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Biomedical subjects

J Briggs

Publications and source records attributed to J Briggs.

At least 91 records · Page 5Linked to original sources
PubMed1978

Alterations in the pyruvate dehydrogenase complex during adaptation to glucose by Neurospora.

A 20-fold induction of the pyruvate dehydrogenase complex, pyruvate dehydrogenase (EC 1.2.4.1) plus dihydrolipoate S-acetyltransferase, (lipoyltransacetylase) (EC 2.3.1.12) plus dihydrolipoyl dehydrogenase, NADH : lipoamide oxidoreductase, (EC 1.6.4.3), from a specific activity of 3.5-65.0 was observed in mitochondrial extracts during adaptation of Neurospora to glucose from acetate media. The extent of ATP-dependent, time-dependent inactivation of the pyruvate dehydrogenase complex was approximately the same in both acetate- and glucose-grown cells, thereby indicating that the low pyruvate dehydrogenase complex activities in acetate-grown cells did not represent phosphorylated pyruvate dehydrogenase complex molecules. High levels of dihydrolipoyl transacetylase (EC 2.3.1.12) were observed in mitochondrial extracts from acetate-grown cells; this lipoyltransacetylase was analyzed on sucrose density gradients and found to be associated with the pyruvate dehydrogenase complex. Digitonin fractionation of mitochondria revealed that both the pyruvate dehydrogenase complex and lipoyltransacetylase were primarily associated with the mitochondrial outer membrane.

Acetates↗
PubMedDate not supplied

High concentrations of p-Glu-His-Pro-NH2 (thyrotropin-releasing hormone) occur in rat prostate.

Thyrotropin-releasing hormone (TRH) immunoreactivity occurs in high concentration within the rat prostate. Previous studies have shown that the immunoreactive species consists of more than one TRH-like tripeptide which cross-reacts in the TRH radioimmunoassay. The component which was highly retained during cation exchange chromatography was subjected to a preparative scale isolation, purification and structural analysis. The methods used included methanol extraction, water-ethyl ether partitioning, cation exchange chromatography, affinity chromatography, high pressure liquid chromatography, TRH radioimmunoassay, in vitro pituitary bioassay, TRH receptor assay, and amino acid analysis. The mean concentration of the predominant amino acids (Glu, His, Pro), 344 pmoles/ml, and the TRH concentration measured by TRH radioimmunoassay prior to acid hydrolysis, 372 pmoles/ml, were nearly identical. Because the material analyzed cochromatographed with synthetic TRH in several chromatographic systems, had a radioreceptor potency which was indistinguishable from that for synthetic TRH, and released TSH and prolactin but not growth hormone from rat pituitaries in vitro, it is concluded that pGlu-His-Pro-NH2 is one of the TRH-like peptides in the rat vental prostate.

Amino Acids↗
PubMedDate not supplied

Rolling circle amplification for scoring single nucleotide polymorphisms.

The analysis of the genetic basis of phenotypic traits is moving towards the complex diseases prevalent in wealthy populations. There is an increasing requirement for the detection of different types of sequence variation, particularly single-nucleotide polymorphisms (SNPs). SNPs occur about once every 100 to 300 bases. High-density SNP maps will help to identify the multiple genes associated with complex diseases such as cancer, diabetes, vascular disease, and some forms of mental illness.

DNA↗
PubMedDate not supplied

Neutron dosimetry with detectors of finite size. II. Experiments and calculations.

In a previous article a theory for detector response in fields of fast neutrons was presented. In the present paper this theory is subjected to experimental tests. For detectors of sizes comparable to the ranges of the neutron produced charged particles the theory predicts the variation of the detector response with detector size and elemental composition of the detector. A tissue-equivalent ionization chamber exposed to a field of 252Cf neutrons was used in the experimental tests of the theory. The size dependence of the response was investigated by varying the chamber gas pressure and the effects of different elemental compositions (mainly hydrogen content) was investigated by using different gases in the chamber (H2, CH4, TE-gas N2, Air, CO2, and Ar). The theory was evaluated both by using chord length distributions to characterize the chamber cavity and with a simplified version using a single mean chord length. The agreement between theory and experiment is generally good.

Models, Biological↗
PubMedDate not supplied

The destination and dependency of patients discharged from care of the elderly units in the West Midlands.

Between November 1988 and January 1989 a prospective survey was undertaken on patients aged 65 years and over who were discharged from the care of geriatricians in seven District General Hospitals. The survey aimed to provide a regional perspective on patient dependency by relating dependency at discharge to the discharge destination. The findings show that the majority of patients were relatively independent and most returned home. A significant number of the very dependent patients were discharged to the community with private residential and nursing homes making an important contribution to the placement of highly dependent patients.

Activities of Daily Living↗
PubMedDate not supplied

Sensor-based system for rapid and sensitive measurement of contaminating DNA and other analytes in biopharmaceutical development and manufacturing.

The Threshold System provides for rapid and highly sensitive measurements of a variety of analytes at low concentration. The operating principles of the measurement system, including signal detection utilizing a proprietary silicon sensor, are described. The first application to run on the Threshold System is a quantitative assay for picogram levels of total DNA. This assay is of great value for monitoring levels of contaminating DNA in purified and in-process biopharmaceuticals. After sample pretreatment, the total assay time is less than two hours. The assay performance characteristics are described, along with data demonstrating sensitivity, precision, and accuracy. Pretreatment procedures for biopharmaceutical proteins are discussed. Two additional applications on Threshold are introduced. First, a universal ligand-binding assay system provides quantitative measurement of antigens or antibodies, in a variety of biological media, with speed, sensitivity, and precision. Second, preliminary results of rapid DNA-probe measurements on Threshold are presented.

Biosensing Techniques↗