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Biomedical subjects

J Sims

Publications and source records attributed to J Sims.

At least 73 records · Page 4Linked to original sources
PubMed1984

Assessment of the value of a competitive protein binding radioassay of folic acid in the detection of folic acid deficiency.

The diagnostic value of the Becton Dickinson Radioassay Kit (125I) for the the assay of red cell folate has been investigated. The assay was acceptable with regards to precision but was non-linear with changing packed cell volume. Sensitivity of the assay was satisfactory, with 24 of 25 folate deficient patients giving red cell folate values which fell below the reference range. Specificity of the assay in the detection of folate deficiency was less satisfactory. As with microbiological assays, a considerable proportion of vitamin B12 deficient patients had low red cell folate values. In addition, low concentrations were found in 12% of patients who were unlikely to be deficient in either vitamin B12 or folic acid.

Binding, Competitive↗
PubMed1983

The effects of saccharin on the metabolism of dietary tryptophan to indole, a known cocarcinogen for the urinary bladder of the rat.

Adult male rats were fed diets containing 0 to 10% saccharin, 2% tryptophan, or 2% tryptophan plus 5% saccharin ad libitum for 1 to 2 months. Saccharin produced a dose-related increase in the urinary excretion of indican which is the main metabolite of indole. The renal clearances of both indican and saccharin were reduced at high plasma concentrations (200 to 300 micrograms/ml) of saccharin, suggesting saturation of renal tubular secretion. The increased amounts of indican in the urine, and of indole in the cecum arose from accumulation of protein and tryptophan in the cecum rather than an increase in the enzyme tryptophanase which metabolizes tryptophan to indole. The high levels of protein in the ceca of rats fed saccharin-containing diets were associated with a dose-related increase in the weight of the contents and wall of the cecum. Administration of 2% tryptophan in the diet increased significantly the amounts of tryptophan in the cecum and in plasma, but produced only small increases in the size of the cecum, the amount of indole present, and the excretion of indican. The effects of saccharin and tryptophan were additive. These effects are consistent with saccharin having a major effect on protein digestion in the intestine such that increased amounts of tryptophan are available in the cecum for microbial metabolism to indole. The greater formation of indole and excretion of indican in the urine suggest that saccharin increases the catabolism of dietary tryptophan to metabolites with known cocarcinogenic activity toward the rat bladder.

Animals↗
PubMed1983

Distension of the urinary bladder in rats fed saccharin containing diet.

The administration of a diet containing 7.5% saccharin ad libitum to rats for 1 month caused an increase in the daily water intake and total urine volume. The greater urine volume was associated with an increase in both the frequency of urination and the average volume per urination. In saccharin-fed rats the total number of urinations per 24 h which exceeded 1.0 ml was increased 3-fold whilst the maximum urination volume detected was almost doubled. These results show that the short-term administration of the high dietary levels used in previous 2-generation cancer bioassays produces functional changes in the urinary bladder, the organ showing an increased incidence of tumours.

Animals↗
PubMed1983

The validity of the Draw-A-Person Test as an anxiety measure.

This review examines the current status of research on indicators of anxiety in the Draw-A-Person Test (DAP). Experimental studies have used stress induction while correlational studies have typically employed the Manifest Anxiety Scale as criterion. Three scoring systems (Engle-Suppes, Handler, Royal) have included most of the available anxiety indices. Methodological problems with this research include failure to control for drawing quality and intelligence, confounding anxiety measurement with defensive response style, and inadequate validation of the scoring systems. Results of the review are summarized in eight specific conclusions.

Anxiety↗
PubMed1982

Somatic mutation in genes for the variable portion of the immunoglobulin heavy chain.

The size of the gene pool potentially encoding antibodies to p-azophenyl arsonate has been examined. A heavy chain-specific full-length complementary DNA clone has been constructed with the use of messenger RNA from a hybridoma that produces antibodies to the arsonate hapten and bears nearly a full complement of the determinants comprising the cross-reactive idiotype (CRI). The sequences of both the complementary DNA clone and the corresponding immunoglobulin heavy chain have been independently determined. A probe for the variable region gene was prepared from the original heavy chain complementary DNA clone and used to analyze, by Southern filter hybridization, genomic DNA from both A/J (CRI positive) and BALB/c (CRI negative) mice. Approximately 20 to 25 restriction fragments containing "germline" variable region gene segments were detected in both strains, and many are shared by both, Since 35 CRI-positive heavy chains have been partially sequenced thus far and 31 are different, the results of the hybridization analysis suggest that somatic mutation events involving the variable region gene segments of the heavy chain play a role in the origin of the amino acid sequence diversity seen in this system.

Amino Acid Sequence↗
PubMed1980

Initiation of DNA replication by the Escherichia coli dnaG protein: evidence that tertiary structure is involved.

The dnaG protein of Escherichia coli initiates DNA replication by synthesizing primer oligonucleotides for elongation by DNA polymerae. The experiments reported here probe the nature of the nucleic acid element recognized by the dnaG protein. Three well-separated groups of nucleotides within the negative-strand origin of the single-stranded phage phi K are protected by the dnaG protein against nuclease digestion. DNA as far as 115 bases from the start site of primer synthesis is involved in binding of the dnaG protein to the replication origin. One molecule of dnaG protein could protect all of these nucleotides if the DNA were folded into a higher-order tertiary structure. Protection of the phi K origin by dnaG protein requires DNA binding protein, and it does not occur if the group of protected nucleotides most distant from the start site is removed from the template. There is no binding of dnaG protein to the complementary strand of the phi K origin-region DNA. The observed protection of the positive strand is due to a functional nucleic acid-protein complex.

Bacterial Proteins↗
PubMed1979

dnaG (primase)-dependent origins of DNA replication. Nucleotide sequences of the negative strand initiation sites of bacteriophages St-1, phi K, and alpha 3.

The simplest known origins of DNA replication occur in the single-stranded bacteriophages. In one set of phages, negative strand synthesis is initiated by a single protein, the product of the Escherichia coli replication gene dnaG. Evidently, in these phages--G4, St-1, phi K, and alpha 3--the origin for negative strand synthesis consists of a nucleic acid element capable of direct recognition by the dnaG priming protein. We have located and sequenced the origins of negative strand synthesis in St-1, phi K, and alpha 3, and compared them with the origin sequence previously determined for G4. In each case, the point at which the negative strand is initiated can be identified at the nucleotide level. The data lead to the following conclusions: 1. In all four phages, the negative strand initiation site occurs within an intercistronic region of approximately 135 bases. While in G4, the origin lies between genes specifying the viral coat proteins F and G, the origin is shifted in St-1, phi K, and alpha 3 to a position between coat protein genes G and H. 2. Extensive nucleotide conservation exists at the negative strand origin, but does not extend into the adjacent coding regions. The conserved origin DNA occurs in two regions, 42 and 45 bases long, which are separated by 13 bases of divergent sequence. 3. Correlated with the two stretches of conserved nucleotide sequence are two regions of potential secondary structure. The start point of negative strand synthesis lies just prior to one of these hairpins. Similarities in both primary sequence and secondary structure can be found between the negative strand origins of G4, St-1, phi K, and alpha 3 and the general origin regions of bacteriophage lambda and of E. coli.

Base Sequence↗
PubMed1978

Site-specific initiation of a DNA fragment: nucleotide sequence of the bacteriophage G4 negative-strand initiation site.

The synthesis of the bacteriophage G4 negative strand is an example of the de novo initiation of a polynucleotide chain. This initiation is performed by the Escherichia coli replication protein dna G which selects a unique site on 5400-base positive-strand template. In this paper we present the nucleotide sequence of the G4 negative-strand initiation site. This is the template element recognized by the dna G priming protein. In conjunction with the sequence of the nascent negative strand, obtained by Bouché, Rowen, and Kornberg [Bouché, J.-P., Rowen, L. & Kornberg, A. (1978) J. Biol. Chem. 253, 765-769], the present data provide a description of a dna G-dependent origin of replication in which one knows the place at which polymerization starts at the nucleotide level.

Base Sequence↗
PubMed1978

Cross contamination of cytological smears, with automated staining machines and bulk manual staining procedures. With a specific study of the problems of the Cytotek and the Shandon Elliott staining machines.

Further development of an individual staining machine is to be strongly encouraged but meanwhile, using bulk stainers, frequent changing of wash fluids and staining solutions, particularly leading up to and following the haematoxylin pot, is essential to reduce the risk of cross contamination. Certain smears, such as from semen or from serous fluids where malignancy is suspected or known, must be stained on separate racks. In some laboratories it is the rule not to stain semen or serous fluids in bulk staining machines at all and this may have to become the rule everywhere until we are provided with safe individual slide stainers.

Adenocarcinoma↗
PubMed1977

Levels of immunoglobulin E (IgE) in paired examinations of serum and synovial fluid in rheumatoid arthritis and reactive synovitis of local origin.

Levels of IgE were examined in pairs of serum and synovial fluid of the knee joint in a series of 78 patients with rheumatoid arthritis (RA), reactive synovitis during osteoarthrosis, and after injury. The IgE levels in synovial fluid were significantly lower (p less than 0.05) in all groups; in RA, they were in significant correlation (r=0.6208, p less than 0.0001) and in direct linear regression to the levels in serum. In 5 patients of the whole series, however, the IgE levels in serum were lower by one order of magnitude as compared with synovial fluid. Serum levels of IgE in RA were in significant correlation and in direct linear regression to the titres of rheumatoid factors according to the latex-fixation test (r=0.3688, p=0.0249) and the haemagglutination test with sheep red cells (r=0.3721, p=0.0235).

Adult↗
PubMed1977

Prehospital cardiac care: illusion of consensus.

To judge standard practice for managing arrhythmias, what an EMT should be able to do in the field, drugs of choice, the success of EMT training, and the quality of EMT performance, clinical algorithms were developed. Branching logic, forcing yes/no decisions and delineating actions for all contingencies helped formalize and systematize EMT management of urgent and emergency cases. The algorithm set was sent to 19 consultants for review of content, sequence, drug dosage, and drug usage. The results indicated lack of consensus on appropriate prehospital cardiac care, but the approval of the algorithm approach.

Allied Health Personnel↗
PubMed1976

The reflex sympathetic dystrophy syndrome. I. Clinical and histologic studies: evidence for bilaterality, response to corticosteroids and articular involvement.

Eleven consecutive patients fulfulling criteria for the reflex sympathetic dystrophy syndrome (RSDS) were studied by quantitative clinical methods, providing measurements of swelling (ring size), tenderness (dolorimeter) and functional capacity (grip strength). The predominantly affected extremity was clearly identified by these technics and its serial progress determined in six patients. Corticosteroid therapy predictably resulted in improvement of all treated patients. Greater tenderness was found in the joints than in the interjoint areas, indicating a possible accentuation of the disease process in juxta-articular tissues. Synovial biopsy specimens in four patients were abnormal, and the histology was presented in detail for the first time. All patients showed bilateral involvement during the study, providing evidence for a central neural mechanism in the RSDS.

Adult↗