA have been examined in gliomas of human (COX) and rat origin (C6) and in mouse neuroblastomas (D2). COX cells fully support HSV-1 replication and show patterns of viral DNA and RNA synthesis similar to those seen in continuous line cells. HSV-1 also grows to high titers in D2 cells but without concomitant high levels of viral DNA and RNA synthesis in the infected cells. Finally, HSV-1 established a persistent infection in C6 cells. Viral mRNA and DNA synthesis could not be detected in these cultures. At cycles of approximately 15--20 days, the persistently infected cultures exhibited massive CPE and relatively high production of infectious HSV.

Animals↗
PubMed1978

Patterns of codon recognition by isoacceptor aminoacyl-tRNAs from wheat germ.

Isoacceptors of Ala-, Arg-, Glu-, Gln-, Ile-, Leu-, Lys-, Ser-, Thr- and Val-tRNAs from wheat germ have been resolved by reverse phast chromatography. Codon recognition properties have been determined on isolated fractions of each of these aa-tRNAs and codon assignments have been made to a number of isoacceptors. Evolutionary changes which have occurred in patterns of codon recognition by isoacceptor aa-tRNAs in wheat germ and other organisms are discussed.

Biological Evolution↗
PubMed1976

Variation in the molecular size of the DNA from closely related strains of type I herpes simplex virus.

We have investigated the comparative genome size of five strains of HSV type 1 (HSV-1). Two of these strains have a common origin and differ in their plaque morphology on HeLa cells, one strain is a wild type isolate, and two others are established laboratory strains. All strains show high sequence homology based on the melting behavior of heteroduplexes. The greatest sequence divergence between any two strains was found to be no more than 10%. There are real differences in the size of the genomes of these strains of HSV-1 as measured by electron microscopy. The shortest and largest genomes measured differ in size by 10%, however, the size of the genomes of all strains are within 5% of a median valve of 87-88X106.

Base Sequence↗
PubMed1975

Controlled study of the cytotoxic food test.

The cytotoxic food test was not found to be an accurate method for diagnosing atopic reactions to foods. Claims that the test correlated with other untoward reactions to foods (eg, headache, diarrhea, fatigue) could not be corroborated. The test itself is time-consuming, dependent on subjective interpretation, and inconsistent in results when repetitive runs are performed on the same patient.

Adolescent↗
PubMed1975

Xeroderma pigmentosum cells contain low levels of photoreactivating enzyme.

Fibroblasts from patients with xeroderma pigmentosum contain low levels of photoreactivating enzyme in comparison to normal cells. Levels vary from 0 (line 1199) to 50 (line 1259) percent of normal. The depressed enzyme levels are not an artifact of low growth rate, age of cell donor, cell culture conditions, assay conditions, the presence of inhibitors, or mycoplasma contamination. We show that human fibroblasts can monomerize pyrimidine dimers in vivo.

Cell Line↗
PubMed1974

Identification of a ventral scent marking pheromone in the male Mongolian gerbil (Meriones unguiculatus).

Sebum from the ventral scent marking gland of the male Mongolian gerbil was fractionated and tested for its ability to elicit behavioral response in a conditioning task and in a stimulus preference situation. The active fraction was identified as phenylacetic acid; both it and a synthetic sample elicited the same behavioral response. Phenylacetic acid appears to be a major pheromone of the male Mongolian gerbil.

Animals↗